基于果实苦涩味新疆核桃资源遗传多样性分析
Genetic Diversity Analysis of Walnut Germplasm Resources Based on Bitter and Astringent of Fruits in Xinjiang
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摘要: 目的:旨在发掘新疆核桃种质材料典型性状。方法:以引进及当地38份核桃为对象,对7个外观指标、7个苦涩指标(单宁、芦丁、绿原酸、槲皮素、儿茶素、香草酸、没食子酸)进行了变异分析、主成分分析、聚类分析。结果:果仁重变异系数最大,果形指数变异系数最小。苦涩味物质中,芦丁变异系数最大,为227.612%;儿茶素、绿原酸和单宁变异系数较小,分别为13.563%、34.635%和35.810%,其中单宁多样性指数最高,最具苦涩物质代表性。苦涩味相关指标多样性指数变动范围为0.015~171.81,其中单宁多样性指数最高。聚类分析将38个核桃种质分为4类,第一类涵盖16个核桃种质,主要是引进加州黑核桃和中宁系列核桃,皆为砧木用种质,其苦涩味含量较低;第二类有1个核桃种质,‘加州黑核桃1’为较好的砧木;第三类有20个核桃种质,主要是阿克苏地区主要栽培品种,其外观品质较优良;第四类只有1个核桃种质,为自然实生后代材料,其单宁含量最高。结论:单宁是核桃果实中主要苦涩味物质,其它成分可能更多发挥保健作用;分析发现"南6-4"单独聚为一类,聚类级别与‘加州黑核桃1’齐平,遗传基础较广泛、进化程度较低,具有较好本地核桃砧木培育应用潜质。研究将为今后筛选新疆丰富核桃资源中低苦涩味种质和优良砧木种质铺垫一定研究思路和方法基础,进一步促进新疆林果业提质增效。Abstract: Objective:To explore the typical characters of walnut germplasm in Xinjiang. Methods:The introduction and localization of 38 varieties of walnut germplasm resources were the main objects. 7 appearance indicators and 7 bitter or astringent indicators (tannin, rutin, chlorogenic acid, quercetin, catechin, vanillic acid, gallic acid) were analyzed for variation, principal component analysis, and genetic diversity analysis. Results:The coefficient of variation of kernel weight was the largest and the coefficient of variation of fruit shape index was the smallest. The variation coefficient of rutin was 227.612%, the variation coefficients of catechins, chlorogenic acids and tannins were relatively small (13.563%, 34.635% and 35.810%, respectively), of which the tannin diversity index was the highest, so the tannin was the representative of bitter substances in the walnut fruit. The bitterness-related index diversity index ranged from 0.015~171.81, with the highest tannin diversity index. The cluster analysis divided 38 walnut germplasms into 4 categories. The first category covered 16 walnut germplasms. The main ones were California black walnuts and Zhongning walnuts, all of which were rootstock germplasms with low bitterness. The second type had 1 walnut germplasm, and California black walnut 1was a good rootstock;the third type had 20 walnut germplasms, mainly the main cultivated varieties in Aksu region, which had good appearance quality;the fourth type had only 1 Walnut germplasm that was a natural material for progeny and had the highest tannin acid content. Conclusion:Tannins were the main bitter and astringent substances in walnut fruit, other components may have more health effects;It was found that the south 6-4 seedling plant may have a good application potential for rootstock breeding. The study will lay a certain research thinking and methods for screening the low bitter and astringent germplasm and the good stock germplasm of the rich walnut resources in Xinjiang in the future, and further promote the improvement of the quality and efficiency of the Xinjiang fruit industry.