大麦与谷类科学

解析青稞种质资源籽粒中赖氨酸含量w(Lys)的差异，对筛选籽粒赖氨酸含量高的青稞品种，提升青稞品种的食用品质具有重要意义。以我国青藏高原地区的166份青稞种质资源为材料，采用茚三酮法提取青稞籽粒中的赖氨酸，用分光光度法测定其赖氨酸含量，分析青稞材料籽粒赖氨酸含量的变异，并对不同来源地的青稞材料进行聚类分析。结果表明：供试的166份青稞材料中，赖氨酸含量的变异幅度为0.275%～0.834%，平均值为0.446%，变异系数为20.88%，以四川材料较高（0.468%），甘肃材料较低（0.385%），表现为四川>西藏>青海>甘肃。以来自西藏朗县的长芒白青稞籽粒的赖氨酸含量最高（0.834%），西藏八宿的白青稞品种含量最低（0.275%）。方差分析表明，166份青稞材料间赖氨酸含量差异存在高度统计学意义（P<0.01）。筛选出赖氨酸含量较高的青稞材料有9份，较低的青稞材料有7份。不同来源地的青稞材料籽粒赖氨酸含量的变异系数以西藏较高，呈西藏>四川>青海>甘肃趋势。聚类分析表明，在遗传距离为0.126时，166份青稞材料可分为4大类。据此，可将青稞籽粒赖氨酸含量分为4级：w(Lys)<0.275 mg/g为第1级，最低；0.275 mg/g≤w(Lys)<0.611 mg/g为第2级，表现较低；0.611 mg/g≤w(Lys)<0.774 mg/g为第3级，表现较高；w(Lys)≥0.774 mg/g为第4级，最高。上述结果为青稞籽粒高赖氨酸含量新品种选育提供参考依据。

The analysis of the difference of lysine content(Lys) in grains of highland barley germplasm resources is of great significance for screening highland barley varieties with high lysine content in grains and improving the edible quality of highland barley varieties.In this paper, 166 highland barley germplasm resources from Qinghai Tibet Plateau in China were used as materials. The lysine in highland barley grains was extracted by ninhydrin method, and the lysine content was determined by spectrophotometry. The variation of lysine content in highland barley grains was analyzed, and the highland barley materials from different sources were clustered. The results showed that among the 166 highland barley materials tested, the variation range of lysine content was 0.275% ～0834%, the average value was 0.446%, and the coefficient of variation was 20.88%. The Sichuan material was higher(0.468%), and the Gansu material was lower(0.385%), showing Sichuan > Xizang > Qinghai > Gansu. The lysine content of long awn white highland barley from Lang County, Xizang was the highest(0.834%), while the content of white highland barley from Basu County, Xizang was the lowest(0.275%). The analysis of variance showed that there was a very significant difference in lysine content among 166 highland barley materials(P < 0.01). Nine highland barley materials with high lysine content and seven highland barley materials with low lysine content were screened. The coefficient of variation of grain lysine content of highland barley materials from different sources was higher in Xizang, showing a trend of Xizang > Sichuan > Qinghai > Gansu. Cluster analysis showed that 166 highland barley materials could be divided into four categories when the genetic distance was 0.126. Accordingly, the lysine content of highland barley grain can be divided into four levels, w(Lys) < 0.275 mg/g is the first level, which is the lowest, 0.275 mg/g≤w(Lys) < 0.611 mg/g is the second level, which is low, 0.611 mg/g ≤w(Lys) < 0.774 mg/g is the third level, which is high, w(Lys) ≥0.774 mg/g is the fourth level,which is the highest. The above results can lay a foundation for the breeding of new varieties with high lysine content in highland barley grains.