桑树植原体含量的周年变化及其对寄主激素水平的影响

ANNIVERSARY VARIATION OF THE PHYTOPLASMAL AMOUNTS IN MULBERRY

采用聚合酶链式反应（ＰＣＲ）检测植原体在桑树体内的分布及其相对含量的周年变化．结果显示，茎部植原体含量在生长季节逐渐升高，７月达到最大，冬季检测不到；叶部与茎部相似但植原体含量在８月达到最大；根部全年均含有植原体，含量较低．此外，用酶联免疫吸附分析（ＥＬＩＳＡ）对桑树内源激素检测的结果显示，病株中生长素、细胞分裂素（Ｚ＋ＺＲ，ＤＨＺ＋ＤＨＺＲ）及赤霉素（ＧＡ３，ＧＡ４）的含量都明显高于健株．

By polymerase chain reaction (PCR),the anniversary variation of phytoplasmal distribution and amount in mulberry plants were determined.It was demonstrated that the phytoplasma was unevenly distributed in its host,and there was a cyclic variation of Its amount at the same part in a yeat.In stem,its amount increased during the growing season,got to the top in July and was undetected in winter.In leaves,the situation was similar to that in stem but the top in August.In roots,its amount was lower and hardly varied in all a year.By enzyme linked immunosolvent assay (ELISA),in addition,it was shown that the levels of auxin,cytokinins (Z+ZR,DHZ+DHZR) and gibberellic acids (GA 3,GA 4) in the diseased plants were higher than those in the healthy ones but abscisic acid did not.It was indicated that the hormone levels in mulberry are related to the phytoplasmal amount.