Correlated Study On Physiological And Biochemic And Clustering Analysis Of Heat Tolerance Of Medium Hybrid Rice

Rice is one of the most important food supplies in the world,there are about half of people as the main food around the world,especially in developing country,rice is very important for social stabilization and economic development.However,with the rapid globalized industrialization resulting in greenhouse effect and temperature rising,high temperature has already become one of the main disastrous factors in crop production.In this study includes combining physiological research with yield characters analysis and molecular genetic research with 37 Medium Hybrid Rice main from Anhui province and other planting regions of south of China,in order to carry out the heat tolerance research.Its main results showed as follows:1 28 Medium Hybrid Rice were grown under high temperature stress,the results of main agronomic characters showed that the seed setting rate was declined under high temperature stress than control.There were differences among different varieties, Lvyou No.1,Gangyou3551,Wandao 153and Liangyou6326 had higher temperature tolerance,however,Tianxie No.1,Xieyou009 andⅡyou7954,were sensitive to higher temperature.2 Physiology and biochemical character research with 8 screened three kind of Medium Hybrid Rice,the results indicate:(1) High temperature stress decreased the chlorophyll,soluble sugar and polyamines content in rice leaves and the decrease amplitude was remarkably correlated with heat susceptibility index(HIS)(r=0.903^**; r=0.722^**;r=0.852^**,0.948^**);increased proline and malondialdehyde(MDA) content. The proline increase amplitude was remarkably negatively correlated with HIS(r=-0.779^**);The MDA increase amplitude was remarkably positively correlated with HIS(r=0.842^**),there were difference between varieties.Better heat tolerance varieties,the The chlorophyll,soluble sugar,soluble protein and polyamines content decrease amplitude was smaller,proline increase amplitude was bigger,MDA increase amplitude was smaller;thus these physiological indexes can be used as the physiological index for heat tolerance determination of rice.(2) Hybrids behave the similar change trend on physiology and agronomic characters,Hybrid heat tolerance had direct relations with parens.Parents had different influence on different varieties and different physiology and biochemical indexes,during different growth stage, Parents has different influence on Hybrids.(3) At the vegetative growth stage,high temperature stress decreased chlorophyll content and the difference was significant at the booting stage(p＜0.05),decreased the soluble sugar content and the difference was remarkable(p＜0.01) at vegetative growth stage and booting stage,decreased proline, soluble protein,malondialdehyde(MDA) and the difference was significant or remarkable at each growth stage,decreased Spermine content and the difference was significant or remarkable at at booting and flowering stage,but Putrescine content change was insignificant,it can't be used as physiological index for heat tolerance determination of rice.At booting stage and flowering stage the temperature was very high,it would significantly reduce the yield of rice.3 17 Medium Hybrid Rice were clustered 5 groups by screened 10 pairs of RAPD primers and 26 pairs of SSR primers,varieties had higher heat tolerance were clustered in the same group,the result was in accordance with physiological and biochemical analytic results.