[Objective] The paper was to explore the flowering habits and fertility of Gaozhou common wild rice （Oryza rufipogon Griff.） in Lingshui of Hainan Province. [Method] The flowering habits, pollen fertility and seed s...[Objective] The paper was to explore the flowering habits and fertility of Gaozhou common wild rice （Oryza rufipogon Griff.） in Lingshui of Hainan Province. [Method] The flowering habits, pollen fertility and seed setting rate of Gaozhou common wild rice in Lingshui of Hainan Province were studied, and compared with the flowering habits of common wild rice in Hainan Province. [Result] Gaozhou common wild rice was able to flower twice a year. The first flowering stage was from mid-April to mid-June for about 60 d, and the daily peak flowering dates were from May 13 to May 22. The daily flowering time was mainly between 11：20 and 13：00, and the peak flowering was at 11：30. The second flowering stage was from late August to late October for about 45 d, and the peak flowering dates lasted from September 8 to September 18. The daily flowering time was mainly from 11：15 to 12：50, and the daily peak flowering was at 11：30. In both flowering stages, the panicles had the same flowering characteristics. The stigma exsertion reached a high value of 95.37% with single （46.23%） and dual （49.14%） stigmas exsertion respectively. A spikelet remained open for 1.5-2.5 h, the angle of spikelet opening varied from 29.9° to 32.4°. At the two flowering stage the average pollen fertility rates were 89.67% and 85.62%, the average seed setting rates were 58.81% and 55.79%, respectively. Hainan population flowered only once （from mid-October to mid-December）, this had significant difference with the performance of Gaozhou common wild rice which flowered twice a year. [Conclusion] The results provided basis for the research on gene flow frequency from transgenic rice to wild rice and its relationship with flowering habits of common wild rice.展开更多
Rice（Oryza sativa L.）, a tropical and subtropical crop, is susceptible to low temperature stress during seedling, booting, and flowering stages, which leads to lower grain quality levels and decreasing rice yields. ...Rice（Oryza sativa L.）, a tropical and subtropical crop, is susceptible to low temperature stress during seedling, booting, and flowering stages, which leads to lower grain quality levels and decreasing rice yields. Cold tolerance is affected by multiple genetic factors in rice, and the complex genetic mechanisms associated with chilling stress tolerance remain unclear. Here, we detected seven quantitative trait loci（QTLs） for cold tolerance at booting stage and identified one cold tolerant line, SIL157, in an introgression line population derived from a cross between the indica variety Guichao 2, as the recipient, and Dongxiang common wild rice, as the donor. When compared with Guichao 2, SIL157 showed a stronger cold tolerance during different growth stages. Through an integrated strategy that combined QTL-mapping with expression profile analysis, six candidate genes, which were up-regulated under chilling stress at the seedling and booting developmental stages, were studied. The results may help in understanding cold tolerance mechanisms and in using beneficial alleles from wild rice to improve the cold tolerance of rice cultivars through molecular marker-assisted selection.展开更多
[ Objective] The stability of resistance heredity of common wild rice against brown planthopper was studied to screen wild rice germplasm with stable resistance, so as to provide resources for rice breeding with resis...[ Objective] The stability of resistance heredity of common wild rice against brown planthopper was studied to screen wild rice germplasm with stable resistance, so as to provide resources for rice breeding with resistance against brown planthopper. [ Method] A total of 1 591 accessions of common wild rice, collected from 46 proterozoic growth locations of Guangxi, were screened to analyze resistance against brown planthopper, and genetic homozygosis in their offspring was detected using bag-selfing or anther culture methods. [ Result] The results showed that most of common wild rice germplasm were heterozygotic, and growth habit and awn of their first self-bred generation showed segregation. Among 1 591 accessions of common wild rice, only 30 accessions showed third to fifth grades of resist- ance against brown planthopper, and most of them showed fifth grade of resistance. Among selfing offspring of 11 resistant materials, the populations from Z1 to Z3 showed segregation of resistant genes, while some materials showed stable resistance in Z4. Out of 11 accessions of materials, resistance of five accessions increased from third grade to first, second and third grades; four accessions increased from fifth grade to first, second and third grades ; two accessions increased from fifth to third grade. Anther culture results showed that 125 accessions of callus from independent origins were obtained after induction by in vitro culture of 6 000 anthers; eight clusters of diploid and two clusters of haploid green seedlings were differentiated, with induction rate of callus as 2.0% and differentiation rate of green seed- lings as 6.4%. Out of eight offspring of anther culture, six showed fifth grade of resistance against brown planthopper and two showed third grade of resistance. [ Conclusion] The stable highly-resistant resources could be obtained and resistance level of common wild rice could be enhanced through bag-selfing and multigeneration identification of resistance against brown planthopper. Anther culture is beneficial to promote genetic homozygosis of resistance of common wild rice against brown planthopper and shorten the screening time.展开更多
