The main problems about research and application of two-line hybrid rice were reviewed, including the confusing nomenclature and male sterile lines classification, the unclear characteristics of photoperiod and temper...The main problems about research and application of two-line hybrid rice were reviewed, including the confusing nomenclature and male sterile lines classification, the unclear characteristics of photoperiod and temperature responses and the unsuitable site selection for male sterile line and hybrid dce seed production. In order to efficiently and accurately use dual-purpose genic male sterile lines, four types, including PTGMS （photo-thermo-sensitive genic male sterile rice）, TGMS （thermo-sensitive genic male sterile rice）, reverse PTGMS and reverse TGMS, were proposed. A new idea for explaining the mechanism of sterility in dual-purpose hybrid rice was proposed. The transition from sterile to fertile was involved in the cooperative regulation of major-effect sterile genes and photoperiod and/or temperature sensitive ones. The minor-effect genes with accumulative effect on sterility were important factors that affected the critical temperature of sterility transfer. In order to make better use of dual-purpose lines, the characterization of responses to photoperiod and temperature of PTGMS should be made and the identification method for the characterization of photoperiod and temperature responses of PTGMS should also be put forward. The optimal ecological site for seed production could be determined according to the historical climate data and the requirements for the meteorological conditions during the different periods of seed production.展开更多
Since the breakthrough of grain yield owing to the development of dwarf rice and three-line system hybrid rice, rice breeding for high yield hardly had showed significant progress in the next successive two decades. I...Since the breakthrough of grain yield owing to the development of dwarf rice and three-line system hybrid rice, rice breeding for high yield hardly had showed significant progress in the next successive two decades. It was considered that utilizing heterosis between subspecific varieties (Oryza sativa L.) would be an effective approach to increase yield further. During 1987-1993, an indica-japonica hybrid Yayou 2 yielded as high as 10.5 t/ha; however, it failed to be commercialized because of seed purity problem due to non-uniform emasculation by chemical agent in seed production, and sensitivity of seed setting in Ft plants to environmental conditions. In the past decade, two inter-subspeific hybrids, Liangyoupeijiu (Peiai 64S/9311, javanica/indica) and Liangyou E32 (Peiai 64S/E32, javanica/ laponica); both of them exhibited grain yield higher than 10.5 t/ha, and were widely judged as the pioneers of super hybrid rice. Liangyoupeijiu has been successfully popularized over 4 million hectare in wide climatic areas, while Liangyou E32 made a yield record and offered a model of plant ideotype for super hybrid rice. It was considered that in combination with plant ideotype, active physiological functions, and wide-range adaptability to ecological conditions, exploitation of indica-japonica heterosis would be the key approach for super hybrid rice breeding.展开更多
Research on hybrid rice in Jiangsu Province, China began in 1970. Great progress has been made since then, which can be divided into three stages according to the development of hybrid rice breeding and production in ...Research on hybrid rice in Jiangsu Province, China began in 1970. Great progress has been made since then, which can be divided into three stages according to the development of hybrid rice breeding and production in Jiangsu Province. The first stage was beginning stage from 1970 to 1980, when progress was mainly made in cytoplasmic male sterile line breeding. The second stage could be described as developing stage, from 1980 to 1995, when indica hybrid rice was rapidly popularized, and japonica hybrid rice became popular later. From 1996, hybrid rice breeding in Jiangsu Province entered the third stage, when both indica and japonica hybrid rice breeding in the three-line system or intersubspecific hybrid rice breeding in the two-line system made a great breakthrough with the successful breeding of the hybrids Feyou 559, 9 You 138 and Liangyoupeijiu. The developing trend of hybrid rice breeding in Jiangsu Province is also discussed.展开更多
