| 1. |
- Batte, Michael, et al.
(författare)
-
Crossbreeding East African Highland Bananas: Lessons Learnt Relevant to the Botany of the Crop After 21 Years of Genetic Enhancement
- 2019
-
Ingår i: Frontiers in Plant Science. - : Frontiers Media SA. - 1664-462X. ; 10
-
Tidskriftsartikel (refereegranskat)abstract
- East African highland bananas (EAHB) were regarded as sterile. Their screening for female fertility with "Calcutta 4" as male parent revealed that 37 EAHB were fertile. This was the foundation for the establishment of the EAHB crossbreeding programs by the International Institute of Tropical Agriculture (IITA) and the National Agricultural Research Organization (NARO) in Uganda in the mid-1990s. The aim of this study was to assess the progress and efficiency of the EAHB breeding program at IITA, Sendusu in Uganda. Data on pollinations, seeds generated and germinated, plus hybrids selected between 1995 and 2015 were analyzed. Pollination success and seed germination percentages for different cross combinations were calculated. The month of pollination did not result in significantly different (P = 0.501) pollination success. Musa acuminata subsp. malaccensis accession 250 had the highest pollination success (66.8%), followed by the cultivar "Rose" (66.6%) among the diploid males. Twenty-five EAHB out of 41 studied for female fertility produced up to 305 seeds per pollinated bunch, and were therefore deemed fertile. The percentage of seed germination varied among crosses: 26% for 2x x 4x, 23% for 2x x 2x, 11% for 3x x 2x, and 7% for 4x x 2x. Twenty-seven NARITA hybrids (mostly secondary triploids ensuing from the 4x x 2x) were selected for further evaluation in the East African region. One so far -"NARITA 7"- was officially released to farmers in Uganda. Although pollination of EAHB can be conducted throughout the year, the seed set and germination is low. Thus, further research on pollination conditions and optimization of embryo culture protocols should be done to boost seed set and embryo germination, respectively. More research in floral biology and seed germination as well as other breeding strategies are required to increase the efficiency of the EAHB breeding program.
|
|
| 2. |
- Batte, Michael, et al.
(författare)
-
Heterobeltiosis in banana and genetic gains through crossbreeding
- 2020
-
Ingår i: Proceedings. - Basel Switzerland : MDPI. ; 36
-
Konferensbidrag (refereegranskat)abstract
- Heterosis, or hybrid vigour, is the superiority of the hybrid for a certain trait over the mean of its two parents. Heterobeltiosis is a form of heterosis where the hybrid is superior to its best parent. Banana breeding is a tedious, time-consuming process, taking up to two decades to develop a hybrid. Understanding heterosis in banana breeding will contribute to selecting right breeding materials for further crossing, thus increasing banana breeding efficiency. Here we document heterobeltiosis by using the recently bred NARITA ‘Matooke’ hybrids and their ancestors. NARITA hybrids, their parents (4x and 2x), grandparents (3x and 2x), and local 3x ‘Matooke’ cultivar checks were planted in a rectangular lattice design with two replications. Yield and other agronomic data were collected at flowering and harvest. The NARITAs were compared with their 3x ‘Matooke’ grandmothers. Heterobeltiosis on bunch weight was calculated with the data of 3 cycles. All the NARITAs showed heterobeltiosis for bunch weight. NARITA 17 had the highest grandparent heterobeltiosis (ca. 250%). Genetic gains due to crossbreeding were determined for fruit yield considering three generations: matooke cultigen (C0), primary tetraploid hybrids (C1) and secondary tetraploid hybrids (C2). The average genetic gain (from C0 to C2) rates for bunch weight (kg) and yield potential (t ha−1 year−1) were 1.4% and 1.3% per year, respectively.
|
|
| 3. |
- Batte, Michael, et al.
(författare)
-
Significant progressive heterobeltiosis in banana crossbreeding
- 2020
-
Ingår i: BMC Plant Biology. - : Springer Science and Business Media LLC. - 1471-2229. ; 20
-
Tidskriftsartikel (refereegranskat)abstract
- BackgroundHeterobeltiosis is the phenomenon when the hybrid's performance is superior to its best performing parent. Banana (Musa spp. AAA) breeding is a tedious, time-consuming process, taking up to two decades to develop a consumer acceptable hybrid. Exploiting heterobeltiosis in banana breeding will help to select breeding material with high complementarity, thus increasing banana breeding efficiency. The aim of this study was therefore to determine and document the level of heterobeltiosis of bunch weight and plant stature in the East African highland bananas, in order to identify potential parents that can be used to produce offspring with desired bunch weight and stature after a few crosses.ResultsThis research found significant progressive heterobeltiosis in cross-bred 'Matooke' (highland cooking) banana hybrids, also known as NARITAs, when grown together across years with their parents and grandparents in Uganda. Most (all except 4) NARITAs exhibited positive heterobeltiosis for bunch weight, whereas slightly more than half of them had negative heterobeltiosis for stature. The secondary triploid NARITA 17 had the highest heterobeltiosis for bunch weight: 249% versus its 'Matooke' grandparent and 136% against its primary tetraploid parent. Broad sense heritability (across three cropping cycles) for yield potential and bunch weight were high (0.84 and 0.76 respectively), while that of plant stature was very low (0.0035). There was a positive significant correlation (P < 0.05) between grandparent heterobeltiosis for bunch weight and genetic distance between parents (r=0.39, P=0.036), bunch weight (r=0.7, P<0.001), plant stature (r=0.38, P=0.033) and yield potential (r=0.59, P<0.001). Grandparent heterobeltiosis for plant stature was significantly, but negatively, correlated to the genetic distance between parents (r=-0.6, P<0.001).ConclusionsSuch significant heterobeltiosis exhibited for bunch weight is to our knowledge the largest among main food crops. Since bananas are vegetatively propagated, the effect of heterobeltiosis is easily fixed in the hybrids and will not be lost over time after the release and further commercialization of these hybrids.
|
|
| 4. |
- Batte, Michael, et al.
