前期施氮对二系杂交水稻分蘖及其成穗的影响

Effects of Nitrogen Application During Early Growth Stage on the Tillers and the Tiller-Panicle Turnover Rate of Two-Line Hybrid Rice

水稻生长前期施氮量与单株分桑数的正相关极显著、与单株有效分美数的正相关显著．前期施氮水平高，则分前终止期延迟施氮水平对分醒始期的影响甚微分率是否有效，决定于分率抽出的时间，与施氮量无关前期施氮可以改善有效分美的稳粒性状，但随着施氮量的增加，分集中后期的无效分迅数显增加。

A very signihcant positive correlation existed between the nitrogen application amount andthe number of per plant tillers. The result also showed a significant positive correlation between the nitrogen application amount and the effective tiller number per plant. When the nitrogen application amountwas higher the date of the tillering termination was prolonged. The level of nitrogen application had a little effect on the initiation of tillers. It depended on the time of tiller emergence when a tiller came to bean ear bearing panicle (EBP). No relationship was found between the nitrogen application amount andthe change of EBP from tillers. Nitrogen application during the early growth stage could improve the characters of the EBP. However, with the increment of nitrogen application, there were an incrase of the invalid tillers produced from the middle to the late stages of growth and a decrease of tiller EBP tumover rate.