西部地区文冠果种群种子特征及主要化学成分的地理变化

通过野外实际调查和测定,对我国西部地区8个文冠果天然群体的种子特征及主要化学成分进行研究。结果表明:8个文冠果种群的种子横径为1.05～1.51cm,纵径为0.86～1.38cm,种形指数为1.07～1.32,种群间存在显著差异;陕西延安种群种子的千粒质量和出仁率均最大,分别为1108.4g和48.28%,显著高于甘肃和青海种群;8个种群的种仁含油率均在53%以上,且不同种群间差异显著;文冠果种仁油含有12种脂肪酸,其中含量最高的是亚油酸(40.90%～46.12%),其次是油酸(29.21%～31.25%);含有17种氨基酸(22.53%～27.58%),包括7种必需氨基酸,占总氨基酸的27.61%。相关分析结果表明:文冠果种形指数表现出明显的地理变化规律,随经度的增加,种形指数逐渐减小;种子千粒质量与4—9月份的降水量呈极显著正相关,与年平均温度呈显著正相关,与年干燥度呈显著负相关;种仁油含量随地理经度的减小而降低,与4—9月份的降水量呈显著正相关;种仁氨基酸含量与地理经度及无霜期相关性显著,随经度和无霜期的增加而增大,即东部地区氨基酸含量较高。

Geographical Change of Seed Characteristic and the Main Chemical Composition of Xanthoceras sorbifolia Population in the West of China

The seed characteristics and main chemical composition of 8 natural populations of Xanthoce sorbifolia in the west of China were studied by field investigation.The results showed that the seed length,width and seed-shape index were 1.05～1.51 cm,0.86～1.38 cm,and 1.07～1.32,respectively,these parameters were significantly different among different populations.The mass of 1 000 seeds and kernel rate from Yan’an of Shaanxi were 1 108.4 g and 48.28%,respectively and significantly higher than those from Gansu and Qinghai population.The average oil content in the seed kernel was over 53%,and there were 12 fatty acids in the oil,among which the linolenic acid was the most(40.90%～46.12%),followed by oleic acid(29.21%～31.25%).There were 17 amino acids in the seed kernel,including 7 essential amino acids(27.61%).The seed index showed a significantly negative correlation with longitude.A positive correlation was observed between the mass of 1 000 seeds and the rainfall from April to September rainfall,as well as the mean annual temperature.The greater the longitude and the longer the frost free period,the higher the content of amino acids.