两个苜蓿品种营养器官解剖结构特征比较

Comparative Study on Anatomical Structure of Vegetative Organs of Two Different Alfalfa Varieties

为了明确具有极强抗虫特性的‘草原4号紫花苜蓿’(Medicagosativa L.‘CaoyuanNo.4’)营养器官的解剖特征,该研究选择具有抗蓟马特性较强的‘草原2号杂花苜蓿’(Medicagovaria Martin.‘CaoyuanNo.2’)为对照,采用显微镜观察比较两品种的根、茎、叶解剖结构特征,为揭示‘草原4号紫花苜蓿’抗蓟马特性提供理论依据。结果显示:(1)‘草原4号紫花苜蓿’根部解剖结构的皮层薄壁细胞厚度、内皮层厚度、形成层厚度、木质部厚度和木射线宽度等5个指标均极显著高于(P<0.01)‘草原2号杂花苜蓿’,其中木射线宽度(159.37μm)是‘草原2号杂花苜蓿’的1.82倍。(2)‘草原4号紫花苜蓿’的茎部厚角组织厚度(21.4μm)极显著高于‘草原2号杂花苜蓿’(P<0.01),而韧皮部宽度、髓直径却均极显著低于‘草原2号杂花苜蓿’(P<0.01)。(3)‘草原4号紫花苜蓿’叶片解剖构造的7个指标均极显著高于‘草原2号杂花苜蓿’(P<0.01),其中栅栏组织层数(2~3层)极明显地高于‘草原2号杂花苜蓿’(1~2层)。研究表明,‘草原4号紫花苜蓿’的组织结构特征具有明显的抗虫特征,且其组织的抗虫特征比‘草原2号杂花苜蓿’更为突出。

In order to clarify the anatomical characteristics of the vegetative organs of‘Caoyuan No.4 alfalfa’with extremely strong insect resistance properties,we selected‘Caoyuan No.2 varia alfalfa’which has anti-thrips characteristics as a control,and used microscope to compare the anatomical structure characteristics of the roots,stems,and leaves of the two varieties,to reveal the anti-thrips characteristics of‘Caoyuan No.4 alfalfa’to provide a theoretical basis.The results showed that:(1)the thickness of the cortical parenchyma,the thickness of the endothelium,the thickness of the cambium,the thickness of the xylem and the width of wood rays of the root anatomical structure of‘Caoyuan No.4 alfalfa’were all significantly higher than that of‘Caoyuan No.2 varia alfalfa’,in which the wood beam width(159.37μm)is 1.82 times of‘Caoyuan No.2 varia alfalfa’(P<0.01).(2)The thick horn tissue thickness(21.4μm)of the stem of‘Caoyuan No.4 alfalfa’is extremely significantly higher than that of‘Caoyuan No.2 varia alfalfa’(P<0.01),while the phloem width and pith diameter are significantly lower than that of‘Caoyuan No.2 varia alfalfa’(P<0.01).(3)The seven indicators of leaf anatomical structure of‘Caoyuan No.4 alfalfa’are significantly higher than that of‘Caoyuan No.2 varia alfalfa’(P<0.01),and the number of palisade tissue layers(2~3 layers)is extremely obvious higher than that of‘Caoyuan No.2 varia alfalfa’(1~2 layer).Studies have shown that the tissue structure of‘Caoyuan No.4 alfalfa’has obvious insect resistance characteristics,and its tissue resistance is more prominent than‘Caoyuan No.2 varia alfalfa’.