促芽肥施用量对杂交中稻再生力的影响与组合间源库结构的关系

Effect of the amount of N application for bud development on the ratooning ability and in association with ratio of source to sink in mid-season hybrid rice

为研究杂交中稻组合间再生稻高产对促芽肥需求量的差异性。以25个杂交中稻组合为材料，通过促芽肥施用量与剪穗叶处理，研究了促芽肥施用量对杂交中稻再生力的影响。头季稻齐穗期组合间着粒数与单茎的叶重、茎鞘干物重呈极显著正相关，与叶粒比和茎粒比呈极显著负相关。头季稻着粒数越多的组合，其满足头季稻高产后剩余的光合产物量越少；头季稻着粒数较高的品种蓄留再生稻高产需要施用的促芽肥量更高。但当头季稻剩余的光合产物量过多或过少时施促芽肥对再生稻都没有显著增产作用。着粒数130～160粒的组合，以每公顷施促芽肥150kg尿素为宜；着粒数170～200粒的组合，以每公顷施促芽肥300kg尿素为佳；着粒数210—2．50粒的组合，每公顷施尿素应高于300kg，但其具体施用量尚有待进一步研究。再生稻高产的促芽肥需求量与头季稻组合间着粒数呈极显著正相关关系。

The objective the present study was to determine the difference of the amount of N application for bud development（NABD） among genes of mid-aeasen hybrid rice. Effect of the amount of NABD on the ratooning abiliy under the amount of NABD and cut leaves and spikelets treatments was investigated using 25 mid-season hybrid rice combinations. At full heading of main crop, there existed highly significant positive correlations between the apikeleta per panicle and dry weight of leaves and stem-sheath per stem,and highly significant negative correlations between the apikeleta per panicle and ratio of leaves to grain and stem to grain respectively. The more spikelets were set on per panicle,the leas photosynthetic matter remained in the basic stems for ratooning rice growth at harvest of main crop. Therefore when ratooning rice is to be cultivated with varieties having many spikelets per panicle of main crop, more amount of NABD will be needed. But the effect of NABD on increasing grain yield of ratooning rice were little when photosynthetic matter remained in the basic stems were very high or low. The varieties of 130 - 160 a,170 -200 spikeleta,210 -250 a were set on per panicle,their best amount of NABD were respective 150,300 and 300 kg above urea per hm^2. There were highly significant positive correlations between the amount of NABD for high yield of ratooning rice and the apikeleta per panicle of main crop.