| 31. |
- Hammenhag, Cecilia, et al.
(författare)
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QTL mapping for domestication-related characteristics in field cress (Lepidium campestre)—a novel oil crop for the Subarctic region
- 2020
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Ingår i: Genes. - : MDPI AG. - 2073-4425. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- Domestication of a new crop requires identification and improvement of desirable characteristics Field cress (Lepidium campestre) is being domesticated as a new oilseed crop, particularly for northern temperate regions.. In the present study, an F-2 mapping population and its F-3 progenies were used to identify quantitative trait loci (QTLs) for plant height (PH), number of stems per plant (NS), stem growth orientation (SO), flowering habit (FH), earliness (ER), seed yield per plant (SY), pod shattering resistance (SHR), and perenniality (PE). A highly significant correlation (p < 0.001) was observed between several pairs of characteristics, including SY and ER (negative) or ER and PE (positive). The inclusive composite interval mapping approach was used for QTL mapping using 2330 single nucleotide polymorphism (SNP) markers mapped across the eight field cress linkage groups. Nine QTLs were identified with NS, PH, SO, and PE having 3, 3, 2, and 1 QTLs, explaining 21.3%, 29.5%, 3.8%, and 7.2% of the phenotypic variation, respectively. Candidate genes behind three of the QTLs and favorable marker alleles for different classes of each characteristic were identified. Following their validation through further study, the identified QTLs and associated favorable marker alleles can be used in marker-aided breeding to speed up the domestication of field cress.
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| 32. |
- Hanifah, Nurul Atilia Shafienaz binti, et al.
(författare)
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Comparative transcriptome profiling provides insights into the growth promotion activity of Pseudomonas fluorescens strain SLU99 in tomato and potato plants
- 2023
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Ingår i: Frontiers in Plant Science. - 1664-462X. ; 14
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Tidskriftsartikel (refereegranskat)abstract
- The use of biocontrol agents with plant growth-promoting activity has emerged as an approach to support sustainable agriculture. During our field evaluation of potato plants treated with biocontrol rhizobacteria, four bacteria were associated with increased plant height. Using two important solanaceous crop plants, tomato and potato, we carried out a comparative analysis of the growth-promoting activity of the four bacterial strains: Pseudomonas fluorescens SLU99, Serratia plymuthica S412, S. rubidaea AV10, and S. rubidaea EV23. Greenhouse and in vitro experiments showed that P. fluorescens SLU99 promoted plant height, biomass accumulation, and yield of potato and tomato plants, while EV23 promoted growth in potato but not in tomato plants. SLU99 induced the expression of plant hormone-related genes in potato and tomato, especially those involved in maintaining homeostasis of auxin, cytokinin, gibberellic acid and ethylene. Our results reveal potential mechanisms underlying the growth promotion and biocontrol effects of these rhizobacteria and suggest which strains may be best deployed for sustainably improving crop yield.
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| 33. |
- Hegay, Sergay, et al.
(författare)
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Comparing genetic diversity and population structure of common beans grown in Kyrgyzstan using microsatellites
- 2012
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Ingår i: Scientific Journal of Crop Science. - 2322-1690. ; 1, s. 63-75
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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.
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| 34. |
- Hegay, Sergay, et al.
(författare)
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Genetic diversity analysis in Phaseolus vulgaris L. using morphological traits
- 2014
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Ingår i: Genetic Resources and Crop Evolution. - : Springer Science and Business Media LLC. - 0925-9864 .- 1573-5109. ; 61, s. 555-566
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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.
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| 35. |
- Hegay, Sergay, et al.
(författare)
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Introducing host-plant resistance to anthracnose in Kyrgyz common bean through inoculation-based and marker-aided selection
- 2014
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Ingår i: Plant Breeding. - : Wiley. - 0179-9541 .- 1439-0523. ; 133, s. 86-91
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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.
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| 36. |
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| 37. |
- Juma, Ibrahim, et al.
(författare)
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Avocado Production and Local Trade in the Southern Highlands of Tanzania: A Case of an Emerging Trade Commodity from Horticulture
- 2019
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Ingår i: Agronomy. - : MDPI AG. - 2073-4395. ; 9
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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.
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| 38. |
- Juma, Ibrahim, et al.
(författare)
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Characterization of Tanzanian Avocado Using Morphological Traits
- 2020
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Ingår i: Diversity. - : MDPI AG. - 1424-2818. ; 12
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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.
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| 39. |
- Juma, Ibrahim, et al.
(författare)
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Comparison of morphological and genetic characteristics of avocados grown in Tanzania
- 2021
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Ingår i: Genes. - : MDPI AG. - 2073-4425. ; 12
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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.
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| 40. |
- Juma, Ibrahim, et al.
(författare)
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Genetic diversity of avocado from the southern highlands of Tanzania as revealed by microsatellite markers
- 2020
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Ingår i: Hereditas. - : Springer Science and Business Media LLC. - 0018-0661 .- 1601-5223. ; 157
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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.
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