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
Using an accession of common wild rice （Oryza rufipogon Griff.） collected from Yuanjiang County, Yunnan Province, China, as the donor and an elite cultivar 93-11, widely used in two-line indica hybrid rice productio...Using an accession of common wild rice （Oryza rufipogon Griff.） collected from Yuanjiang County, Yunnan Province, China, as the donor and an elite cultivar 93-11, widely used in two-line indica hybrid rice production in China, as the recurrent parent, an advanced backcross populations were developed. Through genotyping of 187 SSR markers and investigation of six yield-related traits of two gen- erations （BC4F2 and BC4F4）, a total of 26 QTLs were detected by employing single point analysis and interval mapping in both genera-tions. Of the 26 QTLs, the alleles of 10 （38.5%） QTLs originating from O. rufipogon had shown a beneficial effect for yield-related traits in the 93-11 genetic background. In addition, five QTLs controlling yield and its components were newly identified, indicating that there are potentially novel alleles in Yuanjiang common wild rice. Three regions underling significant QTLs for several yield-related traits were detected on chromosome 1, 7 and 12. The QTL clusters were founded and corresponding agronomic traits of those QTLs showed highly significant correlation, suggesting the pleiotropism or tight linkage. Fine-mapping and cloning of these yield-related QTLs from wild rice would be helpful to elucidating molecular mechanism of rice domestication and rice breeding in the future.展开更多
To identify useful genes from wild rice which have been lost or weakened in cultivated rice has become more and more important for modern breeding strategy. In this study, a BC4 population derived from 94W1, an access...To identify useful genes from wild rice which have been lost or weakened in cultivated rice has become more and more important for modern breeding strategy. In this study, a BC4 population derived from 94W1, an accession of common wild rice (Oryza rufipogon Griff.) from Dongxiang in Jiangxi Province of China, as the donor, and a high-yielding Indica cultivar (O. sativa L.), 'Guichao 2', as the recipient, was used to identify quantitative trait loci (QTL) associated with yield and its components. Based on the analysis for the genotype of BC4F1 population with 87 SSR markers distributed throughout the genome and investigation of the plant height, yield and yield components of BC4F2, a total of 52 QTLs, were detected. Of 7 QTLs associated with grain yield per plant, 2 QTLs on chromosome 2 and chromosome 11 for grain yield, explaining 16% and 11% of the phenotypic variance respectively, were identified. The alleles from Dongxiang common wild rice in those two loci could increase the yield of 'Guichao 2' by展开更多
Using 36 SSR markers and 889 accessions of common wild rice in China, the genetic diversity and the divergence among different geographical populations are investigated. Guangdong Province has the largest number of al...Using 36 SSR markers and 889 accessions of common wild rice in China, the genetic diversity and the divergence among different geographical populations are investigated. Guangdong Province has the largest number of alleles, which account for 84% of the total alleles detected in the study, followed by Guangxi Province. The Nei's gene diversity indices, from high to low, are in the sequence of Hainan, Guangdong, Guangxi, Fujian, Hunan, Jiangxi, and Yunnan provinces. Two genetic diversity centers of Chinese common wild rice are detected on the basis of geographic analysis, i.e., the region covering Boluo, Zijin, Lufeng, Haifeng, Huidong and Huiyang counties of Guangdong Province and the region covering Yongning, Longan, Laibin and Guigang counties of Guangxi Province. The common wild rice in Yunnan, Hunan, Jiangxi, and Fujian provinces are diverged into respectively independent populations with relatively large genetic distances, whereas, those in Hainan, Guangdong and Guangxi provinces have relatively low genetic divergence. Under the condition of geographic separation, natural selection is considered as one of the primary forces contributing to the divergence of common wild rice in China.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.
基金supported by grants from the Project of Conservation and Utilization of Agro-Wild Plants of the Ministry of Agriculture of Chinathe National High-Tech Research and Development ("863") Program of China (No. 2006AA100101)the "111" Project (No. B06003)
文摘Using an accession of common wild rice （Oryza rufipogon Griff.） collected from Yuanjiang County, Yunnan Province, China, as the donor and an elite cultivar 93-11, widely used in two-line indica hybrid rice production in China, as the recurrent parent, an advanced backcross populations were developed. Through genotyping of 187 SSR markers and investigation of six yield-related traits of two gen- erations （BC4F2 and BC4F4）, a total of 26 QTLs were detected by employing single point analysis and interval mapping in both genera-tions. Of the 26 QTLs, the alleles of 10 （38.5%） QTLs originating from O. rufipogon had shown a beneficial effect for yield-related traits in the 93-11 genetic background. In addition, five QTLs controlling yield and its components were newly identified, indicating that there are potentially novel alleles in Yuanjiang common wild rice. Three regions underling significant QTLs for several yield-related traits were detected on chromosome 1, 7 and 12. The QTL clusters were founded and corresponding agronomic traits of those QTLs showed highly significant correlation, suggesting the pleiotropism or tight linkage. Fine-mapping and cloning of these yield-related QTLs from wild rice would be helpful to elucidating molecular mechanism of rice domestication and rice breeding in the future.
基金This work was supported by the "973" Project (Grant No. 2001CB108800)China National High-Tech Research and Development Program ("863" Program)the National Tackle Key Problem Project of the Ministry of Science and Technology of China.
文摘To identify useful genes from wild rice which have been lost or weakened in cultivated rice has become more and more important for modern breeding strategy. In this study, a BC4 population derived from 94W1, an accession of common wild rice (Oryza rufipogon Griff.) from Dongxiang in Jiangxi Province of China, as the donor, and a high-yielding Indica cultivar (O. sativa L.), 'Guichao 2', as the recipient, was used to identify quantitative trait loci (QTL) associated with yield and its components. Based on the analysis for the genotype of BC4F1 population with 87 SSR markers distributed throughout the genome and investigation of the plant height, yield and yield components of BC4F2, a total of 52 QTLs, were detected. Of 7 QTLs associated with grain yield per plant, 2 QTLs on chromosome 2 and chromosome 11 for grain yield, explaining 16% and 11% of the phenotypic variance respectively, were identified. The alleles from Dongxiang common wild rice in those two loci could increase the yield of 'Guichao 2' by
基金the National Basic Research and Development Program of China (Grant No. 2004CB117201)Program for Changjiang Scholars and Innovative Re-search Team in UniversityProgramme of Introducing Talents of Discipline to Universities (Grant No. 111-2-03)
文摘Using 36 SSR markers and 889 accessions of common wild rice in China, the genetic diversity and the divergence among different geographical populations are investigated. Guangdong Province has the largest number of alleles, which account for 84% of the total alleles detected in the study, followed by Guangxi Province. The Nei's gene diversity indices, from high to low, are in the sequence of Hainan, Guangdong, Guangxi, Fujian, Hunan, Jiangxi, and Yunnan provinces. Two genetic diversity centers of Chinese common wild rice are detected on the basis of geographic analysis, i.e., the region covering Boluo, Zijin, Lufeng, Haifeng, Huidong and Huiyang counties of Guangdong Province and the region covering Yongning, Longan, Laibin and Guigang counties of Guangxi Province. The common wild rice in Yunnan, Hunan, Jiangxi, and Fujian provinces are diverged into respectively independent populations with relatively large genetic distances, whereas, those in Hainan, Guangdong and Guangxi provinces have relatively low genetic divergence. Under the condition of geographic separation, natural selection is considered as one of the primary forces contributing to the divergence of common wild rice in China.
