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ABSTRACT White mold, caused by Sclerotinea sclerotiorum (Lib.) de Bary is one of the most important diseases of the common bean (Phaseolus vulgaris L.) worldwide. Physiological resistance and traits related to disease avoidance such as architecture contribute to field resistance. The aim of this study was to verify the efficiency of recurrent selection in physiological resistance to white mold, “Carioca” grain type and upright habit in common bean. Thirteen common bean lines with partial resistance to white mold were intercrossed by means of a circulant diallel table, and seven recurrent selection cycles were obtained. Of these cycles, progenies of the S0:1, S0:2 and S0:3 generations of cycles III, IV, V and VI were evaluated. The best (8 to 10) progenies of the seven cycles were also evaluated, in two experiments, one in the greenhouse and one in the field. Lattice and/or randomized block experimental designs were used. The traits evaluated were: resistance to white mold by the straw test method, growth habit and grain type. The most resistant progenies were selected based on the average score of resistance to white mold. Subsequently, they were evaluated with regard to grain type and growth habit. Recurrent selection allowed for genetic progress of about 11 % per year for white mold resistance and about 15 % per year for the plant architecture. There was no gain among cycles for grain type. Progeny selection and recurrent selection were efficient for obtaining progenies with a high level of resistance to white mold with “Carioca” grain type and upright habit.

The objectives of this study were to verify the resistance of common bean lines derived from recurrent selection for white mold resistance and to identify those more stable to different isolates; to compare the aggressiveness of different Sclerotinia sclerotiorum isolates; and to verify isolates x lines interaction. Fifteen common bean lines were evaluated, twelve derived from recurrent selection for white mold resistance, one non-adapted source of resistance (Cornell 605), one moderately resistant and adapted (VC-16) and one susceptible to white mold (Corujinha). Ten isolates were used to inoculate the common bean lines through the straw test. A total of ten experiments were performed, one for each isolate. The randomized complete block design with three replications was used in each experiment. Each plot had five plants inoculated in two main branches, therefore the plot data was the average of the ten evaluations through a scale of nine grades. Diallel analysis were used to estimate the general reaction capacity (lines) and general aggressiveness capacity (isolates) to measure the resistance to white mold and the aggressiveness of the isolates, respectively. The GGE biplot analysis was used to group the common bean lines based on their resistance alleles and identify those more instable to the isolates. The resistance of the lines P4 and P10 was similar to Cornell 605, and they had stable reaction to different isolates and "Carioca" grain type. The lines of the advanced cycles of recurrent selection accumulated more favorable alleles than those of the first cycles, confirming the efficiency of the recurrent selection to increase white mold resistance in common bean. In addition, it was identified more aggressive isolates, UFLA 109 and UFLA 116, and a small magnitude of isolates x lines interaction, indicating a predominance of the horizontal resistance of the lines.

This study was realized with the objective of verifying the resistance to white mold of common bean progenies derived from recurrent selection for resistance to angular leaf spot. The plant material used was obtained from a program of recurrent selection, which was started by crossing seven lines with carioca grain type with ten sources of resistance to angular leaf spot according to the partial diallel scheme. To evaluate the resistance to white mold, it was verified the reaction of 17 parents plus 35 selected progenies, to oxalic acid. Huge heterogeneity among the parents was observed, showing that some of them have resistance alleles to white mold, and thus, there is a possibility of recombine these alleles through the recurrent selection and obtaining progenies with high levels of resistance. Even in initial cycles, some progenies exhibited resistance to white mold similar to the one of cultivar 'G-122', which presents good level of resistance to this disease. This leads to infer that the original population already had some level of physiological resistance for the reaction to absorption of oxalic acid, and also for resistance to angular leaf spot. Thus, among the selected progenies for resistance to angular leaf spot, grain type and high yield, at least four progenies have resistance to white mold similar to the source of resistance 'G-122'.

The common bean cultivar “BRSMG Realce”, recommended for the state of Minas Gerais, has high yield potential and resistance to powdery mildew, bacterial wilt and to anthracnose pathotypes 65, 73, 77, 81, 91, 475 and 479. The plants and pods are high, resulting in lower loss during mechanical harvest

This study compared severity of angular leaf spot in common bean lines, based on the healthy and diseased leaf area, andthe graded scale. We used 12 common bean lines in the dry and rainy seasons. Two contiguous experiments were conducted in eachseason, with and without chemical control of the pathogen. We evaluated the percentage of the healthy and diseased leaf area; severitybased on a graded scale and the area under the disease progress curve; and yield. The diseased or healthy leaf area is efficient toevaluate the severity of angular leaf spot with a sample of 20 to 30 leaflets per plot. For all traits, the results of central and borderareas did not differ, indicating that the evaluation of border rows is unnecessary and, finally, the severity assessment of the upper planthalf can discriminate the lines more efficiently.

A backcross breeding program between commercial common bean cultivars (VC3 and M20) and sources of resistance(Ex-Rico 23 and G122) was conducted with a view toward selecting carioca (beige with brown stripes) progenies resistant to whitemold. Forty-eight progenies (27 F2:6 BC1 and 21 F1:5 BC2) were evaluated for yield, growth habit, grain type and pathogen responseby two methodologies for assessment (“straw test” and “oxalic acid”). The methods were effective in discriminating the progenies,showing differing results, for they may assess different resistance mechanisms. Thus, they should be used together. Simultaneousselection for yield, growth habit, grain type and white mold resistance proved to be viable. The most appropriate strategy was to uselower intensities of selection and prioritize traits such as resistance and grain type, which are essential for commercial acceptance.Two progenies proved their superiority for the breeding program for they combine the traits of resistance and favorable grain type.

The bean cultivar BRSMG União as a new option of a bean cultivar with jalo grains for the state of Minas Gerais. The cultivar BRSMG União had an average grain yield of 9.8% above the mean of the controls (Jalo EEP 558 and BRS Radiante) and was resistant to powdery-mildew.

The cultivar BRSMG Madrepérola, recommended for cultivation in Minas Gerais, has the feature of maintaining a light grain color for a longer period than other Carioca grain cultivars. The yield potential is high and the resistance level good to the major anthracnose races in the region.

The present study aimed to use DNA markers to select plants for the first and second backcross (BC) of two distinct populations of common bean, carrying the QTL for resistance to white mold and RAPD and microsatellite markers to identify the plants of the BC population more similar to their recurrent parent. For this, it was used the lines G122 (resistant - P1) as donor parent and VC3 (susceptible - P2) as recurrent parent for generation of the population F1RC1-GV evaluated for resistance to white mold by means of the SCAR Phs and genotyped with RAPD primers. In the F1RC2-EM population were used the lines Ex Rico 23 (resistant) as donor parent and M20 (susceptible) as recurrent parent evaluated for resistance to white mold, by means of RAPD primers O12.1600 and O15.1800 and genotyped with microsatellite (SSR) primers. Genetic similarity (sgij) between each BC plant and the recurrent parent was estimated using the Sorensen-Dice coefficient. The proportion of the SSR alleles derived from the recurrent parent was also estimated and, simultaneously, genetic similarity and the proportion of SSR alleles were efficient for identifying plants more similar to the recurrent parent. It was found that marker assisted selection (MAS) contributes to reducing the number of BC in at least a generation.

The objective of the research was to investigate the nature and magnitude of the genetic factors involved in theresistance of the common bean to white mold. The lines G122 (resistant) and M20 (susceptible) were crossed to yield F1 and F2generations and F2:3 progenies. The experiment was set up using the random block design with two replications, each of which wasevaluated twice with fungal inoculations being performed on 28 and 38 day-old plants using the straw test method. Six to eight daysafter inoculation evaluations were conducted on individual plants and at the level of means of progenies using a diagrammatic scaleranging from 1 to 9. The additive-dominance model adopted was efficient, and the genetic control of resistance was predominantlydue additive effects. Estimates of broad-sense heritability indicated that selection would be more efficient when based on the meansof progenies and when successive inoculations are employed.

