Studies On Ratooning Characters Of Axillary Buds Of Series Combinations From Peiai64S

In this study, four two-line hybrid combinations whose female parents are PeiAi64S were used. They are PeiAi64S/E32, PeiLiangYou500, PeiAi64S/B52 and LiangYouPeiJiu respectively. The growth and developmental properties and ratooning properties were studied. The main results are as follows:1. As for the whole yield of two crops. PeiAi64S/E32 was highest, PeiAi64S/B52 was second.2. The order of the contribution of yield components to yield of ratooning rice was: number of effective panicle>spikelets per panicle>seed setting percent>1000-grain weight.3. Yield components of main crop could affect on ratooning rate: Positive correlation existed between number of effective panicle, 1000-grain weight and ratooning rate respectively; Negative correlation existed between spikelets per panicle, seed setting percent and ratooning rate respectively.4. The source-sink properties of main crop could affect on ratooning rate: Positive correlation existed between LAI of booting stage, export percentage of the matter in stems and sheaths and ratooning rate respectively.5. Increasing tiller-bearing percent is advantageous to enhancing ratooning rate and yield of ratooning rice.6. Roots in ratooning crop consist of roots of main crop and ratooning roots, and ; roots of main crop is the main part. Ratooning roots mainly come from ratooning tillers of lower nodes. Higher stubble was advantageous to recovery and maintenance of root vigor of main crop; Lower stubble was advantageous to production of ratooning roots. When stubble was 10 cm, the percentage of ratooning roots to the whole roots was 34.38%.7. In vivo, the ratooning rate of axillary buds from different nodes showed (from the top): the 2nd > the 3rd > the 4th > the 5th. But in vitro, the trends above was uncertain , and the difference between nodes became smaller. In vitro, leaf number per culm became more; and the lower node was, the more increase was. In vitro, the plant height, the panicle length and grain number per panicle distinctly increased from upper nodes to lower ones, and the difference between nodes was bigger than that of ratooning rice in vivo. The dependence of upper nodes' axillary buds in vivo to nutrition matter in stem and sheath was bigger than that of lower ones, and the limit of nutrition supply to development of lower nodes" axillary buds was bigger.