Differences In Flavonoid And Phenolic Contents And Drought Resistance Of Two Varieties Of Medicine And Food Dual-use Adsuki Bean Seedlings

Adsuki bean has high nutritional value and is rich in starch,proteins,calcium,iron,phenol and flavonoid compounds.It is traditional rain fed crops in China with high dietary and medicinal value.In the wake of changing climate,drought is one of the vital factors limiting crop productivity.Adsuki bean plays an important role in raiseing land use rates,enriching the diversity of agricultural by-products,and increasing the household income of farmers.At present,the study of drought tolerance in Adsuki bean are rarely reported.In this study,PEG was used for simulating drought stress.We analyzed and compared the changes and differences in water status,antioxidant system and flavonoid and phenolic contents of medicine and food dual-use adzuki bean seedlings of different strains.To reveal the physiological and biochemical changes of adsuki bean under PEG stress.The main results as follows:1.The water loss rate of the two lines of Adsuki bean seedlings increased continuously at 0-12 h after the leaves were detached,and the water loss rate of the line XD13-12 was always higher than that of the line XD15-03.Under PEG stress,the RWC of lines XD13-12and XD15-03 decreased,and XD13-12 decreased more than XD15-03.PEG stress caused the chlorophyll content in the leaves of the two lines of Adsuki bean seedlings to decrease,and the chlorophyll content of line XD15-03 was relatively less affected by drought.The water condition and photosynthetic characteristics of line XD15-03 under PEG stress are better than line XD13-12,line XD15-03 has stronger water retention.2.Under PEG stress,the O₂^-and H₂O₂ contents in the leaves of the two lines of Adsuki bean seedlings showed an upward trend.The increase of O₂^-and H₂O₂ content in the leaves of line XD13-12 was greater than that of line XD15-03.PEG stress caused a large amount of MDA accumulation in the leaves of the two lines.Line XD13-12 had a higher MDA content,and the degree of cell lipid peroxidation and membrane damage was more serious.Under PEG stress,the antioxidant enzyme activity were increased in the seedling leaves of the two lines,and the increase of the antioxidant enzyme activity in the leaves of line XD15-03 was greater than that of XD13-12.Under PEG stress,the accumulation of proline was higher in the leaves of line XD15-03.Under PEG stress,line XD15-03 had better antioxidant properties than XD13-12.3.The growth of seedlings of the two lines of Adsuki bean were inhibited under PEG stress.Under PEG stress,the plant height,root length,fresh weight of above-ground part,dry weight of underground part and total biomass of line XD13-12 decreased significantly,and its growth was inhibited more severely.PEG stress induced an increase in the soluble protein and soluble sugar content in the leaves of the two lines of Adsuki bean seedlings,and a decrease in the vitamin C content.The soluble protein and soluble sugar content of line XD15-03 increased more than XD13-12,and the vitamin C content decreased less than XD13-12.Under PEG stress,the growth of line XD15-03 was better than that of XD13-12,and its tolerance to drought stress was stronger.4.Under PEG stress,the content of total flavonoids with a trend of rising first and then decreasing in the seedling leaves of the two lines of Adzuki bean.The content of total flavonoids in line XD13-12 under PEG stress for 48 hours decreased more than XD15-03.PEG stress induced the accumulation of total phenols in the leaves of the two lines of Adsuki bean seedlings,and the increase in total phenols content of line XD15-03 was higher than that of XD13-12.The accumulation of active substances such as flavonoids and phenols in the leaves of seedlings of strain XD15-03 under PEG stress was higher than that of strain XD13-12.In short,XD15-03 has stronger antioxidant capacity,water retention,higher active substance content,and stronger drought resistance under PEG stress.It is expected to be popularized as a dryland variety.