8个桑品种的植株茎叶解剖结构及与耐旱性的关联分析

Anatomical Structures of Stem and Leaf from Eight Mulberry Varieties and Their Correlationship with Drought Tolerance

以干旱、半干旱和湿润地区来源的8个桑品种的植株为材料,采用石蜡切片法和光学显微镜技术对其茎、叶进行解剖结构观察,根据桑树的解剖结构特征分析不同桑品种对干旱的耐受能力差异及桑树对干旱环境的适应性变化,并筛选出能表征桑树耐旱能力的重要解剖结构特征性状。不同桑品种植株叶片的角质层厚度、叶片厚度、栅栏组织厚度、海绵组织厚度和下表皮厚度均存在显著差异,植株茎的导管孔径、导管密度、木质部厚度、韧皮部厚度、茎直径和髓直径等在各桑品种间也有显著差异。对桑品种间具有显著差异的解剖结构性状进行主成分分析,筛选出12项茎、叶解剖结构性状指标作为桑树耐旱能力评价的代表性性状指标,进一步将这些指标数据转换为隶属函数值,8个桑品种的耐旱性相关解剖结构特征性状的隶属函数值从大到小,即显示的耐旱性从强到弱依次为吴堡桑、白桑、新一之、甜桑、育2号、育711号、湖桑32号、陕桑305。

The stem and leaf anatomical structures of eight mulberry varieties from arid,semi-arid,and humid regions were observed by using paraffin sectioning and optical microscopy. Anatomical structure was used to analyze the differences in drought tolerance of different mulberry varieties and their adaptative changes in response to drought. Important anatomical traits that contribute to drought tolerance were screened out based on comparative analysis of anatomical structures. There were significant differences in cuticle thickness,leaf thickness,palisade tissue thickness,sponge tissue thickness,lower epidermis thickness of leaves,and in vessel diameter,vessel density,xylem thickness,phloem thickness,stem diameter,pith diameter of stems among eight mulberry varieties. Based on the principal component analysis（ PCA） of anatomical structures with significant differences among these mulberry cultivars,twelve stem and leaf anatomical structure traits were selected as representative traits to evaluate drought tolerance of mulberry tree. The subordinative function value of twelve representative traits was obtained and used to rank the drought tolerance of eight mulberry varieties. The drought tolerance of these eight mulberry varieties in order from strong to weak was as follows： Wubusang,Baisang,Neo-Ichinose,Tiansang,Yu No. 2,Yu No. 711,Husang No. 32 and Shansang No. 305.