Herdabilidade da resistência de pessegueiro à bacteriose foliar

Abstract

The use of cultural techniques and adapted cultivars become viable production of peach (Prunus persica L. Batsch) in Brazil. In most producing regions of the country there isn’t accumulation of adequate cold, the relative humidity is high in summer and with strong winds in some regions, contributing to the spread of pathogens. One of the most important diseases of peach is the bacterial leaf spot (BLS) (Xanthomonas arboricola pv. pruni). This disease is difficult to control and affects leaves, shoots and fruits, and favorable climatic conditions can cause reduced productivity of peach. To reduce its occurrence in areas susceptible to disease, the use of resistant cultivars is essential. The aim of this study was to classify genitors and progenies as to BLS and the heritability of this character. The evaluations were conducted in the collection of genotypes peach of the experimental orchard of the UTFPR, Pato Branco - Paraná. The experiment was conducted in three cycles of vegetative growth of peach (2011/2012, 2012/2013 and 2013/2014) and involved parents considered resistant and susceptible to BLS, and progeny derived from crosses of these genotypes. In field was evaluated the severity and defoliation of genotypes, to further measure the healthy area duration (HAD). It was found that the resistance to X. arboricola pv. pruni is conferred by quantitative inheritance, and none of the genotypes showed immunity to the disease. The average observed heritability (0,51) indicates that the use of these genitors can be effective in developing cultivars with higher levels of resistance.