Development of NILs with Cl-gene of Rice Restorer and Evaluation on the Near-isogenic level

The anatomization,effects on agronomic characters,inheritance and gene location of clustered character in different rice resources have been analyzed by some researchers.Z1820,a new spontaneous mutant with clustered spikeletsgene(Cl-gene),was founded in breeding materials.Restorers(LH17 and N45) as recurrent female parents and Z1820 as non-recurrent parent,two NILs(Cl-LH17 and Cl-N45) were obtained in the purpose of studying the effects on agronomic characters,gene location of this Cl-gene. The method of morphologic comparability and the technology of SSR marker were introduced into the polymorphism analysis and the near-isogenic level evaluation on those two pairs of Cl-NILs.The main results are as follow:(1) For LH17 and Cl-LH17,there was significant difference in plant height and panicle length but not in effective tillers per plant,spikelets per panicle and percentage of grain setting;for N45 and Cl-N45,there was significant difference only in panicle length(Table 1).(2) Among the detected 120 pairs of SSR primers(10 pairs every chromosome),only RM7434 on chromosome 6 was amplified polymorphic bands between LH17 and Cl-LH17,but there are four primers(RM6297,on chromosome 3;RM587,7434,on chromosome 6;RM3583,chromosome 7) which were produced polymorphic bands in N45 and Cl-N45;Another four SSR primers near RM7434 were produced polymorphic bands in NILs and their recurrent parents,and RM5957 was a polymorphic primer to LH17 and Cl-LH17 but not to N45 and Cl-N45.(3) The numbers of double,three and four-clustered spikelets in Cl-N45 were all bigger than those in Cl-LH17 and the clustering level(based on clustered rate) of Cl-N45 was also bigger than that of Cl-LH17.Those results indicated that the plant height and panicle length were decreased by Cl-gene from Z1820 but effective tillers per plant,spikelets per panicle,and percentage of grain setting were not changed;LH17 and Cl-LH17 are one pair of ideal Cl-NILs and they can be propitious to be used in the lucubration of the Cl-gene;the spikelets-clustered phenotype was different in different genetic background.The high quality NILs can be easily developed and the near-isogenic level can be objectively evaluated by the combining utilization of classical methods and modern molecular marker technologies.