This study was designed to elucidate the grain filling characteristics and the causes of poor grain plumpness of some two-line hybrid rice combinations and their hormonal mechanism. Six varieties, including three two-...This study was designed to elucidate the grain filling characteristics and the causes of poor grain plumpness of some two-line hybrid rice combinations and their hormonal mechanism. Six varieties, including three two-line hybrid rice combinations, that show differences in seed-setting and grain filling, were used. And the contents of starch, sucrose, zeatin （Z） ＋ zeatin riboside （ZR）, indole-3-acetic acid （IAA）, and abscisic acid （ABA）, the ethylene evolution rate, activities of sucrose synthase （SuSase） and starch synthase （StSase） in grains, the seed-setting and grain filling rate were investigated. The correlations amongst these were analyzed. The results showed that the poor grain filling of two-line hybrids was mainly attributed to the higher unfilled grain rate and the lower filling degree of inferior grains. During the early and mid grain filling periods, the sucrose content in inferior grains was greater than that in superior grains for the combinations with poor grain filling, indicating that the substrate concentration was not the principal factor for their slow grain filling and poor grain plumpness of the inferior grains of two-line hybrids. Z ＋ ZR, IAA, and ABA in superior grains were obviously greater than those in inferior grains at early grain filling stage. The maximum and mean contents of Z ＋ ZR, IAA, and ABA were positively very significantly correlated with the maximum and mean grain-filling rate, filling degree, and grain weight. The evolution rate of ethylene was greater in inferior grains than in superior grains and greater for the combinations with poor grain plumpness than those with good grain plumpness at the early or mid filling stages. The evolution rate of ethylene was negatively and significantly correlated with the grain filling rate, the grain filling degree, and the grain weight. Spraying ethephon （ethylene-releasing agent） at the early grain filling stage increased the evolution rate of ethylene, reduced the ABA content and activities of SuSase 展开更多
By inducing frequency, intensity and duration of lower temperature in the middle and last ten-day periods in August in the rice-growing areas of southern China, increasing temperature for safe seed production was defi...By inducing frequency, intensity and duration of lower temperature in the middle and last ten-day periods in August in the rice-growing areas of southern China, increasing temperature for safe seed production was defined as 2℃. During the sensitive period of fertility, characters of panicle height and canopy structure of TGMS rice, Pei＇ai64S, were measured. Results showed that temperature changes caused by irrigation in fields were below 40 cm of rice plant, and heating effect was significant at 20 cm when the temperature was increased by 3.1 ℃. For the present study, the following irrigation techniques were put forth： the water depth of 15-20 cm, current water used, irrigating after 17：00 and bailing at 10：00 in sunny or cloudy weather, irrigating on whole day, in shady or rainy weather, increasing inflows and outflows in large fields. In the present experiment, pollen fertility and self-fertilized seed setting rate accepted that the techniques were feasible and effective for against lower temperature and safeguarding seed production of two-line hybrid rice.展开更多
Liliangyou 3822 is a novel indica hybrid rice variety that exhibits disease resistance,high yield,lodging resistance,and late maturity.It employs a self-selected two-line sterile line,Li 38S,and a self-selected restor...Liliangyou 3822 is a novel indica hybrid rice variety that exhibits disease resistance,high yield,lodging resistance,and late maturity.It employs a self-selected two-line sterile line,Li 38S,and a self-selected restorer line,R22.This variety was subjected to a regional test of indica late-maturing groups in the middle and lower reaches of the Yangtze River in 2020.The results demonstrated that the average yield of the variety was 9.95 t/hm 2,which was 10.67%higher than that of the control Fengliangyou 4,indicating a highly significant yield increase.In the continuous test in 2021,the average yield was 9.74 t/hm 2,representing a 6.52%increase over the control,which also exhibited a significant increase.Finally,the average yield of the two years regional test was 9.84 t/hm 2,which was 8.58%higher than that of the control.In the 2021 production test,the average yield of the variety was 9.32 t/hm 2,which was 12.19%higher than that of the control,indicating a remarkably significant yield increase.In 2022,the variety was validated by the National Crop Variety Approval Committee(GSD 20220143).展开更多
The insecure problems of seed production have seriously hampered the healthy and sustainable development of two-line hybrid rice.The safety issues on seed production of two-line hybrid rice and current research situat...The insecure problems of seed production have seriously hampered the healthy and sustainable development of two-line hybrid rice.The safety issues on seed production of two-line hybrid rice and current research situation were pointed out in this paper.The three main reasons for unsafety in seed production of twoline hybrid rice were unsuitable site selection,high critical sterility-inducing temperature and the drift of critical temperature.In this paper,strategies and measures were put forward based on many years of practice.It could