中文摘要：

采用石蜡切片法和组织离析法分别对3种柑橘实生砧木和2种体细胞杂种的根系木质部和导管分子的解剖结构进行了比较。结果表明：（1）粗柠檬、红橘和枳3种实生砧木根系的木质部和韧皮部呈同心圆环状排列，而‘红橘＋枳’和‘红橘＋粗柠檬’两种体细胞杂种木质部和韧皮部呈“海星状”排列，结构异常。（2）导管所占的面积和密度均以生长势较强的粗柠檬为大，以生长势较弱的枳为小；体细胞杂种没有明显规律。（3）柑橘导管分子属于孔纹导管，穿孔板均为单穿孔，大多分布于端壁上；导管分子两端具尾、倾斜、侧壁穿孔等性状的有无及其比例反映出生长势的差异及其输导能力的强弱。（4）粗柠檬具有较好输导能力的导管分子结构，而枳较差；体细胞杂种根系的导管分子长度和直径都大于其亲本，在导管分子性状上，向不利于输导能力的较原始性状偏移。

英文摘要：

By paraffin method and tissue segregation procedure, the vessel elements and xylem of three citrus seedling rootstocks and their two allotetraploid somatic hybrids were comparatively studied. It showed that ： （ 1 ） The root xylem and phloem of three citrus seedling rootstocks assumed the concentric circle arrangement, while that of the somatic hybrid rootstocks red tangerine ＋ trifoliate orange, red tangerine ＋ rough lemon arranged unusually, like starfish. （2） Total vessel/xylem area and vessel density were the highest for rough lemon, but the lowest for trifoliate orange which is less vigorous. （3） Citrus vessel elements all belong to pitted vessel, with perforation plate being simple and always distributed in end wall. The difference of growth potential and nutrient transportability among citrus rootstocks could be reflected by whether the vessel elements have the tail, slope, simple perforation and their proportion in side wall. （4） Rough lemon has good vessel element structure to reflect its strong transportability while that of trifoliate orange is weak. The length and tangential diameter of vessels in citrus somatic hybrid rootstocks are larger than their parents, and have polyploid characteristics; In vessel element character, citrus somatic hybrid rootstocks tend to have more primitive characters which are disadvantageous to transportability.