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Characterization of Interspecific Hybrids Between Oryza sativa L. and Three Wild Rice Species of China by Genomic In Situ Hybridization
Author(s) -
Tan GuangXuan,
Xiong ZhiYong,
Jin HuaJun,
Li Gang,
Zhu LiLi,
Shu LiHui,
He GuangCun
Publication year - 2006
Publication title -
journal of integrative plant biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.734
H-Index - 83
eISSN - 1744-7909
pISSN - 1672-9072
DOI - 10.1111/j.1744-7909.2006.00336.x
Subject(s) - biology , oryza sativa , hybrid , genome , genetics , oryza , chromosome , botany , oryza rufipogon , gene
In the genus Oryza , interspecific hybrids are useful bridges for transferring the desired genes from wild species to cultivated rice ( Oryza sativa L.). In the present study, hybrids between O. sativa (AA genome) and three Chinese wild rices, namely O. rufipogon (AA genome), O. officinalis (CC genome), and O. meyeriana (GG genome), were produced. Agricultural traits of the F 1 hybrids surveyed were intermediate between their parents and appreciably resembled wild rice parents. Except for the O. sativa × O. rufipogon hybrid, the other F 1 hybrids were completely sterile. Genomic in situ hybridization (GISH) was used for hybrid verification. Wild rice genomic DNAs were used as probes and cultivated rice DNA was used as a block. With the exception of O. rufipogon chromosomes, this method distinguished the other two wild rice and cultivated rice chromosomes at the stage of mitotic metaphase with different blocking ratios. The results suggest that a more distant phylogenetic relationship exists between O. meyeriana and O. sativa and that O. rufipogon and O. sativa share a high degree of sequence homology. The average mitotic chromosome length of O. officinalis and O. meyeriana was 1.25‐and 1.51‐fold that of O. sativa , respectively. 4′,6′‐Diamidino‐2‐phenylindole staining showed that the chromosomes of O. officinalis and O. meyeriana harbored more heterochromatin, suggesting that the C and G genomes were amplified with repetitive sequences compared with the A genome. Although chromocenters formed by chromatin compaction were detected with wild rice‐specific signals corresponding to the C and G genomes in discrete domains of the F 1 hybrid interphase nuclei, the size and number of O. meyeriana chromocenters were bigger and greater than those of O. officinalis. The present results provide an important understanding of the genomic relationships and a tool for the transfer of useful genes from three native wild rice species in China to cultivars. (Managing editor: Li‐Hui Zhao)