This study aimed to determine the minimum number of plants per plot to assess the field resistance in common beanto white mold. Thirteen cultivars were inoculated with six isolates of Sclerotinia sclerotiorum and evaluated in a randomized blockdesign with three replications and plots consisting of 1-m rows with 15 plants. Plants were inoculated by the straw test as proposedby Petzoldt and Dickson (1996), to evaluate partial resistance in a greenhouse. Eight days after inoculation the disease severity wasevaluated on a 1-9 diagrammatic scale, where 1 = asymptomatic plants to 9 = plant death. To determine the minimum number ofplants per plot, the following methods were used: maximum curvature, segmented linear model, quadratic segmented model and therelative CV model. There were significant differences among cultivars and isolates and no significant cultivar - isolate interaction.It was observed that eight plants per plot is an adequate number to assess the reaction of common bean to white mold.

The aim of this study was to characterize and estimate the genetic similarity among 93 cassava accessions. The DNAamplification was performed with 14 microsatellite primers. The amplification products were separated by a polyacrylamide gelelectrophoresis, showing a polymorphism formation, through which the accessions were discriminated against. The genetic similarityamong accessions of cassava was estimated by the Dice coefficient. Cluster analysis was carried out using the UPGMA method. Thepolymorphic primers amplified a total of 26 alleles with 2-4 alleles per loci. The genetic similarity ranged from 0.16 to 0.96. Theaverage values for observed and expected heterozygosity were 0.18 and 0.46, respectively. Twenty genetic similarity clusters weredetermined, demonstrating diversity among accessions, suggesting the possibility of heterotic hybrid generation.

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 F2:3 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.

Conduziu-se este trabalho, com o objetivo de caracterizar a variabilidade genética entre 116 acessos de açaizeiro da coleção de germoplasma da Embrapa Amazônia Oriental por marcadores microssatélites (SSR). As reações foram efetuadas com base em 116 amostras de DNA, utilizando sete primers SSR. Os níveis de polimorfismo e as estimativas das distâncias genéticas de Roger foram determinados pelas frequências alélicas e agrupado pelo método UPGMA. Os sete locos SSR revelaram 42 alelos com média de 6 alelos por loco. O conteúdo de informação de polimorfismo (PIC) variou de 0,60 a 0,86 com média de 0,75 e as heterozigosidades observada (Ho) e esperada (He) foram de 0,54 e 0,75, respectivamente. A distância genética média entre todos os acessos foi de 0,61, variando de 0 a 0,96. O método UPGMA formou seis agrupamentos distintos delimitados pela distância genética média (dg m = 0,61). Os acessos de açaizeiro possuem alta diversidade para ser explorada em programas de melhoramento, sendo pelo menos quatro deles altamente divergentes com base nos marcadores SSR.The objective of this work was to characterize genetic variability among 116 accessions of assai palm of the Embrapa Eastern Amazon Germplasm Collection, were examined with microsatellite (SSR) markers. The 116 DNA sample were utilized in the reactions with seven SSR loci. The levels of polymorphism and Roger's genetic distance were estimated from allele frequencies and clustered with the UPGMA method. The seven SSR loci revealed 42 alleles, with average of 6 alleles per locus. The polymorphic information content (PIC) varied from 0.60 to 0.86, with average of 0.75 and observed (Ho) and expected (He) heterozygosities were 0.54 and 0.75, respectively. The mean genetic distance between all accessions was 0.61, varying from 0.00 to 0.96. The UPGMA dendrogram presented six distinct groupings, delimited by the mean genetic distance (dg m = 0.61). The accessions of assai palm possess high diversity that may be explored in breeding program and germplasm organization, with at least, four highly divergent accessions.

Objetivou-se, neste trabalho, identificar linhagens de feijão que reúnam, além da resistência à antracnose, alta produtividade de grãos do tipo carioca e resistência à mancha angular. Foram utilizadas 194 linhagens F5:6 extraídas de sete famílias segregantes, selecionadas do cruzamento entre os genitores H147 e B1. A linhagem H147 possui grãos tipo carioca, portadora do alelo Co-5, que confere resistência a várias raças de Colletotrichum lindemuthianum. A linhagem B1 também possui grãos tipo carioca e é portadora do alelo Co-4, que confere resistência a outro grupo de raças do mesmo patógeno. As linhagens foram avaliadas na safra das águas 2005/2006, em Lavras, com a cultivar Talismã e H147 como testemunhas, com base na produtividade e tipo de grãos. Foram selecionadas 99 linhagens, as quais foram avaliadas na safra da seca/2006, juntamente com a testemunha Talismã, com base na produtividade, tipo de grão e resistência à mancha angular. Dessas 99 linhagens, foram selecionadas 24, as quais foram avaliadas na safra de inverno/2006 em Lavras e Lambari, com base no tipo de grão e produtividade. Essas 24 linhagens foram inoculadas com a raça 321 de C. lindemuthianum, que quebra a resistência conferida pelo alelo Co-4, mas não o Co-5. Para verificar a presença do alelo Co4 foi utilizado um marcador SCAR que amplifica um fragmento de 950 pb por meio do primer SAS 13. Foi possível identificar 14 linhagens que possuem a pirâmide de alelos Co-4/Co-5 e entre elas, quatro destacaram-se em todos os caracteres avaliados.The objective of the research was to identify bean strains that possess at the same time resistance to anthracnose, high grain yield of Carioca grain type and resistance to angular leaf spot. 194 strains F5:6 were taken from seven segregating families derived from the cross H147 x B1. The H147 line has Carioca grain type and Co-5 resistance allele to several races of C. lindemuthianum. The B1 line also has the Carioca grain type, and the Co-4 resistance allele against others races of the same pathogen. The strains were evaluated in the spring/summer (2005/2006) in the municipality of Lavras, in the Southern of the State of Minas Gerais, with the Talismã cultivar and H147 line as check, based mainly on grain type and grain yield. 99 strains, together with the Talismã check, were selected and evaluated based on grain yield, grain type and angular leaf spot resistance in the summer (2006) in the same place. From these 99 strains, 24 strains were selected and evaluated in the winter/spring (2006) in two places, Lavras and Lambari, based on the type of grain and productivity, and using the same check. Those 24 strains were also inoculated with the race 321 of C. lindemuthianum that break the resistance of the Co-4 allele, but not of the Co-5. The SCAR marker using the SAS13 primer was used to detect the presence of the Co-4 allele. Fourteen strains were identified that have the Co-4/Co-5 allele pyramid, and, among them, four stand out in all evaluated features.

Objetivou-se neste trabalho, selecionar famílias de feijoeiro promissoras para a produtividade de grãos com tipo de grãos ideal utilizando informações fenotípicas e de marcadores moleculares ligados a QTLs. Foram utilizadas 100 famílias F3:7, avaliadas em três safras, com dois experimentos/safra, totalizando seis experimentos. A primeira safra foi a da seca/2007, na qual conduziu-se um experimento em Lavras-MG e o outro em Ijaci-MG. Nas safras de inverno/2007 e águas 2007/2008, foram conduzidos, em cada uma, um experimento em Lavras-MG e outro em Lambari-MG. Em todos eles foi utilizado o delineamento látice triplo 10x10, com parcelas de duas linhas de dois metros. As famílias foram avaliadas pela sua produtividade de grãos. Em apenas um dos experimentos de cada safra foi avaliado o tipo de grão. Os dados foram submetidos à análise de variância individual e conjunta, por local e por safra. 480 marcadores microssatélites foram testados para identificar polimorfismo entre os genitores. Os oito marcadores polimórficos identificados foram utilizados para a genotipagem das famílias. Entre esses, cinco explicaram parte da variação da produtividade de grãos. Os marcadores explicaram pequena porcentagem da variação fenotípica e apresentaram alta interação QTLs x ambientes. O ganho com a seleção fenotípica para produtividade de grãos foi de 7,4%, e de 9,6% para tipo de grãos, adotando a intensidade de seleção de 5%. A seleção assistida por marcadores foi equivalente à fenotípica para produtividade de grãos, porque apenas um marcador mais estável contribuiu para a seleção com base na média dos ambientes.The objectives of this research were to select com mon bean families with high grain yield and ideal grain type using phenotypical information and molecular markers linked to the QTLs. One hundred F3:7 families were evaluated in three seasons, in two field experiments per season. Two experiments were set up in the counties of Lavras and Ijaci in the dry season/2007, other four experiments were set up in Lavras and Lambari, two in the winter season/2007 and two in the 2007/2008 rainy season. A 10x10 lattice design was used in all experiments, using 2m-long plots and rows 50cm apart. The families were evaluated based on grain yield in all experiments, and based on grain type in one experiment per season. Moreover, 480 microsatellite markers were tested in the parents. Eight markers were polymorphic and used for genotyping the families. Among them five explained part of the grain yield variability and presented high interaction by environments. Selecting 5% of the families the genetic gain was of 7,4% for grain yield and 9,6% for grain type. The marker-assisted selection gave a similar result to the phenotypic selection because only one more stable marker of the along with average grain yield was used in the selection.

