小苗机插大穗型杂交粳稻增产优势及形成特征

Advantages of Yield Formation and the Characteristics of Large Panicle Type Japonica Hybrid Rice Machine-transplanted with Young Seedling

为探明小苗机插大穗型杂交粳稻在淮北地区的增产优势及其产量形成特征，选用在苏中地区表现较好的大穗型杂交粳稻甬优2640、甬优2638和甬优1640为试验材料，并以当地种植面积较大的超级稻品种连粳7号、新稻18和宁粳4号作为对照，在高产栽培条件下进行比较试验。结果表明，大穗型杂交粳稻的产量显著高于中穗型超级常规粳稻品种，因为其每穗粒数较多能形成群体足够总粒数，且结实率较高。中穗型超级稻虽群体穗数较多，但因每穗粒数不够多，造成总粒数明显少于大穗型杂交粳稻，故影响到产量的提高。大穗型杂交粳稻产量形成的鲜明特点是成穗率高，中后期叶面积指数、光合势、群体干物质积累和群体生长率显著大于中穗型常规粳稻。两年试验结果显示，每穗粒数与产量的相关系数最大，其次是总颖花数。在淮北地区小麦茬田小苗机插采用大穗型杂交粳稻有显著的增产优势，增产幅度在7．68％-12．14％。

The advantages of yield formation and the characteristics of large panicle type japonica hybrid rice of Yongyou 2640, Yongyou 2638,Yongyou 1640, which had a better performance in Huaibei area, were machine-transplanted and studied under high- yield cultivation measures in 2011 and 2012, with new super rice varieties LiandaoT, Xindaol8 and Ningdao 4 grown widely in local as control. It was showed that the yields of large panicle type japonica hybrid rice was significantly higher than that of super japonica flee, because of its more grain number per panicle, and resulted enough total grain number of groups, and higher seed setting rate. For superjoponica rice, although with more panicles number, but less enough number of grain per panicle resulted less total grain number, and less yield. It has a significant characteristics that percentage of earbearing tiller, leaf area index, photosynthetic potential, growth rate and dry matter accumulation of population, were significantly greater in large panicle type japonica hybrid rice than that in mid- dle conventional japonica rice in yield formating of middle and late period, and the yields of the former is 7.68%~12.14% higher than the later in rice following wheat in Huaibei area. The research showed that the biggest correlation coefficient （0.980） exists between number of grain per panicle and yield.