结实前水分供应对寒地水稻灌浆动态和产量的影响

以垦鉴稻5号为材料,采用负压式土壤湿度计监测土壤水势,通过防雨棚内的盆栽控水试验研究了结实前水分供应对寒地水稻灌浆动态和产量影响。研究结果表明,结实前进行-8～-10kPa的间歇控水处理,垦鉴稻5号的经济产量增加;垦鉴稻5号优、劣势粒的平均生长速率(■)和最大生长速率(Gmax)值升高,中势粒表现则相反;垦鉴稻5号优、中势粒相当于生长终值百分数的I值升高,劣势粒表现则相反;垦鉴稻5号优势粒的活跃生长期D缩短,中、劣势粒的相反;垦鉴稻5号各粒位生长速率最大时的生长量(WmaxG)值增大。结实前进行-18～-20kPa和-28～-30kPa的持续控水处理,垦鉴稻5号的经济产量均极显著降低;垦鉴稻5号优势粒的■和Gmax值降低,中势粒、劣的相反;垦鉴稻5号各粒位的I值升高、活跃生长期D缩短、Wmax.G值增大。

Effects of Water Supply During Stage of Before-heading on Filling Dynamics and Yield of Rice in Cold Regions

With Kenjian 5Rice as experimental materials,the effects of water supply during the stage of before-heading on filling dynamics and yield of rice in cold regions were studied with pots under rainproof shelter.Water dynamics in the pots were monitored by examining soil water potential(SWP)using negative pressure soil moisture tensiometers.The results indicate that intermittent irrigation at SWP between-8～-10kPa increased economic yield of Kenjian 5Rice significantly,along with increases of average growth rate(■)and maximum growth rate(Gmax)of the superior grains and inferior grains and decreases of ■ and Gmaxof the middle grains.The index I values of superior grains and middle grains were improved,despite those of the middle grains.The growing active days(D)were shortened for the superior grains,while elongated for the inferior grains and middle grains.The weight per 1 000grains(WmaxG)was increased for all the three grades of the rice grains.On the contrary,with unremitting irrigation at SWP between-18～-20kPa and-28～-30kPa during the stage of before-heading,economic yield of Kenjiandao 5were significantly reduced,indicating by increased ■ and Gmaxvalues for the superior grains and decreased ■ and Gmaxvalues for the middle grains and inferior grains,and raised I values,shortened Dand increased Wmax.Gfor the grains of all the three grades.