藏北野生驯化早熟禾的生产性能和品质评价

基于藏北地区饲草缺乏和草地植被退化等问题,开展野生牧草资源的开发利用研究,驯化筛选适宜藏北高寒区种植的优质乡土早熟禾。选取西藏野生的中亚早熟禾（Poa litwinowiana）、渐尖早熟禾（P. attenuata）和冷地早熟禾（P. crymophila）为材料,以国审栽培品种青海冷地早熟禾（P. crymophila cv. Qinghai）为对照,在海拔4 512m环境条件下完成田间种植,分析比较不同早熟禾的生长特性和营养品质。结果显示,随生育期推进,供试材料地上生物量、株高、中性洗涤纤维和酸性洗涤纤维含量呈现逐渐增加的现象,粗蛋白质和粗脂肪含量下降。乳熟期3种材料的地上生物量均显著（P<0.05）高于对照品种,其根系生物量大小排序为渐尖早熟禾>中亚早熟禾>冷地早熟禾>对照;冷地早熟禾的粗蛋白含量显著（P<0.05）高于渐尖早熟禾,渐尖早熟禾的酸性洗涤纤维和中性洗涤纤维含量最低。采用熵权赋值法的灰色系统理论对乳熟期不同早熟禾生产性能及营养品质指标进行综合评价,优劣顺序为渐尖早熟禾>冷地早熟禾（野生种）>中亚早熟禾>青海冷地早熟禾（栽培种）。

Evaluation of Productivity and Quality of Wild Domestication Poa annua L. in Northern Tibet

In order to explore the approaches for alleviating forage shortage and grassland degradation in northern Tibet, this study carried out a domestication experiment with Poa litwinowiana, P. attenuata and P. crymophila, P. crymophila cv. Qinghai was the control, for screening the high-quality local Poa annua forage suitable for the alpine regions. Analyses and comparisons were made on the growth characteristics and nutritional quality of different experimental materials under field conditions at 4 512m elevation. The results showed that the above-ground biomass, plant height and neutral detergent fiber (NDF) and acid detergent fiber (ADF) of Poa annua were gradually increased, the crude protein (CP) and crude fat (CF) decreased with the prolongation of growth stage. The above-ground biomass of three wild Poa annua in the milk maturity stage was significantly higher (P<0.05) than that of the control; the order of root biomass was P. attenuata > P. litwinowiana > P. crymophila > P. crymophila cv. Qinghai. The CP content of P. crymophila was significantly higher (P<0.05) than that of P. attenuate, and ADF and NDF contents of P. attenuate was the lowest. The gray system theory of entropy weighting method was used to evaluate the productivity and nutrient quality of different Poa annua in milk maturity stage, the order was showed that P. attenuata > P. crymophila (wild species) > P. litwinowiana > P. crymophila cv. Qinghai (cultivated species).