Studies On Regulation Technology Of Lodging Resistance In High Quality Edible Rice

The experiments with Zhong-100 and Zhong-1 as high quality edible rice varieties are conducted to research lodging resistance by different Nitrogen levels and plant growth regulator (PGR) treatments ,with which Xiang-28 and Xiang-1O are taken as control varieties. The N.P.K content of plants~ characters of culm~. strength to break and lodging index~. activity of Phenlalanine ammonia lyase(PAL) and Peroxidase.. economical characters and yield by all treatments are reported. 1. PGR can reduce plant height about 5-10cm and culm length about 0.5-lcm,It can also widen the leaves and improve the plant shape. It benefits to prevent lodging. By 3 levels of Nitrogen treatments PGR can increase strength to break of culm greatly, and the strength to break decreases with nitrogen increase. 2. Activity of PAL and Peroxidase which help to synthesize Cellulose and Nigose is affected by different treatments. The PAL of 2nd and 3rd culm from the base in Zhong-1 00 by PGR treatment is higher than the control. Activity of PAL of root and culm of Zhong-l decreases with Nitrogen increase. Activity of PAL and Peroxidase by PGR treatments are higher than the control. 3. By 3 levels of Nitrogen treatments nonstructural carbohydrate content( especially to glucide content) at middle and late stage can be improved obviously with PGR treatment. It can absorb water and keep stem full and increase strength to break. 4. The Nitrogen content is the highest at tilling stage. The Nitrogen content and the ratio of N/P205 in the stem & sheath increases with Nitrogen use.. At harvest stage, the ratio of N/P205 is about I .8-2.5,the lodging problem is not serous when ratio of N/P205 below 1.8-2.5 .The ratio of N/P205 at harvest stage is regarded as index that can judge whether the fertilizer is too much. 5. The beginning of elongation stage is suitable time for PGR use. It can increase ti1lers~ improve effective panicle number and ear-bearing percentage. However, the effect by heavy Nitrogen treatment the result is more obvious. 6. Zhong-100 and Zhong-1 by PGR treatment can increase yield in different Nitrogen treatments. Yield increase can attribute to effective panicle number .. seed-setting percent and 1000-grains weight increase, effective panicle number can increase 30 X i04/hm 2 seed-setting percent can improve 5-10 points,1000-grains weight can increase 1-1.5g. PGA can induce Carbohydrate to grains and improve harvest index obviously. Postgraduate Zhiyuan Huang (Crop cultivation & Tillage) Directed by Professor Yingbin Zou Professor Xianguo Qing...