Abstract:

As one of the most important economic crops in Xinjiang，Hami melon（Cucumis melo L.）is of high reputation over the world. However，virus diseases are currently a serious threat for sustainable production of Hami melon because of the lack of effective antivirus chemical and appropriate virus-control method. To develop virus-resistant varieties，young leaves of Hami melon with virus-infected symptoms were collected from Shanshan county，which is one of the major Hami melon growing locations in Xinjiang. This specimen was biologically cloned by three local lesion passages in Chenopodium quinoa. Such biologically cloned virus is hereafter called an isolate，which was further identified by RT-PCR amplification，molecular cloning and sequencing. The results showed that the purified isolate was Watermelon mosaic virus（WMV），which was then inoculated to some common commercial melon varieties and 13 international universal hosts for identification of melon powdery mildew physiological races by mechanical rubbing，the laboratory evaluation of virus resistance indicated that there was no immune and high resistance varieties in the present study. The number of resistance，moderate resistance，sensitivity，and high sensitivity varieties were 1，11，10，and 3，respectively，out of these，cultivar Iran H showed resistance to WMV isolate.

Key words: melon, Watermelon mosaic virus, evaluation for the resistance, isolate