Variation analysis of main nutrients and functional components in different populations of Carya dabieshanensis

Abstract:【Objective】The study aimed to investigate the diversity and variation pattern of the contents of main nutrients and functional components in nut kernels of Carya dabieshanensis in the nature distribution of Dabie mountain area, in order to provide reference for the nutritional quality evaluation, the new variety breeding.【Methods】Based on the records of the resource investigation of C. dabieshanensis, 198 germplasm resources from 19 natural populations were collected in Jinzhai County, Luotian County and Huoshan County, respectively. 1.5-3.0 kg healthy mature fruits were randomly selected from the periphery of each sample for nutrient determination, and the distance between the treess was over 50 meters. 11 main nutrients and functional components were determined. The protein content was determined by spectrophotometry. The content of fat was determined with the Soxhlet extractor method.The dannin was quantified with spectrophotometry method. The starch and soluble sugars were determined by anthranone colorimetry. The qualene was determined with gas chromatography and the vitamin E with high performance liquid chromatography. One-way ANOVA and multiple comparisons were performed using Minitab7 software, and coefficient of variation (CV), phenotypic differentiation coefficient (Vst) of each nutrient component trait were calculated. The correlation analysis and principal component analysis were performed using SPSS23.0 software.【Results】The natural population of C. dabieshanensis had abundant diversity in the contents of main nutrients and functional components in nut kernels. The one- way ANOVA showed that there were significant differences (p＜0.01) in nutrients and functional components between the differnt populations. The multi-comparison of 11 characters in the 19 populations of C. dabieshanensis showed that there were significant differences in nutrients and functional components between the different populations. The highest fat content was in the JWB population, reaching (67.95±1.05) g · 100 g^-1 , followed by the JYLW, JWZD, JGY and JYL populations, although they had no significant difference with the JWB population, while the difference between the JWB population and other populations reached significant level. The protein content of the JSZC opulation was highest, reaching (10.48±0.98) g · 100 g^-1 , except that it had no significant difference with the JTY population, it had significant difference with other populations. The content of squalene, tannin, total phenol and α-vitamin E were all highest the JBQ population, which were (471.52±21.20) mg · kg^{- 1} , (64.01±53.38) g·kg^-1 , (96.91±8.77) g·kg^-1 and (1.51±0.37) mg·kg^-1 , respectively. The content of β-vitamin E was highest in the JSZL population, reaching 0.49 mg·100 g^-1 , it was significantly different from the other 18 populations except for the HTJB. The content of γ-vitamin E was highest in the JYCS population, reaching 32.35 mg · 100 g^-1 , except for no significant difference with the JWZD, JBQ and JGXL populations, it had significant difference with the other 15 populations. The mean phenotypic differentiation coefficient was 68.68% among the populations, indicating that the variance among the populations was the main source of the phenotypic variation. The average variation coefficient of the 11 traits ranged from 2.3% to 25.18%, with an average of 13.46%. The variation coefficient of the fat was smallest, only 2.3%, followed by the protein, 7.91%; and the variation coefficient of the β- vitamin E was highest, reaching 25.18%, followed by the starch, α-vitamin E, β-vitamin E, δ-vitamin E. At population level, the average variation coefficients were 7.09%-27.34%, and the JGXZ population had the most abundant diversity. The correlation analysis revealed that the 10 pairs had significant correlation in main nutrients and functional components, the fat had the greatest correlation with the other components, and had extremely significant negative correlation with the total phenol (-0.815), soluble sugar (-0.682), tannin (-0.670) and protein (-0.456), respectively. The significantly negative correlation between the total phenol, soluble sugar, tannin, protein was detected, whereas, there were no significantly correlations about the starch and δ-vitamin E. The principal component analysis showed that the cumulative contribution rate of the first four principal components in this study was 78.22% , it basically could cover the main information of the 11 main nutrients and functional ingredients. The first principal component represented the fat, soluble sugar, total phenol, tannin and squalene; the second principal component represented the protein, α-vitamin E, δ-vitamin E. The third principal component represented the content of β- vitamin E, and the fourth principal component represented the content of starch. Each main nutrients and functional components occupied an important position in the ingredients.【Conclusion】The content of main nutritional and functional components in the natural population of C. dabieshanensis had rich diversity both within the populations and between the populations, the main nutrients and functional components had great potential for selective breeding. The fat was the most stablecontent, and it had the greatest correlation with the other components. The main source of variation about the main nutrients and the functional components existed in between the populations.