Seleção a campo no Recôncavo Baiano de híbridos de limoeiros para resistência à tristeza

Abstract

In Brazil, there is a low diversification of the citrus species used, which makes crops very vulnerable to diseases. As the Citrus tristeza virus (CTV) is endemic in Brazil, it is possible to select CTV-resistant hybrid varieties for its control. In this work, we evaluated the reaction of lemon trees and their hybrids to natural infection by CTV isolates in Cruz das Almas, in the Reconcavo Baiano region. Volkamerian lemon tree (VKLT), Cravo lemon tree (CLT), Palm orange tree (POT), Valencia orange tree (VOT), Sunki mandarin tree (SMT), Swingle citrumelo tree (SCT) and Trifoliate orange tree (TOT) were used as parents. VKLT x CLT, VKLT x POT, VKLT x VOT, SMT x (CLT x TOT) and CLT x SCT hybrids were produced. These were kept in the field, being evaluated as for stem pitting intensity when aged between four and seven years. The crosses that provided a higher percentage of CTV-resistant hybrids were CLT x SCT, VKLT x CLT and SMT x (CLT x TOT). On the other hand, the crosses between VKLT and POT, VKLT and VOT showed a higher percentage of susceptible hybrids. In this work, CTVresistant lemon hybrids were generated. The information will allow to direct new crosses of lemon, aiming to obtain hybrids with a higher level of tristeza resistance.