浅谈两系杂交水稻育种

主要回顾了发展两系杂交水稻的历史,研究进展及在选育过程中所遇到的问题及解决方法,其中包括温度对光温敏不育系的影响,不育起点温度"漂变"等.     

水稻光温敏不育系“六圃法”提纯保真原种繁殖体系的建立与应用

【目的】水稻光温敏不育系的提纯保真繁殖对于两系法杂交水稻的发展和应用具有十分重要的意义。现有提纯繁殖技术多以防止起点温度漂移为目的,而忽视了生物学性状的提纯保真。为解决这些问题,本研究结合光温敏不育系Y58S的多年大规模原种生产实践,建立了水稻光温敏不育系"六圃法"提纯保真原种繁殖体系。【方法】该技术体系基本步骤如下:首先,直接从生产上大规模制种使用的不育系种子中取样,种植"典型单株筛选圃",进行典型单株初选;其次,通过"起点温度鉴定圃"筛选不育起点温度基本一致的核心单株,进行起点温度纯化;然后,通过"群体观察圃"、"配合力鉴定圃"和"制种试验圃"来确保光温敏不育系的遗传背景基本纯合和表型整齐一致,从而决选保真核心株系,进而获得保真核心种子;最后,建立连续稳定的品种"专一性原种繁殖圃"来实现原原种和原种的高纯度生产。【结论】实践证明,该技术体系可确保获得育性稳定、表型整齐,且遗传背景来源基本一致的光温敏不育系原种,大幅度提高水稻光温敏不育系繁殖的安全可靠性和生产效率。2008年以来,应用该技术体系生产了249万kg Y58S生产用种,基本消灭了同形可育株,纯度全部达到99.5%以上。目前这些Y58S生产用种已经全部销售给各种业公司进行杂交制种,生产的杂交种子推广1474万hm2以上。     

两系法高粱不育系“九疑糯粱S-1”选育及应用研究

1994年,在对"湘糯粱S-1"进行育性转换观察试验时发现,在高于其不育上限临界温度23.8℃的温度条件下存在个别不育变异株。以这些变异株为材料,经过7年10代的系统与定向选育,成功选育出了遗传性状稳定、育性转换温度为28℃的新的高温型高粱两用不育系"九疑糯粱S-1"。该不育系的育性转换温度比原不育系"湘糯粱S-1"提高了4.2℃,大大提高了制种的安全性,降低了制种成本。以"九疑糯粱S-1"为母本,湘10721为父本进行配组,表现极强的杂种优势,一般每公顷产量达6750kg以上,高产丘块达9808.5kg。     

水稻光温敏核不育机理设想及光温敏核不育系选育策略

为更深入了解水稻光温敏核不育的遗传机理,综述了我国水稻光温敏核不育机理研究取得的成就及存在问题,提出了水稻光温敏核不育机理新设想,即水稻光温敏不育系中不存在光敏不育基因和温敏不育基因,其育性转换是主效不育基因与发育感光基因或(和)发育感温基因相互作用的结果;正常水稻品种中存在的不育基因位点(微效不育基因)可影响光温敏核不育系的不育起点温度,微效不育基因聚合越多,则不育系不育起点温度越低;微效不育基因完全纯合,则不育起点温度不会漂变。基于不育机理新设想,提出了光温敏核不育系选育的策略,即不同生态区、不同生态类型的光温敏核不育系选育的光温指标不一样,增压选择是选育低不育起点温度核不育系的技术核心,全面提高综合性状水平和配合力是选育实用光温敏核不育系技术的关键。     

水稻两用核不育系研究进展

概述了水稻两用核不育系育性转换规律、不育起点温度和育性漂移的研究,介绍了两用核不育系的选育途径与方法,分析了两用核不育系选育存在的主要问题,简述了两用核不育系选育的成果,并对今后的研究方向做了展望。     

两系法杂交水稻研究和应用中若干问题的思与行

指出了当前我国两系法杂交水稻研究和应用中面临的主要问题,即两系法杂交水稻体系中不育系的称谓和分类不规范,生产上利用的水稻两用核不育系育性温光反应特性研究不清楚,水稻两用核不育系繁殖和两系法杂交稻制种基地选择不当等。针对当前情形,结合多年育种实践,提出了解决这些问题的对策及措施。建议将水稻两用核不育系分为长光高温不育型、高温不育型、短光低温不育型、低温不育型等四种类型。提出了水稻光温不育机理设想,即水稻光温敏核不育系育性转换是主效不育基因与其位置相近的发育感光基因或(和)发育感温基因相互作用的结果,微效不育基因可影响两用核不育系的不育起点温度。只有深入研究光温敏型不育系育性的光温组合效应,且获得具体的光温指标,才能更好地指导两系法杂交水稻制种和不育系繁殖。提出了水稻两用核不育系育性光温特性的鉴定方法以及两系法杂交稻种子生产应根据不育系育性温光特性和历史气象资料来合理安排基地和时段。     

广东省实用型水稻低温敏核不育系选育技术

根据广东省的生态条件和耕作制度,确定了广东省应以选育起点温度＜23.5℃的低温敏型两用核不育系为主的育种方向,总结了一套"广州-乳源-三亚"穿梭育种的低温敏核不育系选育程序,可使不育系选育进程每年增加2个世代,并据此选育出GD-1S等一批低温敏核不育系.     