(författare)
-
Suitability of existing Musa morphological descriptors to characterize East African highland 'matooke' bananas
- 2018
-
Ingår i: Genetic Resources and Crop Evolution. - : Springer Science and Business Media LLC. - 0925-9864 .- 1573-5109. ; 65, s. 645-657
-
Tidskriftsartikel (refereegranskat)abstract
- Morphological traits are commonly used for characterizing plant genetic resources. Germplasm characterization should be based on distinctly identifiable, stable and heritable traits that are expressed consistently and are easy to distinguish by the human eye. Characterization and documentation of a representative sample of East African highland bananas (Lujugira-Mutika subgroup) was carried out following an internationally accepted standard protocol for bananas. Eleven cultivars were characterized using an existing set of minimum descriptors (31 qualitative and quantitative traits) with the aim of determining stable descriptors and the ability of these descriptors to distinguish among East African highland banana cultivars. There was variation in stability of these descriptors within cultivars and across the 11 cultivars. Only 10 (32%) out of 31 descriptors studied were stable in the 11 cultivars. However, they had similar scores and therefore are not suitable to distinguish between cultivars within this group. Nonetheless, these 10 descriptors may be useful for distinguishing the East African highland bananas as a group from other groups of bananas. A few descriptors were unique to the cultivar 'Tereza' and may be used to distinguish this cultivar from other 'matooke' cultivars. None of the quantitative descriptors were stable.
|
|
| 5. |
- Dida, Mulatu Geleta, et al.
(författare)
-
Analysis of Genetic Diversity of Fescue Populations from the Highlands of Bolivia Using EST-SSR Markers
- 2022
-
Ingår i: Genes. - : MDPI AG. - 2073-4425. ; 13
-
Tidskriftsartikel (refereegranskat)abstract
- In the highlands of Bolivia, native Festuca species are an important source of feed for animals due to their high tolerance to low temperatures and drought. Using simple sequence repeat (SSR) markers developed from expressed sequence tags (ESTs), the genetic diversity of 43 populations of Festuca species from Oruro, La Paz, Potosi and Cochabamba departments was evaluated for the purpose of providing information for effective conservation and breeding. In total, 64 alleles were detected across the 43 populations. SSR locus NFA 142 (with 12 alleles) had the highest number of detected alleles, while locus FES 13 (with eight alleles) had the highest polymorphism information content (PIC) at 0.55. Based on Nei’s genetic distance between populations, the unweighted pair group method with arithmetic mean (UPGMA) cluster analysis revealed two major clusters, each consisting of populations from the four departments. However, the analysis of molecular variance (AMOVA) revealed that only 5% of the total variation separated these two groups, indicating low genetic differentiation between the populations. It was also found that there was a low but significant differentiation (0.08%) between the population groups of the four departments (p = 0.01). The newly developed EST-SSR markers are highly valuable for evaluating the genetic diversity of Bolivian fescues and other related species.
|
|
| 6. |
- Edin, Eva, et al.
(författare)
-
Genetic diversity and occurrence of the F129L substitutions among isolates of Alternaria solani in south-eastern Sweden
- 2016
-
Ingår i: Hereditas. - : Springer Science and Business Media LLC. - 0018-0661 .- 1601-5223. ; 153
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Early blight, caused by the fungus Alternaria solani, occurs on potato mainly in the south-eastern part of Sweden, but also in other parts of the country. The aim of this study was to investigate the genetic diversity of A. solani populations from different potato growing regions in south-eastern Sweden using AFLP marker analysis. In addition, the cultured isolates were examined for substitutions in the gene encoding cytochrome b, associated with loss of sensitivity against QoI fungicides.Results: Nei's gene diversity index for the Swedish populations of A. solani revealed a gene diversity of up to 0.20. Also genetic differentiation was observed among populations of A. solani from different locations in south-eastern Sweden. The mitochondrial genotype of the isolates of A. solani was determined and both known genotypes, GI (genotype 1) and GII (genotype 2), were found among the isolates. The occurrence of the F129L substitution associated with a loss of sensitivity to strobilurins was confirmed among the GII isolates. In vitro conidial germination tests verified that isolates containing the F129L substitution had reduced sensitivity to azoxystrobin and, at a lower extent, to pyraclostrobin.Conclusions: Genetic diversity was relatively high among isolates of A. solani in south-eastern part of Sweden. F129L substitutions, leading to reduced sensitivity to strobilurins, have been established in field populations, which may have implications for the future efficacy of QoI fungicides.
|
|
| 7. |
|
|
| 8. |
|
|
| 9. |
|
|
| 10. |
- Gustavsson, Larisa, et al.
(författare)
-
Varför äpplen på banken?
- 2011
-
Ingår i: Pomologen. - 1650-9455. ; 11, s. 10-15
-
Tidskriftsartikel (populärvet., debatt m.m.)
|
|
| 11. |
- Hailu, Faris, et al.
(författare)
-
Quality Assessment with HPLC in Released Varieties of Tetraploid (Triticum durum Desf.) Wheat from Ethiopia and Spain
- 2016
-
Ingår i: Cereal Research Communications. - : Springer Science and Business Media LLC. - 0133-3720 .- 1788-9170. ; 44, s. 617-627
-
Tidskriftsartikel (refereegranskat)abstract
- Quality of durum wheat is of importance for pasta production. Our aim was to evaluate the quality of released durum wheat at Ethiopia by the use of pheno-quality traits as well as composition and amount and size distribution of proteins; these attributes were also compared with the same ones for Spanish released wheat grown in the same environment. Large variation was obtained among the released durum wheat for all parameters investigated. The evaluation of protein parameters indicated the varieties Klinto, LD-357, Tob-66 and Ude to have suitable protein composition for pasta production, while Tob-66 showed high protein concentration and Tob-66, LD-357 and Yerer showed high gluten strength. The most promising E(t)hiopian variety for pasta production as to the results from the present study was Tob-66. Also, LD-357 showed promising protein characteristics, although the kernels were white, which is not desired for pasta production. Some of the evaluated varieties might be of interest for production of local leavened bread although the quality is not good enough for pasta production.
|
|
| 12. |
- Hedrén, Mikael, et al.
