Genotype-environment interaction for seed yield and ODAP concentration of Lathyrus sativus L. and L-cicera L. in Mediterranean-type environments

In 1994, 407 L. sativus and 96 L. cicera lines were evaluated for phenology, seed yield and seed ODAP (a neurotoxin) concentration in the Mediterranean-type climate of south-western Australia. A selected number of lines from this study were grown at three sites in south-western Australia in 1995 and 1996, to examine genotype-environment interactions on seed yield and ODAP concentration in the seed of the two Lathyrus spp. Principal components analysis showed that L. sativus lines grown in 1995 and 1996 could be divided into two geographical origins: Indian sub-continent and Mediterranean/European. Those lines of Mediterranean/European origin were consistently higher yielding (both in 1994 and 1995/96), with much larger seeds and later phenology. In L. cicera seed yield was closely associated with greater mean seed weight and to a lesser extent with early phenology. The genotype-environment study indicated that higher yielding lines of both species generally responded to favourable environments; in the case of L. sativus the Mediterranean/European lines and for L. cicera the larger seeded, earlier phenology lines. For both species, genotype was the most important determinant of ODAP concentration and environment had less influence. Genotype-environment interactions had no effect on seed ODAP concentrations. In terms of seed yield, both species showed substantial potential in the environments tested. Further improvements in adaptation, seed yield and reduction in ODAP are possible in both species.