Monogenic Control of Basic Vegetative Phase and Photoperiod-sensitive Phase in Rice

Lm which belongs to the linkage group I is one of the primary loci controlling heading time of cultivated rice and is also associated with photoperiod sensitivity. The effects of alleles of the Lm locus on two phases of the vegetative growth duration, the basic vegetative phase and the photoperiod-sensitive phase, were analysed by growing two isogenic lines with Lme and Lmu allelles under natural and controlled daylengths. Heterozygotes (Lme/Lmu) were maintained during 15 generations Lrom F1 through BC4F11 in the cross between the Malaysian cultivar Morak Sepilai and the Japanese cultivar Fujisaka 5, which was used as the recurrent parent for the successive four backcrosses. Fujisaka 5 and Morak Sepilai transmitted the early-maturing allele Lme and the late-maturing allele Lmu to their hybrid progenies, respectively.