| Grass pea (Lathyrus sativus L.) is an important food, feed and fodder legume drought resistant crop. A strong epidemiological association is known to exist between consumption of grass pea and lathyrism. A neurotoxin, {dollar}beta{dollar}-N-Oxalyl-L-{dollar}alpha,beta{dollar}-diaminopropionic acid (ODAP) has been identified to be the causative principle. This study was undertaken to investigate the mode of inheritance of the neurotoxin, a prerequisite for the development of neurotoxin free or low neurotoxin lines. Five grass pea lines with low to high ODAP concentration were inter-crossed in all possible combinations (both crosses and reciprocals). Parents, F{dollar}sb1{dollar} and F{dollar}sb2{dollar} progenies were evaluated under field condition and ODAP analyzed by ortho-phthalaldehyde spectrophotometric method. Many of the progenies of low x low ODAP crosses were found to be low in ODAP concentration which indicated that the low ODAP lines shared some genes in common for seed ODAP content. However, wider variation of ODAP in F{dollar}sb2{dollar} progenies as compared to parental and F{dollar}sb1{dollar} progenies, suggested the presence of different modifier genes between lines. The F{dollar}sb1{dollar} progenies of the low ODAP x high ODAP crosses were intermediate in ODAP concentration which indicated lack of complete dominance either by low or high ODAP. The F{dollar}sb2{dollar} progenies segregated covering the entire parental range. The continuous variation, together with very close to normal distribution of the F{dollar}sb2{dollar} population both of low x low and low x high ODAP, crosses indicated ODAP to be quantitatively inherited. Reciprocal crosses produced different results in some cases indicating a maternal effect on ODAP concentration. Broad sense heritability of ODAP concentration was estimated to be in the range of 17 to 93%. |
