切段长度、种植深度和覆草对矩镰荚苜蓿根茎出芽和成苗生长的影响

Effects of cutting length, planting depth and mulch⁃ ing thickness on rhizome bud sprouting and shoot development of Medicago archiducis-nicolai

摘要:

为探究对矩镰荚苜蓿(Medicago archiducis-nicolai)根状茎切段无性繁殖的影响因素，以祁连山东段高山草甸自然分布的矩镰荚苜蓿为试验材料，设置 2 个切段长度(20 cm 和 10 m)、2 个种植深度(10 cm 和 5 cm)、3 个覆草措施(覆草 3 cm、覆草 1 cm 和无覆草)共 12 个处理，研究了不同处理对矩镰荚苜蓿根茎出芽和成苗生长的影响。结果表明：1)覆草措施对成苗率、叶龄和单株地下生物量有显著影响，无覆草处理下成苗率、叶龄和单株地下生物量最高，3 cm 覆草次之；2)切段长度和种植深度均对成苗率有显著影响，分别在 20 cm 切段长度和 5 cm 种植深度处理下成苗率最高；3)多因素方差分析结果显示，只有覆草厚度×种植深度交互作用对根茎繁殖产生显著影响，且仅对单株地上生物量影响显著，在 10 cm 种植深度和 0 cm 覆草厚度交互处理下，单株地上生物量最大；4)TOPSIS 模型综合评价分析显示，20 cm 切段长度×10 cm 种植深度×0 cm 覆草组合处理，是矩镰荚苜蓿根状茎无性繁殖的最佳栽培条件。

Abstract:

To investigate the factors affecting the asexual propagation of Medicago archiducis - nicolai rhizome segments，Alpine meadows with natural distribution of Medicago archiducis - nicolai in the eastern part of Qilian Mountains was taken as the experimental site. Two cutting lengths of 20 cm and 10 cm，two planting depths of 10cm and 5 cm，and three mulching thicknesses of 3cm，1cm and 0 cm were set in the experiment. Rhizome seedling rate， leaf age and plant height growth indexes were measured. The results showed that：1)Mulching thickness had signifi- cant effects on leaf age，underground biomass per plant and seedling formation rate，which were mainly represented as 0cm mulching ＞3 cm coverage ＞1 cm coverage and that the underground biomass per plant and seedling forma- tion rate were the highest under 1cm and 0cm mulching；2)Segment length and planting depth had significant effects on seedling growth rate，and the seedling growth rate was the highest under 20 cm segment length and 5 cm planting depth；3)The results of multi-factor ANOVA showed that only the interaction of mulch thickness×planting depth had a significant effect on rhizosphere propagation，but only significant affected the aboveground biomass per plant. Under the interaction of 10 cm planting depth and 0 cm mulch thickness，the aboveground biomass per plant was the largest；4)The comprehensive evaluation and analysis of TOPSIS model showed that the combination of 20 cm seg- ment length，10 cm planting depth and0 cm grass covering was the best cultivation condition for asexually propagating alfalfa rhizome in this experiment.