O objetivo deste trabalho foi selecionar famílias de feijoeiro-comum, com alta produtividade de grãos, por meio de seleção fenotípica e de seleção assistida por marcadores moleculares (SAM). Foram avaliadas 394 famílias, de quatro populações, e seus seis genitores, no Município de Lavras, em dois experimentos: um na geração F3:4, na safra das águas de 2005/2006, em látice simples 20x20; e outro na geração F3:5, na safra da seca de 2006, em látice triplo 20x20. Foram estimados parâmetros genéticos e fenotípicos, e foi realizada a genotipagem das famílias, com marcadores microssatélites associados a QTL controladores da produção de grãos, previamente identificados. Também foram realizadas análises de associação por marcas simples, entre os marcadores e a produção de grãos, e foi obtido um índice para a SAM. A ampla variabilidade entre famílias e as altas estimativas de herdabilidade possibilitaram obter elevados ganhos com a seleção fenotípica. Os marcadores explicaram pequena percentagem da variação fenotípica e apresentaram alta interação QTL x ambiente e QTL x população. A SAM gerou baixos ganhos e a coincidência de famílias selecionadas pelas duas metodologias foi baixa, o que evidencia, neste caso, a ineficiência da SAM, principalmente pela pouca disponibilidade de marcadores ligados a QTL.The objective of this work was to select common bean families with high grain yield, using phenotypic and marker-assisted selections (MAS). Evaluations were made for 394 families of four populations and their six parents, in Lavras county, Minas Gerais, Brazil. Two field experiments were conducted: one in the F3:4 generation, in the rainy season of 2005/2006, using a 20x20 simple lattice design; and other in the F3:5 generation, in the dry season of 2006, using a 20x20 triple lattice design. Genetic and phenotypic parameters were estimated, and the families were genotyped with microsatellite markers for grain yield quantitative trait loci (QTL), that had been identified previously. Simple marker association analysis was performed between markers and grain yield, and an index was estimated for MAS. The high variability between families and the heritability estimates made high genetic gains possible through phenotypic selection. The markers explained a small percentage of phenotypic variation, and presented high QTL x environment and QTL x population interactions. The MAS achieved small gains, with low coincidence of families selected by both methodologies, showing, in this case, that the MAS inefficiency was mainly due to the low number of available markers.

Objetivou-se no trabalho, selecionar linhagens de feijoeiro comum que reunissem, além da alta produtividade, porte ereto e grãos do tipo Carioca, também a resistência à antracnose e à mancha angular. O material experimental constituiu-se de 143 linhagens oriundas de três famílias segregantes F1:4RC2 {[(G2333 X ESAL 696) X ESAL 696] X CI 140}. Foram conduzidos quatro experimentos em três localidades da região sul de Minas Gerais, avaliando-se a produção, o tipo de grão, o porte e a reação à mancha angular. A reação à antracnose foi determinada a partir de inoculações de plantas jovens de cada linhagem, com as raças 2047 e 1545, mantidas em câmara de nevoeiro por três dias e transferidas para casa de vegetação com irrigação por aspersão, a cada quatro horas. Selecionaram-se quatro linhagens com alta produtividade, porte mais arbustivo, grãos tipo carioca e com resistência à mancha angular (nota até 4). Uma das linhagens selecionada possui o alelo Co-4², outras duas possuem o alelo Co-7 de resistência à antracnose e a última, embora seja suscetível à antracnose, possui resistência à mancha angular (nota 3,97) e maior produtividade de grãos.Aiming to select common bean lines with high grain yield, Carioca grain type, upright plant habit and resistant to anthracnose and angular leaf spot, 143 lines were selected from three families of the cross F1:4RC2 {[(G2333 X ESAL 696) X ESAL 696] X CI 140}. The promising lines were selected based on the agronomical traits in four field experiments, set up in three places in Southern MG State using the square lattice design. The reaction of each line to the anthracnose was evaluated by inoculating the seedlings using the races 1545 and 2047, and kept in humid chamber during three days, and then moved to greenhouse with sprinkle irrigation every four hours. Four lines with high grain yield, upright plant habit, Carioca grain type, and resistance to angular leaf spot (score up to 4) were selected. Among them one of the lines has the Co-4² allele for anthracnose resistance, two lines have the Co-7 allele, and the last one, although susceptible do anthracnose, presented the highest grain yield and angular leaf spot resistance (score 3,97).

Na obtenção de cultivares de feijão com resistência à antracnose, outros atributos agronômicos também devem ser considerados para atender a preferência do consumidor e do produtor. Neste trabalho, objetivou-se identificar famílias de feijão que reúnam, além da resistência à antracnose, alta produtividade, grãos tipo Carioca e porte ereto. Foram cruzados os genitores CNFC 10706, B1 portador do alelo de resistência à antracnose Co-4 e H147 portador do alelo de resistência Co-5. Os três possuem grãos semelhantes ao Carioca. Inicialmente foram avaliadas 224 famílias F2:3, derivadas dos três cruzamentos, mais a cultivar Talismã como testemunha, no inverno/primavera de 2004, em Lavras, com base no tipo de grão. Foram selecionadas 99 famílias F2:4 e avaliadas com a testemunha Talismã, na seca de 2005 em Lavras e Lambari. Essas 99 famílias foram também inoculadas com as raças 593 e 337 de C. lindemuthianum, para auxiliar na seleção daquelas portadoras dos alelos de resistência Co-4 e Co-5. As 35 famílias F2:5 remanescentes, foram avaliadas no inverno/primavera de 2005, em Ijaci, MG. Em todos os experimentos foi utilizado, o delineamento látice quadrado. As 35 famílias foram novamente inoculadas com as raças 65 e 321. Por meio das inoculações e também com o uso de um marcador molecular SCAR ligado ao alelo Co-4, foi possível identificar a constituição genética da maioria das 35 famílias quanto à reação antracnose e selecionar quatro que reúnem, simultaneamente, tipo de grãos semelhante ao Carioca, porte ereto e boa produtividade, além de serem portadoras dos alelos Co-4 e Co-5 de resistência à antracnose.In the common bean breeding, besides anthracnose resistance other agronomical traits need to be considered for achieving the producer and consumer requirements. So the aims of this research were to select common bean families resistant to anthracnose, high grain yield, Carioca grain type and upright plant type. The lines CNFC 10706, B1 and H147 were crossed. All of them have Carioca grain type. The B1 line is resistant to anthracnose due to the Co-4 allele, and the H147 due to the Co-5 allele. From the CNFC 10706 x H147, CNFC 10706 x B1 and H147x B1, 224 F2:3 families plus the check Talismã were evaluated in the winter/spring of 2004, in Lavras county, based on grain type. Ninety nine families were selected and evaluated, plus the check, in the "seca" of 2005 at Lavras and Lambari county. The families were also inoculated with the 337 and 593 races of C. lindemunthianum for selecting those with the Co-4 and Co-5 resistant alleles. The 35 selected families (F2:5) were evaluated in the winter/spring of 2005, in Ijaci county. The square lattice design was used in all experiments. Those 35 families were also inoculated with the 65 and 321 races of C. lindemunthianum. Through the inoculations and the Co-4 SCAR marker the genetic constitutions of most of the 35 families were identified. Four families were selected with Carioca grain type, upright plant type, high grain yield and besides bearing the Co-4 and Co-5 alleles for anthracnose resistance.

