| 1. |
|
|
| 2. |
|
|
| 3. |
- Salomon, Björn, et al.
(författare)
-
Evolutionary process of Hordeum brachyantherum 6x and related tetraploid species revealed by nuclear DNA sequences
- 2009
-
Ingår i: Breeding Science. - : Japanese Society of Breeding. - 1344-7610 .- 1347-3735. ; 59, s. 611-616
-
Tidskriftsartikel (refereegranskat)abstract
- A hexaploid form of Hordeum brachlyantherum ssp. brachyantherum was discovered in California in 1980, and its origin has since been studied over the past three decades. We applied EF-G, a nuclear DNA sequence, to infer the parents of the hexaploid form. In polyploid taxa, amplified DNAs were cloned into a vector, and EF-G copies were amplified from the colonies by PCR and digested with restriction enzymes to separate different types. Phylogenetic analysis was performed based on the DNA sequences. The result showed that H. brachyantherum ssp. brachyantherum 6x and 4x carried one identical DNA sequence of 910 bp, and had closely related DNA sequences of 931 bp. H. brachyantherum ssp. brachyantherum 6x and H. marinum ssp. gussoneanum 2x shared one identical DNA sequence of 915 bp. From these results we hypothesized that H. brachyantherum ssp. brachyantherum 6x has evolved by an outcrossing between H. marinum ssp. gussoneanum 2x and H. brachyantherum ssp. brachyantherum 4x, followed by a chromosome doubling. Our results also indicate that H. marinum was involved in the polyploidization of H. secalinum, H. capense, and H. marinum. The origins of H. jubatum and H. depressum are discussed.
|
|
| 4. |
|
|
| 5. |
|
|
| 6. |
- Carlsson, Anders
(författare)
-
Plant oils as feedstock alternatives to petroleum - A short survey of potential oil crop platforms
- 2009
-
Ingår i: Plant Breeding. - : Elsevier BV. - 0179-9541 .- 1439-0523. ; 91, s. 665-670
-
Forskningsöversikt (refereegranskat)abstract
- Our society is highly depending on petroleum for its activities. About 90% is used as an energy source for transportation and for generation of heat and electricity and the remaining as feedstocks in the chemical industry. However, petroleum is a finite source as well as causing several environmental problems such as rising carbon dioxide levels in the atmosphere. Petroleum therefore needs to be replaced by alternative and sustainable sources. Plant oils and oleochemicals derived from them represent such alternative sources, which can deliver a substantial part of what is needed to replace the petroleum used as feedstocks.Plant derived feedstock oils can be provided by two types of oil qualities, multi-purpose and technical oils. Multi-purpose oils represent oil qualities that contain common fatty acids and that can be used for both food and feedstock applications. Technical oil qualities contain unusual fatty acids with special properties gained from their unique molecular structure and these types of oils should only be used for feedstock applications. As a risk mitigation strategy in the selection of crops, technical oil qualities should therefore preferably be produced by oil crop platforms dedicated for industrial usage. This review presents a short survey of oil crop platforms to be considered for either multi-purpose or technical oils production. Included among the former platforms are some of the major oil crops in cultivation such as oil palm, soybean and rapeseed. Among the later are those that could be developed into dedicated industrial platforms such as crambe, flax, cotton and Brassica carinata. The survey finishes off by highlighting the potential of substantial increase in plant oil production by developing metabolic flux platforms, which are starch crops converted into oil crops. (c) 2009 Elsevier Masson SAS. All rights reserved.
|
|
| 7. |
- Ranius, Thomas, et al.
(författare)
-
Development of tree hollows in pedunculate oak (Quercus robur)
- 2009
-
Ingår i: Forest Ecology and Management. - : Elsevier BV. - 0378-1127 .- 1872-7042. ; 257, s. 303-310
-
Tidskriftsartikel (refereegranskat)abstract
- Many invertebrates, birds and mammals are dependent on hollow trees. For landscape planning that aims at persistence of species inhabiting hollow trees it is crucial to understand the development of such trees. In this study we constructed an individual-based simulation model to predict diameter distribution and formation of hollows in oak tree populations. Based on tree ring data from individual trees, we estimated the ages when hollow formation commences for pedunculate oak (Quercus robur) in southeast Sweden. At ages of about 200-300 years, 50% of the trees had hollows. Among trees < 100 years old, less than 1% had hollows, while all > 400-year-old trees had hollows. Hollows formed at earlier ages in fast-growing trees than in slow-growing trees, which may be because hollows are formed when big branches shed, and branches are thicker on fast-growing trees in comparison to slow-growing trees of the same age. The simulation model was evaluated by predicting the frequency of presence of hollows in relation to tree size in seven oak stands in the study area. The evaluation suggested that future studies should focus on tree mortality at different conditions. Tree ring methods on individual trees are useful in studies on development of hollow trees as they allow analysis of the variability in time for hollow formation among trees. (C) 2008 Elsevier B.V. All rights reserved.
|
|
| 8. |
|
|
| 9. |
- Åkerström, Andreas, et al.
(författare)
-
Effects of Sampling Time and Nitrogen Fertilization on Anthocyanidin Levels in Vaccinium myrtillus Fruits
- 2009
-
Ingår i: Journal of Agricultural and Food Chemistry. - : American Chemical Society (ACS). - 0021-8561 .- 1520-5118. ; 57, s. 3340-3345
-
Tidskriftsartikel (refereegranskat)abstract
- Vaccinium myrtillus berries (bilberries) contain antioxidants, in particular anthocyanins, which are secondary metabolites that have proven health-promoting effects. Bilberries were collected at the Svartberget research forest in northern Sweden from plots with no, low, and high applications of NH(4)NO(3) on three replicated dates in each year from 2005-2007, and their anthocyanidin contents were analyzed by high performance liquid chromatography. Their mean total anthocyanidin contents Were 9.0, 6.2, and 22.7 mg/g DW in 2005, 2006, and 2007, respectively. The values were significantly higher in 2005 than in 2006 and significantly higher in 2007 than in both previous years, across all three sampling dates. In addition, anthocyanidin contents were significantly affected by sampling date in all years (P < 0.001); they were linearly correlated with the thermal sum in 2005 and 2007 but rose between the first and second sampling occasions and subsequently declined in 2006. No significant effect of nitrogen fertilization on total anthocyanidin levels was detected in any of the studied years. The results indicate that climatic factors and yearly fluctuations influence anthocyanidin biosynthesis and degradation more strongly than nitrogen availability. To our knowledge, this is the first time this effect of sampling time on anthocyanins in mature bilberries has been shown.
|
|
| 10. |
|
|