(författare)
-
Patterns of polyploid evolution in Greek marsh orchids (Dactylorhiza; Orchidaceae) as revealed by allozymes, AFLPs, and plastid DNA data
- 2007
-
Ingår i: American Journal of Botany. - 0002-9122. ; 94:7, s. 1205-1218
-
Tidskriftsartikel (refereegranskat)abstract
- Polyploidy is common in higher plants, and speciation in polyploid complexes is usually the result of reticulate evolution. We examined variation in nuclear AFLP fingerprints, nuclear isozymes, and hypervariable plastid DNA loci to describe speciation patterns and species relationships in the Dactylorhiza incarnatalmaculata polyploid complex (marsh orchids; Orchidaceae) in Greece. Several endemic taxa with restricted distribution have been described from this area, and to propose meaningful conservation priorities, detailed relationships need to be known. We identified four independently derived allopolyploid lineages, which is a pattern poorly correlated with prevailing taxonomy. Three lineages were composed of populations restricted to small areas and may be of recent origins from extant parental lineages. One lineage with wide distribution in northern Greece was characterized by several unique plastid haplotypes that were phylogenetically related and evidently older. The D. incarnatal maculata polyploid complex in Greece has high levels of genetic diversity at the polyploid level. This diversity has accumulated over a long time and may include genetic variants originating from now extinct parental populations. Our data also indicate that the Balkans may have constituted an important refuge from which northern European Dactylorhiza were recruited after the Weichselian ice age.
|
|
| 13. |
- Hegay, Sergay, et al.
(författare)
-
Comparing genetic diversity and population structure of common beans grown in Kyrgyzstan using microsatellites
- 2012
-
Ingår i: Scientific Journal of Crop Science. - 2322-1690. ; 1, s. 63-75
-
Tidskriftsartikel (refereegranskat)abstract
- Common bean (Phaseolus vulgaris L.) is an important export crop in Kyrgyzstan. The aim of this study was to assess the extent of genetic diversity, determine the population structure, and relate to the main gene pools grown in Kyrgyzstan. Twenty-eight common bean accessions (including five Kyrgyz cultivars, and main references from the Mesoamerica and South America) were evaluated with microsatellites. Nine polymorphic microsatellites were used to estimate genetic diversity and heterozygosity. The number of alleles per microsatellite locus ranged from 2 to 4 and there were a total of 24 alleles. The observed heterozygosity of each accession over all loci ranged from 0 to 0.11 (with an average of 0.01), while the expected average heterozygosity was 0.05, which could reflect the self-pollinating breeding behavior of common beans. The analysis of molecular variance further revealed that 94.71% of the total variation was accounted by differences among accessions (Fst =0.947; p<0.001). Cluster analysis grouped accessions in two gene pools: 16 belong to the Andean and 12 to the Mesoamerican gene pool. The microsatellites separated accessions in Mesoamerican gene pool from Durango and Jalisco races, which were grouped together. We also observed that the most divergent accessions were the Kyrgyz cultivars, which may be related to the Mesoamerican races. Andean accessions were less diverse than Mesoamerican accessions in this study. This research confirms the ability of microsatellites to differentiate common bean accessions, even using a small sample size, and to be able to assign modern cultivars to their gene pools or races.
|
|
| 14. |
- Hegay, Sergay, et al.
(författare)
-
Genetic diversity analysis in Phaseolus vulgaris L. using morphological traits
- 2014
-
Ingår i: Genetic Resources and Crop Evolution. - : Springer Science and Business Media LLC. - 0925-9864 .- 1573-5109. ; 61, s. 555-566
-
Tidskriftsartikel (refereegranskat)abstract
- Common bean (Phaseolus vulgaris) is an important export crop in Kyrgyzstan since the end of the twentieth century. Genetic diversity analysis of common bean populations is useful for breeding programs, as it helps to select genetic material to be used for further crossing. Twenty-seven common bean accessions were analyzed using 13 qualitative morphological traits. In some cases, obtained morphological data were combined with previously published results based on microsatellite markers. The similarity matrices generated from the molecular and morphological data were significantly correlated (r = 0.49, P < 0.01). Cluster analyses based on Dice's similarity coefficient were constructed based on morphological data and the combined data set of morphology and microsatellite, and both grouped the 27 accessions according to their origin: 15 belonged to the Andean and 12 to the Mesoamerican gene pool. On average, the Andean accessions were less diverse than the Mesoamerican accessions. The average diversity based on the Shannon diversity index for the 13 qualitative morphological traits was 0.05. Overall, this study revealed that qualitative morphological markers are efficient in assigning modern cultivars to their gene pools of origin.
|
|
| 15. |
- Hegay, Sergay, et al.
(författare)
-
Introducing host-plant resistance to anthracnose in Kyrgyz common bean through inoculation-based and marker-aided selection
- 2014
-
Ingår i: Plant Breeding. - : Wiley. - 0179-9541 .- 1439-0523. ; 133, s. 86-91
-
Tidskriftsartikel (refereegranskat)abstract
- Common bean (Phaseolus vulgaris L.) is one of the most important legume crops for human consumption. However, its grain yield can be reduced by up to 90% by the seedborne disease, anthracnose. Fungicide treatment is costly and time-consuming. The introduction of host plant resistance against this disease appears, therefore, to be crucial for enhancing the productivity of this crop in Kyrgyzstan. The use of DNA-based markers in backcrossing programmes may help speed up the breeding for resistance. In this study, we used a combination of inoculation tests and a DNA marker (SCAreoli marker) to track the transfer of host-plant resistance (Co-2 gene) from two donor cultivars, Vaillant' and Flagrano', to susceptible Kyrgyz cultivars Ryabaya', Kytayanka' and Lopatka', which are widely grown in the country. The segregating offspring were evaluated to test the reliability of the SCAreoli marker as selection aid for host-plant resistance to anthracnose. Our study showed that a co-dominant DNA marker can successfully be used in backcross breeding to distinguish segregating material in different market classes of common bean.
|
|
| 16. |
|
|
| 17. |
- Johansson, Eva, et al.
(författare)
-
Economically Viable Components from Jerusalem Artichoke (Helianthus tuberosus L.) in a Biorefinery Concept.
