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
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.
