Abstract:

【Objective】 This study was aimed to analyze the difference of source-sink components in conventional indica rice cultivars with different panicle weights（PW）and to provide valuable information for the cultivation and genetic improvements of lager PW cultivars. 【Method】 Eighty-eight and 122 conventional indica rice cultivars were solution-cultured in 2001 and 2002, respectively. Leaf area index (LAI),dry matter weight (including root, culm and sheath, leaves, panicle), nitrogen content in different organs, yield and its components were measured. Based on PW, these cultivars were classified into 6 types from low to high by the MinSSw method, to study their difference in source and sink components. 【Result】 LAI and green leaf weight at heading and maturity stages, leaf weight per unit leaf area in large PW types of indica rice were superior to those of cultivars with small PW type, however, decline rate of LAI during grain filling period was lower in large-PW cultivar. Elevation LAI could improve PW; Cultivars with large PW showed higher net assimilation rate during grain filling period, and sink potential, grain yield per unit leaf area, sink potential per unit leaf area, sink potential per unit dry matter weight and sink potential per unit N accumulation at heading stage were also higher in cultivars with large PW than those of cultivars with small PW type, enhancing PW could improve sink potential, PW was significantly influenced by green leaf weight at heading stage, net assimilation rate, sink potential per unit area, sink potential per unit leaf area, sink potential per unit N accumulation and grain yield per unit leaf area. 【Conclusion】 LAI, sink and their respective components in large PW types of indica rice were superior to those of cultivars with small PW type. PW was significantly influenced by source traits including green leaf weight at heading stage, net assimilation rate, and sink traits including sink potential per unit area, sink potential per unit leaf area, sink potential per unit N accumulation, grain yield per unit leaf area.

Key words: conventional indica rice, cultivars, panicle weight, source, sink