minimize the risk in seed production of two-line hybrid rice by selecting dual-purpose genic male sterile line with lower critical sterility-inducing temperature and long lower temperature resistant time.Based on the climate data and climatic demands of the ＂three safe-periods＂ in seed production,a new idea for determining appropriate bases and periods for seed production was proposed by using computer technology,which solved the aimless selection of sites and periods for the seed production of two-line hybrid rice.Besides,we established a system of single plant selection and identification method and original seed propagation with cyclic cold water,which could reduce the generation number of original seed propagation in seed production and avoid the drift of critical sterility-inducing temperature.This paper improved the seed production safety in the three aspects of seed nature,seed source and seed production site.展开更多
Knowledge of rice(Oryza sativa L.)genes and various DNA markers can be used in genomic breeding programs aimed at developing improved elite rice cultivars.We used an efficient genomic breeding approach to pyramid four...Knowledge of rice(Oryza sativa L.)genes and various DNA markers can be used in genomic breeding programs aimed at developing improved elite rice cultivars.We used an efficient genomic breeding approach to pyramid four resistance genes(Pi2,Xa23,Bph14,and Bph15)in the popular photoperiod-and thermosensitive genic male sterile(PTGMS)rice line Feng39S.We performed foreground selection for the target genes,followed by recombinant selection and background selection.This process reduced the sizes of the genomic segments harboring the target genes(566.8 kb for Pi2,1143.9 kb for Xa23,774.7 kb for Bph14,and 1574.9 kb for Bph15)and accelerated the recovery of the recurrent parent genome to proportions ranging from 98.77%to 99.16%,thus resulting in four near-isogenic lines.To assemble the four resistance genes in Feng39S,we performed a double-way cross combined with foreground and background selection to generate two improved lines of Feng39S(Pi2+Xa23+Bph14+Bph15)with a recurrent parent genome recovery of 98.98%.The two lines showed agronomic performance,grain quality,and fertility–sterility transition characteristics similar to those of the original Feng39S line.The newly developed PTGMS lines and corresponding hybrid combinations were resistant to various field blast isolates and seven representative isolates of bacterial blight.At the seedling stage,the lines also showed resistance against brown planthopper.This study provides an efficient and accurate genomic breeding approach for introducing desirable traits into PTGMS lines.展开更多
In the present paper, to build model of two-line queuing system with losses GI/G/2/0, the approach introduced by V.S. Korolyuk and A.F. Turbin, is used. It is based on application of the theory of semi-Markov processe...In the present paper, to build model of two-line queuing system with losses GI/G/2/0, the approach introduced by V.S. Korolyuk and A.F. Turbin, is used. It is based on application of the theory of semi-Markov processes with arbitrary phase space of states. This approach allows us to omit some restrictions. The stationary characteristics of the system have been defined, assuming that the incoming flow of requests and their service times have distributions of general form. The particular cases of the system were considered. The used approach can be useful for modeling systems of various purposes.展开更多
Hybrid wheat is recognized as a preferred approach to improve wheat yield,and it will be a competition focus in high-tech seed industry in the future. We have made a breakthrough for the first time in creation of two-...Hybrid wheat is recognized as a preferred approach to improve wheat yield,and it will be a competition focus in high-tech seed industry in the future. We have made a breakthrough for the first time in creation of two-line hybrid wheat system,which reaches the world leading level in wheat research and has laid an important foundation for the future direction of the world wheat research. Similar to hybrid rice,the innovation of two-line hybrid wheat system is another achievement in science and technology. The application of hybrid wheat in China will greatly increase the food production,and make a great significance to food production and food security. This paper introduces the development process and major breakthrough of hybrid wheat in China,and the main bottleneck and countermeasures in the application of hybrid wheat.展开更多
