Pedro Crescêncio Souza Carneiro

Characterization of genetic variability among common bean genotypes by morphological descriptors

The purpose of this study was to characterize the genetic variability in 100 genotypes of the Active Germplasm Bank of common bean of the Federal University of Vicosa, by morphological descriptors, classify them in groups of genetic similarity and to identify the degree of relevance of descriptors of genetic divergence. The genotypes were evaluated based on 22 quantitative and qualitative morphological descriptors. The high-yielding genotypes V 7936, Gold Gate, LM 95103904, 1829 S 349 Venezuela, and PF 9029975, CNFC 9454 and Fe 732015, with upright growth, have potential for use as parents in common bean breeding programs. By genetic divergence analysis, the genotypes were clustered in eight groups of genetic dissimilarity. By methods of principal components, 9 of the 22 descriptors were eliminated, for being redundant or little variable, suggesting that 10-20 morphological descriptors can be used in studies of characterization of genetic variation.

Common bean breeding for resistance to anthracnose and angular leaf spot assisted by SCAR molecular markers

The objective of the present study was to assess the genetic potential of inbred carioca common bean families from five populations derived from crossings involving elite lines and a disease-resistant line (Ruda-R), and to assess the efficiency of SCAR molecular markers in selecting plants resistant to anthracnose and angular leaf spot, at the time of bulk formation. Plant architecture, yield and grain type were assessed. Significant effect among families within population was observed, suggesting wide genetic variability for the characters assessed. Twenty-six superior families were selected. The families contained the greatest number of markers, identified by SCAR molecular markers in the F4 generation. Eighteen of these families were resistant to the races 65 and 453 of Colletotrichum lindemuthianum and five were resistant to the race 63.23 of Pseudocercospora griseola. Thus selection assisted by SCAR markers, in the F4 generation, was an important tool in common bean breeding.

Caracterização fenotípica e molecular de genitores de feijão tipo carioca quanto à resistência a patógenos

Abstract€–€The present study aimed at the phenotypic and molecular characterization of 31€genotypes of thecarioca-type common bean regarding the resistance to anthracnose, rust and angular leaf spot (ALS) pathogens.Thirteen pathotypes of Colletotrichum lindemuthianum , two of Uromyces appendiculatus and seven of Pseudocercospora griseola were inoculated. In the molecular characterization, five molecular markers, identifiedin advance, and linked to the different alleles of pathogens’ resistance, were used. Seven genotypes showedresistance to 12€pathotypes of C.€lindemuthianum . Nine genotypes presented resistance to five pathotypes of P.€griseola . Ten genotypes were resistant to the pathotypes of U.€appendiculatus . The lines VC€2, VC€3 andVC€5, besides Ruda-R (line pyramided with five genes which confer resistance to some pathotypes of anthracnose,rust and ALS), were the stood out for multiple resistance to the pathogens above described. Molecularpolymorphism was detected between the most genotypes with Ruda-R, which indicates the possibility of usingthe molecular markers SCARF10, SCAR Y20, SCARAZ20, SCARH13 and OPX1 1 .Index terms:

Common bean breeding to improve red grain lines

The purpose of this study was to evaluate the performance potential of red bean lines, derived from populations of the first cycle of recurrent selection in the common bean breeding program of the Federal University of Vicosa, Minas Gerais. In the F3:5, F3:6 and F3:7 generations, 243 families from 18 segregating populations were evaluated. These families were conducted by the bulk-within-families method and from the best, 154 lines were obtained and evaluated in the dry season of 2006 (F7: 9) and of 2007 (F7: 10), Coimbra - MG. The estimates of genetic and phenotypic parameters revealed variability among families. The method bulk within F3-derived families proved useful for bean breeding. The most promising lines that may be included in future tests of value for cultivation and use (VCU), and will possibly be recommended for planting in the state of Minas Gerais, were derived from the populations Vermelhinho/AN9022180//Vermelhinho/Vermelho2157, Vermelhinho//Vermelhinho/ IAPAR81,Vermelhinho/LR720982// Vermelhinho/AB136 and Vermelhinho/AB136//Vermelhinho/ Vermelho2157.