直立穗型水稻研究进展

The Research Progress on Erect Panicle Type of Rice

对不同穗型水稻穗功能、穗部性状和穗型遗传及直立穗型水稻群体生理生态等特性进行了综述。结果表明 ,不同穗型水稻穗的光合能力均较弱 ,可视为非同化器官 ,但当穗部光照条件变劣时 ,籽粒成熟率和千粒重明显下降 ,直立穗型品种下降幅度更大 ;不同穗型水稻1、2次枝梗及其着生籽粒在穗轴上的分布规律相似 ,直立穗型水稻结实率偏低主要是因为中下部2次枝梗籽粒结实率相对更低造成的 ,选择1次枝梗籽粒比率较高、2次枝梗籽粒主要分布在穗轴上部的直立穗型水稻品种有利于提高其结实性 ;目前发现的水稻穗型基因都是主效核基因 ,且有显性和隐性之分 ,直立穗型基因具有一定的多效性 ,往往导致性状变异的相互关联 ;直立穗型水稻群体光照及温度、湿度、CO2 浓度等生态条件较为优越 ,故生育后期叶面积指数(LAI)衰减较慢 ,群体光合速率(CAP)高值持续期长。因此 ,直立穗型水稻群体物质生产能力较强 ,生物产量较高 ,这是其最终经济产量较高的物质基础。

The physiological and ecological properties of different panicle type rice were overviewed,the different panicle function,charˉacter and heredity were also surveyed.It showed that the panicle had little photosynthetic capacity and posited as non-assimilating organ.The rate of maturity and seed weight of the erect panicle type detracted obviously when the intensity of illumination weakened,and they were lower than the curved one.The reason of low seed rate of erect panicle was the second ramifications'seed rate being lower relatively.Higher seed ratio in the first ramifications and the spike-stalk of the second ramifications was important for more seeds on panicles.Rice panicle type is controlled by major nuclear genes,which can be divided into two types,dominance and recesˉsives.The gene of erect panicle type has certain pleiotropism,which can be interrelated to the properties variation.The illumination,temperature,humidity and concentration of CO 2 in the erect panicle type population are superior to the curved one,and the LAI has relatively slower attenuation in the anaphase and has a longer high CAP period.So the erect panicle type population has a bigger dry material production capacity and higher biological yield,these are the physical basis of high economic yield.