[Objective] The aim of this study was to explore the inheritance pattern of the resistance of two-line hybrid rice to false smut. [Method] A moderate susceptible TGMS line 33S as the female parent, was crossed with 30...[Objective] The aim of this study was to explore the inheritance pattern of the resistance of two-line hybrid rice to false smut. [Method] A moderate susceptible TGMS line 33S as the female parent, was crossed with 30 susceptible restorer lines and 23 resistant restorer lines. Then false smut resistance of the hybrid F1 and parents were identified. [Result] All F1 of 33S crossed with 30 susceptible re- storer lines were susceptible to rice false smut. The F1 of 33S crossed with 23 re- sistant restorer lines showed dominant, incompletely dominant or recessive inheri- tance. Dominant and incompletely dominant inheritance accounted for 87.0%. The diseased panicle rate, disease index, average diseased grains per panicle, and the highest diseased grains per panicle of F1 shared highly significant positive correla- tions with corresponding indicators of restorer lines. [Conclusion] This study provides references for genetic improvement of two-line hybrid rice.展开更多
基金supported by the National High Technology Research and Development Program of (Grant No.2010AA101304)the Transformation Fund for Agricultural Science and Technology Achievements (Grant No.2007GB2D200226)the Natural Science Foundation of Hunan Province,China(Grant No. 10JJ4012)
文摘The main problems about research and application of two-line hybrid rice were reviewed, including the confusing nomenclature and male sterile lines classification, the unclear characteristics of photoperiod and temperature responses and the unsuitable site selection for male sterile line and hybrid dce seed production. In order to efficiently and accurately use dual-purpose genic male sterile lines, four types, including PTGMS （photo-thermo-sensitive genic male sterile rice）, TGMS （thermo-sensitive genic male sterile rice）, reverse PTGMS and reverse TGMS, were proposed. A new idea for explaining the mechanism of sterility in dual-purpose hybrid rice was proposed. The transition from sterile to fertile was involved in the cooperative regulation of major-effect sterile genes and photoperiod and/or temperature sensitive ones. The minor-effect genes with accumulative effect on sterility were important factors that affected the critical temperature of sterility transfer. In order to make better use of dual-purpose lines, the characterization of responses to photoperiod and temperature of PTGMS should be made and the identification method for the characterization of photoperiod and temperature responses of PTGMS should also be put forward. The optimal ecological site for seed production could be determined according to the historical climate data and the requirements for the meteorological conditions during the different periods of seed production.
文摘Since the breakthrough of grain yield owing to the development of dwarf rice and three-line system hybrid rice, rice breeding for high yield hardly had showed significant progress in the next successive two decades. It was considered that utilizing heterosis between subspecific varieties (Oryza sativa L.) would be an effective approach to increase yield further. During 1987-1993, an indica-japonica hybrid Yayou 2 yielded as high as 10.5 t/ha; however, it failed to be commercialized because of seed purity problem due to non-uniform emasculation by chemical agent in seed production, and sensitivity of seed setting in Ft plants to environmental conditions. In the past decade, two inter-subspeific hybrids, Liangyoupeijiu (Peiai 64S/9311, javanica/indica) and Liangyou E32 (Peiai 64S/E32, javanica/ laponica); both of them exhibited grain yield higher than 10.5 t/ha, and were widely judged as the pioneers of super hybrid rice. Liangyoupeijiu has been successfully popularized over 4 million hectare in wide climatic areas, while Liangyou E32 made a yield record and offered a model of plant ideotype for super hybrid rice. It was considered that in combination with plant ideotype, active physiological functions, and wide-range adaptability to ecological conditions, exploitation of indica-japonica heterosis would be the key approach for super hybrid rice breeding.
文摘Research on hybrid rice in Jiangsu Province, China began in 1970. Great progress has been made since then, which can be divided into three stages according to the development of hybrid rice breeding and production in Jiangsu Province. The first stage was beginning stage from 1970 to 1980, when progress was mainly made in cytoplasmic male sterile line breeding. The second stage could be described as developing stage, from 1980 to 1995, when indica hybrid rice was rapidly popularized, and japonica hybrid rice became popular later. From 1996, hybrid rice breeding in Jiangsu Province entered the third stage, when both indica and japonica hybrid rice breeding in the three-line system or intersubspecific hybrid rice breeding in the two-line system made a great breakthrough with the successful breeding of the hybrids Feyou 559, 9 You 138 and Liangyoupeijiu. The developing trend of hybrid rice breeding in Jiangsu Province is also discussed.
基金This study was supported by the National Natural Science Foundation of China （30671225）the Natural Science Foundation of Jiangsu Province, China （BK2006069, BK2007071）the National Key Technologies R＆D Program, China （2006BAD02A13-3-2）.
