A study on variability of fat-related traits in cultivated and wild soybean germplasm in China

صينى. 分析中国大豆栽培和野生种质资源脂肪及脂肪酸组分含量（本文简称脂肪性状）的变异特点，筛选优异种质，为不同生态区域大豆脂肪性状育种提供材料和依据。从中国全国各大豆生态区抽取代表性的栽培和野生材料进行田间试验，测定脂肪性状，进行各性状变异特点分析，并应用多元变异指数、聚类和主成分法分析中国和各生态区大豆脂肪性状的综合变异。（1）中国栽培大豆脂肪平均含量为17.21%，比野生种提高6.22%；油酸平均含量为23.25%，提高7.75%；亚麻酸平均含量为8.00%，减低4.23%；亚油酸平均含量为53.53%，减低2.57%；但栽培种的变异小于野生种；不同生态区均有此同一趋势。栽培大豆和野生大豆的饱和脂肪酸含量在全国和各区差异均不大。（2）中国野生群体及各生态区群体脂肪性状的多元变异度均大于相应的栽培种，长期人工选择使栽培种的变异相对减小，但多元变异方向相对较宽。（3）栽培种脂肪含量与来源地纬度呈极显著正相关，而野生种未见相关，推论栽培种脂肪含量与纬度的相关主要应是人工选择的结果。（4）筛选得到高脂肪、高油酸、高亚油酸、低亚麻酸的优良材料，其中N23547和N23697为兼具高脂肪（＞23%）、高油酸（＞30%）、低亚麻酸含量（5%左右）的优异资源。栽培大豆脂肪、油酸平均含量显著高于野生种，亚麻酸平均含量显著低于野生种，亚油酸平均含量略低于野生种，饱和脂肪酸平均含量与野生种差异不大。脂肪性状在各个生态区域内均存在丰富的变异，区域间的变异并不比区域内大。栽培种脂肪含量与纬度的相关主要是人工选择的结果。筛选出一批优异种质。

إنجليزي. The aim of the present study is to evaluate the variability of content of fat and major fatty acids (hereafter referred to as fat-related traits) in cultivated and wild soybean germplasm in China and to screen accessions superior in fat-related traits so as to provide materials and guidelines in the improvement of fat-related traits in various eco-regions. The cultivated and wild soybean germplasms from various eco-regions were sampled, tested, and analyzed for their fat-related traits. Based on single trait analyses, multivariate index, principal component analysis and cluster analysis were carried out to investigate the comprehensive variability of all fat-related traits in cultivated and wild soybeans from various eco-regions. The average fat content of cultivated soybean in the whole country was 17.21%, 6.22% higher than that of wild soybean; that of oleic was 23.25%, 7.75% higher than the wild; that of linoleic acid was 53.53%, 2.57% lower than the wild; and that of linolenic acid was 8.00%, 4.23% less than the wild; however, the variability of the fat-related traits in cultivated soybean was smaller than those in wild soybean. A similar tendency was observed in various eco-regions. As for the saturated fatty acids, no large difference was observed between the two species in the whole country as well as in various eco-regions. The multivariate variability in wild soybean was larger than that in cultivated soybean in whole country as well as in various eco-regions. The long term artificial selection reduced the variability, but made a wider direction of variation in cultivated soybean. A significant positive correlation was observed between fat content and source latitude of accessions in cultivated soybean, but not in wild soybean, indicating the correlation in cultivated soybean was mainly due to artificial selection for fat content in the history. Elite accessions with high fat content, high oleic acid content, high linoleic acid, low linolenic acid were screened out, respectively. Among them, N23547 and N23697 were the best with high fat content more than 23%, oleic acid more than 30% and linolenic acid less than 5%. The average contents of fat and oleic acid of cultivated soybean were significantly higher than, the average content of linolenic acid was significantly lower than, and the average content of linoleic acid was a little lower than that of the wild soybean, while no significant difference in saturated fatty acids between the two species in China. Large variation of fat-related traits existed within all the eco-regions in the two species, even larger than those among eco-regions. The significant correlation between fat content and source latitude was mainly due to the long term artificial selection for fat content in the history.