| In2010～2011, field experiment was conducted using four regulation techniques, isotope tracer technique, erasing redundant buds technique, node-cuttage and chemical control technique, to study the ratooning properties of axillary buds from different nodes under conditions of natural matrix (in vivo), node cottage (in vitro) and one-bud-retention matrix, and effect of hormone treatment on ratooning properties of axillary buds from different nodes under matrix condition. The main results are as follows:1. Comparative study on the ratooning characteristics, matter production and distribution between ratooning rice and its main crop showed that:plant height, panicle length, LAI, dry matter weight per plant, yield and grain number per panicle of rationing rice was about1/2,2/3,1/8,1/5,2/5and1/3of that of main crop, respectively. Comparing to main crop, photosynthesis rate, root activity, the transportion percent of starch in stem and sheath, and specific leaf weight of ratooning rice were higher, while1000-grain weight, crop growth rate was lower, chlorophyll content, the transportion percent of solube sugar in stem and sheath of ratooning rice were lower. Net assimilation rate and ratio of grain number to leaf area of rationing rice were3and2.7times of those of main crop, respectively. Rice quality of ratooning rice was better than that of main crop slightly.2. Study on the ratooning properties of axillary buds from different nodes in natural matrix showed that:the number of effective panicle and seed setting rate affected yield of ratooning rice mostly. The number of effective panicles and it's contribution to yield were decreased with the decrement of node, and the2nd and3rd node from the top contributed70%to the total yield. Contents of IAA and GA3showed trend of lower-node buds> higher-node ones. Content of CTK in higher-node buds was higher than that in lower-node buds in2d～7d after harvest of main crop, the contrary trend was observed in12d～22d after harvest of main crop.3. Studied on the ratooning properties of axillary buds from different nodes in vitro showed that:the number of effective panicle and grain number per panicle affected the yield of ratooning rice mostly. LAI, dry matter weight per hill were significantly positively related with yield of ratooning rice, and chlorophyll content, photosynthesis rate and root activity were positively related with yield of ratooning rice. On the20th d after node-cuttage, length, quantity and diameter of roots were increased with the increment of node, and growth of lower-node roots was faster than that of higher-node roots. Content of IAA showed trend of higher-node buds> lower-node ones. Content of GA3in lower-node buds was higher in7d-12d after node-cuttage, while it showed the contrary trend in17d-22d after node-cuttage. Content of CTK in higher-node buds was higher on the7th d after node-cuttage, while it was showed the contrary trend in12d-22d after node-cuttage.4. Studies on the ratooning properties of axillary buds from different nodes under one-bud-retention matrix showed that:yield of rationing rice was increased with the decrement of nodes, and grain number per panicle was the most important factor affected yield of ratooning rice. Significant positive correlation between photosynthesis rate, grain-leaf ratio, LAI and yield of rationing rice existed, and positive correlation existed between chlorophyll content, root activity, specific leaf weight, dry matter weight per hill, crop growth rate, net assimilation rate and yield of rationing rice. Improvement of photosynthesis rate, grain-leaf ratio and LAI was the effective path to heighten yield of rationing nee.5. Study on effect of hormone treatment on ratooning properties of axillary buds showed that:grain number per panicle was the primary factor affected yield of ratooning rice. As for improve the yield and matter distribution, IAA2, GA3-2,6BA1and compounded agent3were the optimal hormone treatment. Yield of rationing rice showed trend of compounded agent3> IAA2>6BA1> GA3-2. Comparing to CK, the increasing extent of yield of ratooning rice from4th node from the top was biggest in hormone treatment, and that of3rd node from the top was smallest. Chlorophyll content and photosynthesis rate were significantly related positively with the ratooning yield, and LAI, dry matter weight per hill, root activity, content of total N and carbohydrate were related positively with the ratooning yield.
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