文摘This study was designed to elucidate the grain filling characteristics and the causes of poor grain plumpness of some two-line hybrid rice combinations and their hormonal mechanism. Six varieties, including three two-line hybrid rice combinations, that show differences in seed-setting and grain filling, were used. And the contents of starch, sucrose, zeatin （Z） ＋ zeatin riboside （ZR）, indole-3-acetic acid （IAA）, and abscisic acid （ABA）, the ethylene evolution rate, activities of sucrose synthase （SuSase） and starch synthase （StSase） in grains, the seed-setting and grain filling rate were investigated. The correlations amongst these were analyzed. The results showed that the poor grain filling of two-line hybrids was mainly attributed to the higher unfilled grain rate and the lower filling degree of inferior grains. During the early and mid grain filling periods, the sucrose content in inferior grains was greater than that in superior grains for the combinations with poor grain filling, indicating that the substrate concentration was not the principal factor for their slow grain filling and poor grain plumpness of the inferior grains of two-line hybrids. Z ＋ ZR, IAA, and ABA in superior grains were obviously greater than those in inferior grains at early grain filling stage. The maximum and mean contents of Z ＋ ZR, IAA, and ABA were positively very significantly correlated with the maximum and mean grain-filling rate, filling degree, and grain weight. The evolution rate of ethylene was greater in inferior grains than in superior grains and greater for the combinations with poor grain plumpness than those with good grain plumpness at the early or mid filling stages. The evolution rate of ethylene was negatively and significantly correlated with the grain filling rate, the grain filling degree, and the grain weight. Spraying ethephon （ethylene-releasing agent） at the early grain filling stage increased the evolution rate of ethylene, reduced the ABA content and activities of SuSase
基金The research was supported by the National Natural Science Foundation of China （30370830）.
文摘By inducing frequency, intensity and duration of lower temperature in the middle and last ten-day periods in August in the rice-growing areas of southern China, increasing temperature for safe seed production was defined as 2℃. During the sensitive period of fertility, characters of panicle height and canopy structure of TGMS rice, Pei＇ai64S, were measured. Results showed that temperature changes caused by irrigation in fields were below 40 cm of rice plant, and heating effect was significant at 20 cm when the temperature was increased by 3.1 ℃. For the present study, the following irrigation techniques were put forth： the water depth of 15-20 cm, current water used, irrigating after 17：00 and bailing at 10：00 in sunny or cloudy weather, irrigating on whole day, in shady or rainy weather, increasing inflows and outflows in large fields. In the present experiment, pollen fertility and self-fertilized seed setting rate accepted that the techniques were feasible and effective for against lower temperature and safeguarding seed production of two-line hybrid rice.
文摘Liliangyou 3822 is a novel indica hybrid rice variety that exhibits disease resistance,high yield,lodging resistance,and late maturity.It employs a self-selected two-line sterile line,Li 38S,and a self-selected restorer line,R22.This variety was subjected to a regional test of indica late-maturing groups in the middle and lower reaches of the Yangtze River in 2020.The results demonstrated that the average yield of the variety was 9.95 t/hm 2,which was 10.67%higher than that of the control Fengliangyou 4,indicating a highly significant yield increase.In the continuous test in 2021,the average yield was 9.74 t/hm 2,representing a 6.52%increase over the control,which also exhibited a significant increase.Finally,the average yield of the two years regional test was 9.84 t/hm 2,which was 8.58%higher than that of the control.In the 2021 production test,the average yield of the variety was 9.32 t/hm 2,which was 12.19%higher than that of the control,indicating a remarkably significant yield increase.In 2022,the variety was validated by the National Crop Variety Approval Committee(GSD 20220143).
基金Supported by the Project for the Commercialization of Agricultural Research Findings in China(2011GB2D200007)the National High Technology Research and Development Program of China (863 Program) Planning for the Development of High-Technology Research in China(2010AA101304)the National Natural Science Foundation of China(31371714)~~
文摘The insecure problems of seed production have seriously hampered the healthy and sustainable development of two-line hybrid rice.The safety issues on seed production of two-line hybrid rice and current research situation were pointed out in this paper.The three main reasons for unsafety in seed production of twoline hybrid rice were unsuitable site selection,high critical sterility-inducing temperature and the drift of critical temperature.In this paper,strategies and measures were put forward based on many years of practice.It could minimize the risk in seed production of two-line hybrid rice by selecting dual-purpose genic male sterile line with lower critical sterility-inducing temperature and long lower temperature resistant time.Based on the climate data and climatic demands of the ＂three safe-periods＂ in seed production,a new idea for determining appropriate bases and periods for seed production was proposed by using computer technology,which solved the aimless selection of sites and periods for the seed production of two-line hybrid rice.Besides,we established a system of single plant selection and identification method and original seed propagation with cyclic cold water,which could reduce the generation number of original seed propagation in seed production and avoid the drift of critical sterility-inducing temperature.This paper improved the seed production safety in the three aspects of seed nature,seed source and seed production site.
