INHERITANCE OF NEUROTOXIN (ODAP) CONTENT, FLOWER AND SEED COAT COLOR IN GRASS PEA (LATHYRUS-SATIVUS L)

A strong epidemiological association is known to exist between the con sumption of grass pea and lathyrism. A neurotoxin, beta-N-Oxalyl-L-alp ha, beta-diaminopropanoic acid (ODAP) has been identified as the causa tive principle. This study was undertaken to investigate the mode of i nheritance of the neurotoxin ODAP, flower and seed coat colour in gras s pea. Five grass pea lines with low to high ODAP concentration were i nter-crossed in all possible combinations to study the inheritance of the neurotoxin. Parents, F-1 and F-2 progenies were evaluated under fi eld condition and ODAP analyzed by an ortho-phthalaldehyde spectrophot ometric method. Many of the progenies of low x low ODAP crosses were f ound to be low in ODAP concentration indicating the low ODAP lines sha red some genes in common for seed ODAP content. The F-1 progenies of t he low ODAP x high ODAP crosses were intermediate in ODAP concentratio n and the F-2 progenies segregated covering the entire parental range. This continuous variation, together with very close to normal distrib ution of the F-2 population both of low x low and low x high ODAP cros ses indicated that ODAP content was quantitatively inherited. Reciproc al crosses, in some cases, produced different results indicating a mat ernal effect on ODAP concentration. Blue and white flower coloured lin es of grass pea were inter-crossed to study the inheritance of flower colour. Blue flower colour was dominant over the white. The F-2 progen ies segregated in a 13:3 ratio indicating involvement of two genes wit h inhibiting gene interactions. The gene symbol LB for blue flower col our and LW for white flower colour is proposed.