摘要
紫花苜蓿(Medicago sativa)是我国粮草间作系统的重要草种。然而,间作系统极端的弱光环境常造成紫花苜蓿产量大幅下降,选育耐阴品种是解决这一瓶颈问题的主要途径。为此,该研究以20份紫花苜蓿种质资源为供试材料,采用绿色遮阳网叠加设置遮光率为0(全光照)、52.9%(中度遮光)和71.8%(重度遮光)3种遮阴处理,测定不同光强下紫花苜蓿分蘖期6个形态指标(茎粗、株高、一级侧根数、根瘤数、根颈分蘖数和茎叶夹角)、7个生长指标(叶干质量、单株生物量、叶面积、比叶面积、叶质量比、茎质量比和根质量比)和5个生理指标(叶绿素a含量、叶绿素b含量、总叶绿素含量、类胡萝卜素含量和叶绿素a/b)的变化,以0和52.9%遮光率的耐阴系数为基础数据,通过主成分分析、隶属函数分析、聚类分析和逐步回归分析法综合评价20份紫花苜蓿供试材料的耐阴性并筛选其鉴定指标。结果表明:随光强减弱,紫花苜蓿的茎粗、根瘤数和根颈分蘖数呈下降趋势;总叶绿素含量呈上升趋势;一级侧根数、叶干质量、单株生物量和叶面积呈先上升后下降趋势,其他指标变化趋势不一致,且不同品种间存在较大差异。结合主成分分析、隶属函数分析和聚类分析,按耐阴性的强弱可将20份供试材料划分为3个类型:耐阴型(4份材料)、半耐阴型(8份材料)和敏感型(8份材料)。通过逐步回归分析,建立了评价紫花苜蓿耐阴性的最优回归方程:D=–0.108+0.071X10+0.049X6+0.208X14+0.027X4+0.096X7+0.052X3+0.048X5,估计精度在93.72%以上,筛选出叶面积、叶干质量、茎叶夹角、根瘤数、一级侧根数、根颈分蘖数和叶绿素a含量等7个指标作为紫花苜蓿耐阴性的鉴定指标。该研究结果可为紫花苜蓿耐阴品种的选育提供优良材料和科学依据,并有助于紫花苜蓿高效间作体系的构建与优化。
Aims Alfalfa(Medicago sativa)is an important forage in the intercropping system.However,the extreme weak light environment in the intercropping system often leads to a significant decrease in alfalfa yield,and breeding shade-tolerant cultivars is the main way to solve this bottleneck problem.Methods In this study,20 alfalfa germplasm resources were used as test materials,and the shading rates were 0(full light),52.9%(moderate shading)and 71.8%(heavy shading)were used to determine the changes in six morphological indexes(stem diameter,height,number of primary lateral root,number of root nodule,number of root crown tiller,angle of stem to leaf),seven growth indexes(leaf mass,plant biomass,leaf area,specific leaf area,the percentage of leaf mass,stem mass and root mass in total biomass),and five physiological indexes(chlorophyll a content,chlorophyll b content,total chlorophyll content,carotenoid content,chlorophyll a/b ratio)during the tillering stage of alfalfa under different light intensities.Based on the shading rates of 0 and 52.9%,principal component analysis,membership function analysis,cluster analysis,and stepwise regression analysis were used to comprehensively evaluate the shade tolerance of alfalfa germplasm resources and screen their identification indicators.Important findings(1)The stem diameter,the number of root nodule,and the number of root neck tillering of alfalfa decreased with the decrease of light intensity.The total chlorophyll content showed an increasing trend.The number of primary lateral root,leaf dry mass,biomass per plant,and leaf area showed a trend of first increase and then decrease,while the trends of other indexes were inconsistent,and there were significant differences among different cultivars.(2)Combining principal component analysis,membership function analysis and cluster analysis,the 20 test materials could be divided into three types according to their shade tolerance:shade tolerant(4 test materials),semi-shade tolerant(8 test materials),and shade-sensitive(8 test materials).(3)By stepwise regression analysis,the optimal regression equation was established:D=–0.108+0.071X10+0.049X6+0.208X14+0.027X4+0.096X7+0.052X3+0.048X5,the precision of estimation was above 93.72%.Seven indexes,including leaf area,leaf dry mass,angle between stem and leaf,number of root nodules,number of primary lateral roots,number of root neck tillering,and chlorophyll a content were selected as shade tolerance identification indexes for alfalfa.The results would provide good materials and scientific basis for the breeding of alfalfa cultivars with shade tolerance,and contribute to the construction and optimization of alfalfa intercropping systems.
作者
张琨
钱敏
汪阳
李志华
孔令娜
李明洋
马瑾煜
努尔艾合麦提•玉苏普
陈乙一
成沂芮
张焕仕
覃凤飞
渠晖
ZHANG Kun;QIAN Min;WANG Yang;LI Zhi-Hua;KONG Ling-Na;LI Ming-Yang;MA Jin-Yu;YUSUPU Nueraihemaiti;CHEN Yi-Yi;CHENG Yi-Rui;ZHANG Huan-Shi;QIN Feng-Fei;QU Hui(College of Agro-grassland Science,Nanjing Agricultural University,Nanjing 210095,China;Institute of Grassland Research,Chinese Academy of Agricultural Sciences,Hohhot 010010,China;College of Agriculture,Nanjing Agricultural University,Nanjing 210095,China;College of Plant Protection,Nanjing Agricultural University,Nanjing 210095,China;College of Horticulture,Jinling Institute of Technology,Nanjing 210038,China)
出处
《植物生态学报》
北大核心
2025年第5期773-787,共15页
Chinese Journal of Plant Ecology
基金
南京农业大学校级大学生创新创业训练项目(202326XX004)资助。
关键词
紫花苜蓿
耐阴性
综合评价
多元统计分析
鉴定指标
Medicago sativa
shade tolerance
comprehensive evaluation
multivariate statistical analysis
identification index
