青藏高原青稞赖氨酸含量空间分布及其与环境因子的关系

青藏高原是地球上生态环境最复杂的地区,也是大麦的起源中心之一。为探究裸大麦(青稞)赖氨酸含量的空间分布规律及与环境因子的关系,利用农学和地理学相结合的方法,在青稞主种植区选取了83个样点数据,通过逐步回归分析法和随机森林回归分析法建立数学模型。结果表明,在地理水平方向上,形成了藏中和藏东2个青稞赖氨酸含量高值区;在地理垂直方向上,赖氨酸含量在海拔2 700 m以下和4 200 m以上分别形成2个高峰区;影响青稞赖氨酸含量的环境因素从大到小依次是土壤全氮含量年均日照时数年均降水量年均相对湿度8月平均降水量。由此可见,青稞赖氨酸含量高值分布区位于喜马拉雅山脉、冈底斯-念青唐古拉山脉、喀喇昆仑山脉交汇的高山峡谷地带,是生态环境最复杂地区,是西藏野生大麦群体发现地之一。环境对青稞赖氨酸含量有重要影响,其中最主要环境因素是土壤全氮含量、年均日照时数、年均降水量。本研究结果为青藏高原青稞育种、栽培和加工提供了科学依据。

Spatial Distribution of Lysine Content in Highland Barley and Its Relationship with Environmental Factors in Qinghai-Tibet Plateau

The Qinghai-Tibet plateau is one of the centers of origin of barley and the most complex ecological environment on Earth.83 sampling points were selected in the main planting area of barley using agronomic and geography methods to study the spatial distribution of lysine content in highland barley and its relationship with environmental factors.The mathematical model was established by using stepwise regression analysis and random forest regression analysis.The results showed that it is high for lysine content in two regions of central Tibet and eastern Tibet in the geographical horizontal direction.In the vertical direction,the lysine contents show two peaks below 2 700 m and above 4 200m respectively.Environmental factors affecting lysine content of the highland barley follow the order of soil total nitrogen content ＞ average sunshine hours ＞ average annual precipitation ＞ average annual relative humidity ＞ August average precipitation.So the distribution of high content of lysine in the barley was located in the Himalayas,the Gangdise-Nyainqentanglha Mountains and the Karakorum Mountains,which is one of the most complex ecological regions and the wild barley was found in Tibet.Environment has important influence on the lysine content of the highland barley.The main environmental factors affecting the content of lysine in the highland barley were soil total nitrogen,average annual sunshine hours and annual precipitation.The results provide a scientific basis for breeding,cultivation and processing of the highland barley in Qinghai-Tibet Plateau.