- 2015
-
Ingår i: International Journal of Molecular Sciences. - : MDPI AG. - 1422-0067 .- 1661-6596. ; 16:4, s. 8997-9016
-
Forskningsöversikt (refereegranskat)abstract
- Biorefinery applications are receiving growing interest due to climatic and waste disposal issues and lack of petroleum resources. Jerusalem artichoke (Helianthus tuberosus L.) is suitable for biorefinery applications due to high biomass production and limited cultivation requirements. This paper focuses on the potential of Jerusalem artichoke as a biorefinery crop and the most viable products in such a case. The carbohydrates in the tubers were found to have potential for production of platform chemicals, e.g., succinic acid. However, economic analysis showed that production of platform chemicals as a single product was too expensive to be competitive with petrochemically produced sugars. Therefore, production of several products from the same crop is a must. Additional products are protein based ones from tubers and leaves and biogas from residues, although both are of low value and amount. High bioactive activity was found in the young leaves of the crop, and the sesquiterpene lactones are of specific interest, as other compounds from this group have shown inhibitory effects on several human diseases. Thus, future focus should be on understanding the usefulness of small molecules, to develop methods for their extraction and purification and to further develop sustainable and viable methods for the production of platform chemicals.
|
|
| 18. |
- Juma, Ibrahim, et al.
(författare)
-
Avocado Production and Local Trade in the Southern Highlands of Tanzania: A Case of an Emerging Trade Commodity from Horticulture
- 2019
-
Ingår i: Agronomy. - : MDPI AG. - 2073-4395. ; 9
-
Tidskriftsartikel (refereegranskat)abstract
- Avocado crop in Tanzania is sparingly investigated regardless of being an important fruit commodity. This study was undertaken to explore the yield and the value chain of this crop in the country. Data were collected mainly by face-to-face interviews with 275 avocado farmers, 231 avocado traders and 16 key informants. Descriptive statistics, Chi-square test and one-way analysis of variance were used for data analysis. The average crop yield ranged from 76 to 124 kg plant(-1) between regions. The average price for the farmers' produce ranged from US$ 0.30 to 0.45 kg(-1) between regions. About 72% of the farmers were dissatisfied with avocado business whereas 79% of the traders were pleased with it. A number of challenges were found hindering the development of the avocado industry in Tanzania, which in turn affects the fruit yield and the value chain. Addressing these challenges at the national, regional, district and village levels is important for improving the livelihood of Tanzanian farmers growing this crop, given the fact that a good proportion of the country's population is employed in the agricultural sector and most of the reported challenges also affect the value chain of other crops.
|
|
| 19. |
- Juma, Ibrahim, et al.
(författare)
-
Characterization of Tanzanian Avocado Using Morphological Traits
- 2020
-
Ingår i: Diversity. - : MDPI AG. - 1424-2818. ; 12
-
Tidskriftsartikel (refereegranskat)abstract
- Two-hundred and twenty-six old avocado trees (Persea americana Mill) derived from seeds were selected from eight districts of the Mbeya, Njombe and Songwe regions in Tanzania. The tree, leaf, fruit and seed characteristics were studied using the descriptors for avocado (Persea spp.) from the International Plant Genetic Resources Institute. Cross tabulation and Chi-square tests were conducted in order to assess the distribution of traits between districts and altitude ranges. Principle coordinate analysis (PCoA) and hierarchical cluster analysis (HCA) were used to assess variation of traits within and among districts. Various morphological features were observed among the samples which point to the existence of the Mexican, Guatemalan and West Indian avocado races in Tanzania. The biplot from PCoA revealed extensive variation between the sampled trees at the district level but no clear groupings of the samples based on geographic location. Likewise, dendrograms ensuing from the neighbor-joining and Wards methods displayed that the avocado samples from the same district and even region differed considerably. This morphological trait variation suggests high diversity that may help in planning germplasm management and conservation, as well as breeding strategies in the future.
|
|
| 20. |
- Juma, Ibrahim, et al.
(författare)
-
Comparison of morphological and genetic characteristics of avocados grown in Tanzania
- 2021
-
Ingår i: Genes. - : MDPI AG. - 2073-4425. ; 12
-
Tidskriftsartikel (refereegranskat)abstract
- Tanzania has been growing avocado for decades. A wide variability of the avocado germplasm has been found, and the crop is largely contributing to the earnings of the farmers, traders, and the government, but its genetic diversity is scantly investigated. With the purpose of comparing morphological and genetic characteristics of this germplasm and uncovering the correlation between them and the geographical location, 226 adult seedling avocado trees were sampled in southwestern Tanzania. Their morphological characters were recorded, and their genetic diversity was evaluated based on 10 microsatellite loci. Discriminant analysis of principal components showed that the germplasm studied consisted of four genetic clusters that had an overall average gene diversity of 0.59 and 15.9% molecular variation among them. Most of the phenotypes were common in at least two clusters. The genetic clusters were also portrayed by multivariate analysis and hierarchical clustering for the molecular data but not for the morphology data. Using the Mantel test, a weak significant correlation was found between the genetic, morphological, and geographical distances, which indicates that the genetic variation present in the material is weakly reflected by the observed phenotypic variation and that both measures of variation varied slightly with the geographical sampling locations.
|
|
| 21. |
- Juma, Ibrahim, et al.
(författare)
-
Genetic diversity of avocado from the southern highlands of Tanzania as revealed by microsatellite markers
- 2020
-
Ingår i: Hereditas. - : Springer Science and Business Media LLC. - 0018-0661 .- 1601-5223. ; 157
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Avocado is an important cash crop in Tanzania, however its genetic diversity is not thoroughly investigated. This study was undertaken to explore the genetic diversity of avocado in the southern highlands using microsatellite markers. A total of 226 local avocado trees originating from seeds were sampled in eight districts of the Mbeya, Njombe and Songwe regions. Each district was considered as a population. The diversity at 10 microsatellite loci was investigated. Results: A total of 167 alleles were detected across the 10 loci with an average of 16.7 ± 1.3 alleles per locus. The average expected and observed heterozygosity were 0.84 ± 0.02 and 0.65 ± 0.04, respectively. All but two loci showed a significant deviation from the Hardy-Weinberg principle. Analysis of molecular variance showed that about 6% of the variation was partitioned among the eight geographic populations. Population FST pairwise comparisons revealed lack of genetic differentiation for the seven of 28 population pairs tested. The principal components analysis (PCA) and hierarchical cluster analysis showed a mixing of avocado trees from different districts. The model-based STRUCTURE subdivided the trees samples into four major genetic clusters. Conclusion: High diversity detected in the analysed avocado germplasm implies that this germplasm is a potentially valuable source of variable alleles that might be harnessed for genetic improvement of this crop in Tanzania. The mixing of avocado trees from different districts observed in the PCA and dendrogram points to strong gene flow among the avocado populations, which led to population admixture revealed in the STRUCTURE analysis. However, there is still significant differentiation among the tree populations from different districts that can be utilized in the avocado breeding program.
|
|
| 22. |
- Juma, Ibrahim, et al.