A seringueira [Hevea brasiliensis (Willd. ex. Adr. de Juss) Muell.-Arg.] é uma espécie nativa da região amazônica e compreende a maior fonte produtora de borracha natural do mundo. Na busca de condições mais favoráveis ao cultivo, além da busca pela auto-suficiência na produção de borracha natural, o cultivo da seringueira migrou para outras regiões do país. Objetivou-se, com o presente trabalho, estimar a similaridade genética de genótipos de seringueira, provenientes de regiões distintas do país, Lavras-MG (UFLA) e Campinas-SP (IAC), por meio de marcadores moleculares RAPD. A análise foi efetuada em 41 indivíduos, representados por 17 genótipos diferentes, com base em 19 primers, que geraram 121 fragmentos polimórficos. Os dados foram analisados utilizando o software NTSYS-pc - 2.1, por meio do coeficiente de Dice e pelo método das médias (UPGMA). A similaridade genética entre o material analisado variou de 0,56 a 1,00. Na análise do dendrograma, foram observados 18 grupos. Os clones (RRIM600, GT1, PB235, PL PIM e FX2261), utilizados em diferentes repetições, foram idênticos, quando comparados entre si, entretanto o mesmo não foi observado para os clones identificados como RRIM 701. Os resultados obtidos sugerem que o material avaliado na UFLA é o mesmo implantado no IAC, exceto o RRIM 701, mostrando uma ampla variabilidade genética, disponível para estudos e propagação da cultura.The rubber tree [Hevea brasiliensis (Willd. ex. Adr. de Juss) Muell.-Arg.] is a native species from Amazon region, and represents the biggest source of natural rubber in the world.. However, the rubber tree culture has had an expansion to other brazilian regions, in search of more favorable conditions for its cultivation and self-sufficiency in natural rubber. The aim of this work was to estimate genetic similarity among rubber tree clones, from different Brazilian regions, Lavras (UFLA) and Campinas (IAC), by using RAPD molecular markers. The analysis was made using 41 individual plants, which represent 17 different clones, based on 19 primers, which raised 121 polymorphic fragments. The data were analysed with NTSYS-pc - 2.1 software, by using Dice coefficient and UPGMA method. Genetic similarity among the materials showed variation from 0,56 to 1,00. In dendogram analysis, 18 groups were observed. The clones RRIM600, GT1, PB235, PLPIM and FX2261 used in different replications, were identical, when compared among themselves. However, results were not the same for the clones identified by RRIM 701. Results suggest that the UFLA material is the same of IAC material, except for RRIM 701, showing wide genetic variability available for studies and culture propagation.

Caracterizou-se a diversidade genética entre acessos de açaizeiro por meio de marcadores RAPD. Foram analisados 116 acessos conservados na coleção de germoplasma da Embrapa Amazônia Oriental, Belém, PA com base em 28 primers. A matriz binária foi utilizada para a obtenção das dissimilaridades genéticas, pelo complemento artimético do coeficiente de similaridade de Dice, e também para a análise de bootstrap. As dissimilaridades genéticas foram representadas em um dendrograma gerado pelo método UPGMA. Os primers revelaram 263 bandas polimórficas e apresentaram ampla diversidade genética entre os acessos, variando de 0,06 a 0,67, sendo dois acessos de Chaves, PA, os mais divergentes. Mas, alguns acessos da mesma procedência apresentaram baixas dissimilaridades. O dendrograma permitiu a formação de oito grupos, delimitados pela dissimilaridade genética média (dg m: 0,40): dois formados por um único acesso; dois constituídos por dois acessos e os demais por vários subgrupos com acessos de diferentes locais. O número ideal de bandas para a estimativa da diversidade genética entre os 116 acessos foi de 180. Logo, o número de bandas empregado neste estudo foi eficiente para caracterizar com precisão as relações genéticas entre os acessos de açaizeiro. Os acessos divergentes devem ser úteis na formação de coleções nucleares e em programas de melhoramento genético.One characterized the genetic diversity among accessions of assai palm using RAPD markers. One hundred and sixteen accessions conserved in the Embrapa Eastern Amazon germplasm collection, in Belém, PA, were analyzed using 28 primers. The data of the binary matrix were used to estimate the genetic dissimilarities using the arithmetical complement of Dice similarity coefficient and also for the bootstrap analysis. The genetic dissimilarities were represented in a dendrogram generated by the UPGMA method. The primers revealed 263 polymorphic RAPD loci presented wide genetic diversity among the accessions, varying from 0,06 to 0,67, being two accessions of the Chaves, PA the most divergent. But, some accessions of the same origin presented low dissimilarities. The dendrogram allowed the formation of eight groups delimited by the genetic mean dissimilarity (dg m: 0,40): two formed by a single accession; two constituted by two accessions and the others for several sub-groups with accessions of different origin. The ideal number of bands for estimating the genetic diversity among 116 accessions was 180. Therefore, the number of bands used in this study was efficient to characterize with precision the genetic relationship among the accessions of assai palm. The accessions divergent should be useful in the formation of nuclear collections and genetic breeding.

Para identificar QTLs para produtividade de grãos e peso de 100 sementes em feijoeiro (Phaseolus vulgaris L.), foram usados microssatélites influenciados pela seleção natural, identificados na população derivada do cruzamento 'Carioca MG' x 'ESAL 686', conduzida pelo método da população até a geração F24. Foram avaliadas 107 linhagens da geração F8 e 107 da F24 em três épocas distintas: inverno de 2001 (F8:9 e F24:25) em Ijaci; águas de 2001 (F8:10 e F24:26) e secas de 2002 (F8:11 e F24:27) ambos em Lavras. Utilizou-se o delineamento látice simples 18 x 18 em Ijaci, e triplo nas duas outras épocas. Entre os 105 pares de primers utilizados, 30 foram polimórficos nos genitores e no bulk de DNA das linhagens F24 e utilizados, juntamente com as avaliações experimentais, na análise de regressão linear múltipla - Stepwise. Foram identificados sete QTLs para a produtividade de grãos em F8 e seis QTLs em F24, sendo o marcador derivado do 'ESAL686' (BM156) o que exibiu maior efeito para aumentar a produtividade. Para peso de 100 sementes foram identificados cinco marcadores em F8 e dois em F24, todos provenientes do genitor 'ESAL686' e o que contribuiu com o maior peso foi o X61293. A maioria dos QTLs se expressou em um só ambiente.Aiming to identify QTLs for grain yield and for 100 seed weight of common bean (Phaseolus vulgaris L.), microsatellite markers (SSR) affected by natural selection were selected in a population derived from the cross 'Carioca MG' x 'ESAL 686', advanced by the bulk breeding until F24. One hundred and seven F8 lines, and 107 F24, were evaluated in three environments: Winter of 2001 (F8:9 and F24:25) at Ijaci county; spring/summer of 2001 (F8:10 and F24:26) and summer/fall of 2002 (F8:11 and F24:27), both at Lavras county. Simple lattice 18 x 18 experimental design was used at Ijaci, and triple lattice in the others environments. Thirty polymorphic pair of primers were selected among 105, through the parents and a bulk of the F24 lines. The molecular and the experimental data were used in the multiple linear regression analysis (stepwise). Seven QTLs for grain yield were identified in F8 and six in F24, and the BM156 marker (derived from 'ESAL 686') showed the major effect. For 100 seed weight five QTLs were identified in F8 and two in F24, all of them derived from 'ESAL 686', and the major effect was exhibited by X61293 marker. Most of the QTLs expressed in only one environment.

Vários programas de melhoramento genético de feijoeiro no Brasil visam obter cultivares com menor índice de acamamento, ou seja, com porte ereto. Um dos caracteres relacionados a este fenótipo é o 'stay green', que é a senescência tardia do caule e folhas em relação às vagens. Com intuito de verificar a eficiência da seleção direta sobre o fenótipo 'stay green', utilizou-se a descendência do cruzamento entre as cultivares Carioca MG (com 'stay green') e Carioca 300 Vagens (sem 'stay green'). O caráter foi avaliado em 89 famílias F2:3 na safra da seca de 2000 e F2:4 na safra de inverno 2000. Juntamente com as famílias, foram incluídos os dois genitores e nove cultivares em um experimento em látice 10 x 10, com duas repetições nas secas e três repetições no inverno. Foi utilizado um diagrama de notas para avaliação do 'stay green'. Verificou-se que a seleção direta foi pouco efetiva, especialmente quando realizada em uma época para se obter o ganho em outra, em razão da interação famílias x ambientes ser um complicador para obtenção de cultivares com esse fenótipo, como mostrou a herdabilidade realizada de 22,9%. A seleção baseada no comportamento médio das famílias foi mais eficiente.Some common bean breeding programs in Brazil aim at obtaining upright cultivars. The stay green is one of the phenotypes responsible for that type of plant habit, and it means late senescence of stem and leaves in relation to the pods. Aiming at verifying the efficiency of selection for stay green, the cultivars Carioca MG (with stay green) and Carioca 300 Vagens (without stay green) were crossed, and derived 89 F2:3 families that were evaluated in the dry season, and in the winter of year 2000. Besides the families, both parents and nine checks were included in the experiments using a 10 x 10 square lattice, with two replications in the dry season and three in the winter. The treatments were evaluated using a score diagram for stay green. Direct selection showed low efficiency due to the high families by environments interaction, since it was confirmed by the realized heritability of only 22.9%. Selection based on average family performance showed to be more effective.

