Breeding Utilization Of Purple Mutation Of Rice

It is the foundation to develop the photo-thermo period sensitive genic male sterile(P/TGMS)lines in the heterosis utilization of two-line hybrid rice.In order to investigation the breeding application of P/TGMS lines labeled with purple leaf color which were obtained by irradiation of Peiai64S,the color character,inheritance, main agronomic traits of the mutants and the agronomic traits of their hybrids were studied.The main results were as following:The leaves of the mutants displayed the purple during their growing stage,and the leaf purple depth was affected by sunlight.First,the new leaf was green,then the leaf become to purple from the leaf tip to base.Finally,the panicle branch and floret also become to purple.Genetic analysis indicated that the leaf purple was a recessive trait.Zi1,zi3,zi6 and zi8 were respectively controlled by 2 genes,which one is an inhibitor gene.Zi2, zi4,zi5,zi7 and zi10 were respectively controlled by 3 genes,and one is an inhibitor gene.The agronomic traits analysis indicated that the growing duration and leaves number of zi2 were increased.The two mutants of purple color showed increase in plant panicle length,flag leave,secondary leave from top,the third leave from top. And there was no difference in floret length,floret width and their ratio between these mutants and Peiai64S.Compared with Peiai64S,there was increase in gain number per panicle of zi3 and decrease of that in zi2.Panicle exsertion and outcrossing rate were poor.The critical points of temperature of these mutants were similar to the original lines,zi2 and zi3 were non pollen type of male sterile.The hybrids of these mutants had similar characteristics with original-hybrids in plant type and the development of tiller and plant height.The different hybrids showed different yield components.The potential yield of zi2-hybrids was the same as that of original-hybrids and the yield of zi3-hybrids was lower than that of original-hybrids. This study indicated that zi2 has the good breeding utilization prospect.