Evaluation Of Resveratrol Content And Identification Of Genotypes With High Resveratrol In Peanut

Peanut(Arachis hypogaea L.),commonly known as "groundnut" or "longevity nut",is a nutrient-rich and edible oil crop which has an important position in agricultural production in China.Peanut seed is mainly composed of lipids,proteins,sugars and some functional components,such as vitamin E,resveratrol,soluble fiber,etc.Resveratrol,a natural polyphenol compound,has significant antioxidant activity and significant effects on anti-cancer,cardiovascular and cerebrovascular protection,as well as strengthening immunity.Peanut was reported to be one of the small numbers of the plant species containing resveratrol besides grapes and Polygonum cuspidatum.Developing novel varieties with high resveratrol content and discovering the accumulation mechanism of resveratrol in peanut seeds are important directions for peanut breeding.The extraction and detection methods for peanut resveratrol were modified and optimized in the present study according to the previous research results in other crops.The modified and optimized methods were validated in 404 germplasm accessions.Seven genotypes with high resveratrol contents were identified.The main findings are as follows:1.The extraction and detection methods of resveratrol in peanut seeds were optimized.To solve the problems of low extraction rate,long extraction time and excessive impurities in the crude extract by traditional methods,we optimized the extraction and detection methods of resveratrol from peanut seeds.Combining the methods of enzymatic hydrolysis and ultrasonic treatment,resveratrol was extracted from peanut seeds with the optimal condition: enzyme concentration was 3 g/L,digestion time was 120 min,and ultrasonic time was 20 min.Compared with other extraction methods(Ethanol Extraction),the extraction efficiency of this optimized method was about 11.8 times higher.We used high performance liquid chromatography(HPLC)to detect the content of resveratrol.The peak area of sample detected in the HPLC system had strong correlation with its concentration(R2 = 0.9991).The optimized method has high stability(RSD = 0.95%).The recoveries obtained from the spiked samples were varied from 83.66% to 120.68%.In addition,the detection limit and quantification limit of the method are 0.006 ?g/g and 0.051 ?g/g,respectively.2.The variation of resveratrol content in peanut resources was evaluated.A total of 404 accessions were planted in four environments in Wuhan,Xiangyang,and Zhanjiang in 2017-2018 and their seeds were air-dried after harvesting.Subsequently,the resveratrol content was detected by HPLC.Overall,the average resveratrol content was 0.525 ?g/g;the range of variation was from 0.106 to 1.711 ?g/g,and the coefficient of variation was 40.8%.In 2017 WH,the content of resveratrol ranged from 0.106 to 1.177 ?g/g and averaged at 0.435 ?g/g.The coefficient of variation was 46.5%,and there were 42 varieties over 0.7 ?g/g.In 2018 WH,the content of resveratrol ranged from 0.157 to 1.224 ?g/g and averaged at 0.568 ?g/g.The coefficient of variation was 34.6%,and there were 91 varieties over 0.7 ?g/g.In 2018 XY,the content of resveratrol ranged from 0.147 to 1.711 ?g/g and 0.591 ?g/g.The coefficient of variation was 38.9%,and there were 100 varieties over 0.7 ?g/g.In 2018 ZJ,the content of resveratrol ranged from 0.165 to 1.350 ?g/g and averaged at 0.504 ?g/g.The coefficient of variation was 37.9%,and there were 53 varieties over 0.7 ?g/g.3.Seven accessions with high resveratrol content were identified.According to the results of resveratrol contents of 404 accessions under four environments,we found that 91 accessions with a content of more than 0.7 ?g/g in 2018 WH.However,only 20,39 and 30 accessions were discovered in 2017 WH,2018XY,and 2018 ZJ respectively among the 91 accessions identified in 2018 WH.Seven accessions including Zh.h7788,Zh.h1197,Zh.h8454,Zh.h0602,Zh.h0682,Zh.h5874 and WH4280 had resveratrol contents higher than 0.7 ?g/g in the all four environments involved.The above results provided material and theoretical basis for developing novel varieties with high resveratrol content.