Agaricus blazei (Murrill) ss. Heinem. é um cogumelo nativo do Brasil que vem despertando a atenção de vários pesquisadores em todo o mundo, devido às suas propriedades farmacológicas e nutricionais. Este trabalho teve por objetivo, analisar a variabilidade genética de alguns isolados utilizados comercialmente, por meio de marcadores RAPD. Foram analisados nove isolados de A. blazei, provenientes de diferentes regiões do Brasil e, como controle, dois isolados de A. bisporus. Todos eles fazem parte da coleção de fungos do Laboratório de Cogumelos Comestíveis e Medicinais do DBI/UFLA. Diferentes primers aleatórios foram utilizados, gerando um total de 139 bandas polimórficas. Procedeu-se a avaliação de similaridade genética entre os isolados pelo coeficiente de Dice e análise de agrupamento pelo método UPGMA. Os resultados revelaram que dos 9 isolados de A. blazei, 6 (CS1, CS3, CS4, CS6, CS8 e CS9) apresentaram uma alta similaridade genética, sendo considerados isolados de uma mesma origem ou clones. O isolado CS2 foi o que apresentou a maior divergência genética em relação aos demais, seguido dos isolados CS5 e CS7, os quais formaram cada um, um grupo a parte, com médias de 60,6%, 88,7% e 91,3% de similaridade genética, respectivamente.Agaricus blazei (Murrill) ss. Heinem. is a Brazilian native mushroom which has called the attention of several researchers all over the world due to its nutritional and pharmacological properties. The objective of this study was to evaluate the genetic variability of some isolates commercially used, using RAPD markers. Nine isolates of A. blazei were analyzed, from different regions in the country, and two isolates of the A. bisporus, which served as control group. All of them are part of the collection of mushroom of the Edible and Medicinal Mushroom Laboratory of DBI/UFLA. For RAPD analysis, different random primers were used, generating 139 polymorphic bands. The genetic similarity evaluation was proceeded between the isolates by means of Dice coefficient and grouping analysis through the UPGMA method. The results showed that from the 9 isolates of A. blazei, 6 (CS1, CS3, CS4, CS6, CS8 e CS9) have shown a high genetic similarity and these were considered isolates of the same origin or clones. The CS2 was the isolate which showed the higher genetic divergence in relation to the others, followed by the CS5 and CS7, with averages of 60.6%, 88.7% and 91.3% genetic similarity, respectively.

O objetivo deste trabalho foi selecionar populações segregantes de feijoeiro promissoras para a produtividade de grãos e com polimorfismo para marcadores microssatélites ligados a QTL relacionados previamente à produtividade de grãos. Foram utilizadas 49 linhagens, avaliadas em dois experimentos em látice triplo. Sete linhagens foram selecionadas e intercruzadas no esquema dialélico e também genotipadas com 24 marcadores microssatélites ligados a QTL previamente identificados. As populações foram avaliadas em blocos completos casualizados, com três repetições. Foram observadas diferenças significativas entre as capacidades gerais (CGC) e específicas de combinação (CEC) e os efeitos não-aditivos foram mais pronunciados. As linhagens RC1-10 e Z-9 se destacaram em razão das elevadas estimativas de g i. Entre os microssatélites, 25% foram polimórficos. Foram selecionadas quatro populações para a seleção de famílias com base na avaliação das linhagens, na análise dialélica e no polimorfismo entre os marcadores microssatélites. Destacou-se a população RC1-10 x Z-9, formada por genitores de alta CGC, com alta média e CEC e ainda grãos do tipo Carioca. Considerando o baixo número de microssatélites polimórficos obtidos nas populações, pode-se concluir haver necessidade de utilização de maior número de microssatélites ligados a QTL da produção de grãos.The objective of this work was to select promising common bean segregant populations for grain yield and polymorphic to microsatellite markers for grain yield QTL previously identified. Fourty nine lines were utilized and evaluated in two field trials in a triple lattice. Seven lines were selected and intercrossed in a diallel scheme and genotyped with 24 single sequence repeat (SSR) markers associated to grain yield QTL previously identified. Populations were evaluated in a randomized block design with three replications. Significant differences in the general and specific combining ability were observed, and the non-additive effects were highest. The outstanding lines were RC1-10 and Z-9 due to the highest g i values. Twenty five percent of the markers were polymorphic. Four populations were chosen for selecting families based on the line evaluations, the diallel analysis and the polymorphism of SSR markers. Among the segregant populations, RC1-10 x Z-9 is remarkable for having high CEC, high grain yield of the Carioca type, and their parents expressed high CGC. Considering the low number of polymorphic microsatellite markers in each population, it is necessary to use higher number of microsatellite markers associated to grain yield QTL.

Este trabalho teve como objetivo estimar a divergência genética entre acessos de açaizeiro conservados na coleção de germoplasma da Embrapa Amazônia Oriental, em Belém, PA, por meio de descritores morfoagronômicos. A avaliação foi realizada em 87 acessos, com base em 22 caracteres: sete relativos à planta, três à floração, três a frutos e nove à produção de frutos, no período de 1995 a 2001. Foram efetuadas análises univariadas e multivariadas, com estimativas das dissimilaridades obtidas pela distância euclidiana média padronizada, e formação dos agrupamentos obtida pelos métodos UPGMA e Tocher. Os acessos apresentaram alto índice de variação na maioria dos caracteres. As distâncias genéticas entre os pares de acessos variaram de 0,09 a 1,87, com média de 1,39. O método UPGMA dividiu os acessos em cinco grupos, enquanto o de Tocher formou 24 agrupamentos. Os cinco acessos indicados como mais divergentes devem compor programas de intercruzamentos, para obtenção de genótipos superiores.The objective of this research was to estimate the genetic divergence among accessions of the assai palm, sampled in the germplasm collection of Embrapa Amazônia Oriental based on morphoagronomic traits, at Belém, PA. The 22 morphoagronomic traits were evaluated in 87 accessions, from 1995 to 2001. Among the 22 traits, seven were relative to the plant, three to the flowering, three to the fruit, and nine to the fruit production. The traits were analyzed using univariate and multivariate analysis. The estimates of the dissimilarities were obtained by the average Euclidian distance with standardized data, and the groupings by UPGMA and Tocher methods. The accessions presented high variation index in the majority of the characters. Genetic distances among accession pair varied from 0.09 to 1.87, with average of 1.39. The method UPGMA divided the accessions into five groups, while the Tocher method formed 24 groupings. The five accessions indicated as more divergent must be used in breeding programs aiming at the obtention of superior genotypes.

The objective of this study was to evaluate the effect of fertilization by autopollen on maize kernel weight. Fivesingle cross hybrids (30F90. A2555, DKB333B, 2223, and 2324) were planted and hybrid leaf samples taken for DNAextraction. The crosses 2223XDKB333B; 2223XA2555; 2324XDKB333B and 2324XP30F90 were performed. Ten kernels ofeach ear of each cross were separated, sown in a greenhouse and the DNA of the respective seedlings was extracted, to identifythe kernel origin. The results obtained here demonstrated that allopollen increased the mean kernel weight by 16.5mg (gainof 4.65%). The proportion of sampled allopollen to self pollen was statistically equal, according to the c2 test, demonstratingthat there were no significant differences between the proportion of fertilized and sampled allopollen and autopollen in the ear.It was concluded that compared to autopollen, allopollen increases the mean weight of fertilized grain.

