The Preliminary Study On Methods For Determination Of Rice Seed Vigor

Rice is an important food crop in China.Seed vigor,as an important index to measure seed quality,has always been a hot research topic in seed science.At present,the standard germination test is still the main method for the determination of rice seed vigor.In this paper,64 varieties of seed samples were used as the research object.Seedling growth,adversity germination,related physiological indexes were determined,simultaneously,standard germination tests and field emergence tests were carried out.Correlation analysis was used to determine the more suitable method for determining the vigor of different types of rice seeds.A scientific basis for the development of rice seed vigor measurement standard was provided this paper.The main conclusions are as follows:1.Evaluation of seed vigor test methods for different types of rice(1).Evaluation of methods for determination of seed vigor of japonica conventional rice: These indicators including root length on the 6th day of seed germination,the stress germination rate of seeds treated with 15% PEG,1.0% NaCl,high temperature 35-38?,drowned for 5 days,45? aging for 48 h,the electrical conductivity and content of soluble sugar at 24 h after seed shelling soaked.?-amylase,CAT enzyme activity,MDA and Pro content in embryo after germination 3 days,can be used as the index of seed vigor determination.(2).Evaluation of methods for determination of seed vigor of indica conventional rice: These indicators including root length on the 6th day of seed germination,the stress germination rate of seeds treated with 15% PEG,1.0% NaCl,high temperature 35-38?,drowned for 5 days,41? aging for 96 h,low temperature 10?-30?,and the content of volatile aldehydes during seed germination,can be used as the index of seed vigor determination.(3).The validation of candidate indices in the determination of seed vigor of hybrid rice: These indicators including root length of the third day of seed germination,the stress germination rate of seeds treated with PEG,1.5% NaCl,high temperature 35-38?,can be used as an indicator of seed vigor determination.Based on the above methods for determination of seed vigor,the methods of root length,drought stress,salt stress and high temperature stress can be recommended as methods of vigor determination in rice seed,especially the method of root length,whose experiment is simple,rapid and accurate.2.Seed vigor evaluation for different varieties of riceHigh and low vigor varieties were screened out by standard germination test and field seedling emergence test.The high vigour varieties of japonica conventional rice were "Jia hua 1","Huai dao 5","Nan jing 44","Yan feng 47","Zhe jing 88" and "Xiu shui 05",while the low vigor varieties were "Huai rice 10","Jing jing 8","Yun jing 31","Shen nong 265" and "Zhen nuo 19".The high vigour varieties of indica conventional rice were "Jin zao 47","Zhen zhu nuo","Yang dao 6","Dian tun 502",and "Hong you 4",while the low vigor varieties were "Jin xiang nuo","San jiang 2","Nong le 1" and "Tong nian 1".The varieties with high vigor of hybrid rice were "Yong you 9","C liang you 0861" and "Zhong zhe You 1",while the low vigor varieties were "Zhong you 838","Yong you 15" and "Chun you 927(Zhe)."...