Monitoring of Bremia lactucae races in lettuce in São Paulo State in 2014

• Grant number: 14/11242-8
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: September 01, 2014
• End date: July 31, 2016
• Field of knowledge: Agronomical Sciences - Agronomy - Plant Health
• Principal Investigator: Leila Trevisan Braz
• Grantee: Marcus Vinícius Marin
• Host Institution: Faculdade de Ciências Agrárias e Veterinárias (FCAV). Universidade Estadual Paulista (UNESP). Campus de Jaboticabal. Jaboticabal , SP, Brazil

Abstract

Lettuce is the group most consumed vegetables in Brazil; however, the difficulty of producing it has been increasing, mainly due to infestation of production areas by Bremia lactucae, which causes downy mildew. Despite the benefits provided by planting resistant cultivars, the use of resistance genes in lettuce, has a short duration, because of the wide genetic variability of B. lactucae. Thus, it appears that the annual monitoring of places for the presence or absence of new strains of B. lactucae is of great importance since it becomes possible to select genes that confer resistance to disease. Given the above, the aim of this study: monitor the races of B. lactucae in lettuce main producing places of São Paulo. The isolates collected will be taken to the Laboratory of Genetics and Breeding vegetable crops, the Department of Plant Production (UNESP-FCAV) were inoculated on the susceptible cultivar Solaris, until you get the number of sporangia enough to use in the test for differentiation of races. After the isolates will be inoculated on the differential cultivar and, on the same day of the first onset of sporulation in the susceptible cultivar 'Green Tower (DM 0)', the differential cultivar was evaluated for presence or absence of lesions sporulating and necrotic spots. All materials that have proved susceptible to certain races will have their values summed within each group and the result is separated by a slash, and we could identify the breeds present in each isolate. (AU)