籼粳亚种间育性位点分型及籼粳杂交稻育性位点模式研究OA北大核心CSTPCD

[Objective]The objective of this study is to investigate the distribution of inter-subspecific fertility loci in indica rice,japonica rice,and indica-japonica hybrid rice in China.This involves establishing a pattern of fertility loci to achieve compatibility between different subspecies,exploring new indica-japonica hybrid rice patterns,and laying a molecular basis for improving materials and breeding designs for inter-subspecific compatibility.[Method]Specific markers for indica and japonica rice were used to screen for inter-subspecific fertility loci in rice materials from China.Several indica and japonica rice varieties were crossed with each other,and the pollen fertility and seed setting rate of the resulting hybrids were statistically analyzed.[Results]There was limited genetic exchange between indica andjaponica rice at the fertility loci.Due to introgression of fertility loci from indica rice,japonica rice could be classified into type Ⅰ(pure japonica)and type Ⅱ(with introgressed indica loci such as Sci,Sdi,and Sei).When S5 was incompatible,the seed setting rate of inter-subspecific hybrid rice was approximately 50％,while it increased to about 80％when compatible.Heterozygosity at Sa,Sb,Sc,or Sd loci had minimal impact on pollen fertility,but heterozygosity of Se/pf12/RHS12 significantly reduced it.The detection results of inter-subspecific hybrid rice materials indicated that the basic fertility loci pattern was homozygous or compatible S5 along with several other fertility loci for pollen fertility.The pollen fertility and seed setting rate of F1 hybrids from the indica two-line male sterile line Shen 08S with S5n andjaponica type Ⅱ rice were normal.[Conclusion]S5 is the core locus controlling female gamete fertility,while loci affecting male gamete fertility have an additive effect.Se may be an indispensable locus among them.The possible basic genetic locus patterns for achieving fertility compatibility between indica and japonica subspecies include SS5+SSe+two other loci among Sa,Sb,Sc,and Sd.The'maternal indica paternal japonica'model,utilizing two-line indica rice male sterile lines with wide compatibility as female parents and japonica rice as male parents,presents another feasible inter-subspecific hybrid rice model.