Identificação de marcadores microssatélites relacionados ao escurecimento de grãos em feijão

Abstract

Resumo -O objetivo deste trabalho foi identificar marcadores microssatélites ligados ao loco de características quantitativas (QTL) responsável pelo escurecimento tardio do tegumento de feijões do tipo carioca, a fim de reduzir o tempo de avaliação necessário para seleção quanto a essa característica. Foram utilizados dados de avaliação fenotípica de 185 progênies F 2:3 derivadas do cruzamento VC-3 x 'BRSMG Majestoso', para o estudo do controle genético do escurecimento dos grãos. Com esses dados, foram confeccionados dois "bulks" segregantes de DNA, empregados para a avaliação de 444 pares de primers SSR. Os aplicativos computacionais GQMOL e Sisvar foram utilizados para avaliar as segregações, confeccionar um grupo de ligação e realizar análises de marca simples e de regressão múltipla pelo método "backward". Oito marcadores apresentaram polimorfismo nos "bulks". Seis desses marcadores foram agrupados em um grupo de ligação de 80,49 cM, e destes, três mostraram-se estreitamente ligados ao QTL responsável pelo escurecimento tardio dos grãos. O marcador PVM02TC116 cossegregou com o QTL em questão, e os marcadores PVESTBR-98 (2,00 cM) e PV176 (12,24 cM) flanqueiam essa região, o que sugere elevada eficiência para possível uso na seleção assistida.Termos para indexação: Phaseolus vulgaris, locos de características quantitativas, marcador molecular, seleção assistida, SSR. Identification of microsatellite markers associated with seed-coat darkening in common beanAbstract -The objective of this work was to indentify microsatellite markers linked to the quantitative trait loci (QTL) responsible for the late seed-coat darkening in the carioca type common bean, in order to reduce the evaluation time spent in selection for this trait. Data of seed-coat darkening of 185 F 2:3 progenies derived from the cross VC-3 x 'BRSMG Majestoso', were used. Out of these data, two segregating DNA bulks were constructed to evaluate 444 SSR primers. The applicatives GQMOL and Sisvar were used to evaluate the segregations, elaborate the linkage groups, and to perform single mark and regression analysis (backward method). Eight markers were polymorphic in the DNA bulks. Six of them were mapped in a 80.49-cM linkage group. Out of these six markers, three were very close to the QTL responsible for the late grain darkening. The PVM02TC116 marker co-segregate with that QTL, and the PVESTBR-98 (2.00 cM) and PV176 (12.24 cM) ones flank it, which indicates that high efficiency in the assisted selection is possible.

Estimates of genetic parameters of late seed-coat darkening of carioca type dry beans

“…Silva et al (2008). A fact which proves this association is identification of a molecular marker associated with tannin content and the grain darkening scores performed by Couto et al (2010). Thus, tannin content may be used as a criterion for selection of progenies with late seed-coat darkening of grains.…”

Genetic Control of Seed Coat Darkening in Common Bean Cultivars from Three Market Classes

“…Simple sequence repeat (SSR) and single nucleotide polymorphism (SNP) markers closely linked to these genes have already been identified (Couto et al, 2010;Felicetti et al, 2012), and some of them have already been validated using populations with carioca seeds (Alves, 2014;Alvares et al, 2019). Alvares et al (2019) used lines obtained from four different populations to validate the microsatellites PVM02TC116 and Pvsd-1158, whereas Alves (2014) used these two markers and another four SSR markers (PVESTBR-98, PV176, Pvsd-1157, and Pvsd-0028) in lines from one population.…”

Research Article Identification of SSR markers linked to partial resistance to soybean rust in Brazil from crosses using the resistant genotype IAC 100

“…Leaf tissue samples from each progeny (F 4:5 and F 7:8 ) and from the parents were collected during the R3 stage, labelled in plastic bags and stored in ultra-freezer (-80ºC) until they were used for nucleic acid extraction. Genomic DNA samples from the parents and progenies were purified according to a protocol based on the cetyltrimethyl ammonium bromide (CTAB) technique proposed by Doyle and Doyle (1990), with a few modifications (Couto et al, 2010). Approximately 50 mg of leaf tissue for each genotype was macerated and placed into 1.5-mL microtubes.…”