【作者】 王月胜；

【导师】 于林清；

【作者基本信息】 甘肃农业大学 ， 草业科学， 2008， 硕士

【摘要】 本文对13个不同来源的苜蓿品种于生长当年进行了根颈、根系特征、根部各指标相关性分析、主成分分析、形态学聚类分析、苜蓿的越冬率及苜蓿根颈直径和入土深度与越冬率的关系、苜蓿根系中过氧化物酶(POD)活性与抗寒性关系的研究。研究结果如下:1不同苜蓿品种间根颈特征差异明显,根颈直径、入土深度以Maverick为最大,供试苜蓿品种间根颈分枝数无明显差异。不同苜蓿品种间根系特征差异明显或显著,主根长度以肇东最大,为16.5cm,主根直径以Maverick最高,达0.63cm,Maverick侧根条数最大,为4.6条,公农1号侧根位置最大,为3.9cm,供试品种中肇东侧根直径最大,为0.33cm,以上各品种(Maverick,肇东,公农1号)在主根长度、主根直径、侧根数、侧根直径、侧根位置等指标上明显或显著高于国内外其它品种。2对各品种根部指标进行相关性分析表明:根系各指标中,除主根长和侧根位置外,其余各指标(包括根颈直径、主根直径、侧根数、侧根直径)都呈正相关,且达到显著或极显著水平;主根长和侧根位置与其它指标相关性并不显著。对不同苜蓿品种根系指标主成分分析表明:第一成分(根颈直径)的特征贡献率为46.4190%,是分析的主要方面。其次为主根直径和主根长度。特征贡献率分别为20.9041%和17.9611%。苜蓿根系形态学聚类分析表明,第一类根系形态相近的有Maverick和公农1号;第二类根系形态相似的包括草原3号、中苜1号、肇东、克旗黄花、阿勒泰等5个品种;第三类包括润布勒、CUF101、草原2号、直立黄花、Legend等4个品种,第四类仅有准格尔1个品种。3试验根据越冬率将13个苜蓿品种划分为四个等级,Maverick、草原3号、草原2号均为抗寒性较强的品种,为4级;克旗黄花、公农1号、直立黄花、阿勒泰、润布勒、肇东、Legend为抗寒性中等品种,为3级;中苜1号、准格尔为抗寒性较弱品种,为2级;CUF101为抗寒性最弱的品种,越冬率仅35%,为1级。根颈直径、入土深度与越冬率之间的相关性研究表明,根颈直径与入土深度及越冬率均成正相关,达到显著或极显著水平。4从13个苜蓿品种低温处理后过氧化物酶活性比较看,克旗黄花过氧化物酶活性明显高于其它品种,说明其抗寒性最强;其次是Maverick、直立黄花、草原2号、草原3号,它们之间存在显著差异;活性最差的是准格尔、CUF101,说明其抗寒性最弱,其次是中苜1号和肇东;其余品种过氧化物酶活性居中,且它们之间差异显著,说明其抗寒性中等。更多还原

【Abstract】 A study was conducted to determine the crown, root system characteristics , the correlation analysis of index in root system, the principal component analysis, the root system morphology cluster analysis, the winter survival rate, the correlation analysis of index in crown diameter,crown depth and winter survival rate, the frosted symptoms of the over-wintering, POD activity for different alfalfa varieties,etc,of thirteen alfalfa with different origins1 The reselt indicated that there was significantly difference of the character of crown in cultivars,The crown diameter, crown depth was greatest in Maverick, there was no significantly difference in crown branch. There was significantly difference of the character of root system in cultivars, Zhaodong has the longest tap root(16.5cm)and lateral root diameter(0.33cm), Maverick has the greatest tap root diameter(0.63cm) and lateral root number(4.6), lateral root position was greatest in Gongnong No.1(3.9cm), the indexes in all over the alfalfa cultivars were significantly higher than all of the others.2 Correlation analysis indicated that,except for the tap root length and lateral root position,other indexes of root including crown diameter, tap root diameter, lateral root number, lateral root diameter was significantly or high significantly positive correlation, the correlation among the tap root length and lateral root position with other indexes was not significant. Principal component analysis indicated that the frist component contribution rate is 46.4190%,it is main aspects,the next is root diameter and tap root length, contribution rate is 20.9041% and 17.9611%. The root system morphology cluster analysis indicated that the frist root system morphology similar,including Maverick and Gongnong No.1,the second including Caoyuan No.3, Zhongmu No.1, Zhaodong, Keqihuanghua, Aletai,the third including Rambler, Caoyuan No.2, Zhilihuanghua, Legend,CUF101,the last one is Zhungeer.3 Cold_tolerance analysis indicated that the varieties with strong cold resistance were Maverick, Caoyuan No.3, Caoyuan No.2.The varieties with medium cold resistance were Keqihuanghua, Gongnong No.1, Zhilihuanghua, Aletai, Rambler, Zhaodong, Legend.The varieties with weak cold resistance included Zhongmu No.1 and Zhungeer. The varieties with weakest cold resistance was CUF101, winter survival rate was 35%.The correlation analysis of index in crown diameter,crown depth and winter survival rate indicated that the crown diameter,crown depth and winter survival rate was significantly or high significantly positive correlation.4 The POD activity was significantly different among alfalfa varieties under cold stress.The POD activity of Keqihuanghua was stronger than that of the others, secondly was Maverick, Caoyuan No.3, Zhilihuanghua, Caoyuan No.2. Zhungeer and CUF101,showing their cold resistance were weakest,the others suggesting the medium cold resistance.更多还原