我国光敏核不育水稻研究进展

光敏核不育水稻是我国水稻科学工作者石明松于1973年首次发现的一种具有宝贵应用价值的特异种质材料,它具有长日照条件下不育,短日照条件下可育的育性转换特性。光敏核不育水稻的发现引发了我国杂交水稻育种在方法上产生全新的变革,开辟了“两系法”杂交水稻育种的新领域。1光周期对光敏核不育水稻育性转换的影响光周期影响光敏核不育水稻的生长、发育和育性转换。元生朝等（1987,1988）研究认为,光敏核不育水稻农垦585及其衍生的各类光敏核不育系在生长、发育及育性转换过程中存在两个光周期反应。第一光周期反应诱导生长点由营养生长…     

光敏、温敏雄性核不育水稻不育基因研究进展

简要要概述了光敏、温敏核雄性不育水稻不育基因表达的条件，光温信号的接受与传递及不育基因的探索工作。     

水稻光敏核不育系选育及利用研究

通过对水稻光敏核不育系沈粳1S和沈粳2S的选育过程和对沈阳地区的环境分析,阐述了水稻光敏核不育技术在沈阳地区应用的可行性,提出了水稻光敏核不育系在沈阳地区应用的关键技术难点,以及解决的方法和有待需要解决的问题。     

温光弱感型光敏核不育水稻3088s选育研究

３０８８ｓ是一个粳籼交偏粳型的光敏核不育系，其开花习性表现为籼粳中间型。其光敏不育性的光照 范围较宽，育性转换的临界光长为１３：００～１３：３０，比晚粳型光敏不育系晚半小时以上。３０８８ｓ光敏不育性的温 度范围亦较宽，长日不育的低限温度较低，为２４．５～２５℃，比同类两用不育系低１．５～３．５℃；短日可育的上限温 度较高，为３０～３２℃。在遗传分类上３０８８ｓ为温光弱感型光敏核不育系，光温互补作用较强，因而具有稳定的不 育期和稳定的可育期。     

湖北光敏核不育水稻在华南的利用研究

湖北光敏核不育水稻农垦58(HPGMR以下简称农垦58S)在水稻两系法杂种优势利用上具有重要的应用价值。我们从1983年起,对这一种质资源在华南的育性转换,以及将光敏育性转换基因导入籼稻中的效果和表达进行了研究,为华南地区转育利用农垦58S提供依据。 一、材料与方法 (一)材料:农     

乙烯与光敏核不育水稻育性转换关系

 研究了乙烯与光敏核不育水稻(PGMR)农垦58S育性转换的关系。发现幼穗的乙烯释放速率在育性转换的适宜温度中长日照处理明显比短日照处理高， 但在低温长日照下大为降低而在高温短日照下又可雏持高水平的乙烯释放， 幼穗乙烯释放速率与花粉可育度之间呈极显著负相关。在不育条件下用乙烯代谢抑制剂氨基乙氧基乙烯基甘氟酸(AVG)处理，可诱导花粉可育性的明显表达， 由此初步证明农垦58S幼穗的乙烯释放速率受到光周期和温度的共同调节，井与育性转换的光温作用模式极为吻合；乙烯参与育性转换的调节，可能在花粉败育中起关键性作用。     

光敏核不育水稻育性转换的临界温度选择与鉴定的思考

光敏不育系的育性转换是光温共同作用的结果。从实用的角度出发，以高温临界温度高、低温临界温度低、光敏温度范围宽、光温互补作用强的不育类型最为适用。低温临界温度低的选择关键是在长日低温条件下选不育株；高温临界温度高的选择关键是在短日高温条件下选可育株。在进行人控低温临界温度指标的鉴定时，应尽量模拟盛夏低温的光温条件。     

50份光敏核不育材料引种观察简报

１９８９—１９９０年，将５０份光敏核不育材料（其中籼型２７份，粳型２３份）在南京自然条件下，对其育性表达、开花习性及其农艺性状的表现，进行了系统观察。     

短日照在光敏核不育水稻幼穗发育中的作用探讨

短日（ＳＤ）、长日（ＬＤ）和不同天数的短、长日照处理光敏核不育水稻１０５Ｓ 和对照常规品种１０５。ＬＤ处理的植株始终不分化，一直处于营养生长状态；而先经６，９或１２ ＳＤ诱导再经ＬＤ处理的植株，结果表明ＳＤ具有：诱导幼穗分化的作用；提高可育程度的作用， 但１０５Ｓ对ＳＤ提高可育程度的作用较不敏感，还具有加速幼穗发育进程、缩短生育期的作用。在 不同的光周期处理下，１０５Ｓ和１０５叶片的过氧化物酶同工酶及其酶活性均有差异，较突出的差异 在ＳＤ（９）叶片中，这与ＳＤ提高可育程度的作用有关．     

