The genetic control of mildly restricted branching in narrow-leafed lupin (Lupinus angustifolius L.)

Abstract

The indeterminate growth habit of most cultivars of narrow-leafed lupin(Lupinus angustifolius) results in undue competition between podgrowth and branch growth, and sometimes poor partitioning of dry massto grain. Selection of restricted-branching genotypes has been proposedas a method to overcome this problem. The restricted branching (RB)trait occurs in two forms, mild and severe. This paper reports the patternof genetic control of mild RB derived from a number of independentsources. The trait, as indicated by the number of leaves on the uppermostbranch, was found to be quantitative (quasi-continuous), but highlyheritable, and largely controlled by additive genetic effects. There was noconsistent correlation of this trait with the number of leaf nodes on themain stem or the time to flowering. It should therefore be possible toobtain different combinations of branching pattern and maturity datethrough plant breeding, and to assess their adaptation to a range ofenvironments.