Sele??o de progênies de maracujazeiro-amarelo vigorosas e resistentes à verrugose (Cladosporium cladosporioides)

摘要

The scab (Cladosporium cladosporioides) is a harmful disease of the yellow passion fruit vine (Passiflora edulis f. flavicarpa). It attacks young tissues of leaves, branches, flowers and fruits, causing necrosis at the infected site. Three passionfruit cultivars and 39 half-sibling progenies were evaluated for plant vigor and scab incidence at the Department of Phytotechnics of the Federal University of Vi?osa, in Brazil, in February 2003. A randomized block design with three replication and four plants per parcel were aplayed. Plant vigor and incidence of scab were evaluated according to a scale varying from one (less vigor or low incidence) to five (higher vigor or higher incidence). The selection was simulated independently for resistance to scab and plant vigor and by means of two selection indexes involving the two characters. The selection index 2, with weight -2: 1 for resistance to scab and plant vigor, respectively, gave the most balanced estimated selection gains, around 10% for each one of the characters, and was adopted in this work. Heritabilities of 44,68% and 56,53% were estimated for resistance to scab and plant vigor, respectively. The progenies 2, 3, 6, 7, 19, 20, 22, 27, 32 and 36 were selected based in the selection index 2.