The wide compatibility gene,S 5 n,can overcome embryo sac sterility between indica and japonica subspecies of rice.Therefore,it is very important to characterize the features of the S 5 n sequence to reveal the origin...The wide compatibility gene,S 5 n,can overcome embryo sac sterility between indica and japonica subspecies of rice.Therefore,it is very important to characterize the features of the S 5 n sequence to reveal the origin and evolution of S 5 n.In this paper,26 cultivated rice haplotypes and 22 wild rice accessions harboring S 5 n were used to sequence S 5 n.The results showed that 15 genotypes among the 48 materials were fully consistent with control cultivar 02428(CK).The other 33 accessions had different degrees of variation in the S 5 n sequence.Variations in the coding region mainly occurred in the second exon and eight materials showed a 10-bp deletion at 1710–1719 bp,including wild(O.nivara)and cultivated rice,such as IRW501 and Yuetai B.S 5 n sequences were not biased and evolved neutrally.The 48 materials could be divided into 4 categories using a phylogenetic tree of the amino acid sequences.Most of the wild rice clustered together,and the cultivated rice clustered into another group.Eight cultivated rice and O.nivara(wild rice)clustered in another group,which were found to lack 10 consecutive bases in exon 2.Eight rice varieties with high numbers of differences in their S 5 n coding regions were crossed with testers(typically indica and japonica)to produced test cross F 1 populations.The F 1 s were examined for their ability to overcome indica-japonica hybrid sterility.The result showed that the embryo sac fertility of S 5 n-containing hybrids increased significantly compared with control hybrids,but there were no differences among the materials with divergent sequences,indirectly proving that S 5 n is a non-functional 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 acces...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 the National Natural Science Foundation of China(30971756)National Natural Science Foundation of China-Joint Fund with Guangdong(U0631003)
文摘The wide compatibility gene,S 5 n,can overcome embryo sac sterility between indica and japonica subspecies of rice.Therefore,it is very important to characterize the features of the S 5 n sequence to reveal the origin and evolution of S 5 n.In this paper,26 cultivated rice haplotypes and 22 wild rice accessions harboring S 5 n were used to sequence S 5 n.The results showed that 15 genotypes among the 48 materials were fully consistent with control cultivar 02428(CK).The other 33 accessions had different degrees of variation in the S 5 n sequence.Variations in the coding region mainly occurred in the second exon and eight materials showed a 10-bp deletion at 1710–1719 bp,including wild(O.nivara)and cultivated rice,such as IRW501 and Yuetai B.S 5 n sequences were not biased and evolved neutrally.The 48 materials could be divided into 4 categories using a phylogenetic tree of the amino acid sequences.Most of the wild rice clustered together,and the cultivated rice clustered into another group.Eight cultivated rice and O.nivara(wild rice)clustered in another group,which were found to lack 10 consecutive bases in exon 2.Eight rice varieties with high numbers of differences in their S 5 n coding regions were crossed with testers(typically indica and japonica)to produced test cross F 1 populations.The F 1 s were examined for their ability to overcome indica-japonica hybrid sterility.The result showed that the embryo sac fertility of S 5 n-containing hybrids increased significantly compared with control hybrids,but there were no differences among the materials with divergent sequences,indirectly proving that S 5 n is a non-functional 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.
