Analysis of dry matter translocation during grain filling stage of rice - focusing on the cellular contents and cell wall materials.

摘要

To clarify the translocation pattern of photosynthetic products, and the effects of crop growth rate (CGR) and reserve substances before heading on the dry matter accumulation in the panicle during the grain filling stage, the dynamics of dry matter in rice cultivars Nipponbare (japonica), Zhongyou No. 3 (indica) and Shanyou 63 (hybrid rice variety) grown at the paddy field of Shinshu University in central Japan were examined. The dry matter in the stover and panicle was divided into two fractions: (1) cellular contents (CC) that could be degraded by crude enzymes ( alpha -amylase and proteinase) and (2) cell wall materials (CW) that could not be degraded. The dry matter accumulation rate in the panicle was related to CGR in Nipponbare and Zhongyou No. 3, and to the rate of dry matter translocation from stover to panicle in Shanyou 63. The accumulation rate of CW in a stover was related to CGR of all cultivars. The maximum rate of translocation from stover to panicle was observed earliest in Nipponbare, followed by Zhongyou No. 3 and Shanyou 63. The maximum panicle growth rate was observed earliest in Zhongyou No. 3, followed by Nipponbare and Shanyou 63. The rate of dry matter accumulation in the panicle during the early grain filling stage was lowest in Shanyou 63. The dry matter accumulation rate in the panicle was higher in the late grain filling stage than in the early grain filling stage. Thus, Shanyou 63 was suggested to have a lower ability to degrade stored compounds in the stover or have a higher content of water-soluble materials.