物理性限制籽粒容积对冬小麦籽粒生长的影响

Effect of Physical Restraint on Kernel Growth in Winter Wheat

在温室和大田条件下,用6个冬小麦品种,于籽粒胚乳细胞分化高峰之后,以物理性限制籽粒容积的方法,研究了粒重的增长与籽粒含水率、淀粉合成速率之间的关系。物理性限制处理改变了籽粒的形状,加速了籽粒的脱水过程,影响了淀粉的合成能力,缩短了有效灌浆期,最终降低了粒重,这是物理性限制和生理性抑制共同作用的结果,说明籽粒容积及胚乳细胞对碳水化合物的转化能力亦是制约粒重的主要因素。

Two experiments were conducted in a greenhouse and fields to evalute the effect of physical restriction of the kernel on kernel growth.The plastic restriction device(PRD)wasconstructed from a 3.45-mm diam.plastic drinking straw cut into 1.8 cm lengths.10kernel on the treated plants were placed in the PRD's and samples were taken at frequentintervals to determine kernel fresh mass,dry mass,nitrogen and carbonhydrate concentration.Einal weight(mg·kernel^(-1))of kernels from PRD's was decreased relative to control plants.Mature kernels from PRD's were cylindrical in shape and had a high N concentration.The initial kernel growth rate(KGR)of kernels in the PRD's was similar tothe control kernels,however,when the kernel mass reached contain level the KGR wasdrastically decreased and there was also a decline in kernel water content.At the sametime,the kernel lost the efficiency of biochemical processes involved in the conversion ofsucrose to starch.The data demonstrate that physical restraint has a physical nad physiological effect on the ability of kernel to accumulate dry matter.