Screening Of Honglian(HL) Sterile And Fertility-restorer Gene In Asian Cultivated Rice (Oryza Sativa L.)

Rice (Oryza sativa L.) is one of the world's important food crops, The basic andapplied research play an important role to guarantee food production to meet with thesteadily growing population. As a new source of germplasm, The Hongliancytoplasmic male sterile (HL-CMS) rice has been demonstrated having great potentialfor hybrid rice production. A number of hybrid rice cultivars derived from HL-CMSlines have been developed, which showed good grain quality, improved resistance todisease and higher grain yields. The study on the HL-CMS and the fertility restorergenes will take a great promotion to the sustainable development of hybrid rice. Tosuch an ends, The screening of HL sterile and restores gene in Asian cultivation ricewere performed, and the main results are as follows:1. The discovery of chimeric gene orfH79 related to Honglian CMS provides usthe possibility to detect the distribution of Honglian cytoplasm in rice varieties usingorfH79 as the probe. Which will greatly enhance the efficiency and the reliability ofdeveloping new or similar HL-CMS line in the breeding program of rice. In ourresearch, 137 Asian cultivated rice varieties were analyzed, the PCR amplificationand sequencing results showed that three lines were identified having the HonglianCMS related gene orfH79, the three lines are Q5, 860 and 861. The hybrid F₁ and thebackcross BC₁F₁ derived from the cross between 860 and the HL maintainer YuetainB (YB) was sterile, the other two F₁ were fertility and the BC₁F₁ populations showedfertility segregation, x² value were 0.293 and 0.190 respctively, the sterile andnon-sterile plants segregation is 1:1, which shows that the two species containing apair of restorer gene. 2. use 137 Asian representative cultivated rice varieties for the screeningHL-restoring gene in Asian cultivated varieties, We screening the species withRf5/Rf6 gene co-segregated SSR marker RM3510 and RM5373, Expected to getRf5/Rf6 different allele fragments in cultivated rice. PCR amplification showed thatthere are different allele fragments in 27 materials, we carry out 27 test-crosscombinations via YtA as female parents with all 27 materials those have differentallele fragments contrast to Rf5/Rf6, The results of test-cross indicate that there isonly one materials doesn't have honglian-Fertility restorer gene.we used 15 materialsfor genetic analysis, There were14 materials fit to the genetic mode of only one pairof Rf gene for HL-CMS .at the same time,we take Allelism test in 5 materials whichhave different allele fragments contrast to Rf5/Rf6. IR64,Pengshan-tie-ganzhan andWuda-daozbong had different profile to the 9311 and Milyang23 at the loci of Rf5/Rf6,which means that they are possible three new Rf loci. The allelism analysis showedthat. the recombination frequency between IR64 and 9311 and Milyang23 was31.81% and 18.95% respectively,The recombination frequency between Pengshan-tie-ganzhan and 9311 and Milyang23 was 27.2% and 5.33% respectively. Therecombination frequency between Wuda-daozhong and 9311 and Milyang23 was24.20.% and 12.96% respectively The recombination frequency between IR64andPengshan-tie- ganzhan was 19.04%.The results showed that there were at least morethan 2 new new honglian-Rfloci.in Pengshan-tie-ganzhan and IR64.