基金supported by the National Natural Science Foundation of China(31821005)Hubei Provincial Natural Science Foundation of China(2020CFB192)the Fundamental Research Funds for the Central Universities of China(2662019QD051).
文摘Knowledge of rice(Oryza sativa L.)genes and various DNA markers can be used in genomic breeding programs aimed at developing improved elite rice cultivars.We used an efficient genomic breeding approach to pyramid four resistance genes(Pi2,Xa23,Bph14,and Bph15)in the popular photoperiod-and thermosensitive genic male sterile(PTGMS)rice line Feng39S.We performed foreground selection for the target genes,followed by recombinant selection and background selection.This process reduced the sizes of the genomic segments harboring the target genes(566.8 kb for Pi2,1143.9 kb for Xa23,774.7 kb for Bph14,and 1574.9 kb for Bph15)and accelerated the recovery of the recurrent parent genome to proportions ranging from 98.77%to 99.16%,thus resulting in four near-isogenic lines.To assemble the four resistance genes in Feng39S,we performed a double-way cross combined with foreground and background selection to generate two improved lines of Feng39S(Pi2+Xa23+Bph14+Bph15)with a recurrent parent genome recovery of 98.98%.The two lines showed agronomic performance,grain quality,and fertility–sterility transition characteristics similar to those of the original Feng39S line.The newly developed PTGMS lines and corresponding hybrid combinations were resistant to various field blast isolates and seven representative isolates of bacterial blight.At the seedling stage,the lines also showed resistance against brown planthopper.This study provides an efficient and accurate genomic breeding approach for introducing desirable traits into PTGMS lines.
文摘In the present paper, to build model of two-line queuing system with losses GI/G/2/0, the approach introduced by V.S. Korolyuk and A.F. Turbin, is used. It is based on application of the theory of semi-Markov processes with arbitrary phase space of states. This approach allows us to omit some restrictions. The stationary characteristics of the system have been defined, assuming that the incoming flow of requests and their service times have distributions of general form. The particular cases of the system were considered. The used approach can be useful for modeling systems of various purposes.
文摘Hybrid wheat is recognized as a preferred approach to improve wheat yield,and it will be a competition focus in high-tech seed industry in the future. We have made a breakthrough for the first time in creation of two-line hybrid wheat system,which reaches the world leading level in wheat research and has laid an important foundation for the future direction of the world wheat research. Similar to hybrid rice,the innovation of two-line hybrid wheat system is another achievement in science and technology. The application of hybrid wheat in China will greatly increase the food production,and make a great significance to food production and food security. This paper introduces the development process and major breakthrough of hybrid wheat in China,and the main bottleneck and countermeasures in the application of hybrid wheat.
基金Supported by Major Science and Technology Project of Hunan Province(2013FJ1008)~~
文摘[Objective] The aim of this study was to explore the inheritance pattern of the resistance of two-line hybrid rice to false smut. [Method] A moderate susceptible TGMS line 33S as the female parent, was crossed with 30 susceptible restorer lines and 23 resistant restorer lines. Then false smut resistance of the hybrid F1 and parents were identified. [Result] All F1 of 33S crossed with 30 susceptible re- storer lines were susceptible to rice false smut. The F1 of 33S crossed with 23 re- sistant restorer lines showed dominant, incompletely dominant or recessive inheri- tance. Dominant and incompletely dominant inheritance accounted for 87.0%. The diseased panicle rate, disease index, average diseased grains per panicle, and the highest diseased grains per panicle of F1 shared highly significant positive correla- tions with corresponding indicators of restorer lines. [Conclusion] This study provides references for genetic improvement of two-line hybrid rice.
