SciELO - Scientific Electronic Library Online

 
vol.30 issue6Localization of hydrogen peroxide during defense response of tomato against Stemphylium solaniPreservation methods and growth of Xanthomonas campestris pv. viticola in culture medium varying temperature, pH and NaCl concentration author indexsubject indexarticles search
Home Pagealphabetic serial listing  

Fitopatologia Brasileira

On-line version ISSN 1678-4677

Abstract

ZANDONA, Carla et al. Genetic mechanism of resistance to Xanthomonas axonopodis pv. malvacearum in three cotton cultivars. Fitopatol. bras. [online]. 2005, vol.30, n.6, pp. 647-649. ISSN 1678-4677.  http://dx.doi.org/10.1590/S0100-41582005000600013.

Angular leaf spot of cotton (Gossypium hirsutum) caused by Xanthomonas axonopodis pv. malvacearum (Xam) is an economically important disease in Brazil. The severity of the disease depends on climatic conditions and the type of cultivar. The disease is not satisfactorily controlled by the use of chemicals, but with control depending basically on the use of healthy seed and resistant varieties. Cultivars DeltaOPAL, EPAMIG Liça and Fibermax 986 are the best sources of resistance to Xam, since besides resistance, these cultivars possess desirable agronomic characteristics. The objective of the present investigation was to verify the mechanism of resistance to angular leaf spot in these three resistant cotton cultivars by crossing them with the susceptible cultivar BRS Ita 90, under glasshouse conditions. Parental populations F1 and F2 were evaluated in the glasshouse after inoculation with an aggressive isolate of Xam. All the three of the cultivars revealed different mechanisms of resistance. In cvs. DeltaOPAL and EPAMIG Liça, resistance is governed by one dominant gene, whereas in cv. Fibermax 986, the resistance is governed by two dominant, independent and complementary genes.

Keywords : Gossypium hirsutum; angular leaf spot; black arm.

        · abstract in Portuguese     · text in Portuguese     · Portuguese ( pdf epdf )

 

Creative Commons License All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License