O objetivo deste trabalho foi identificar famílias de feijoeiro com resistência a Colletotrichum lindemuthianum e Phaeoisariopsis griseola e com outros fenótipos agronômicos desejáveis. As famílias utilizadas foram obtidas do cruzamento entre a linhagem H91, portadora de três alelos de resistência à antracnose, com três famílias F2:5 resistentes à mancha-angular, derivadas da cultivar Jalo EEP 558. Foi utilizado o delineamento látice quadrado em todos os experimentos. Inicialmente, foram avaliadas 144 famílias F2:3, no inverno de 2004, em Lavras, MG, com base no tipo de grão. Foram selecionadas 80 famílias F2:4 e avaliadas com a testemunha BRSMG Talismã, no período das águas de 2004/2005, no mesmo local. Considerando-se o tipo de grão e a resistência à mancha-angular e antracnose, foram mantidas 48 famílias F2:5, que foram avaliadas na seca de 2005, em Lavras e Lambari, MG. Essas 48 famílias passaram por inoculação das raças 2047, 73 e 1545 de C. lindemuthianum, para verificação da presença dos alelos de resistência Co-4², Co-5 e Co-7, respectivamente. Foram identificados genótipos da maioria das 48 famílias, quanto à reação à antracnose, das quais se destacaram quatro, em relação ao tipo de grão semelhante ao 'Carioca', de porte ereto, produtividade elevada e resistência à mancha-angular.The objective of this work was to select common bean families resistant to Colletotrichum lindemuthianum and Phaeoisariopsis griseola and, also, with superior agronomical traits. Families used were obtained from crosses of H91 lineage, bearer of three alleles resistant to anthracnose, and F2;5 families derived from the cultivar Jalo EEP 558, which is resistant to angular leaf spot. Square lattice design was used in all experiments. Initially the F2:3 families (144) were evaluated in the winter of 2004, in Lavras county, MG, Brazil, based on grain type. Eighty families (F2:4) were selected and evaluated with the check BRSMG Talismã, in the wet periods of 2004/2005, in the same place. Considering grain type, anthracnose and angular leaf spot resistances, 48 families (F2:5) were selected and evaluated in the dry period of 2005, in two places, Lavras and Lambari, MG. These 48 families were also inoculated with the 2047, 73 and 1545 races of C. lindemuthianum, in order to verify the presence of alleles of resitance Co-4², Co-5 and Co-7, respectively. Genotypes with anthracnose resistance were identified in most families, four of which are outstanding for their ideal 'Carioca'-like grain, with upright plant, high grain yield and resistance to angular leaf spot.

O objetivo deste trabalho foi selecionar descritores morfoagronômicos quantitativos para caracterizar acessos de açaizeiro para produção de frutos e avaliar a eficiência do descarte dos descritores redundantes. Foram avaliados 28 descritores, envolvendo caracteres da planta (7), de floração (4), de frutos (6) e agronômicos (11), em 87 acessos, de 21 procedências, pertencentes à coleção de germoplasma da Embrapa Amazônia Oriental, em Belém, PA. Os dados foram submetidos à análise de componentes principais, usando a distância euclidiana média padronizada, com seleção dos descritores baseada na informação simultânea de dois procedimentos e na eficiência do descarte, pela comparação dos agrupamentos formados pelo método de Tocher entre os 28 caracteres e os selecionados. No primeiro critério, foram selecionados dez descritores e no segundo, 21; com base nos dois procedimentos, 22 descritores foram considerados importantes, representando redução de 21,43% dos caracteres avaliados. O descarte de descritores não ocasionou perda de informação. Portanto, sete caracteres da planta, três de floração, três de frutos e nove agronômicos são descritores relevantes na avaliação de germoplasma de açaizeiro para frutos.The objective of this work was to select morphological and agronomic quantitative descriptors to characterize accessions of euterpe palm for the production of fruits and to evaluate the efficiency of descriptors selection. Twenty-eight descriptors were used, including seven characters from plant, four from flowering, six from fruits, and eleven agronomic traits, evaluated in 87 accessions from 21 origins, at Embrapa Amazônia Oriental Collection, in Belém, PA, Brazil. Data were submitted to the principal components analysis, using the standardized average Euclidian distance. The selection of the descriptors was accomplished based on information from two procedures. Their efficiency was compared by groups formed among the 28 selected characters using the Tocher method. In the first criterion, ten descriptors were selected, and in the second 21 descriptors, but 22 were considered important in the two methods, representing a reduction of 21.43% of the evaluated traits. There was no loss of information. Therefore, seven characters from plant, three from flowering, three from fruits, and nine agronomic traits are important descriptors in the evaluation of euterp palm germplasm to fruits.

Visando associar na seleção de novos genótipos de feijoeiro comum características favoráveis como o tipo de grão, a produção de grãos e a resistência à mancha angular e antracnose, foi realizado o cruzamento entre a cultivar Rosinha e a linhagem ESAL 693, ambas precoces e com hábito de crescimento tipo I. Adicionalmente, a linhagem ESAL 693 é resistente à mancha angular e à antracnose e a 'Rosinha' é suscetível a ambas. As famílias foram avaliadas da geração F­2:3 até F­2:6 sendo ao final, selecionadas as 23 superiores. Em todos os experimentos foi utilizado o delineamento látice e como testemunhas a ESAL 693 e 'Rosinha'. Foi observada ampla variabilidade genética entre as famílias incluindo as 23 selecionadas, tendo sido obtidas estimativas de herdabilidade de 51,29% para a produtividade de grãos, 74,11% para o tipo de grão e 93,64% para a reação à mancha angular. Nove famílias destacaram-se em relação às três características estudadas; porém, duas com grãos semelhantes ao 'Carioca' e uma com grão semelhante ao 'Rosinha', apresentando também resistência à antracnose e boa capacidade de cozimento. Existe a possibilidade de seleção, dentro dessas famílias, de linhagens precoces e que reúnam as características desejadas.Aiming to select common bean plants with high grain yield, ideal grain type and resistant to anthracnose and angular leaf spot, the cultivar Rosinha and the line ESAL 693 were crossed. Both have early cycle, growth habit I, and ideal grain types. ESAL 693 is resistant to angular leaf spot and anthracnose, and 'Rosinha' is susceptible for both traits. The families were evaluated from F­2:3 to F­2:6 generation, and the best 23 were selected. Square lattice design, and the checks 'Rosinha' and ESAL 693 were used in all experiments except in the first when 'Rosinha' was not included. A broad genetic variability was detected even among the remaining 23 families, when the heritability estimated for grain yield was 51,29%, for grain type was 74,11%, and for resistance to angular leaf spot was 93,64%. Among the best nine families in these three traits, two with 'Carioca' grain type and one with 'Rosinha' were also resistant to anthracnose and higher cooking capacity. So, there is a possibility to select lines with the desired phenotypes within these families.

The effect of natural selection on microsatellite simple sequence repeat (SSR) alleles was investigated in two distinct common bean (Phaseolus vulgaris) generations (F8 and F24) derived from the cross between the P. vulgaris cultivars Carioca MG x ESAL 686. The F2 segregant population was propagated by the bulk method and 107 plants were sampled in two generations (F8 and F24). Each plant generated one family which was replicated by the bulk method to F8:11 and F24:27 families from which DNA was extracted. Thirty pairs of microsatellite primers were polymorphic for the parents and the bulk of the F24:27 families. Out of 30 loci selected by natural selection, 29 microsatellite alleles came from the Carioca MG parent and one allele came from the ESAL 686 parent. Natural selection affected all the generations and its intensity was specific for each locus and generation. Therefore all the alleles selected at each locus must be important for adaptation in a breeding program.

O objetivo deste trabalho foi identificar entre as linhagens de feijoeiro resistentes à antracnose, aquelas com alta produtividade, tipo de grãos Carioca, resistência à mancha-angular (Phaeoisariopsis griseola) e porte arbustivo. Foram avaliadas 256 linhagens oriundas de um programa de melhoramento genético por retrocruzamentos. Quatro experimentos foram conduzidos em três locais no Estado de Minas Gerais, em que foram avaliadas a produção e o tipo de grãos, o porte e a reação à mancha-angular. Observaram-se acentuadas diferenças genéticas entre as linhagens e, conseqüentemente, as herdabilidades foram também elevadas e propiciaram acentuados ganhos com a seleção. A maioria das correlações fenotípicas estimadas entre os caracteres não foi significativa, indicando a possibilidade de seleção de linhagens superiores em todos os fenótipos de interesse. Foram selecionadas cinco linhagens com alto potencial produtivo, grãos do tipo Carioca, porte arbustivo e maior nível de resistência à mancha-angular, sendo que duas delas possuem uma pirâmide de alelos de resistência à antracnose.Besides the anthracnose resistance, the objective of this research was to identify lines with Carioca grain type, high grain yield, angular leaf spot resistance (Phaeoisariopsis griseola), and upright plant architecture. Two hundred and fifty six lines from a backcross breeding program aiming to get anthracnose resistance lines were evaluated. Four field trials were set up in three places of the Minas Gerais State, and grain type and yield, reaction to angular leaf spot and plant architecture were measured. Great genetic differences were observed among the lines and therefore, the heritabilities estimates were also of great magnitude and assure considerable selection progress. The majority of the phenotypic correlation among the evaluated traits were not significant, suggesting the possibility to select improved lines for all traits. Five superior lines were selected, with high grain yield, Carioca grain type, angular leaf spot resistance and upright plant architecture which could become new cultivars. Two of them have a pyramid of anthracnose resistance alleles.