Low temperature and sparse light in early spring is one of the factors causing reduction for rice production. So it is important to develop cold tolerance cultivars. In the present study, cold tolerance characters of ...Low temperature and sparse light in early spring is one of the factors causing reduction for rice production. So it is important to develop cold tolerance cultivars. In the present study, cold tolerance characters of 36 parents and 423 rice lines from 68 hybrid groups were investigated at seedling stage under low tempera- ture and sparse light conditions in field. There were 10 parent accessions with strong cold tolerance of level 1. Among them, 3 were common wild rice accessions; 4 were japonica rice cultivars; 2 were indica rice; 1 was offspring from hybrid be- tween indica and japonica.There were 33 lines with strong cold tolerance of level 1 from the hybrid groups of common wild rice,and 15 from the hybrid groups of IRBB5, and only 3 from the hybrid groups of BPHR96. There were abundant cold tolerance resources in rice germplasm. It was feasible to develop cold tolerance cul- tivars from the hybrids among common wild rice, japonica cultivars and indica culti- vars.展开更多
基金Supported by Special Project of GM(2009ZX08011-010B,2008XZ08011-011)~~
文摘[Objective] The paper was to explore the flowering habits and fertility of Gaozhou common wild rice （Oryza rufipogon Griff.） in Lingshui of Hainan Province. [Method] The flowering habits, pollen fertility and seed setting rate of Gaozhou common wild rice in Lingshui of Hainan Province were studied, and compared with the flowering habits of common wild rice in Hainan Province. [Result] Gaozhou common wild rice was able to flower twice a year. The first flowering stage was from mid-April to mid-June for about 60 d, and the daily peak flowering dates were from May 13 to May 22. The daily flowering time was mainly between 11：20 and 13：00, and the peak flowering was at 11：30. The second flowering stage was from late August to late October for about 45 d, and the peak flowering dates lasted from September 8 to September 18. The daily flowering time was mainly from 11：15 to 12：50, and the daily peak flowering was at 11：30. In both flowering stages, the panicles had the same flowering characteristics. The stigma exsertion reached a high value of 95.37% with single （46.23%） and dual （49.14%） stigmas exsertion respectively. A spikelet remained open for 1.5-2.5 h, the angle of spikelet opening varied from 29.9° to 32.4°. At the two flowering stage the average pollen fertility rates were 89.67% and 85.62%, the average seed setting rates were 58.81% and 55.79%, respectively. Hainan population flowered only once （from mid-October to mid-December）, this had significant difference with the performance of Gaozhou common wild rice which flowered twice a year. [Conclusion] The results provided basis for the research on gene flow frequency from transgenic rice to wild rice and its relationship with flowering habits of common wild rice.
基金supported by the National Natural Science Foundation of China(31371585 and 30971755)the Beijing Youth Talent,China(31056102)
文摘Rice（Oryza sativa L.）, a tropical and subtropical crop, is susceptible to low temperature stress during seedling, booting, and flowering stages, which leads to lower grain quality levels and decreasing rice yields. Cold tolerance is affected by multiple genetic factors in rice, and the complex genetic mechanisms associated with chilling stress tolerance remain unclear. Here, we detected seven quantitative trait loci（QTLs） for cold tolerance at booting stage and identified one cold tolerant line, SIL157, in an introgression line population derived from a cross between the indica variety Guichao 2, as the recipient, and Dongxiang common wild rice, as the donor. When compared with Guichao 2, SIL157 showed a stronger cold tolerance during different growth stages. Through an integrated strategy that combined QTL-mapping with expression profile analysis, six candidate genes, which were up-regulated under chilling stress at the seedling and booting developmental stages, were studied. The results may help in understanding cold tolerance mechanisms and in using beneficial alleles from wild rice to improve the cold tolerance of rice cultivars through molecular marker-assisted selection.
