VARIABILIDADE DE Fusarium oxysporum f. sp. Lycopersici E RESISTÊNCIA DE TOMATEIRO À MURCHA-DE-FUSÁRIO

This study aimed to investigate the variability of populations of Fusariumoxysporum f. sp. lycopersici causal agent of fusarium wilt of tomato, fromcommercial fields in the Regions Agreste and Sertão, Pernambuco State, andevaluate aspects related to disease resistance. Different commercial tomatofields were visited, plants with disease symptoms were collected for isolationsand, subsequent characterization of the pathogen populations in relation toepidemiological components and races. Additionally resistance sources wereidentified and tomato progenies evaluated for disease resistance undergreenhouse conditions. In the studied areas exists higher prevalence of F.oxysporum f. sp. lycopersici race 2 in relation to race 1, however, larger variabilitywas obtained in relation to epidemiological components. The cvs. BHRS-2,3,Floradade, Grande Rio, Secullus, Rotan-4 and TX 450-08 were the mostresistant to the races of the pathogen, being therefore suitable for the tomatogenetic breeding for disease resistance.Este estudo teve por objetivos investigar a variabilidade de populações deFusarium oxysporum f. sp. lycopersici, agente causal da murcha-de-fusário dotomateiro, oriundas de plantios comerciais da região Agreste e Sertão doEstado de Pernambuco e avaliar aspectos relacionados a resistência à doença.Diferentes áreas de plantio comercial de tomateiro foram visitadas e plantascom sintomas da doença coletadas para obtenção dos isolados e, posterior,caracterização das populações do fitopatógeno, quanto aos componentesepidemiológicos e raças. Complementarmente, foram identificadas fontes deresistência e avaliadas progênies de tomateiro quanto a resistência à doença,em casa de vegetação. Nas áreas estudadas, existe alta prevalência da raça 2de F. oxysporum f. sp. lycopersici em relação a raça 1, no entanto, variabilidademaior foi obtida quando estudados os componentes epidemiológicos. Ascultivares BHRS-2,3, Floradade, Rio Grande, Secullus, Rotan-4 e TX 450-08apresentaram-se como as mais resistentes às raças do patógeno, sendo portantoindicadas para o melhoramento genético da planta visando resistência a doenç

Plant breeding in the semiarid region of Brazil: examples of success

The Northeastern region of Brazil comprises the Caatinga biome (900,000 km²) part of which is a semiarid region with rainfed and irrigated production systems. Among the successful breeding programs are cashew and cotton. The first led to a substantial increase in nut production in Ceará, Rio Grande do Norte and Piauí and the second bred a naturally colored cotton fiber, now processed in small clothing industries in Paraiba, exporting to 11 countries. In the lower-middle São Francisco valley, the previously grown onion was replaced by improved varieties, on 90% of the production area, and by industrial tomato, introduced by research in 1972, which came to be used on more than 80% of the area at the time. The participation of the private sector and continuity of breeding programs were crucial for the success. More examples of success are expected with the establishment of postgraduate courses in Agricultural Sciences in the Semiarid region