(författare)
-
Polyphenolic Content and Radical Scavenging Activities of the Peel, Pulp and Seed of Avocado (Persea americana Mill.) Grown in Tanzania
- 2023
-
Ingår i: Tanzania Journal of Science. - 0856-1761 .- 2507-7961. ; 49, s. 230-239
-
Tidskriftsartikel (refereegranskat)abstract
- Avocado is a healthy fruit and the consumption is continuously growing worldwide. The fruit contains polyphenolic compounds with antioxidant effects. Globally, research has been devoted to exploring the fruit quality, especially compounds with antioxidant effects, from different avocado-growing sites. However, the fruit quality of the Tanzanian avocado has so far not been investigated. In this study, the contents of polyphenols in peel, pulp and seed of avocados sampled in south-western Tanzania are described. The levels of total polyphenolic and flavonoid contents were measured, and antioxidant activity was evaluated using a 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. The total polyphenolic content was highest in the seed and lowest in the peel (424 and 200 mg GAE/100 g DW, respectively). As for the total flavonoid content, the pulp had the highest value of 36.98 mg RE/100 g DW, while the seed had the lowest value of 32.54 mg RE/100 g DW. The overall average half maximal effective concentration (EC50) values in decreasing order, corresponding to an increasing antiradical activity, were 4.90 (peel), 3.63 (seed) and 3.24 µg/mL (pulp). The seed and peel possessed high levels of total polyphenolic and flavonoid content, thus demonstrating substantial antioxidant capacity. Seed and peel can potentially be processed and included in the diet to provide inexpensive antioxidant ingredients of natural origin. Consumption of the seed will not only improve human health but also reduce the environmental pollution, as many thousand tonnes of avocado seeds are produced in Tanzania per year; a huge amount currently remains as waste.
|
|
| 23. |
- Mukamuhirwa, Alphonsine, et al.
(författare)
-
Concurrent Drought and Temperature Stress in Rice—A Possible Result of the Predicted Climate Change: Effects on Yield Attributes, Eating Characteristics, and Health Promoting Compounds
- 2019
-
Ingår i: International Journal of Environmental Research and Public Health. - : MDPI AG. - 1660-4601 .- 1661-7827. ; 16:6, s. 1043-1043
-
Tidskriftsartikel (refereegranskat)abstract
- Despite the likely increasing co-occurrence of drought and heat stress, not least in equatorial regions, due to climate change, little is known about the combinational effect of these stresses on rice productivity and quality. This study evaluated the impact of simultaneous drought and temperature stress on growth, grain yield, and quality characteristics of seven rice cultivars from Rwanda, grown in climate chambers. Two temperature ranges—23/26 °C night/day and 27/30 °C night/day—together with single or repeated drought treatments, were applied during various plant developmental stages. Plant development and yield were highly influenced by drought, while genotype impacted the quality characteristics. The combination of a high temperature with drought at the seedling and tillering stages resulted in zero panicles for all evaluated cultivars. The cultivar ‘Intsindagirabigega’ was most tolerant to drought, while ‘Zong geng’ was the most sensitive. A “stress memory” was recorded for ‘Mpembuke’ and ‘Ndamirabahinzi’, and these cultivars also had a high content of bioactive compounds, while ’Jyambere’ showed a high total protein content. Thus, climate change may severely impact rice production. The exploitation of genetic diversity to breed novel rice cultivars that combine drought and heat stress tolerance with high nutritional values is a must to maintain food security.
|
|
| 24. |
- Mukamuhirwa, Alphonsine, et al.
(författare)
-
Effect of intermittent drought on grain yield and quality of rice (Oryza sativa L.) grown in Rwanda
- 2020
-
Ingår i: Journal of Agronomy and Crop Science. - : Wiley. - 0931-2250 .- 1439-037X. ; 206, s. 252-262
-
Tidskriftsartikel (refereegranskat)abstract
- The climate change will contribute drought and temperature extremes to rice growing systems, especially when cultivated in equatorial regions. To evaluate opportunities to cultivate and breed drought-tolerant rice, seven rice cultivars were evaluated in Rwanda for recurring morphological drought scores, grain yield and components, and quality characteristics. The cultivation conditions, that is site and drought treatment, impacted morphological drought scores, growth and yield attributes, while cultivar affected quality attributes. Thus, site showed a higher impact on grain yield and components than drought and cultivar, with generally a reduced grain yield at the low-temperature site, as a result of low spikelet fertility. Morphological drought scores were generally increased by drought, while drought at the reproductive stage at the high-temperature site was negative for yield and its components. The cultivars "Intsindagirabigega" and "Jyambere" were adapted to high-temperature site conditions. The cultivar "Intsindagirabigega" had the highest amylose content, and "Mpembuke," the highest antioxidant capacity. Thus, climate change with increased temperature and drought extremes may increase rice productivity in cool areas, while especially drought at reproductive stage will be detrimental in low altitude areas with high temperature. Cultivar variation indicated opportunities for selection and breeding of climate change tolerant rice cultivars which should be of immediate priority.
|
|
| 25. |
- Mukamuhirwa, Alphonsine, et al.
