杂交水稻栽培特性研究

作者系统研究了杂交水稻“四优2号”、“汕优2号”等的秧苗素质、分蘖特性、根系发育、叶组、结实率、叶、根与产量构成因素之间的关系以及高产群体动态结构。并进行生产技术考察、高产验证和推广,普遍获得增产。

A STUDY ON THE GROWING CHARACTERISTICS OF THE HYBRID RICE

This paper studied the seedling quality, tillering characteristics, root development, leaf groups and grain development, relationship between leaf-root and yield, yield components, and the dynamic structures of rice population on hybrid rice "Siyou 2", "Shanyou 2", "Shanyou 3"etc. in 1976-1982. Results were summarized as follows: 1. There dominant characters appeared in the hybrid rice, i.e., vigo rous ti1lers, flourishing root systems and larger panicle-spikelets. Seedlings of multiple-tiller laid the foundation of these three preeminment traits. In comparison with single culm, the seedling of multiple tillers excelled in the economic use of manure and seeds, large rooting multiple, greater diameter of culm, higher spikelets per panicle. 2. The negative partial correlation of the hybrids between the modal position of the main stem and the number of ears was significant. The yield of tillering panicle in 2 0 and 3/0 nodes amounted to 49% of the total yield. The correlations were close between tiller growth and carbon nutrition, nitrogen nutrition respectiAely. 3. Hybid rice presented larger panicle and more multiple spikelets than the normal rice varieties, but the percentages of filled grains were less, owing to the decrease of photosynthetic rate after heading. Thus the allotment of nutrinets became less, and more multiples appeared in weakly spikelets per panicle. However, the number of filled grains increased with the full sunlight, optimal temperature, and humidity after heading. The grain filling development was seriouly influenced either by high temperature or low temperature, especially 35 C maximun temperature above or daily temperature below 230 Cc. at bloonmig stage. 4. plants of hybrids "Shan-you 2 "and "Si-you 2 "had culm diameter, volume, dry weight of roots and the density of superficial roots larger than those of normal rice cultivars. However, the hybrid plants showed that the maximum rooting per day at climax were about the time of highest tillering activity. The highest daily sap bleeding coincided with the greatest tiller development. Then some of the tillers died, making the total number of tillers decline. The dry weight of roots increased up to the booting stage. Daily sap bleeding occurred in dough stage as the secondary summit bleeding. Irrigated field plots with water layer at early growth stage, and field maintenance of weteess here-after promoted flourishing root systems. Larger panicles multiple spikelets and higher percentage of filled grains were also induced. 5. From the data obtained in this study, the leaves on the main stem are classified according to their functions under the following four categories. The leaves 1/0-3/0, that emerged at the seedling stage, greatly influenced the quality of seedling. Leaves 4/0-9/0 (10/0) that emerged at the tillering stage, affected the number of tillers and panicles. Leaves 1/0 (11/0)-12/0 (13/0) that emerged at the time of stem elongation affected the internodal dry weight and the number of grains per panicle. Leaves 13/0 (14/0)-15/0(16/0) that emerged at the stage of panicle differentiation influenced the percentage of filled grains and kernel-weight. 6. The index of temperature summation of growth-development on hybrid rice was 36.09 at the panicle initiation stage, 56. 54 in the reduction division stage, and 68.9 in the heading stage. 7. Results of analysis showed that the partial correlation between the yield and the sum total of grains was significant. However, statistical analysis showed that the sum total of grains of both "Shan-you 2 "and "Si-you 2 "hybrids depended upon the numbers of available panicles multiplied by the basic number of grains per panicle. According to the data obtained in this study, we propose that the seedling numbers, tillers, and panicles of the dynamic structure of high yield field fall under the ratio of 1:3:2.