栽培条件对水稻粒重的影响及其原因分析

Effect of Cultural Conditions on Grain Weight and It's Causes in Rice

应用3个水稻品种,设计氮、磷肥处理37个,从籽粒着生部位、谷粒体积、比重、灌浆过程、灌浆物质供应水平以及根系活力等方面,对不同栽培条件下饱粒千粒重的差异及其原因进行了探讨。(1)不同处理间全穗饱粒千粒重的极差汕优63为3.91g,Koganemasari为5.43g,9004为7.62g;(2)稻穗不同部位饱粒千粒重的提高幅度为下部枝梗籽粒大于中部枝梗籽粒,中部枝梗籽粒大于上部枝梗籽粒,一、二次枝梗趋势一致;(3)饱粒千粒重与谷壳重、谷粒体积呈极显著线性正相关,品种间表现一致,粒重与谷粒比重的关系因品种而异;(4)主要灌浆期灌浆速率越大,饱粒千粒重越高,主要灌浆期的持续时间越长,饱粒千粒重越低;(5)单位面积颖花量与饱粒千粒重呈极显著线性负相关,每朵颖花所占有灌浆物质量与饱粒千粒重呈极显著正相关;(6)提高结实期颖花根活量能显著提高饱粒千粒重,其中迟开花的下部枝梗籽粒饱粒千粒重的提高幅度明显大于早开花的上、中部枝梗籽粒,一、二次枝梗趋势一致。

Mid-maturity hybrid indica rice Shanyou 63, late-maturity japonica rice 9004 and Japanese japonica rice Koganemasari were treated in 37 nitrogen and phosphorus supplying rate and date treatments. Grain bearing part on the panicle, grain volume, specific gravity of grain, filling rate and period, root activity were investigated for analysing the cultural effect on fully-filled grain weight. Results were as follows: 1. The 1000 fully-filled grain weight in differ ent treatments ranged 3. 91g in Shanyou 63, 5. 43g in Koganemasari and 7. 62g in 9004. 2. With the raising of average fully-filled grain weight of the whole panicle, the increment of ful ly-filled grain weight in lower part of the panicle was greater than that of middle part of the pani cle , which was in turn greater than that of upper part of the panicle. The same tendency was ob served in spikelets of both primary and secondary branches. 3. Fully-filled grain weight was pos itively linearly correlated with grain volume at 0. 01 probability level in all three varieties. The re lationship between grain weight and specific gravity of grain varied with variety. 4. The higher the filling rate during the main grain filling period, the greater the fully-filled grain weight. The longer the main grain filling period, the lighter the fully-filled grain weight. 5. Fullyfilled grain weight was negatively linearly correlated with spikelets per unit area, but positively linearly cor related with the amount of filling material per spikelet. 6. Raising the spikelet-root activity in the ripening period would result in higher fully-filled grain weight. The increment of fully-filled grain weight of spikelets flowered later in lower part of the panicle was higher than that of spikelets flowered earlier in upper and middle parts of the panicle, same tendency was shown for the spikelets on both primary and secondary branches.