STUDY ON THE RELATIONSHIP BETWEEN SOURCE AND SINK IN DIFFERENT JAPONICA RICE VARIETIES I. THE CHARACTERISTICS OF SINK-SOURCE AND DIVISION OF CLASSIFICATION IN DIFFERENT JAPONICA RICE VARIETIES
Under field experimental condition characteristics and classification between sink and source of several main rice varieties from Liaoning and Jilin province were studied by means of leafcutting and of reducing the number of flowers. The results showed that the varieties tested could be divided into four types on the basis of the sink-source under intermediate level of fertilities (7.5 kg N/mu): ① the sink-limited type (Xiu Za and Qiu Guang), ② the source-limited type (Liao Jing 5 and Shen Nong 522-3), ③ the source-sink-harmonic type (S22), and ④ the source-sink saturated type (Qing Xi 96). Among the four types, varieties within the first type had the highest in seed-setting rate, harvest indexes and yield. Both seed-setting rate and harvest indexes of varieties of the second type were the lowest, although the number of the grains Per panide and the number of flowers per unit area were higher. Seed-setting rate and harvest indexes in the varieties of other types were between those of the first and of the second.