基金Supported by Natural Science Foundation of Guangxi(2012GXNSFDA053008)Natural Fund of Guangxi (2012GXNSFBA053040)+6 种基金Science and Technology Development Project of Guangxi (GKN 1347013-3)Special Projects of International Cooperation in Science and Technology (2012DFA31220)General Project of Specific Research Activities in Guangxi Academy of Agricultural Sciences(2012YM04)Youth Science and Technology Project in Guangxi Academy of Agricultural Sciences (GNK 2013YQ11)Team Project of Specific Superior Subject for Fundamental Research in Guangxi Academy of Agricultural Sciences (GNK2013YT05)Natural Science Foundation of Guangxi (GKQ 0991053)Youth Science and Technology Project in Guangxi Academy of Agricultural Sciences(GNK 2013JQ21)
文摘[ Objective] The stability of resistance heredity of common wild rice against brown planthopper was studied to screen wild rice germplasm with stable resistance, so as to provide resources for rice breeding with resistance against brown planthopper. [ Method] A total of 1 591 accessions of common wild rice, collected from 46 proterozoic growth locations of Guangxi, were screened to analyze resistance against brown planthopper, and genetic homozygosis in their offspring was detected using bag-selfing or anther culture methods. [ Result] The results showed that most of common wild rice germplasm were heterozygotic, and growth habit and awn of their first self-bred generation showed segregation. Among 1 591 accessions of common wild rice, only 30 accessions showed third to fifth grades of resist- ance against brown planthopper, and most of them showed fifth grade of resistance. Among selfing offspring of 11 resistant materials, the populations from Z1 to Z3 showed segregation of resistant genes, while some materials showed stable resistance in Z4. Out of 11 accessions of materials, resistance of five accessions increased from third grade to first, second and third grades; four accessions increased from fifth grade to first, second and third grades ; two accessions increased from fifth to third grade. Anther culture results showed that 125 accessions of callus from independent origins were obtained after induction by in vitro culture of 6 000 anthers; eight clusters of diploid and two clusters of haploid green seedlings were differentiated, with induction rate of callus as 2.0% and differentiation rate of green seed- lings as 6.4%. Out of eight offspring of anther culture, six showed fifth grade of resistance against brown planthopper and two showed third grade of resistance. [ Conclusion] The stable highly-resistant resources could be obtained and resistance level of common wild rice could be enhanced through bag-selfing and multigeneration identification of resistance against brown planthopper. Anther culture is beneficial to promote genetic homozygosis of resistance of common wild rice against brown planthopper and shorten the screening time.
基金Supported by Guangxi Natural Science Foundation Item,China(2013GXNSFBA019-066)Guangxi Science Research and Technology Development Project,China(Guikezhong14121001-2-4)Nanning Municipal Science Research and Technology Development Plan Item,China(20132304)~~
文摘Low temperature and sparse light in early spring is one of the factors causing reduction for rice production. So it is important to develop cold tolerance cultivars. In the present study, cold tolerance characters of 36 parents and 423 rice lines from 68 hybrid groups were investigated at seedling stage under low tempera- ture and sparse light conditions in field. There were 10 parent accessions with strong cold tolerance of level 1. Among them, 3 were common wild rice accessions; 4 were japonica rice cultivars; 2 were indica rice; 1 was offspring from hybrid be- tween indica and japonica.There were 33 lines with strong cold tolerance of level 1 from the hybrid groups of common wild rice,and 15 from the hybrid groups of IRBB5, and only 3 from the hybrid groups of BPHR96. There were abundant cold tolerance resources in rice germplasm. It was feasible to develop cold tolerance cul- tivars from the hybrids among common wild rice, japonica cultivars and indica culti- vars.
