Screening Of Two New Cytoplasmic Male Sterile Lines And Restore Lines In Rice

Sterility gene orfH79 and orf216 are involved in Honglian-Cytoplasmic male sterility(HL-CMS). The fertility restoration of HL-CMS is controlled by two fertility restorer genes, Rf5 and Rf6. In order to study the interaction between the CMS/Rf systems, molecular markers were used to screen the materials which contain the separated gene, respectively. The main results are as follows:1) In order to achieve the material which only contains CMS gene orfH79, the costructed population of orfH79-containing wild rice Oryza rufipogon with AA genome backcrossed with YTB was used and the orfH79-containing plants were screened by PCR with specific molecular makers of orfH79 and orf216, and pollen fertiltiy detection. The line, named L-orfH79, contained only orfH79 and no orf216 was selected, and the staining abortion phenotype of its pollen was idenitified by 1%I2-KI staining.2) To analyze the distribution of CMS gene orf216 in cultivated rice, the 824 cultivated varieties were PCR-screened by 2 specific gene makers of orf216 gene and 9 accessions were initially selected. And then using both orfH79 and orf216 markers to screen those 9 accessions, two orf216-containg accessions(IR43 and IR73546) without orfH79 identified, which were further validated by southern blot.3) Using specific gene makers, designed from Rf5 and Rf6, comboned with self-fertilized seed setting rate, three near-isogenic ines(NIL), L-Rf5, L-Rf6, and L-Rf5-6, respectively with high stable fertility and pure genotype were selected from previously constructed NIL populations, respectively containing Rf5, Rf6, Rf5 plus Rf6. In addition, the down-regulated expression of orf216 and orfH79 in those 3 NILs were observed by real-time PCR analysis.