GENETIC-ANALYSIS OF THE MASS OF THE FLAGL EAF IN WHEAT

The inheritance of the fresh and dry mass of wheat flagleaves and of t heir relative water content was analysed in an 8x8 half-diallel crossi ng experiment. The inheritance of fresh and dry mass exhibited similar trends. In both cases a preponderance of additive gene effects was ob served with slight partial dominance. The heritability index had a val ue of h(2)=0.76 for fresh mass and h(2)=0.66 for dry mass. Great simil arity was also shown by the configuration of the parents for the two t raits. The inheritance of relative water content was also determined d ecisively by additive gene effects, but in this case overdominance was observed. The heritability index was thus lower (h(2)=0.42). The conf iguration of the parents was quite different from that observed for fl agleaf mass, thus confirming the independent genetic determination of these two traits. The results support the suggestion that selection fo r high flagleaf mass in the interests of greater, more stable yields i s feasible and can be combined with a reduction in the relative water content of the leaf, an important factor in drought tolerance.