以催芽后播种砂培1个月的枳、红桔和香橙实生苗为材料,采用体视显微镜和扫描电镜等方法对根系生长和根毛形态进行观察,探讨根系形态差异与树体不同表现特征间的关系。结果表明,3种柑桔实生苗根系的生长发育差异显著,根系生物量和根冠比均表现为红桔>香橙>枳,苗期以红桔的根系生长速度较快。不同柑桔的根系形态特征差异较大,枳实生苗表现为侧根较发达,红桔和香橙实生苗则是主根生长较好,两者的侧根数量和侧根长度均显著不及枳。3种柑桔的根毛均不分叉,分布不均匀,且侧根根毛密度显著高于主根根毛密度。不同柑桔的根毛形态和主根根毛的分布差异较大:红桔和香橙的主、侧根的根毛密度均大于枳;枳主根的根毛分布表现为上段(根基)、中段和下段(根尖)的根毛密度依次递减,红桔与此相反,香橙则是中段>下段>上段。 The root growth and root hairs morphology were observed by stereomicroscope and scanning electron microscopy after germination of the seedlings of trifoliate orange, red tangerine and orange which were inoculated with sand for one month after germination. The morphological differences of root system and the different performance characteristics of the tree Relationship. The results showed that there were significant differences in the root growth and development of the three kinds of citrus seedlings. The root biomass and the ratio of root and shoot of the three kinds of citrus fruits were red orange> orange> trifoliate orange. The morphological characteristics of different citrus roots were quite different. The lateral roots were more developed in Poncirus trifoliata and the main roots of Citrus reticulata and Orange were better. The numbers of lateral roots and lateral roots of both citrus rootstock were significantly lower than those of Poncirus trifoliata. The root hairs of the three kinds of citrus did not bifurcate and distributed unevenly, and the root hair density of the lateral root was significantly higher than that of the main root. The distribution of root hairs and main root hairs of different citrus varieties are quite different: the root hair density of main and lateral root of red orange and orange are greater than that of trifoliate orange; root hair distribution of main root of trifoliate orange is the upper (root), middle and lower (apical) Root hair density in descending order, red orange and on the contrary, orange is the middle> lower> upper.