不同品质类型小麦籽粒蛋白质、淀粉积累过程的基因型差异

对 3个具有不同蛋白质含量的大面积推广小麦品种宁麦 9号 (低蛋白 )、苏麦 6号 (中蛋白 )和重庆面包麦(高蛋白 )籽粒灌浆期蛋白质、淀粉含量的动态变化进行了研究。结果表明 ,(1) 3个品种在籽粒灌浆过程中 ,粒重的增加、籽粒蛋白质、淀粉含量存在极显著的差异 ;(2 ) 3个品种在开花后 2 2 d前经历了淀粉含量的快速增加、蛋白质含量下降期 ;(3)三个品种在整个灌浆至乳熟阶段淀粉持续积累 ,至花后 37d仍有较高的积累速率 ;重庆面包麦乳熟期(开花后 32 d之后 )蛋白质积累较宁麦 9号和苏麦 6号快 ,而宁麦 9号乳熟期蛋白质积累几乎停止     

耐低钾基因型水稻成熟期籽粒淀粉与蛋白质含量变化

以2个耐低钾基因型水稻N18,N19和1个低钾敏感型水稻N27为材料,在缺钾条件下,分析耐低钾基因型水稻籽粒在成熟期淀粉含量、蛋白质含量的变化。结果表明：在不施钾肥即缺钾条件下,耐低钾基因型水稻籽粒中总淀粉含量较低钾敏感型的略有增加,且直链淀粉含量占总淀粉含量的比例低于钾敏感型;耐低钾基因型水稻籽粒中可溶性蛋白质含量也较低钾敏感型的高,但是钾元素的含量差异并不明显。     

The Effect of the Amount of Nitrogen Fertilizer on Starch Metabolism in Leaf Sheath of Japonica and Indica Rice Varieties during the Heading Period

Abstract

The effects of the amount of nitrogen fertilizer on the starch metabolism of rice leaf sheath during the heading period in the japonica rice variety, cv. Nipponbare were compared with those in the indica varieties, cv. Tetep and Johna. The rice plants were grown under a low- (similar to the standard nitrogen level in paddy field) or high-nitrogen condition, and the starch content of the second leaf sheaths below the flag leaf was analyzed from the second leaf stage (growth stage 1) until 21 days after the heading (growth stage 7). The starch content of the plants grown under the high-nitrogen condition at the heading stage (growth stage 4) was lower than that under a low-nitrogen condition in all the varieties. The decrease in the activity of starch branching enzyme (SBE) was considered to be important for the repression of starch accumulation under a high-nitrogen condition. Under the high-nitrogen condition, Nipponbare accumulated more starch in the second leaf sheath than indica varieties at the heading stage. However, the phenomenon could not be accounted for by the activities of AGPase and SBE. Semi-quantitative RT-PCR analysis suggested that the lower activities of SBE in the second leaf sheath under the high-nitrogen condition may be due to, at least in part, the decrease in the expression level of RBE4.     

Effects of Weak Light on Starch Accumulation and Starch Synthesis Enzyme Activities in Rice at the Grain Filling Stage

Photosynthetic product in rice plant is transported to grains mainly in the form of sucrose. Sucrose in the grains eventually becomes starch through a series of enzymatic reactions [1-2]. The starch weight accounts for 90% of the brown rice [3-4], so the course of the rice grain filling is the biochemical process in which starch is mainly formed, and the factor of light is indispensable at the course. Much research has been conducted to study the influence of the light on the grain starch synt…     

Difference in the Physical Properties of White-Core and Non-White-Core Kernels of the Rice Varieties for Sake Brewing is Unrelated to Starch Properties

Abstract

This study was designed to determine whether or not the difference in the physical properties between white-core and non-white-core kernels of the rice varieties for sake brewing is associated with their starch properties. We used two rice cultivars for sake brewing, Senbon-nishiki and Yamada-nishiki, from three different plots in Hiroshima prefecture. Hardness values of kernels were significantly higher in non-white-core than in white-core kernels in both varieties. Vickers hardness (VH) values were lowest at the center of the kernel in both types of kernels. VH values of white-core tissues of white-core kernels were significantly lower than those of corresponding tissues of non-white-core kernels. No significant differences were observed between the two types of kernels in VH values of the surrounding translucent tissues and in the starch properties (amylose content, pasting properties analyzed using a rapid viscoanalyzer and gelatinization properties analyzed using a differential scanning calorimetry). These results suggest that the difference in physical properties between the two types of kernels of the rice varieties for sake brewing are associated with the difference in structure of endosperm cells and not in starch properties.