%0 Journal Article %T Sele£¿£¿o de linhagens de melancia resistentes ao Watermelon mosaic virus e ao Papaya ringspot virus %A Beserra J¨²nior %A Jos¨¦ Evando Aguiar %A Figueira %A Antonia dos Reis %A Maluf %A Wilson Roberto %J Ci¨ºncia e Agrotecnologia %D 2007 %I Universidade Federal de Lavras %R 10.1590/S1413-70542007000500044 %X twenty advanced watermelon breeding lines, derived from the cross between cv. crimson sweet (susceptible) and pi 595201 (resistant to wmv and prsv-w), were screened for resistance to both potyviruses. the twenty lines, among with crimson sweet and pi 595201, were inoculated with either wmv or prsv-w, in two different greenhouse trials. plants were evaluated for symptoms 35 and 49 days after the first inoculation (dai), using a scale from 1 (no symptoms) to 5 (severe mosaic and foliar distortion). evaluations at 35 dai indicated that lines 1, 2 and 20 had good levels of resistance to both wmv and prsv-w, with ratings of 1,95, 1,80 and 2,25 for wmv, and of 2,50, 2,30 and 2,50 for prsv-w, respectively. lines 5, 7 and 13 were resistant to wmv only, whereas lines 3, 10 and 18 were resistant to prsv-w only. the reaction of the lines 49 dai remained essentially unchanged. the existence of lines with resistance to wmv only and to prsv-w only, along with lines with resistance to both viruses, indicates that resistance to wmv and prsv-w are under control of different genes. %K cucurbitaceae %K genetic control %K potyvirus. %U http://www.scielo.br/scielo.php?script=sci_abstract&pid=S1413-70542007000500044&lng=en&nrm=iso&tlng=en