Biological and serological characterization of viruses of summer squash crops in Yugoslavia

Abstract

A survey on summer squash open field crops was carried out during 2000 and 2001 in order to identify the major viruses infecting these crops in different localities. Plants showed different types of symptoms: mild mosaic, chlorotic spotting, distinctive mosaic, blistering of leaf lamina leaf yellowing, deformation of leaf lamina, knobbed fruits and stunting of plants. The symptoms were very variable but showed the viral nature of the investigated summer squash diseases. The collected samples were tested by bioassay and by two serological methods ELISA and EBIA using cucumber mosaic cucumovirus (CMV), zucchini yellow mosaic potyvirus (ZYMV), watermelon mosaic potyvirus 2 (WMV-2), zucchini yellow flack potyvirus (ZYFV) watermelon mosaic potyvirus 1 (WMV-1), squash mosaic comovirus (SqMV) and cucurbit aphid-borne yellows polerovirus (CABYV) polyclonal antisera. In all tested samples single or mixed infection with ZYMV, CMV and WMV-2 was detected. The most prevalent virus infecting summer squash was ZYMV. This is the first report of ZYMV, the most destructive virus infecting cucurbits, in Yugoslavia. It was also proven that the identified viruses are transmissible by Aphis gossypii in a non-persistent manner, but possible role of seed in virus transmission was not confirmed.

U toku 2000. i 2001. godine izvršen je pregled useva tikvica za jelo da bi se identifikovali osnovni virusi infektivni za tikvice u različitim lokalitetima. Biljke su pokazivale različite simptome: blagi mozaik hlorotičnu pegavost, izraženi mozaik, klobučavost liske, žućenje lista deformacije liske, bradavičaste izraštaje na plodu i kržljavost biljaka. Simptomi su veoma varijabilni i na osnovu njih se ne može obaviti determinacija virusa prouzrokovača oboljenja. Sakupljeni uzorci su testirani biotestom, kao i sa dve serološke metode, ELISA i EBIA korišćenjem poliklonalnih antiseruma na cucumber mosaic cucumovirus (CMV), zucchini yellow mosaic potyvirus (ZYMV), watermelon mosaic potyvirus 2 (WMV-2) zucchini yellow flack potyvirus (ZYFV), watermelon mosaic potyvirus 1 (WMV-1), squash mosaic comovirus (SqMV) i cucurbit aphid-borne yellows polerovirus (CABYV). U svim ispitivanim uzorcima dokazana je pojedinačna ili mešana infekcija sa ZYMV, WMV-2 i CMV. Najčešće infekcije su bile sa ZYMV. Ovaj virus, jedan od najdestruktivnijih virusa na vrežastim kulturama, prvi put je konstatovan u našoj zemlji. Takođe je utvrđeno da se identifikovani virusi prenose na neperzistentan način vašima Aphis gossypii, a moguća uloga semena u pojavi oboljenja nije potvrđena.