华南番木瓜病毒病及环斑病毒株系的调查鉴定

根据田间调查、病毒粒子和内含体形态、血清反应、寄主范围和症状、昆虫介体、物理性质、潜育期等试验结果、认为华南４省区的番木瓜病毒病只有ＰＲＶ一种。根据在西葫芦上的症状特点，将ＰＲＶ初步区分为４个株系，即Ｙｓ、Ｖｂ、Ｓｍ和Ｌｃ。在３１３份标样中，它们单独所占比例分别为４０．５７％，１０．２２％，０．６４％，４．４７％，Ｙｓ＋Ｖｂ（复合侵染）占４４．０８％，这表明Ｙｓ为优势株系，Ｖｂ次之，Ｌｃ和Ｓｍ发生少分布不广。研究结果还表明，以前有人报道的ＰＭａＬＶ实则是本研究的Ｖｂ，而不是一个新病毒。

INVESTIGATION AND IDENTIFICATION OF PAPAYA VIRUSES AND RINGSPOT VIRUS STRAINS IN SOUTH CHINA

Papaya ringspot virus(PRV)only was found in this survey in South China.Based on the different symptom expressions on Cucurbita pepo, 4 PRV strains were preliminarily identified.They were Ys, Vb,Sm and L These 4 PRV strains could be basically identifled by the morphology of virus particles and inclusions, serological reactions, host range,transnllssbility by Myzus persicae.and physical properties. The Sm easily caused necrotic local lesions on Chenopodium quinoa, and successfully back-inoculated to papaya and C.pepo.Among a total of 313 papaya virus samplcs collccted,40. 57% of them were infected with Ys,22% with Vb,44.08% with the above 2 strains mixed,4.47% with Lc,0.64% with Sm,This research showed that papaya malformed leaf virus(PMaLV) reported was not a new virus of papaya. but a strain of PRV,i.e. Vb strain.