The objective of this study was to identify RAPD and SSR markers associated with a resistant allele for angular leaf spot (Phaeoisariopsis griseola) from the line 'ESAL 550', derived from the Andean 'Jalo EEP 558' cultivar, to assist selection of resistant genotypes. The resistant line 'ESAL 550' and the susceptible cultivar 'Carioca MG' were crossed to generate F1 and F2 populations. One hundred and twenty F2:3 families were evaluated. The DNA of the 12 most resistant families was bulked and the same was done with the DNA of the 10 most susceptible, generating two contrasting bulks. One RAPD and one SSR marker was found to be linked in coupling phase to the resistant allele. The SSR marker was amplified by the primer PV-atct001(282C), and its distance from the resistant allele was 7.6 cM. This is the most useful marker for indirect selection of resistant plants in segregating populations. The RAPD marker was amplified by the primer OPP07(857C) linked in coupling phase to the resistant allele, and distant 24.4 cM. Therefore, this RAPD marker is not so useful in assisting selection because it is too far from the resistant allele.

The obtention of genetically improved cultivars is the main objective of breeding programs, whose efficiency is increased by a careful choice of parents. Based on both general (GCA) and specific (SCA) combining abilities for grain yield, the purpose of this research was to choose the most promising populations of common beans, for line selection. GCA and SCA were measured by means of a complete diallel without reciprocals, using twelve cultivars/lines. Parents and corresponding F2 segregating populations were evaluated for grain yield by a 9 x 9 triple square lattice design. It was found that the segregating populations differed in grain yield, with predominant SCA effects, but with significant GCA effects as well. Among the populations derived from parents with positive GCA values, Aporé x CI-128, CI-128 x Pérola, PF-9029975 x Ouro Negro, and CI-128 x Ouro Negro also showed positive SCA values and high grain yields, therefore being the most promising populations for grain yield improvement. The highest values of specific combining ability were observed in populations H-4-7 x ESAL 693, CI-128 x Pérola, and A-285 Rudá x IAC Carioca Aruã, which must be the most segregating ones. Hybrid combinations with a high SCA deriving from at least one parent with high GCA were: Pérola x CI-128 and Ouro Negro x Pérola. Although line ESAL 693 presented the lowest GCA value, one of its derived populations, ESAL 693 x H-4-7, had the highest SCA and heterosis values. The high correlation between heterosis and SCA indicates that heterosis can be useful when SCA is not available.

Earliest possible prediction of seed-yield potential of autogamous crop populations increases breeding program efficiency by saving time and resources. Alternatives for obtaining seed-yield predictions were compared by evaluating four common-bean populations in F1 and F2 generations together with the parents. Mean components (m + a' and d) and variances were estimated. The potential of each population was predicted by using both these and the Jinks and Pooni (1976) procedure, which allows probability estimation of each population of originating lines surpassing a determined standard. Estimate efficiency was determined by evaluating performances of 62 F5:7 families from each population. Mean component m + a' estimates obtained for the F1 and F2 generations proved efficient in predicting seed yield of F7 generation lines as did d for estimate variance among F7 generation families. In addition, the Jinks and Pooni (1976) procedure proved efficient in early prediction of common bean population genetic potentials, especially when using the m + a' estimate.

Plant resistance to pathogens is the most efficient form of disease control. However, identification of resistant genotypes is often difficult, especially when the genetic basis for the host-pathogen relationship is unknown. This study was carried out to test a methodology capable of providing, in a simple way, information about host vertical and horizontal resistance as well as pathogen virulence. A simulation using twenty, ten, and five pathogen races and twenty hosts was carried out. Host reaction was controlled by ten genes with two alleles each. Eight genes had little effects, one had medium and the other strong effects. Genetic control of pathogenicity was identical to that of the host. Only homozygous genotypes were used for pathogens and hosts in this simulation, with no epistatic effects. Simulation was based on the expected disease severity with the inoculation of twenty hosts with twenty pathogen races, according to additive and interactive models proposed by Parlevliet and Zadoks (Euphytica 26: 5-21, 1977). Data were analyzed by model IV of Griffing, using a partial diallel scheme. A high correlation was found between general reaction ability (GRA) and potential host resistance, which proved to be an indicator of horizontal resistance. A high correlation between general aggressivity ability (GAA) and potential pathogenicity of the race also proved to be an aggressivity indicator. Specific interaction ability (SIA) is an indicator of host vertical resistance and pathogen virulence. Simulation with a lower number of races (ten and five) showed similar results. SIA was significant in both the interactive and additive models.A resistência de plantas a patógenos é a forma mais viável de controle de doenças. No entanto, a identificação de genótipos resistentes muitas vezes é difícil, principalmente pelo desconhecimento da relação patógeno-hospedeiro. O objetivo desse trabalho foi testar uma metodologia que conseguisse, de maneira simples, informar sobre a resistência vertical e horizontal dos hospedeiros e também sobre a agressividade e virulência dos patógenos. Para isso foi realizada uma simulação utilizando vinte, dez e cinco raças do patógeno e vinte hospedeiros. A reação do hospedeiro era controlada por 10 genes com 2 alelos cada. Desses genes, 8 eram de pequeno efeito, 1 de médio e 1 de grande. No patógeno o controle genético era idêntico ao hospedeiro. Foi considerada na simulação apenas a presença de locos em homozigose, com ausência de epistasia. A simulação baseou-se na severidade de doença esperada com a inoculação dos vinte hospedeiros com as vinte raças do patógeno, segundo os modelos aditivo e interativo (com modificações) propostos por Parlevliet e Zadoks (Euphytica 26: 5-21, 1977). A análise dos dados foi através do modelo IV de Griffing (1956), utilizando o esquema de dialelo parcial. Encontrou-se uma alta correlação entre capacidade geral de reação (GRA) e a resistência horizontal, e também alta correlação entre capacidade geral de agressividade (GAA) e a patogenicidade potencial da raça, mostrando ser indicador da agressividade. A capacidade específica de interação (SIA) revelou-se um indicador da resistência vertical do hospedeiro e da virulência do patógeno. A simulação com número menor de raças (10 e 5) mostrou resultados similares aos obtidos com as 20. Tanto no modelo interativo quanto no aditivo a SIA mostrou-se significativa, indicando ser possível a existência da interação patógeno com hospedeiro nos dois modelos.

O objetivo do trabalho foi selecionar famílias de feijão adaptadas às condições de inverno do sul de Minas Gerais. A partir das populações segregantes L3272 x (Carioca x TU) e L3272 x ESAL 601 foram selecionadas 230 famílias que foram previamente avaliadas no cultivo de inverno no sul de Minas Gerais. Foram mantidas 103 famílias, sendo 79 de ciclo normal e 24 precoces. Esses dois grupos de famílias foram avaliados independentemente, em dois locais, no inverno de 1995. As famílias selecionadas foram avaliadas em um único experimento, no inverno de 1996. Em todos os experimentos foram avaliados os caracteres produtividade de grãos, número de dias para o florescimento, e reação ao patógeno Erysiphe polygoni. Os resultados mostraram heterogeneidade entre as famílias no que tange a todos os caracteres estudados, permitindo a seleção de famílias adaptadas às condições de inverno. A correlação genética entre o número de dias para o florescimento e a reação ao patógeno Erysiphe poligoni foi baixa e negativa. As estimativas das herdabilidades no sentido amplo foram relativamente elevadas quanto a todos os caracteres, nos dois grupos de famílias avaliados. A herdabilidade no sentido amplo, referente a famílias de ciclo normal, foi semelhante à estimativa da herdabilidade realizada.The purpose of the present work was to select common bean families adapted to the winter conditions of South of Minas Gerais State, Brazil. 230 families were selected from segregant populations L3272 x (Carioca x TU) and L3272 x ESAL 601. They were evaluated in the winter crops in the South of Minas Gerais, and the 103 most promising ones were selected. The families selected were divided in two sets. The first, with 79 normal cycle families, and the second, with 24 precocious families, which were assessed in two locations, in 1995. The best 24 families were evaluated in the winter of 1996. The traits considered were grain yield, number of the days to flowering and reaction to Erysiphe polygoni. The results showed heterogeneity among families to all traits studied. This heterogeneity allows the selection of families adapted to the winter conditions. The genetic correlation between number of the days to flowering and reaction to Erysiphe polygoni is low and negative. The estimates of heritabilities (broad sense) are relatively high to all traits in the two sets evaluated. The heritability (broad sense) of normal cycle families is similar to realized heritability.

