Effects Of Drought Stress And Rehydration On The Growth And Development Of Different Varieties Of Fagopyrum Tataricum

With the drought-tolerant F.tataricum(Diqing)and drought-sensitive F.tataricum(Heifeng1)as the experimental materials,the pot experiment combined with artificial water control,dealing with water treatment and the two varieties treatment,was carried out to investigate the effect of drought stress at different periods and re-watering on the indexes of different drought-tolerant varieties F.tataricum,such as morphology,physiology and yield,thereby providing the theoretical basis for the cultivation of drought resistant and water-saving F.tataricum with big yield.The main findings are as follows:(1)Under drought stress at seedling,flowering and mature period,the indexes of F.tataricum plant height,stem diameter,leaf area,shoot dry weight,main root length(Heifeng1),average root diameter,root surface area,root volume,root dry weight,root activity,chlorophyll content,IAA content,grain weight per plant,hundred grain weight and yield were lower than under normal water treatment;Compared with normal water supply treatment,the content of main root length(Diqing),MDA content,SOD activity,POD activity,soluble sugar content,free proline content and ABA content were all increased.Therefore,it can be seen that all indexes were affected by drought stress.Drought stress at seedling stage had a great impact on POD activity of F.tataricum,while drought stress at flowering stage had a great impact on shoot dry weight of F.tataricum.But drought stress at maturity stage had a great impact on POD activity of Diqing,and also had a great impact on chlorophyll content of Heifeng1.(2)Under re-watering treatment at flowering and mature stage,the indexes of F.tataricum plant height,stem diameter,leaf area,main root length(Heifeng1),average root diameter,root surface area,root volume,root dry weight,root activity,chlorophyll content,IAA content,grain weight per plant,hundred grain weight,yield were higher,compared with continuous drought stress treatment increased;The content of main root length(Diqing),MDA content,SOD activity,POD activity,soluble sugar content,free proline content,ABA content were lower,compared with the treatment of continuous drought stress.All indexes have recovered in different degrees after rehydration,and the recovery effect of stem and shoot dry weight of Diqing and Heifeng1 per plant grain weight after rehydration in flowering stage was the best for,while under rewatering at mature stage,the recovery effect of Diqing and Heifeng1 per plant grain weight was the best.(3)Different drought-tolerant varieties have different results to drought stress and rehydration.Drought-tolerant varieties of F.tataricum(Diqing)under drought stress treatment,the above ground morphological index,index of root morphology,root activity,osmotic regulation substances and antioxidant enzyme system,endogenous hormone,yield amplitude were less than drought sensitive F.tataricum(Heifeng1)with normal water treatment,which means affected by drought stress is relatively drought sensitive cultivars for light.The variation of all indexes of drought-tolerant F.tataricum was larger than that of drought-sensitive varieties after re-watering,and the recovery effect was better than that of drought-sensitive varieties.(4)The effects of drought stress and rehydration on F.tataricum were different in different periods.Drought stress in different periods had different effects on various indexes of F.tataricum.Compared with normal water treatment in the same period,the variation of each index in drought stress treatment in different periods was as follows: flowering stage >seedling stage> maturity stage,the index from the flowering drought stress treatment is the minimum by using membership function analysis,that is,flowering drought stress had the greatest impact on F.tataricum.There is a different impact of rehydration in flowering and mature stage on various indexes of F.tataricum.Compared with the continuous drought stress treatment in the same period,the variation amplitude of each index showed that the rehydration in flowering stage was greater than that in mature stage by using the membership function analysis,and the index of rehydration at flowering stage was higher than that at maturity stage,that is,the effect of rehydration in flowering stage was better.To sum up,through the study of drought stress at different stages and re-watering on the influence of different varieties F.tataricum growth,it could be found that drought stress especially at flowering stage affected the normal growth of F.tataricum.And the re-watering after drought stress can have equal compensation or part of the compensation effect on F.tataricum,making up for the loss in drought stress.At flowering stage,F.tataricum is more sensitive to water.Drought-tolerant varieties have strong adaptability to drought conditions and have better compensation effect after rehydration.In the production practice,it is supposed to pay attention to the selection of F.tataricum varieties and timely supply water at flowering season.If the irrigation is impossible,it can be adopted by adjusting sowing to make F.tataricum flowering season coincide with the local rainy season,so as to minimize the adverse effects of drought.