Fluorescence in situ hybridization （FISH） and comparative genomic hybridization （CGH） were applied to somatic chromosomes preparations of Oryza sativa, O. officinalis, and O. meyeriana with labeled probes of Cot-1...Fluorescence in situ hybridization （FISH） and comparative genomic hybridization （CGH） were applied to somatic chromosomes preparations of Oryza sativa, O. officinalis, and O. meyeriana with labeled probes of Cot-1 DNA and genomic DNA＇from the cultivated rice. The coverage percentage （%） and size （Mb） of Cot-1 DNA in O. sativa, O. officinalis, and O. meyeriana were 47.1 ±0.16, 38.61 ±0.13, 44.38＋_0.13, and 212.33 ± 1.21,269.42 ± 0.89, 532.56± 1.68 Mb, respectively. The coverage percentage and size of genomic DNA from O. sativa in O. officinalis and O. meyeriana were 91.0, 93.6% and 634, 1 123 Mb, respectively, in which 365 and 591 Mb in O. officinalis and O. meyeriana were from O. sativa genomic DNA, but not from repetitive sequences of O. sativa, and the uncoverage genome size in O. officinalis and O. meyeriana were 64 and 78 Mb, respectively. In addition, karyotype analysis was conducted based on the signal bands of Cot-1 DNA in O. sativa, O. officinalis, and O. meyeriana. The results showed that highly and moderately repetitive sequences in Oryza genus were conserved as the functional genes during evolution. The repetitive sequences reduplication may be one of the important causes of the genome enlargement of O. officinalis and O. meyeriana, and O. officinalis genome enlarged more slowly when compared with O. meyeriana. Based on the above results, it is concluded that O. officinalis and O. meyeriana were formed by reduplication, rearrangement, and gene selective loss during the evolution process.展开更多
Oryza meyeriana Baill （GG genome） is a precious germplasm in the tertiary gene pool of cultivated rice （AA genome）, and possesses important traits such as resistance and tolerance to biotic and abiotic stress. How...Oryza meyeriana Baill （GG genome） is a precious germplasm in the tertiary gene pool of cultivated rice （AA genome）, and possesses important traits such as resistance and tolerance to biotic and abiotic stress. However, interspeciflc crossability barrier, a critical bottleneck restricting genes transfer from O. meyeriana to cultivars has led to no hybrids through conventional reproduction. Therefore, the reasons underlying incrossability were investigated in the present report. The results showed that： （i） at 3-7 d after pollination （DAP）, many hybrid embryos degenerated at the earlier globular-shaped stage, and could not develop into the later pear-shaped stage. Meanwhile, free endosperm nuclei started to degenerate at 1 DAP, and cellular endosperm could not form at 3 DAP, leading to nutrition starvation for young embryo development; （ii） at 11-13 DAP, almost all hybrid ovaries aborted. Even though 72.22% of hybrid young embryos were produced in the interspecific hybridization between O. sativa and O. meyeriana, young embryos were not able to further develop into hybrid plantlets via culturing in vitro. The main reason for the incrossability was hybrid embryo inviability, presenting as embryo development stagnation and degeneration since 3 DAP. Some possible approaches to overcome the crossability barriers in the interspecific hybridization between O. sativa and O. meyeriana are discussed.展开更多
中国“疣粒野稻”的小穗近等长于颗粒野稻,而短于疣粒野稻。内外稃(谷壳)表面电镜扫描形态是:中国“疣粒野稻”的山形瘤状突起分布较密,与颗粒野稻近似,但疣粒野稻则分布较疏。中国“疣粒野稻“的钩毛多为弯锥形:钩毛周围的硅质突起为...中国“疣粒野稻”的小穗近等长于颗粒野稻,而短于疣粒野稻。内外稃(谷壳)表面电镜扫描形态是:中国“疣粒野稻”的山形瘤状突起分布较密,与颗粒野稻近似,但疣粒野稻则分布较疏。中国“疣粒野稻“的钩毛多为弯锥形:钩毛周围的硅质突起为乳头状,顶端圆而光滑。疣粒野稻和颗粒野稻的钩毛为雀嘴形;钩毛周围的硅质突起为火山顶状,顶端具星状冠。以上述形态为主要依据,中国“疣粒野稻”与颗粒野稻和疣粒野稻均有明显区别;在地理分布方面也与上二亚种不同。所以,现将中国“疣粒野稻”另立一新亚种,为瘤粒野稻Oruza meyeriana (Zoll. et Mor.)Baill. subsp. tuberculata W. C. Wu et Y. G. Lu, G. C.展开更多
基金This work was supported by the National High Tech R ＆ D Program of China （863 Program, 2004AA227120） the Scientific Research Foundation for the Returned 0verseas Chinese Scholars, Ministry of Education of China （BZY04003）+1 种基金 China Postdoctoral Science Foundation （20040350574）the Project of Science and Technology for Youth, Wuhan, China （2004500607135）.
