Abstract: Creeping-rooted character was very important for breeding and selection of the new variety of creeping-rooted types and grazing types alfalfa.In this paper, the author discussed the ontogenesis of creeping-rooted character and its performance in various sites of three different regions through two kinds of reproduction (planting and sowinng).The influence of marginal effect on the performance of creeping-rooted character was analysed.The results of these studies were as follows:The underground horizontal root of creeping-rooted alfalfa could form root expansion part and stem primordia on the root through whole growth season.The appearance of creeping-rooted plant was better during the second and third years than during the first and later of the fourth year in the creeping-rooted varieties.When planting with a space 1×1m per plant, the number of branches, range of expansion and hay yield of single plant were obviously higher in creeping-rooted plants than those in noncreeping-rooted plants.The development of creeping-rooted seedlings and the range of expansion of root turion node were influenced by marginal effect.The percentage of creeping-rooted plant was a little higher in marginal rows than in inner rows,and the range of expansion of creeping-rooted seedlings was obsviously larger in marginal rows than that in inner rows.Creeping-rooted alfalfa could show up adventitious stems on roots in the region of semi-arid grassland with castanozem such as Tumuji ranch farm in Inner Mongolia and Baicheng Ranch Farm in Jilin Province, and in the region of black soil where climate was relatively humid such as Gongzhuling in Jilin province, and in the region of cinnamon soil in Beijing.The percentage of ontogenesis of creeping-rooted character was a little lower in Gongzhuling than others.Results also indicated that the region of semi-arid grassland was the best region for the growth of creeping-rooted alfalfa, and for development of adventitious stems on roots.

Key words: Creeping-rooted alfalfa, Creeping-rooted character, Ecological adaptability

摘要： 苜蓿的根蘖性状对于培育根蘖型及放牧型苜蓿新品种具有重要的价值。本文结合根蘖型苜蓿新品评选育研究实践,系统地研究了苜蓿根蘖习性发生与生态适应性。通过三个地区种植和无性扦插两种繁殖方式探讨了苜蓿根蘖发生及在不同生境条件下根蘖性状的表现,分析了边际效应对根蘖表现的影响。本项研究结果表明:根蘖苜蓿植株地下水平根在整个生长季节内均有根膨大部位和根蘖芽的形成。根蘖型苜蓿品种的根蘖植株表现在第三、二年较多,第-年和第四年以后均表现较少。随着生长时间的推移,根蘖苗伸展范围不断向外扩展。在1×1m株行距稀植条件下根蘖植株单株枝条数、伸展范围和单株产草量均明显优于非根蘖植株。边际效应对根蘖型苜蓿品种根蘖苗的发育和根蘖伸展范围有影响,边缘行根蘖株百分率略高于内侧行植株,边缘行根蘖苗伸展范围明显高于内侧行植株。在半干旱草原淡栗钙土地区(内蒙古图牧吉牧场和吉林省白城牧场),及气候相对湿润的粘性黑土地区(吉林省公主岭)和潮土地区(北京),根蘖型苜蓿均能表现根蘖习性。在粘性黑土地区根蘖发生百分率较低。半干旱草原地区最适于根蘖型苜蓿生长和根蘖性状的发育。

关键词: 根蘖苜蓿, 根蘖性状, 生态适应性