Fitopatologia Brasileira (2005) 30, 647-649

Carla Zandoná, Yeshwant R. Mehta, Ivan Schuster, Priscila F.R. Alves, Cleide A. Bomfeti, Kelen R.P. Bibanco, Rosana B. Silva and Lucilene P. Lopes (2005)
Mecanismo genético de resistência em três cultivares de algodoeiro a Xanthomonas axonopodis pv. malvacearum
[Genetic mechanism of resistance to Xanthomonas axonopodis pv. malvacearum in three cotton cultivars]
Fitopatologia Brasileira 30 (6), 647-649
Abstract: 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.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
(original language: Portuguese)
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Database assignments for author(s): Ivan Schuster

Research topic(s) for pests/diseases/weeds:
resistance/tolerance/defence of host

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Xanthomonas citri subsp. malvacearum	Cotton (Gossypium)