The Study Of Variation And Differentiation In The Sheep Grass

The variation and differentiation of Leymus Chinensis population were systemically studied. The results showed that there were great difference in leaf color, spike, heading rate and leaf width in Leymus Chinensis population. It was found that the variation in spike is invariable through transplanting and planting, but the seed production among different spike-types is very different. The wider-leaf-type remained its character after transplanting moreover it was higher in nutrition values.There were three main kinds of leaf color types in Leymus Chinensis population: yellow-green type, gray-green type and gray type .Each leaf color type remain stable under same condition, so the difference in leaf color is based on genetic makeup. Morphological characteristics, photosythetic characteristics, isozymes and nutrient value of three leaf color types of Leymus Chinensis were compared. It was shown that:(1) there was significant difference in plant height, leaf length ,leaf width and basic culm diameter between yellow green type and gray type. The morphological characteristics of gray-green type is between the yellow-gray type and gray type but it is similar to gray type. The variation of leaf color is mainly caused by the concentration of Ca2+, Na~", Mg2+, HCOa'in soil, soil pH and soil hardness.(2) There were same trend in the daily change of net photosynthetic rate and transpiration rate of three leaf color type of Leymus Chinensis. The net photosynthetic rate of gray type was higher than that of gray-green type and yellow-gray type, but its evaporation rate was lower. There were significant difference in using efficiency of solar energy and water between gray type and yellow-gray type. The gray-green type had no difference in using efficiency of solar energy and water with gray type and yellow-graytype.(3) There was great difference in POD isozymes among three leaf color type . The gray type has five isozymes bands but the gray-green type and yellow-gray type only have four POD isozymes bands. Compared with POD isozymes, gray-green type has more relation to yellow-green type. The gray type is relative remote with gray-green type and yellow-green type. There were no distinctive difference in SOD isozymes among three leafcolor types.(4) CP contents and CF contents of gray type is higher than those of gray-green type and yellow-green type, but ADF contents and NDF contents of gray type is lowest among the three leaf color types. The gray type is more valuable in breeding.