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
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
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 and StSase, and decreased the grain filling degree and the grain weight. The results were reversed when cobatous nitrate (an inhibitor of ethylene synthesis) was applied. The results suggested that the hormones and their balance play a role in the regulation of grain filling and enzymatic activities, and the poor grain filling is attributed to the low contents of Z + ZR, IAA, and ABA, and the high evolution rate of ethylene in the inferior grains of some two-line hybrid rice combinations. The results suggested that hormones play important roles in the grain filling of some two-line hybrid rice combinations, and their filling degree can be improved by regulating the hormonal contents.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
Drought is one of the important factors limiting rice production,and the application of new water-saving rice varieties is urgently needed in rice production.Wanliangyou 1008 bred by Institute of Rice Research,Anhui A...Drought is one of the important factors limiting rice production,and the application of new water-saving rice varieties is urgently needed in rice production.Wanliangyou 1008 bred by Institute of Rice Research,Anhui Academy of Agricultural Sciences is a new two line hybrid rice variety with some good traits,including high drought resistance,high yield and good disease resistance.Wanlingyou 1008 was obtained by crossing drought-resistant high-quality restorer line DJ1008 and disease-resistant two-line sterile line Wan 25S.In this paper,the breeding process,characteristics and seed production technology of the variety were described in detail.展开更多
For satellites in orbits,most perturbations can be well modeled;however the inaccuracy of the atmospheric density model remains the biggest error source in orbit determination and prediction.The commonly used empirica...For satellites in orbits,most perturbations can be well modeled;however the inaccuracy of the atmospheric density model remains the biggest error source in orbit determination and prediction.The commonly used empirical atmospheric density models,such as Jacchia,NRLMSISE,DTM,and Russian GOST,still have a relative error of about 10%-30%.Because of the uncertainty in the atmospheric density distribution,high accuracy estimation of the atmospheric density cannot be achieved using a deterministic model.A better way to improve the accuracy is to calibrate the model with updated measurements.Twoline element(TLE)sets provide accessible orbital data,which can be used in the model calibration.In this paper,an algorithm for calibrating the atmospheric density model is developed.First,the density distribution of the atmosphere is represented by a power series expansion whose coefficients are denoted by the spherical harmonic expansions.Then,the useful historical TLE data are selected.The ballistic coefficients of the objects are estimated using the BSTAR data in TLEs,and the parameterized model is calibrated by solving a nonlinear least squares problem.Simulation results show that the prediction error is reduced using the proposed calibration algorithm.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
目的 探讨基于膜解剖指导下的胃左系膜、胃后系膜、胰腺系膜三三交汇处TJ点至左侧膈肌脚内侧缘顶点“两点一线”为解剖标志的胃底体一体化游离方式(two points and one line model, TPOL模型)腹腔镜袖状胃切除术(LSG)的可行性与安全性...目的 探讨基于膜解剖指导下的胃左系膜、胃后系膜、胰腺系膜三三交汇处TJ点至左侧膈肌脚内侧缘顶点“两点一线”为解剖标志的胃底体一体化游离方式(two points and one line model, TPOL模型)腹腔镜袖状胃切除术(LSG)的可行性与安全性。方法 我院2019年1月~2022年1月收治的肥胖病或肥胖合并代谢综合征病人135例,均行LSG治疗。根据胃底体游离方式不同,分为两组,研究组68例,采用TPOL模型LSG手术。对照组67例,采用常规LSG手术。比较两组病人手术时间、胃底游离时间、术中出血量、住院时间、术后胃漏、出血、胃食管反流发生率等指标。结果 所有病人均顺利完成LSG手术,术后随访12~36个月。研究组与对照组手术时间分别为(56.13±10.56)分钟和(62.45±12.74)分钟,胃底游离时间分别为(6.34±4.16)分钟和(12.58±6.37)分钟,住院时间分别为(3.84±0.42)天和(4.06±0.69)天,术中出血量分别为(10.87±1.28)ml和(15.56±3.39)ml,术后胃食管反流发生率分别为5例(7.35%)和13例(19.40%),两组比较差异有统计学意义(P<0.05)。两组术后12个月多余体重减少以及术后出血、胃漏等并发症比较,差异无统计学意义(P>0.05)。结论 基于膜解剖指导下的胃后TJ点至左侧膈肌脚内侧缘顶点“两点一线”为解剖标志的胃底体一体化游离方式(TPOL模型)LSG术可高效、安全、完整游离胃底,对LSG的胃底规范化游离具有临床价值。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.