文摘Fluorescence in situ hybridization （FISH） and comparative genomic hybridization （CGH） were applied to somatic chromosomes preparations of Oryza sativa, O. officinalis, and O. meyeriana with labeled probes of Cot-1 DNA and genomic DNA＇from the cultivated rice. The coverage percentage （%） and size （Mb） of Cot-1 DNA in O. sativa, O. officinalis, and O. meyeriana were 47.1 ±0.16, 38.61 ±0.13, 44.38＋_0.13, and 212.33 ± 1.21,269.42 ± 0.89, 532.56± 1.68 Mb, respectively. The coverage percentage and size of genomic DNA from O. sativa in O. officinalis and O. meyeriana were 91.0, 93.6% and 634, 1 123 Mb, respectively, in which 365 and 591 Mb in O. officinalis and O. meyeriana were from O. sativa genomic DNA, but not from repetitive sequences of O. sativa, and the uncoverage genome size in O. officinalis and O. meyeriana were 64 and 78 Mb, respectively. In addition, karyotype analysis was conducted based on the signal bands of Cot-1 DNA in O. sativa, O. officinalis, and O. meyeriana. The results showed that highly and moderately repetitive sequences in Oryza genus were conserved as the functional genes during evolution. The repetitive sequences reduplication may be one of the important causes of the genome enlargement of O. officinalis and O. meyeriana, and O. officinalis genome enlarged more slowly when compared with O. meyeriana. Based on the above results, it is concluded that O. officinalis and O. meyeriana were formed by reduplication, rearrangement, and gene selective loss during the evolution process.
基金Supported by the Guangdong Provincial Key Project of the National NaturalScience Foundation (021037)Guangdong Provincial Natural Science Foun-dation (7301008).
文摘Oryza meyeriana Baill （GG genome） is a precious germplasm in the tertiary gene pool of cultivated rice （AA genome）, and possesses important traits such as resistance and tolerance to biotic and abiotic stress. However, interspeciflc crossability barrier, a critical bottleneck restricting genes transfer from O. meyeriana to cultivars has led to no hybrids through conventional reproduction. Therefore, the reasons underlying incrossability were investigated in the present report. The results showed that： （i） at 3-7 d after pollination （DAP）, many hybrid embryos degenerated at the earlier globular-shaped stage, and could not develop into the later pear-shaped stage. Meanwhile, free endosperm nuclei started to degenerate at 1 DAP, and cellular endosperm could not form at 3 DAP, leading to nutrition starvation for young embryo development; （ii） at 11-13 DAP, almost all hybrid ovaries aborted. Even though 72.22% of hybrid young embryos were produced in the interspecific hybridization between O. sativa and O. meyeriana, young embryos were not able to further develop into hybrid plantlets via culturing in vitro. The main reason for the incrossability was hybrid embryo inviability, presenting as embryo development stagnation and degeneration since 3 DAP. Some possible approaches to overcome the crossability barriers in the interspecific hybridization between O. sativa and O. meyeriana are discussed.
文摘中国“疣粒野稻”的小穗近等长于颗粒野稻,而短于疣粒野稻。内外稃(谷壳)表面电镜扫描形态是:中国“疣粒野稻”的山形瘤状突起分布较密,与颗粒野稻近似,但疣粒野稻则分布较疏。中国“疣粒野稻“的钩毛多为弯锥形:钩毛周围的硅质突起为乳头状,顶端圆而光滑。疣粒野稻和颗粒野稻的钩毛为雀嘴形;钩毛周围的硅质突起为火山顶状,顶端具星状冠。以上述形态为主要依据,中国“疣粒野稻”与颗粒野稻和疣粒野稻均有明显区别;在地理分布方面也与上二亚种不同。所以,现将中国“疣粒野稻”另立一新亚种,为瘤粒野稻Oruza meyeriana (Zoll. et Mor.)Baill. subsp. tuberculata W. C. Wu et Y. G. Lu, G. C.
