Establishment of rapid screening techniques for shade-tolerant rice(Oryza sativa L )

The high potentials of rice production are directly limited by light stress(shade)．Establishing rapid screening techniques for shade-tolerant rice varieties can help to solve this problem．Three rice(Oryza sativa L．)varicties，02428，Nanjing 35 and Sunong 3037，were used to compare the indexes for selecting shade-tolerant rice varieties．The results showed that the green-leaf keeping ability of 10-day rice seedlings under darkness of 7 days is identical to the declining of dry weight and chlorophyll contents of the rice seedlings under low-Light intensity，and also consistent to changes of chlorophyll contents and net photosynthetic rates of rice leaves from tiller to elongation under shading，and comparable to the net photosynthetic rates of flag leaves under transient lower light intensity．Thus，the green leaf-keping ability of rice seedling under darkness could he used to set up a rapid technique for selecting shade-tolerant rice germplasm．