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.
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 and StSase, and decreased the grain filling degree and the grain weight. The results were reversed when cobatous nitrate (an inhibitor of ethylene synthesis) was applied. The results suggested that the hormones and their balance play a role in the regulation of grain filling and enzymatic activities, and the poor grain filling is attributed to the low contents of Z + ZR, IAA, and ABA, and the high evolution rate of ethylene in the inferior grains of some two-line hybrid rice combinations. The results suggested that hormones play important roles in the grain filling of some two-line hybrid rice combinations, and their filling degree can be improved by regulating the hormonal contents.
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.
基金Supported by Anhui Provincial Science and Technology Major Project(202003a06020005,2021d06050002)Joint Research on Crop Varieties in Anhui Province(Rice)+1 种基金Innovation Team of Anhui Academy of Agricultural Sciences(2021YL004)Young Talents of Anhui Academy of Agricultural Sciences.
文摘Drought is one of the important factors limiting rice production,and the application of new water-saving rice varieties is urgently needed in rice production.Wanliangyou 1008 bred by Institute of Rice Research,Anhui Academy of Agricultural Sciences is a new two line hybrid rice variety with some good traits,including high drought resistance,high yield and good disease resistance.Wanlingyou 1008 was obtained by crossing drought-resistant high-quality restorer line DJ1008 and disease-resistant two-line sterile line Wan 25S.In this paper,the breeding process,characteristics and seed production technology of the variety were described in detail.
文摘For satellites in orbits,most perturbations can be well modeled;however the inaccuracy of the atmospheric density model remains the biggest error source in orbit determination and prediction.The commonly used empirical atmospheric density models,such as Jacchia,NRLMSISE,DTM,and Russian GOST,still have a relative error of about 10%-30%.Because of the uncertainty in the atmospheric density distribution,high accuracy estimation of the atmospheric density cannot be achieved using a deterministic model.A better way to improve the accuracy is to calibrate the model with updated measurements.Twoline element(TLE)sets provide accessible orbital data,which can be used in the model calibration.In this paper,an algorithm for calibrating the atmospheric density model is developed.First,the density distribution of the atmosphere is represented by a power series expansion whose coefficients are denoted by the spherical harmonic expansions.Then,the useful historical TLE data are selected.The ballistic coefficients of the objects are estimated using the BSTAR data in TLEs,and the parameterized model is calibrated by solving a nonlinear least squares problem.Simulation results show that the prediction error is reduced using the proposed calibration algorithm.
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).
文摘目的 探讨基于膜解剖指导下的胃左系膜、胃后系膜、胰腺系膜三三交汇处TJ点至左侧膈肌脚内侧缘顶点“两点一线”为解剖标志的胃底体一体化游离方式(two points and one line model, TPOL模型)腹腔镜袖状胃切除术(LSG)的可行性与安全性。方法 我院2019年1月~2022年1月收治的肥胖病或肥胖合并代谢综合征病人135例,均行LSG治疗。根据胃底体游离方式不同,分为两组,研究组68例,采用TPOL模型LSG手术。对照组67例,采用常规LSG手术。比较两组病人手术时间、胃底游离时间、术中出血量、住院时间、术后胃漏、出血、胃食管反流发生率等指标。结果 所有病人均顺利完成LSG手术,术后随访12~36个月。研究组与对照组手术时间分别为(56.13±10.56)分钟和(62.45±12.74)分钟,胃底游离时间分别为(6.34±4.16)分钟和(12.58±6.37)分钟,住院时间分别为(3.84±0.42)天和(4.06±0.69)天,术中出血量分别为(10.87±1.28)ml和(15.56±3.39)ml,术后胃食管反流发生率分别为5例(7.35%)和13例(19.40%),两组比较差异有统计学意义(P<0.05)。两组术后12个月多余体重减少以及术后出血、胃漏等并发症比较,差异无统计学意义(P>0.05)。结论 基于膜解剖指导下的胃后TJ点至左侧膈肌脚内侧缘顶点“两点一线”为解剖标志的胃底体一体化游离方式(TPOL模型)LSG术可高效、安全、完整游离胃底,对LSG的胃底规范化游离具有临床价值。