Inter-subspecific hybrids between indica and japonica varieties yield strong biological heterosis, but it is difficult to utilize the hybrids directly in commercial production due to sterility of F1. A special gene S5...Inter-subspecific hybrids between indica and japonica varieties yield strong biological heterosis, but it is difficult to utilize the hybrids directly in commercial production due to sterility of F1. A special gene S5n may overcome the hybrids sterility, which is caused by the interaction between S5 loci. Recently, S5n had been cloned, and it was revealed containing a large DNA deletion sequence that made the gene nonfunctional, compared to S5i or S5j. We designed a pair of primers flanking the deletion sequence of S5n, and then applied to distinguish the varieties with S5n or non-S5n, convincing result suggested that the primers could be served as functional molecular marker to efficiently identify the new germplasm with S5n. Using the functional marker, we surveyed 197 varieties from China National Micro-core Rice Collection, and found ten of which represented S5n including following varieties: Haobuka, Sanbangqishiluo, Mubanggu, Xiaohonggu, Mowanggu’neiza, Laozaogu, Fanhaopi, Feie’nuo2, Baoxie-7B, Teqingxuanhui. Among them, two varieties Sanbangqishiluo and Laozaogu was previously reported to contain S5n gene. Further sequence analysis on the DNA sequence covering both sides of deletion in S5n of the 10 varieties confirmed that the detected sequences in above varieties was identical with those of varieties containing S5n, such as 02428 and Linglun. These results suggested that the gene in S5 locus of the ten varieties was also nonfunctional and it proved the presence of S5n gene.展开更多
Oryza rufipogon exhibits abundant genetic diversity and contains many elite genes. In this work, a total of 441 accessions of O. rufipogon were genetically examined using the functional marker S5n, revealing that 18 a...Oryza rufipogon exhibits abundant genetic diversity and contains many elite genes. In this work, a total of 441 accessions of O. rufipogon were genetically examined using the functional marker S5n, revealing that 18 accessions carried the S5n allele with a heterozygous genotype (S5nS5i/j). Of these accessions, 14 were from Guangdong Province, 2 from Guangxi Zhuang Autonomous Region, 1 from Hainan Province and 1 from Jiangxi Province. Further sequence analysis spanning both sides of the deletion in S5n allele of O. rufipogon confirmed that this allele is identical with that of 02428, a wide-compatibility variety of domesticated rice. The segregation ratio of the 3 genotypes (S5iS5i/S5jS5j:S5nS5i/j:S5nS5n) among 15 self-bred progenies of O. rufipogon significantly deviated from the Mendelian expectation (1:2:1) in that the proportion of plants exhibiting S5n heterozygous and homozygous genotypes was much lower in the progeny. Sequence analysis of full-length S5n alleles indicated that a few base pairs were different between O. rufipogon and O. sativa, and it was presumed that S5n may be an ancient allele. The fertility of the embryo sac in plants with an S5n heterozygous genotype was low, suggesting the existence of other genes controlling embryo sac fertility in the wild rice.展开更多
基金Supported by Joint Fund of the National Natural Science Foundation of China-Guangdong Province (Grant No. U0631003)
文摘Inter-subspecific hybrids between indica and japonica varieties yield strong biological heterosis, but it is difficult to utilize the hybrids directly in commercial production due to sterility of F1. A special gene S5n may overcome the hybrids sterility, which is caused by the interaction between S5 loci. Recently, S5n had been cloned, and it was revealed containing a large DNA deletion sequence that made the gene nonfunctional, compared to S5i or S5j. We designed a pair of primers flanking the deletion sequence of S5n, and then applied to distinguish the varieties with S5n or non-S5n, convincing result suggested that the primers could be served as functional molecular marker to efficiently identify the new germplasm with S5n. Using the functional marker, we surveyed 197 varieties from China National Micro-core Rice Collection, and found ten of which represented S5n including following varieties: Haobuka, Sanbangqishiluo, Mubanggu, Xiaohonggu, Mowanggu’neiza, Laozaogu, Fanhaopi, Feie’nuo2, Baoxie-7B, Teqingxuanhui. Among them, two varieties Sanbangqishiluo and Laozaogu was previously reported to contain S5n gene. Further sequence analysis on the DNA sequence covering both sides of deletion in S5n of the 10 varieties confirmed that the detected sequences in above varieties was identical with those of varieties containing S5n, such as 02428 and Linglun. These results suggested that the gene in S5 locus of the ten varieties was also nonfunctional and it proved the presence of S5n gene.
基金supported by the Joint Fund of the National Natural Science Foundation of China-Guangdong Province (Grant No.U0631003)
文摘Oryza rufipogon exhibits abundant genetic diversity and contains many elite genes. In this work, a total of 441 accessions of O. rufipogon were genetically examined using the functional marker S5n, revealing that 18 accessions carried the S5n allele with a heterozygous genotype (S5nS5i/j). Of these accessions, 14 were from Guangdong Province, 2 from Guangxi Zhuang Autonomous Region, 1 from Hainan Province and 1 from Jiangxi Province. Further sequence analysis spanning both sides of the deletion in S5n allele of O. rufipogon confirmed that this allele is identical with that of 02428, a wide-compatibility variety of domesticated rice. The segregation ratio of the 3 genotypes (S5iS5i/S5jS5j:S5nS5i/j:S5nS5n) among 15 self-bred progenies of O. rufipogon significantly deviated from the Mendelian expectation (1:2:1) in that the proportion of plants exhibiting S5n heterozygous and homozygous genotypes was much lower in the progeny. Sequence analysis of full-length S5n alleles indicated that a few base pairs were different between O. rufipogon and O. sativa, and it was presumed that S5n may be an ancient allele. The fertility of the embryo sac in plants with an S5n heterozygous genotype was low, suggesting the existence of other genes controlling embryo sac fertility in the wild rice.
