Testers for combining ability and selection of papaya hybrids resistant to fungal diseases

Abstract

Genetic resistance represents a sustainable alternative to disease control in papaya crop. The purpose of this studywas to evaluate the use of testers to estimate combining ability and select hybrids resistant to black spot, phoma spot and chocolatespot. The experiment was conducted in a randomized block design with two replications and 20 plants per plot. The severity ofphoma spot and black spot on leaves and the lesion area of black spot and chocolate spot on fruits were evaluated in twoseasons. The combining ability of the following crosses is negative for all traits: tester ‘JS 12’ with ‘Sunrise Solo’ and ‘Kaphoro SoloPV’; tester ‘Americano’ with ‘Caliman M5’, ‘Sunrise Solo’, ’Baixinho de Santa Amália’ and ‘Waimanalo’; and tester ‘Maradol’with ‘Caliman G’, ‘Caliman AM’ and ‘Sunrise Solo PT’. These results may be useful in breeding for disease resistance byhybridization.

Keywords

• Carica papaya
• Asperisporium caricae
• Phoma caricae-papayae
• Colletotrichum gloeosporioides
• specifc combining ability.