穗上不同部位籽粒的稻米垩白度差异的研究

两年的试验结果表明：同一穗上不同部位的籽粒的稻米垩白度存在着显差异，强势粒的垩白度一般小于弱势粒；穗上不同部位米粒的垩白度与谷粒粒重呈负相关趋势；始穗期施氮肥对稻米垩白度的影响因品种不同而异。我们认为，在本试验条件下，灌浆物质不足至少是垩白发生的原因之一。

A STUDY ON THE DIFFERNCE IN THE CHALK DEGREE OF THE GRAINS IN A PANICLE

The results of two year's,experiment showed :there were remarkable differences in thechalk degree of the grains in various positions in a same panicle;the chalk degree of the domi-nant grains was usually smaller than that of the weak grains;there was a tendency that thechalk degrees of the grains in ifferent positions in a paulcle were negatively correlated with thegrain weights;the influences by application of N fertilizer at the beginning of heading variedwith varieties.The authors hold that under the conditions of this experiment the insufficiencyof filling matter is at least one of the factors causing chalkinees.