(författare)
-
Quality and Grain Yield Attributes of Rwandan Rice (Oryza sativa L.) Cultivars Grown in a Biotron Applying Two NPK Levels
- 2018
-
Ingår i: Journal of Food Quality. - : Hindawi Limited. - 0146-9428 .- 1745-4557. ; 2018
-
Tidskriftsartikel (refereegranskat)abstract
- High-yielding rice cultivars with good processing quality and rich in nutrition suitable to a changing climate are of particular importance for future rice-based food production. Here, seven Rwandan rice cultivars were grown in a climate chamber of the biotron facility at the Swedish University of Agricultural Sciences, to be evaluated for their grain yield, nutritional composition, and dough mixing properties. Two different levels of inorganic fertilizer were applied weekly from the seedling stage until flowering. Significant differences for grain yield and quality attributes were found between cultivars. Jyambere showed significantly the highest yield while Ingwizabukungu, Nemeyubutaka, and Jyambere were high in mineral elements content. Ndamirabahinzi and Mpembuke had the highest levels of TPC and TAC. Generally, the lower fertilizer dose resulted in a better performance of the cultivars for both yield and quality attributes. Significantly higher content of Fe, Ca, and Ba was found in grains from the moderate fertilizer dose, whereas K, Na, P, S, Zn, Cd, and Pb increased in grains from the higher fertilizer dose. The cultivar Ndamirabahinzi showed less variability of evaluated characters across fertilizer doses. The results from this study may be used for rice breeding of cultivars with high yield and good grain quality.
|
|
| 26. |
- Muneer, Faraz, et al.
(författare)
-
Economic viability of protein concentrate production from green biomass of intermediate crops: A pre-feasibility study
- 2021
-
Ingår i: Journal of Cleaner Production. - : Elsevier BV. - 0959-6526 .- 1879-1786. ; 294
-
Tidskriftsartikel (refereegranskat)abstract
- Green biomass is a major potential source of proteins for food and feed. This pre-feasibility study evaluates the use of green biomass of buckwheat, phacelia, hemp and oilseed radish grown as intermediate crops (IC) as a feedstock for production of protein concentrates to produce protein-rich food and feed products. We investigated the biomass yield, protein concentration and protein recovery potential of non-fertilized IC, nitrogen-fertilized IC and IC intercropped with legumes, harvested in late summer to autumn during 2017 and 2018 in southern Sweden. In addition, economic assessment of potential protein and fibre feed and food products were evaluated. The results showed that IC fertilized with 40 kg ha1 N and intercropping with legumes contributed to a higher biomass dry matter (DM) yield of 4.9e5.8 t ha1 as compared to between 2.2 and 3.1 t ha1 for non-fertilized IC. Intercropping with legumes also resulted in higher protein yield of 154 g kg1 vs. 103 g kg1 for non-fertilized IC. Among IC, hemp, phacelia and oilseed radish showed up to ca. 25% higher DM yield and up to ca. 70% higher protein concentration as compared to buckwheat. Higher DM yield was obtained when IC were harvested in October and November than in August and September. Economic assessment was made on two feasible protein production pathways; (A) Green and white proteins and (B) total recoverable combined protein fraction (CPF). For all IC, cost per t DM was higher in August due to lower biomass yield as compared to other harvesting months. Nitrogen concentration was the main factor determining the size of revenues. Nitrogen concentration was 34% higher in 2018 compared to 2017 and therefore resulted in higher revenues in that year. Intercropping resulted in higher protein content and therefore contributed to lower breakeven prices of recovered green proteins for all IC. Breakeven price analyses showed that green protein and CPF were economically feasible to market as both bulk and premium products depending on lower (2 V kg1 ) or higher (2e10 V kg1 ) price ranges, respectively. The results demonstrate that use of IC biomass could be a feasible option to produce high value protein-rich products, which can contribute extra income from IC for farmers.
|
|
| 27. |
- Nynäs, Anna-Lovisa, et al.
(författare)
-
Protein Fractionation of Leafy Green Biomass at the Pilot Scale: Partitioning and Type of Nitrogen in the Fractions and Their Usefulness for Food and Feed
- 2024
-
Ingår i: ACS food science & technology. - 2692-1944. ; 4, s. 126-138
-
Tidskriftsartikel (refereegranskat)abstract
- Fractionation of green biomass often results in fractions with insufficient protein content or quality for food or feed. To understand ways forward, we evaluated the fate of nitrogen (N) and the food or feed suitability of six pilot-scale fractions. The N was present mainly as amino acids (AA) in all fractions (<87%), however, the protein was partly degraded or insoluble in the majority of samples. All protein types and AAs traveled similarly through the fractionation process, giving insignificant separation of RuBisCO versus other proteins, and essential versus nonessential AAs. Water-soluble N compounds were enriched in juice fractions (90-95%), while the protein fractions contained the highest insoluble protein content (13-17%). AA composition in pulp and green juice verified their suitability as feed for ruminants and pigs, respectively. Fractionation of green biomass for food and feed is indeed important, although for sustainable industrial applications, further evaluations are required regarding process feasibility, antinutritional components, and brown juice uses.
|
|
| 28. |
- Persson Hovmalm, Helena
(författare)
-
Effect of Soil Application of Stabilized Ortho Silicic Acid Based Granules on Growth and Yield of Rice (Oryza sativa L.)
- 2023
-
Ingår i: Communications in Soil Science and Plant Analysis. - : Informa UK Limited. - 0010-3624 .- 1532-2416. ; 54, s. 444-452
-
Tidskriftsartikel (refereegranskat)abstract
- Rice (Oryza sativa L.) is one of the most important cereal crops in Rwanda. Present study was aimed assessed the effect of stabilized ortho silicic acid (OSA) based granules on growth and yield of rice. Field experiments were conducted at Rwagitima, Gatsibo district in the Eastern province of Rwanda during two wet seasons in 2019, the first season was between February and May and the second one was from September to December. Two levels of recommended fertilizer doses (RDF; i.e., 200 kg ha(-1) NPK as a basal fertilizer and 100 kg ha(-1) urea as a top dressing fertilizer) were applied solely and along with different doses (10, 15 and 20 kg ha(-1)) of OSA based granules. The treatments were: T-1 (100% RDF), T-2 (75% RDF), T-3 (T-1 +10 kgha(-1) OSA), T-4 (T-1 +15 kgha(-1) OSA), T-5 (T-1 +20 kgha(-1) OSA), T-6 (T-2 +10 kgha(-1)OSA), T-7 (T-2 +15 kgha(-1) OSA) and T-8 (T-2 +20 kgha(-1) OSA). Experiments were laid in a randomized complete block design (RCBD) with three replications. Results showed that the application of 100% RDF +20 kg ha(-1) of OSA granules increased plant height (99.80 cm), tiller number (361) and root length (15.7 cm). Furthermore, yield increments of 28.4% and 19.9% for the first and second seasons, respectively, were obtained in treatments where 100% RDF +20 kgha(-1) of OSA granules were applied. The rice yield in the treatment 75% RDF +20 kg/ha Silixol OSA granules was higher than that recorded with 100% RDF only. This indicates that use of Silixol OSA granules can result in 25% saving of fertilizer (NPK and urea) without compromising the yield. Conclusively, Silixol OSA granules offers good potential for yield increment of rice in Rwanda and, can minimize fertilizer use by 25%.
