Researches on variation effects of two three-line hybrid rice maintainer line of space mutants.

The variations in traits of space-mutated offspring of two maintainer lines of three-line hybrid rice,HT-B and Y Huanong B,were studied.The results showed that the SP1 generation displayed varying degrees of impairment ingerminationrate,bud length,and seeding height,but no evident variation in the other economic traits was found compared with the control.Positive and negative variations in several agricultural traitsemerged in SP2 and SP3 generations and an unusually wide range of variations were discovered in amylose content(AC) from extremely low AC(w = 1.66%) in waxy mutantand to extremely high AC(w = 38.03%) in non-waxy mutant.The pollen sterility and the selfing mature rate of the offspring from test cross between SP4 mutants and their correspondent male sterile lines were also studied.The maintaining ability for male sterility greatly varies in the space mutants,and completely fertile strains found in the offspring from the test cross are promising resources for novel elite maintainer lines.