|VAN SANTEN, EDZARD|
Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/5/2000
Publication Date: N/A
Interpretive Summary: We examined grain yield components in winter-type white lupin across a broad range of environments in the southeastern USA and western France. The objective was to improve our understanding of the importance of yield components and determine which traits should be considered when evaluating germplasm. Pod number and seed size had the greatest effect on grain yield. Breeding for reduced pod abortion and adjusting management practices will help increase pod number per unit area and thus, grain yield. Considerable genetic variability exists for seed size, so selection for a higher, more optimum seed size is possible. Determinate varieties had more uniform seed size than indeterminate germplasm; breeding programs are selecting for this growth habit, so future varieties should have more uniform seed size, which will be important for seed production. Agronomic practices and varieties with optimum genetic potential will have to be developed specifically for France and the southeastern USA. Main stem and primary branch levels were most important for grain yield across environments. Basal branches, those arising near ground level at the base of the main stem, contributed significantly to grain yield in the southeastern USA. This same branch level can be eliminated from French varieties because basal branches use plant assimilates for vegetative growth but rarely produce grain in western France.
Technical Abstract: In winter-type white lupin (Lupinus albus L.), an improved understanding of importance of yield components could be useful when evaluating germplasm. We examined grain yield components across a broad range of environments and determined which traits affected yield. Data were taken from sowing date (SD) and dry matter partitioning(DM)studies. SD studies included 2-3 years in north, central and south Alabama, and one year in north Virginia. The DM study was conducted two years in western France and central Alabama. We used principal component analysis to reduce the number of yield traits analyzed. Pod and seed number, and pod and seed yield were highly correlated (r > +/= 0.80,P < +/= 0.01) with most principal components. Yield components were usually from the same inflorescence level when they were correlated with a principal component. Yield components were also highly intercorrelated (r > +/= 0.80,P < +/= 0.01). Pod number and seed size had the greatest effect on grain yield. Reducing pod abortion and adjusting management practices will help increase pod number, while breeding for higher seed size will increase seed size across environments. Optimum agronomic practices and cultivars will have to be developed specifically for France and the southeastern USA to maximize grain yield. Main stem and primary branches were most important for yield across environments. Cultivar selection will require elimination of basal branches in French germplasm; this same inflorescence will be needed in cultivars for the southeastern USA.