Diagnóstico molecular na interação Geminivírus - tomateiro.

Abstract

The tomato plant is one of the main vegetables in terms of economical and food importance, being cultivated in all the tropical and subtropical regions of the world. Among the problems occur in tomato crop, there are diseases caused by viruses that can vary widely in terms of severity, including answers tolerant than just alter the physiology of host plant, until severe responses that can culminate in the death of the plant. The objective of the project was to diagnose the presence of Geminivirus in tomato plants by molecular markers and identify possible sources of resistance to the virus. The methodology consisted of a survey of tomato producing areas in the region of Cariri Paraibano, municipality of Serra Branca (area 1) and municipality of Amparo (area 2) in order to identify the incidence of the virus in the crop. Foliaceous tomato plant samples were collected for observation, classification of the symptoms, and evaluation of the natural resistance. The foliar samples were also used for DNA extraction, using the method CTAB and Kit Qiagen. Soon after, the viral DNA was evaluated through specific PCR using the molecular markers PAL1v1978 and PAR1c496. Of the 46 samples collected in area 1 and 28 samples in area 2, characteristic symptoms of geminiviruses (whitening of the veins, yellowish spots, leaf deformation, roughness) were observed, corresponding to 13,53% and 8,24%, respectively. In the molecular analysis the DNA extracted by the kit Qiagen it showed up in good quality and quantity, when there is possible the visualization of directions of DNA amplified in the size, brought near, of 1,2 Kb, corroborating with the diagnosis of the DNA viral.