|
|
| 29. |
- Persson Hovmalm, Helena, et al.
(författare)
-
Mellangrödors potential som proteinkälla
- 2021
-
Ingår i: LTV-fakultetens faktablad.
-
Annan publikation (populärvet., debatt m.m.)abstract
- En ökad efterfrågan på lokalt producerade gröna proteiner kräver en ökad avkastning per hektar eller en utökad användning av grön biomassa. Detta projekt fokuserar på möjligheten att utvinna proteiner ur mellangrödor för potentiell användning som livsmedel eller foder.
|
|
| 30. |
|
|
| 31. |
|
|
| 32. |
- Persson Hovmalm, Helena, et al.
(författare)
-
Äpplen för allergiker
- 2009
-
Ingår i: Viola. - 0042-6407. ; , s. 20-21
-
Tidskriftsartikel (populärvet., debatt m.m.)
|
|
| 33. |
- Persson Hovmalm, Helena
(författare)
-
Äpplet - en frukt för alla?
- 2010
-
Ingår i: Pomologen. - 1650-9455. ; 10, s. 4-9
-
Tidskriftsartikel (populärvet., debatt m.m.)
|
|
| 34. |
- Sjöstrand, Joakim, et al.
(författare)
-
Comparison between IAD and other maturity indices in nine commercially grown apple cultivars
- 2024
-
Ingår i: Scientia Horticulturae. - 0304-4238 .- 1879-1018. ; 324
-
Tidskriftsartikel (refereegranskat)abstract
- To maintain storage potential as long as possible, it is important to harvest fruit at optimal maturity. Different maturity indices have been developed, including flesh firmness, soluble solids content, starch degradation, ethylene production, and respiration rate. However, many of them are destructive, time consuming, and may be require some laboratory equipment to perform. The portable device DA-meter (measuring index of absorption difference; IAD) can monitor the chlorophyll decline non-destructively in the field, and could potentially save time. To evaluate the IAD in comparison with other maturity indices, nine common commercial cultivars of apple were investigated in a three-year trial. Correlations between IAD and other maturity indices, especially starch degradation and ripening index by Streif were strong in most cultivars, though variation between years lead to weaker correlations were found last year of the trial. The strongest correlations were found between IAD and harvest date showing that IAD decreased with time in all investigated cultivars. Comparison between IAD and ripening index by Streif showed in some cases that the two indices decreased at the same time, suggesting that IAD could be used to monitor maturity when it is rapid. The suitability to use IAD as a maturity index seems to be cultivar-dependent. For cultivars having a more consistent pattern between years in the decrease of IAD, combined with relatively low variation in IAD at any given time, it could be a good complement to other commonly used maturity indices.
|
|
| 35. |
- Sjöstrand, Joakim, et al.
(författare)
-
Multiple factors affecting occurrence of soft scald and fungal decay in apple during storage
- 2023
-
Ingår i: Postharvest Biology and Technology. - 0925-5214. ; 201
-
Tidskriftsartikel (refereegranskat)abstract
- Some apple cultivars are highly susceptible to soft scald, a physiological disorder that can lead to large losses. The effect of harvest time, gradual cooling regimes and storage conditions on soft scald and fungal decay was investigated in two common apple cultivars, 'Aroma' and 'Frida' in a three year trial 2018-2020. Further, possible relationships between weather conditions during the growing season and 28 d before harvest and soft scald incidence along with fungal decay after storage were studied. The year with the highest rainfall had the highest incidence of soft scald and fungal decay. Our results suggest that the relative humidity during a period of 28 d before harvest was important for later development of soft scald in 'Frida', and together the results from 'Frida' and 'Aroma' showed a moderate correlation between relative humidity and soft scald. Gradual cooling showed conflicting results, and no treatment consistently lowered soft scald incidence. Gradual cooling led to inconclusive results, and storage in ambient air led to higher incidence of soft scald as compared to some investigated ULO storage conditions. Advanced maturity was associated with soft scald development and more fungal decay in one out of three years in 'Aroma', but did not affect incidence in 'Frida'. The etiology of soft scald seems to be dependent of multiple factors.
|
|
| 36. |
- Sjöstrand, Joakim, et al.
(författare)
-
Storage spoilage in Swedish apple production and novel ways of predicting storability
- 2021
-
Ingår i: Acta Horticulturae. - 0567-7572 .- 2406-6168. ; 1325, s. 7-11
-
Konferensbidrag (refereegranskat)abstract
- Swedish apple industry faces many challenges when it comes to storage of apples. Pathogens such as Colleotrichum ssp., Neofabrea ssp., Botrytis cinerea and Penicillium expansum cause substantial losses during storage. Also physiological disorders like soft scald and senescent breakdown contribute to fruit losses. Many of these storage diseases and disorders are aggravated by either a too early or too late harvest time. To estimate optimal harvest time is however difficult and at the moment reliant on destructive maturity tests on a small number of arbitrarily chosen fruits. These tests may therefore not give the full picture of the ripeness across the orchard. To get a better prediction of optimal harvest time, a DA-meter was used in an investigation to compare this non-destructive method with traditional maturity indices. The method has been used in Europe and other parts of the world but optimal values for storage of Swedish apple cultivars are unknown. Storage trials were conducted for two Swedish apple cultivars with the aim of finding the optimal values for harvest. Storage diseases as well as storage disorders were monitored during the trials. For both ‘Aroma’ and ‘Discovery’ there was a higher incidence of storage rot in fruit with lower IAD. Longer storage time was also shown to increase the development of storage rot.
|
|
| 37. |
- Spendrup, Sara, et al.
