Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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    We will mail you new results for this query: keywords==eucalyptus-grandis
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Mapping quantitative trait loci (QTLs) for fatty acid composition in an interspecific cross of oil palm
Singh, R. ; Tan, S.G. ; Panandam, L.M. ; Rahman, R.A. ; Ooi, L.C.L. ; Low, E.T.L. ; Sharma, M. ; Jansen, J. ; Cheah, S.C. - \ 2009
BMC Plant Biology 9 (2009). - ISSN 1471-2229
elaeis-guineensis jacq. - genetic-linkage map - marker-assisted selection - brassica-napus - rapd markers - eucalyptus-grandis - pseudo-testcross - seed oil - microsatellite - identification
Marker Assisted Selection (MAS) is well suited to a perennial crop like oil palm, in which the economic products are not produced until several years after planting. The use of DNA markers for selection in such crops can greatly reduce the number of breeding cycles needed. With the use of DNA markers, informed decisions can be made at the nursery stage, regarding which individuals should be retained as breeding stock, which are satisfactory for agricultural production, and which should be culled. The trait associated with oil quality, measured in terms of its fatty acid composition, is an important agronomic trait that can eventually be tracked using molecular markers. This will speed up the production of new and improved oil palm planting materials. Result: A map was constructed using AFLP, RFLP and SSR markers for an interspecific cross involving a Colombian Elaeis oleifera (UP1026) and a Nigerian E. guinneensis (T128). A framework map was generated for the male parent, T128, using Joinmap ver. 4.0. In the paternal (E.guineensis) map, 252 markers (199 AFLP, 38 RFLP and 15 SSR) could be ordered in 21 linkage groups (1815cM). Interval mapping and multiple-QTL model (MQM) mapping (also known as composite interval mapping, CIM) were used to detect quantitative trait loci (QTLs) controlling oil quality (measured in terms of iodine value and fatty acid composition). At a 5% genome-wide significance threshold level, QTLs associated with iodine value (IV), myristic acid (C14:0), palmitic acid (C16:0), palmitoleic acid (C16:1), stearic acid (C18:0), oleic acid (C18:1) and linoleic acid (C18:2) content were detected. One genomic region on Group 1 appears to be influencing IV, C14:0, C16:0, C18:0 and C18:1 content. Significant QTL for C14:0, C16:1, C18:0 and C18:1 content was detected around the same locus on Group 15, thus revealing another major locus influencing fatty acid composition in oil palm. Additional QTL for C18:0 was detected on Group 3. A minor QTL for C18:2 was detected on Group 2. CONCLUSION: This study describes the first successful detection of QTLs for fatty acid composition in oil palm. These QTLs constitute useful tools for application in breeding programmes
Dynamics in land cover and its effect on stream flow in the Chemoga watershed, Blue Nile basin, Ethiopia
Bewket, W. ; Sterk, G. - \ 2005
Hydrological Processes 19 (2005)2. - ISSN 0885-6087 - p. 445 - 458.
experimental catchments - eucalyptus-grandis - pinus-patula - south-africa - afforestation - mokobulaan - responses - climate
The objective of this study was to analyse changes in stream flow patterns with reference to dynamics in land cover/use in a typical watershed, the Chemoga, in northwestern highland Ethiopia. The results show that, between 1960 and 1999, total annual stream flow decreased at a rate of 1 · 7 mm year-1, whereas the annual rainfall decreased only at a rate of 0 · 29 mm year-1. The decrease in the stream flow was more pronounced during the dry season (October to May), for which a statistically significant decline (0 · 6 mm year-1) was observed while the corresponding rainfall showed no discernible trend. The wet season (June to September) rainfall and stream flow did not show any trends. Extreme low flows analysed at monthly and daily time steps reconfirmed that low flows declined with time, the changes being highly significant statistically. Between 1960 and 1999, the monthly rainfall and stream flow amounts of February (month of lowest long-term mean flow) declined by 55% and 94% respectively. Similarly, minimum daily flows recorded during the three driest months (December to February) showed statistically highly significant declines over the same period. It declined from 0 · 6 m3 s-1 to 0 · 2 m3 s-1 in December, from 0 · 4 m3 s-1 to 0 · 1 m3 s-1 in January and from 0 · 4 m3 s-1 to 0 · 02 m3 s-1 in February (1 · 0 m3 s-1 = 0 · 24 mm day-1 in the Chemoga watershed). In contrast, extreme high flows analysed at monthly (for August) and daily (July to September) time steps did not reveal discernible trends. The observed adverse changes in the stream flow have partly resulted from changes in land cover/use and/or degradation of the watershed that involved destruction of natural vegetative covers, expansion of croplands, overgrazing and increased area under eucalypt plantations. The other contributory factor has been the increased dry-season water abstraction to be expected from the increased human and livestock populations in the area. Given the significance of the stream flow as the only source of water to the local people, a set of measures aimed at reducing magnitudes of surface runoff generation and increasing groundwater recharge are required to sustain the water resource and maintain a balanced dry-season flow in the watershed. Generally, an integrated watershed management approach, whereby the whole of the watershed can be holistically viewed and managed, would be desirable
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