越冬病枝水培与PCR结合检测枣疯病植原体的存活动态

Detection of living phytoplasma in jujube witches' broom by combination of hydroponic culture of diseased overwintering branches and polymerase chain reaction

以感染枣疯病的婆枣为材料进行了以下两方面的研究:其一,采集越冬期和越冬前后的枣疯病枝条并对越冬期枝条进行水培,通过萌芽的症状观察和PCR检测,发现病枝条韧皮部和萌芽内均可扩增出1.5 Kb的枣疯病植原体特异性条带,此结果表明,枣疯病植原体可以在-10℃左右的地区在枣树枝条内安全越冬;其二,利用PCR技术检测了冬季轻病树的病枝、根部、主干及树冠内未表现症状的枝条韧皮部,结果只在病枝内检测到植原体的存在,而在其它部位都未发现植原体。

The branches of Ziziphus jujuba var. pozao infected by witches＇ broom were studied from two aspects. First, through symptom observation and PCR detection of the diseased overwintering branches which were collected respectively in late autumn, winter, and early spring and cultured in hydroponic system, the specific band of phytoplasma of the size of 1.5 Kb fragment was amplified from the diseased branches＇ phloem and the bud. The results indicated that phytoplasma can survive safely in the regions with the lowest temperature of - 10℃ in winter. Secondly, no phytoplasma was detected in the roots, trunks and branches without visible symptom of infected trees through the PCR except for diseased branches. Based on these results, it can be inferred that jujube phytoplasma only exists in di-seased branches in newly infected jujube trees.