水稻籼型不育系选育研究进展

回顾了水稻籼型不育系选育的历史,分别从新质源发掘及利用、不育系选育方法的创新以及"广亲和"理论的应用3个方面阐述了水稻籼型不育系的研究现状,并指出籼型不育系选育存在综合性状水平低、光温敏核不育系配合力低、两系法制种不安全等问题。最后从3个方面,即提高籼型不育系的综合性状,选育高配合力的两系不育系以及解决两系不育系安全制种技术问题,并展望了籼型不育系的育种前景。     

江苏盐城两系杂交稻制种气象安全分析与思考

为了对江苏盐城发展两系杂交稻制种提供科学决策依据,笔者利用该地区最近46 a历史气象数据,借助"两系杂交水稻制种基地与时段选择决策支持系统",分析了江苏省盐城市两系杂交稻制种的气象风险,提出了应对策略。分析表明,江苏盐城两系杂交稻制种不育系育性敏感始期安排在7月25日为最佳,不育起点温度高于23℃的水稻两用核不育系在该地区制种风险较大。提出了合理控制盐城地区两系杂交稻制种面积、选用低不育起点温度的两用核不育系制种、重视不育系核心种子生产、科学安排制种时段、建立有效的种业保险模式的对策,以规避制种风险。     

浅谈北方两系不育系选育方法

依据两系不育系的遗传理论及北方的气候特点,提出了北方两系不育系的选育目标。在不育基因来源上以不育起点温度低、长短光育性转换敏感、一般配合力强、特殊配合力好的材料为亲本,提出了对低代、高代不育材料的选择方法和解决高代不育系育性波动问题的办法,以期推动北方杂交粳稻的快速发展。     

超高产杂交水稻培矮64S/E32和两优培九剑叶对高温的响应

 以汕优63为对照，研究了新育成的两个超级杂交水稻组合培矮64S/E32和两优培九的高温耐受特性。结果表明高温引起了光合效率降低，加重了光合光抑制。光化学、光合电子传递最适温度在28℃左右，光合碳同化的最适温度在35～40℃。高温下通过PSⅡ线性电子传递的能力几乎丧失（下降96.7%～100%），而PSⅡ光化学效率下降较少（8.8%～210%）,暗示PSⅡ光合线性电子传递过程比光化学能转化对高温更敏感。超级杂交稻比对照汕优63更耐高温，其机理可能如下：一是因为超级稻在高温时有更迅速的类胡萝卜素积累，增加其抗氧化能力，减少了因过剩激发能积累引起活性氧产生、积累并伤害光合细胞；二是因为超级稻高温下有高效的叶黄素循环热耗散途径可以耗散过量的激发能； 三是因为超级稻在高温下有稳定的光合功能和较强的光合效率，较高的热稳定蛋白含量。     

Thoughts and Practice on Some Problems about Research and Application of Two-Line Hybrid Rice

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 rice 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.     

选育适合北方气候条件的光温敏核不育水稻的技术探讨

 分别在沈阳设置盆栽人工控制光长试验和连云港进行分期播种试验，研究了农垦58S、培矮64S、衡农-1S和衡农-3S对光温的反应。参试的两用核不育水稻的育性表达对光长核温度的反应不同。一类为高温条件下不育，低温条件下可育；；另一类为高温下可育，低温下不育。北方的低温加大了选育实用型光温敏核不育水稻的难度。提出了辽宁以北地区实用型两用不育系的选育策略核光温临界指标。     

不同杂交中稻品种开花期耐高温性鉴定

2013年、2016年分别以40个杂交中稻品种为材料,在人工气候室和自然高温条件下鉴定了不同品种开花期的耐高温性。结果表明,人工气候室模拟高温下鉴定耐高温指数≥0.5的品种,两种条件下的耐高温指数呈极显著正相关;而人工气候室模拟高温下鉴定的耐高温指数≤0.49的品种,两种条件下的耐高温指数的相关性不显著,原因在于部分在人工气候室模拟高温下鉴定的不耐高温品种在自然条件下因花时早而避开了高温伤害,仍表现出较高的耐高温指数。根据开花期耐高温性可以把杂交水稻分为耐避双重型、耐高温型、避高温型和高温敏感型4种类型。     

