Genetic Analysis And Gene Fine-Mapping Of A Palea Mutant Pd(t)in Rice(Oryza Sativa.l)

Floral organ development is one of the most important research areas in plant developmental biology.In grass,the evolutionary relationship between lemma and palea,and their relationship to the flower organs in dicots have been variously interpreted and wildely debated.In the present study,we carried out morphological and genetic analysis of a palealess mutant named pd(t)[palea degradation(t),pd(t)],with palea degraded,was discovered from rice variety jinhui 323.In this study,the mutants were observed floral organ morphology analysis and agronomic traits,and thus the genes carried by segregating population genetic analysis and molecular marker positioning,and finally through the regional target gene sequence analysis of candidate gene prediction.The results are as follows:(1)Compared with wild-type plants,the most obvious difference was palea incomplete development,curved.So it can't closely link with lemma and can not be closed tightly each other,the number of stamens are 2-6 pieces in the mutant.(2)The mutant pd(t)was crossed with varieties zhonghua 15 and ACC8558 respectively.The hybrid F1 progeny showed normal phenotype of palea.The ?2 test for F2 population showed that the mutant phenotype was controlled by single recessive nuclear gene,named pd(t).(3)F2 populations to use for fine mapping the gene pd(t)was constructed from a cross between the mutant and ACC8558.ultimately we make it between two markers of RM490 and RM243--a physical distance of approximately 60Kb on the short arm of chromosome 1.(4)There were seven annotated genes located in the anchored region.One possible candidate gene LOC_OsO1gl2890 was verified by sequencing and the result found that in the wild-type of the forecasting ORF including the mutation sites length is 942bp,which encodes 313 amino acids;whereas in the mutant,the 124 amino acids coding glutamate(glu)GAA becomes a termination codon TAA.and resulting in premature termination of translation.This gene and its associated sequences is known may belong to a new class of transcriptional regulatory control of floret protein family,Therefore we assumed that the gene LOC_Os01g12890 was the gene pd(t)controlling...