中文摘要：

为揭示黄花苜蓿（Medicago falcata L.）耐牧性的形态学成因机制,探索其耐牧型品种选育的新途径。以从耐牧性鉴定中获得的耐牧性强和弱的2组黄花苜蓿个体植株为材料,对其放牧前后的相关形态指标的观测数据进行分析。结果表明：各形态指标与耐牧性强弱的显著性相关程度依次为根颈宽度〉根颈入土深度〉茎数〉株高,对黄花苜蓿耐牧性的促进作用大小依次为根颈入土深度〉根颈宽度〉茎数〉株高〉株丛茎〉植株投影盖度。根颈入土深度可单独增强黄花苜蓿的耐牧性,其他性状则通过相互协同作用促进其耐牧性。具有根颈粗大且入土深、单株茎数多且株丛大的黄花苜蓿植株耐牧性强,可作为耐牧育种材料早期选育的形态学指标。

英文摘要：

In order to reveal the morphological formation mechanism of grazing tolerance of sickle alfalfa （Medicago falcata L. ） and to explore the new way of grazing-tolerant alfalfa breeding, Two sickle alfalfa groups （strong and weak grazing tolerance） were used to observe a number of morphological traits before and after grazing. The results indicated that the correlation degree order of these traits with grazing tolerance was root collar width 〉 crown depth 〉 stem number 〉 stem length. The determining degree for grazing tolerance was crown depth 〉 root collar width 〉 stem number 〉 stem length 〉 aboveground root collar width 〉 stand projective coverage. The crown depth of Medicago falcata showed out a promoting effect independently on increasing the grazing tolerance, and other traits promoted the grazing tolerance by their interactions. The sickle alfalfa plants with broad and deep-set crowns, prolific branches and large stand showed high tolerance to grazing, and these traits can be used as morphological indicators for grazing-tolerant breeding program in early breeding.