(författare)
-
Consumer attitudes and beliefs towards plant-based food in different degrees of processing - The case of Sweden
- 2022
-
Ingår i: Food Quality and Preference. - : Elsevier BV. - 0950-3293 .- 1873-6343. ; 102
-
Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to gain an understanding of consumer attitudes and beliefs on three different types of plant-based meat alternatives (covering two highly processed Plant Based Meat Alternatives (PBMA) products: a. vegetarian nuggets and b. soy mince, and pulses: c. pre-cooked beans). The analysis was based on data obtained from a questionnaire-based survey (N = 483) conducted in Sweden in November 2020. Consumers were separated into four food preference groups (all of whom consume meat): 1. flexitarians (meat reducers), 2. omnivores (mixed diet), 3. consumers who prefer meat and fish (avoid vegetarian food) and 4. consumers who explicitly prefer to only eat meat (avoid vegetarian food and fish). Products were chosen with the intention that they represent products from a scale ranging from a less processed product (pre-cooked beans), via soy mince (a processed PBMA product) to vegetarian nuggets (ready-to eat processed PBMA). The two PBMA products were also chosen to represent one convenience product (vegetarian nuggets) and one product mainly used as an ingredient (soy mince). Gender, age, education, consumption frequencies, food neophobia, health concern, ranking of qualities, awareness of climate change, and the link between food and climate were explored. The results illustrate differences and similarities between the four groups in attitudes and beliefs as well as the three products. Flexitarians represent the group that expresses the most positive and sustainably connected attitudes and beliefs. Results also show that for all groups, PBMA products are perceived as more modern, artificial and expensive compared to pulses, which, in turn, are perceived as healthier and a better climate choice compared to PBMA products. Meat and "meat and fish" eaters attach much importance to taste, perceived protein content, satiety and domestic origin (from Sweden), whereas omnivores are guided by taste, ease of cooking, health, climate change, and the link between food and climate. The outcome is expected to support policymakers and market actors in developing target group applied strategies addressing differences among the four food preference groups, thereby increasing consumers' intake of sustainable plant-based protein-rich products.
|
|
| 38. |
- Strid, Ingrid, et al.
(författare)
-
Food loss in Sweden : National follow-up methods for increased knowledge about losses and resources in food production
- 2021
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- There is a lack of knowledge about the quantities and causes of food loss and waste, especially in the early stages of the food chain. The studies that have been performed show significant losses already in the primary production, which leads to economic losses for producers and unnecessary environmental and climate impact. Not all food loss can be avoided, but being aware of and optimizing the flows of food production contribute to a more robust food chain. When work and resources have been used to produce the quality that consumers demand, it is more resource efficient that raw materials and products reach the consumer and are consumed. By-products from the food industry can also, with additional processing or handling, to a greater extent be utilized in food products alternatively be used as feed instead of becoming waste.
|
|
| 39. |
- Strid, Ingrid, et al.
(författare)
-
Livsmedelsförluster i Sverige : metoder för ökad kunskap om livsmedelsproduktionens förluster och resurser
- 2021
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Det saknas kunskap om mängder och orsaker till matsvinn, framförallt om förlusterna tidigt i livsmedelskedjan. De studier som finns visar på betydande förluster redan i primärproduktionen vilket leder till ekonomiska förluster för producenter och onödig miljö- och klimatpåverkan. Alla förluster går inte att undvika men att känna till och optimera matproduktionens flöden bidrar till en mer robust livsmedelskedja. När arbete och resurser har använts för att producera den kvalitet som konsumenterna efterfrågar är det mest resurseffektivt att råvaror och produkter når fram till konsumenten och äts upp. Biprodukter från livsmedelsindustrin kan också med annan förädling eller hantering i högre utsträckning ingå i livsmedelsprodukter alternativt utnyttjas som foder istället för att bli avfall.
|
|
| 40. |
- Ustariz Olivera, Karina Rossio, et al.
(författare)
-
Mineral composition and nutritive value of Festuca ecotypes originated from the highland region of Bolivia and cultivars from Argentina
- 2019
-
Ingår i: Australian Journal Of Crop Science. - : Southern Cross Publishing. - 1835-2693 .- 1835-2707. ; 13, s. 1650-1658
-
Tidskriftsartikel (refereegranskat)abstract
- Native grasses constitute the most important source of feed for camelids, sheep and cattle in the highlands of Bolivia, where the genus Festuca is one of the major feed components. This study was carried out to investigate the nutritional value of 11 Festuca ecotypes from the highlands of Bolivia and two cultivars from Argentina (Festuca arundinacea Schreb. cv. ‘Taita’ and Festulolium). All ecotypes were grown in the same experimental field and their protein, ash, cellulose, moisture and micronutrients (Al, B, Ca, Cd, Cu, Fe, K, Mg, Mn, Mo, Na, Ni, P, S, Si and Zn) content was determined. Principal component analysis and unweighted pair group method with arithmetic mean (UPGMA) cluster analysis, based on all nutrients, clearly defined the two Argentinian cultivars as outliers. This differentiation was mainly explained by their cellulose, ash, Mn and Al contents. Analysis of variance based on the origin of the accessions revealed highly significant (P < 0.001) differences for their cellulose, ash, Mn and Mg contents, while they differ significantly (P < 0.05) in Ni, Fe, Na and Al contents. There was a highly significant positive correlation between several pairs of minerals including Mg–Ca (r = 0.94) and Mg–Zn (r = 0.92). Negatively correlated pairs of minerals include B–Fe (r = - 0.65) and B–Ni (r = - 0.58). This study provides useful information about the nutritive quality of Bolivian Festuca ecotypes for their use in breeding programs of this forage grass in the Andean highlands of South America.
|
|
