Screening and evaluation of heat tolerance during the germination stage in Ting's rice
The study subjected 20 Ting's rice varieties,including P0340,CII141,and R289 were treated with high temperature stress during seed germination,normal culture was used as control,10 key germination indexes such as germination potential,germination rate,and root and shoot length were measured.By using the membership function comprehensive evaluation method and grading evaluation value,the heat resistance comprehensive evaluation was carried out.Meanwhile,correlation analysis,regression analysis and cluster analysis were carried out,combined with the determination of hydrogen peroxide(H2O2)and malondialdehyde(MDA)and the activity analysis of superoxide dismutase(SOD),catalase(CAT)and peroxidase(POD),the differences of growth indexes and physiological indexes of different rice varieties at germination stage were discussed,so as to screen rice varieties with strong heat resistance.The results showed that after high temperature treatment,the growth indexes such as germination potential of rice were different between varieties and treatments.In terms of heat resistance comprehensive evaluation,P0340 ranked first,showcasing strong heat tolerance,while Y595 ranked last,indicating weak heat tolerance.Correlation analysis and regression analysis established that germination rate and seedling dry weight could be used as important indexes for heat resistance identification.According to the cluster analysis,the heat resistance of the rice varieties tested was divided into 5 categories:extremely strong,strong,medium,weak and extremely weak.Among them,the variety with strong heat resistance was P0340,the varieties with strong heat resistance were CII141,R289,and Y1544,10 varieties with medium heat resistance included R107 and Δ133,etc.,and 5 varieties with weak heat resistance included PII140 and PII21,etc.The very weak heat resistance variety was Y595.In terms of physiological indexes,compared with control,under high temperature stress,H2O2 and MDA contents of P0340 increased less,the difference was not statistically significant(P>0.05).The activities of SOD,CAT,and POD in P0340 significantly increased compared to the control(P<0.05).These findings suggest that P0340 displays strong heat tolerance during the germination stage,characterized by minimal accumulation of reactive oxygen species and enhanced antioxidant capacity.In conclusion,the identification of the high heat tolerance rice variety P0340 in this study offers a valuable genetic resource for the development of new heat tolerance varieties.
万方数据
维普
