Studies On Productivity And Compensation Of Main Stem Nodes Of Rice

The rice culture is a population culture, which is made of the individual, and the productivity of every plant is based on the yield factors of different main stem nodes. In order to adjust the population structure, it's necessary to know the quantity change trendency of nodal productivity. Recent years, the study on individual plant trend to the node, approaching on the nodal productivity in different points. It is necessary to analysis the adjusting method, the change trend of yield component factors and the transform of physiologic indices to increase yield by applying the productility of different nodes of main stem.Two hybrid rice cultivars, one characterized by a more tillering ability such as Xinongyou 1 and the other cultivar characterized by a middle tillering ability such as Gangyou 725, were used for the experiment to study the productive characteristic. The results showed that if transplant the bigger seedlings with tillers, there would be four nodal groups which were nodal group of seeding plot, transition nodal group, superior nodal group of field and inferior nodal group. The superior nodal group of seeding plot characterized by the most seed-bearing tillers and the more spikelets number per panicle, while the superior nodes of field characterized by the most spikelets number per panicle and the more seed-bearing tillers. The nodal seed-bearing tiller of Xinongyou 1 was in a negative correlation with the nodal spikelets number per panicle, while those of Gangyou 725 were in a positive correlation. The first contribution for yield was the nodal group of seeding plot, second was the superior nodes of field, then was the inferior nodes and finally was the transition nodes.In the field, the first one and the first two nodal position tillers were artificially removed, which were practiced for middle and later occurred tiller respectivily, to study the compensation capacity of rice plants, and the common treatment was the CK. The result showed that middle and later occurred tiller treatments made the seed-bearing tillers diminished a little, the useful tiller position shifted higher , and the seed-bearing tillers of high-nodes increased, especially the Xinongyou 1, while the spikelets number of Gangyou 725 increased, and the seed weight increased a little. The yield of the middle occurred tiller was no variance with the CK significantily, while the treatment of the later occurred tiller declined the yield most significantly.Studied on some physiological indices of the above treatments of Xinongyou 1, the results showed that the content of chlorophyll, soluble sugar, starch, amino acid the root vigor of the earlier occurred treatment were high at first, then declined, and became to the lowest at late growth, while those indices of the middle and the later occurred treatments were lower than the CK, then rose at the middle growth, and the indices of later occurred treatment were high at late growth. In the senescent indices, the enzyme activities of CAT and POD showed that the plants which first became old were treatment of the earlier occorrde tiller, then the middle occurred, and the last was the later occurred tiller.