Effect of Temperature on Pollen Fertility in Inter-Subspecific Rice Hybrids

Seventeen rice varieties and hybrids of different types (indica, japonica, javanica, indica hybrid, japonica hybrid and inter-subspecific hybrid) were evaluated to determine the effect of temperature on pollen fertility in inter-subspecfic hybrids. The pollen fertility of inter-subspecific hybrids was greatly reduced when average daily temperature dropped to 22.0 - 23.0℃at meiosis stage, and the extent of pollen fertility reduction varied greatly with respect to different hybrids. However, the pollen fertility reduction of indica and japonica hybrids and conventional varieties was not obvious under the same regime of temperature conditions. When the average daily temperature dropped to 20℃, the pollen development of conventional varieties and hybrids was also affected. Correlation analysis revealed that there existed a positive correlation between pollen fertility and average daily temperature. A significant difference (P<0.01) was also found between the two correlation coefficients i.e. inter-subspecific hybrids and conventional varieties. Temperature at meiosis stage of pollen mother cell was a key factor in pollen developing, and the pollen fertility of inter-subspecific hybrids was more sensitive to low temperature than that of traditional variety.     

Responses of Photosynthetic Functions to Low Temperature in Flag Leaves of Rice Genotypes at the Milky Stage

The low temperature is one of the major constrains in rice (Oryza sativa L.) production that reduces the grain yield all over the world. In different geographical regions rice varieties often get chilling injury of various degrees and types, especially in the south China, which is double-season rice area in China [1]. Thus, it is crucial to control the abnormal seeding resulting from low temperature and heavy rain [2]. The average temperature of the earth is continuously rising in the past 1…     

Correlation and Regressive Model Between Spikelet Fertilized Rate and Temperature in Inter-Subspecific Hybrid Rice

To study the sensitivity of inter-subspecific hybrid rice to climatic conditions, the spikelet fertilized rate (SFR) of four types of rice including indica-japonica hybrid, intermediate hybrid, indica and japonica were analyzed during 2000-2004. The inter-subspecific hybrids showed lower SFR, and much higher fluctuation under various climatic conditions than indica and japonica rice, showing the inter-subspecific hybrids were sensitive to ecological conditions. Among 12 climatic factors, the key factor affecting rice SFR was temperature, with the most significant factor being the average temperature of the seven days around panicle flowering (T7). A regressive equation of SFR-temperature by T7, and a comprehensive synthetic model by four important temperature indices were put forward. The optimum temperature for inter-subspecific hybrids was estimated to be 26.1-26.6℃, and lower limit of safe temperature to be 22.5-23.3℃ for panicle flowering, showing higher by averagely 0.5℃ and 1.7℃, respectively, to be compared with indica and japonica rice. This suggested that inter-subspecific hybrids require proper climatic conditions. During panicle flowering, the suitable daily average temperature was 23.3-29.0℃, with the fittest one at 26.1-26.6℃. For an application example, optimum heading season for inter-subspecific hybrids in key rice growing areas in China was as same as common pure lines, while inferior limit for safe date of heading was about a ten-day period earlier than those of common pure lines.     

Responses of Yield Characteristics to High Temperature During Flowering Stage in Hybrid Rice Guodao 6

By sowing at different dates during 2005 and 2006 both in paddy fields and greenhouse, a super hybrid rice combination Guodao 6 and a conventional hybrid rice combination Xieyou 46 (as control) were used to analyze the differences in heat injury index, seed setting rate, grain yield and its components. Guodao 6 showed more stable yield and spikelet fertility, and lower heat injury index than Xieyou 46. Further studies indicated that the spikelet sterility is positively correlated with the average daily temperature and the maximum daily temperature, with the coefficients of 0.8604 and 0.9850 (P<0.05) respectively in Guodao 6. The effect of high temperature injury on seed setting caused by maximum daily temperature was lower than that by average daily temperature during the grain filling stage.     

花后不同时段低温对籼粳杂交稻稻米品质性状的影响

【目的】花后低温是影响米质的首要生态因子。为明确花后低温对甬优品种稻米品质性状及淀粉RVA谱特性的影响,【方法】以籼粳杂交稻甬优17号、甬优538和杂交籼稻中浙优1号、常规粳稻浙粳88为材料,采用盆栽试验,通过人工气候箱于水稻花后0-15d(前期)、15-30d(中期)和30d-成熟(后期)分别进行20℃、17℃和14℃的低温处理。【结果】花后低温显著影响供试品种整精米率、垩白度、胶稠度、直链淀粉含量及蛋白质,使甬优品种淀粉RVA谱特征值峰值黏度、热浆黏度、冷胶黏度、崩解值降低,回复值和消减值升高。花后前期低温对稻米加工品质影响最大,而花后中、后期低温对外观品质、蒸煮食味品质和营养品质影响最大,且甬优17号比甬优538对低温更敏感。花后低温对稻米品质影响明显,低温处理影响因品种类型、品质指标及处理时段而异。【结论】生产中应基于品种特性综合考虑稻米各品质指标,在结实期采取相应的米质调优栽培措施,充分发挥籼粳杂交稻品种的品质潜力。