The genetic divergence of 27 common bean (Phaseolus vulgaris L.) cultivars from different races was evaluated using RAPD markers. The association of this divergence with some indirect variability estimates obtained in field experiments was also assessed. Genetic distances were calculated using Sorensen-Dice's similarity coefficient, displayed in a dendrogram (UPGMA method), and by projection in two-dimensional space. Analysis of molecular variance (AMOVA) was used to evaluate the distribution of variance between and within domestication centers. RAPD marker genetic diversity within these centers was also calculated. The correlations between estimates of genetic distances obtained with RAPD markers and estimates of Mahalanobis' generalized distances, specific combination ability, and midparent heterosis obtained from morpho-agronomical traits were also determined. RAPD markers were efficient in separating cultivars according to domestication centers. However, only for Middle American domestication center was there good agreement between the grouping obtained and the proposed classification of races. The genetic divergence obtained with these markers was similar to that provided by morpho-agronomical traits. RAPD markers, however, were not efficient in predicting the specific combination ability and midparent heterosis expressed in crosses.Avaliou-se a divergência genética de 27 cultivares de feijão (Phaseolus vulgaris L.) de diferentes raças, verificando-se ainda o grau de associação desta divergência com algumas estimativas indiretas de variabilidade obtidas em experimentos no campo. As distâncias genéticas foram obtidas pelo complemento do coeficiente de similaridade de Sorensen-Dice e a representação simplificada destas distâncias realizada a partir de um dendrograma (método UPGMA) e pela projeção no espaço bidimensional. Foi realizada uma análise de variância molecular para partição da variância entre e dentro dos centros de domesticação, e calculada a diversidade genética do marcador RAPD dentro destes centros. Também foram estimadas correlações entre as estimativas de distâncias genéticas obtidas a partir destes marcadores com estimativas de distâncias generalizadas de Mahalanobis, capacidade específica de combinação e heterose média, obtidas a partir de características morfo-agronômicas. Verificou-se que os marcadores RAPD foram eficientes na separação dos cultivares, de acordo com os centros de domesticação. Considerando as raças, no entanto, apenas para o centro de domesticação mesoamericano houve uma boa correspondência entre o agrupamento obtido e a classificação proposta. A avaliação da divergência genética por meio destes marcadores forneceu resultados similares aos obtidos, a partir de características morfo-agronômicas, mas estes não foram eficientes na predição da capacidade específica de combinação e da heterose dos cruzamentos.

The alterations caused by eight different similarity coefficients were evaluated in the clustering and ordination of 27 common bean (Phaseolus vulgaris L.) cultivars analyzed by RAPD markers. The Anderberg, simple matching, Rogers and Tanimoto, Russel and Rao, Ochiai, Jaccard, Sorensen-Dice, and Ochiai II's coefficients were tested. Comparisons among the coefficients were made through correlation analysis of genetic distances obtained by the complement of these coefficients, dendrogram evaluation (visual inspection and consensus fork index - CIC), projection efficiency in a two-dimensional space, and groups formed by Tocher's optimization procedure. The employment of different similarity coefficients caused few alterations in cultivar classification, since correlations among genetic distances were larger than 0.86. Nevertheless, the different similarity coefficients altered the projection efficiency in a two-dimensional space and formed different numbers of groups by Tocher's optimization procedure. Among these coefficients, Russel and Rao's was the most discordant and the Sorensen-Dice was considered the most adequate due to a higher projection efficiency in a two-dimensional space. Even though few structural changes were suggested in the most different groups, these coefficients altered some relationships between cultivars with high genetic similarity.Foram avaliadas as alterações provocadas por oito diferentes coeficientes de similaridade no agrupamento de 27 cultivares de feijão analisados por marcadores RAPD. Foram testados os coeficientes de Anderberg, simple matching, Rogers e Tanimoto, Russel e Rao, Ochiai, Jaccard, Sorensen-Dice e Ochiai II, sendo as comparações entre eles realizadas pelas correlações entre as distâncias genéticas obtidas pelo complemento destes coeficientes, e também pela avaliação dos dendrogramas (inspeção visual e índice CIC), eficiência da projeção no espaço bidimensional e grupos formados pelo método de otimização de Tocher. Os resultados evidenciaram que a utilização de diferentes coeficientes de similaridade provocou poucas alterações na classificação dos cultivares em grupos, sendo as correlações obtidas entre as distâncias genéticas maiores que 0,86. Apesar disso, foi observado que diferentes coeficientes alteraram a eficiência da projeção no espaço bidimensional e formaram número diferenciado de grupos pelo método de otimização de Tocher. Dentre estes, o de Russel e Rao apresentou resultados mais discordantes em relação aos demais e o de Sorensen-Dice foi considerado o mais adequado devido a uma maior eficiência de projeção no espaço bidimensional. Mesmo provocando poucas mudanças na estrutura dos grupos mais diferenciados, estes coeficientes alteraram alguns relacionamentos entre cultivares com alta similaridade genética.

BRSMG Majestoso was developed by UFLA/Embrapa Rice and Beans/UFV/EPAMIG and released for the stateof Minas Gerais, Brazil, in view of its high average yield, superior grain quality, anthracnose resistance and low susceptibilityto angular leaf spot.

A cor da semente do feijão, Phaseolus vulgaris L. (Leguminosae-Faboideae), é de grande importância para o consumo no Brasil, por isso, o conhecimento do seu controle genético, em um cruzamento particular, orienta no dimensionamento da população segregante para a seleção do fenótipo de interesse. Então, objetivou-se determinar o controle genético de alguns caracteres relacionados à cor da semente, a partir do cruzamento Rosinha x ESAL 693 (tipo carioca) e prever as chances de seleção dos fenótipos semelhantes aos das cultivares Carioca e Rosinha. Foram avaliadas as cores de fundo e a presença/ausência de listras e halos nas sementes produzidas em plantas F2 e em plantas das famílias F2:3. Constatou-se apenas um gene responsável pela ocorrência de listras na semente e outro pela cor bege clara ou escura de fundo da semente tipo carioca. Para os caracteres presença ou ausência de halo e tipo de semente igual ou diferente da cultivar Rosinha, foram identificados dois genes em cada caso. Excetuando-se a presença de listra, certamente estão também envolvidos genes modificadores no controle dos demais caracteres. Considerando todos os caracteres, esperam-se 11,26% das plantas F2 produzindo sementes do tipo carioca ideal e 12,82% das plantas com sementes do tipo rosinha

Visando identificar famílias com alta capacidade de cozimento dos grãos, foram avaliadas as 23 superiores em produtividade e tipo de grãos, das gerações F2:6/F4:6 (sementes com 8 meses) e F2:7/F4:7 (sementes com 1 mês), provenientes do cruzamento Rosinha x ESAL 693, todas precoces e de hábito de crescimento tipo I. Avaliou-se a capacidade de cozimento e de absorção de água com o cozedor experimental JAB-77 tipo minor, utilizando-se 25 sementes de cada família por parcela e 2 repetições. As famílias diferiram quanto aos dois caracteres e expressaram desempenhos semelhantes nas duas idades de avaliação. Quatro famílias (1, 13, 14 e 15) apresentaram alta capacidade de cozimento nas duas épocas e, entre elas, destacaram-se a 13 a 14 e a 15, as quais apresentaram as maiores estimativas de herdabilidade, sendo as mais promissoras para a seleção de linhagens. A ausência de correlação entre os dois caracteres indica que a capacidade de cozimento é que deve ser avaliada para fins de seleção.