Effect of genotype on yield of narrow-leafed lupin (Lupinus angustifolius) and sandplain lupin (Lupinus cosentinii)

Abstract

Dry matter production, pod set and seed yield were compared among five genotypes of Lupinus angustifolius and six genotypes of L. cosentinii with reduced or non-shattering pods. The genotypes differed in flowering time, alkaloid content and flower colour (L. angustifolius only). Presence of the low alkaloid gene iucundus in L. angustifolius reduced vegetative growth by 25 per cent, and did not significantly reduce seed yield. Susceptibility to 'split' seed, a disorder causing rupture of the testa of the developing seeds was also associated with the iucundus gene. The implications of this are discussed. Flower colour and maturity differences did not significantly affect yield, although there was some suggestion that the white flower and seed colour gene leucospermus reduced pod set and seed yield in earlyflowering genotypes. In L. cosentinii, the presence of the low alkaloid gene sw generally did not significantly affect dry matter or seed yield. An exception was in the very early flowering genotypes where dry matter yield was 23 per cent lower in the low alkaloid line.