POLIMORFISMO DE NOVOS MARCADORES MICROSSATÉLITES DE Phaseolus vulgaris DESENVOLVIDOS A PARTIR DE REGIÕES ALVOS HOMÓLOGAS E LIGADAS À GENES DE RESISTÊNCIA A NEMATOIDE EM Glycine max

Abstract

The adversities to which the bean has been exposed contribute to the high diversity found in the crop, making selection possible. Allied to the alteration of landscapes for planting, the most varied phytosanitary problems arise, like the gall nematodes. An important form of nematode management is the use of resistant varieties, the DNA markers are a rapidly valuing biotechnological tool that can help in the exploration and use of available genetic resources. We aimed to characterize the polymorphism of candidate microsatellite markers in P. vulgaris associated with genes that confer resistance to the nematode. The experimental development took place in the laboratory and greenhouse located at the IF Goiano - Campus Urutaí. Twenty-six bean cultivars belonging to Embrapa's germplasm were genotyped for nine microsatellite markers and phenotyped as to the behavior of hostility to Meloidogyne incognita and M. javanica. Genomic DNA was obtained from young leaves using the CTAB 2% method. PCRs were performed according to the reagent manufacturer Invitrogen. The PCR fragments were separated by electrophoresis and stained with silver nitrate. The design of the phenotyping assays used were carried out in 26 genotypes, being completely randomized with five replications. The inoculation was carried out 7 days after germination, with a suspension of 3000 eggs of second stage juveniles. The evaluations took place 45 days after inoculation, according to the Hartman method. The plants were classified according to the level of resistance and tolerance. For genotyping, polymorphism was observed, but we cannot yet say that this genetic marking corresponds to resistance genes, considering that the phenotyping bioassays did not show any variation in resistance and susceptibility to the M. incognita nematode. Finally, six new microsatellite markers of P. vulgaris heterologous to target regions of genes that confer genetic resistance to nematodes in Glycine max are available for validation.