Although much appreciated in Brazil, commercial popcorn is currently cropped on a fairly small scale. A number of problems need to be solved to increase production, notably the obtaintion of seeds with good agronomic traits and good culinary characteristics. With the objective of developing superior genotypes in popcorn, a second cycle of intrapopulation recurrent selection based on inbred S 1 families was carried out. From the first cycle of selection over the UNB-2U population, 222 S 1 families were obtained, which were then divided into six sets and evaluated in a randomized complete block design with two replications within the sets. Experiments were carried out in two Brazilian localities. The analysis of variance revealed environmental effects for all evaluated traits, except popping and stand, showing that, for most traits, these environments affected genotype behavior in different ways. In addition, the set as source of variation was significant for most of the evaluated traits, indicating that dividing the families into sets was an efficient strategy. Genotype-by-environment interaction was detected for most traits, except popping expansion and stand. Differences among genotypes were also detected (1% F-test), making viable the proposition of using the genetic variability in the popcorn population as a basis for future recurrent selection cycles. Superior families were selected using the Smith and Hazel classic index, with predicted genetic gains of 17.8% for popping expansion and 26.95% for yield.

-The objective of this work was to determine the combining ability and heterosis, for productivity and yield components, in diallel hybrids derived from crossings between BRSMG-Talismã, IPR Uirapuru, FT Soberano, BRS Campeiro, IAC Tybatã, and IPR Juriti parent cultivars. Fifteen hybrids were generated from diallel crosses, excluding reciprocals. The general and specific combining abilities were significant for plant height, number of pods per plant, number of seeds per plant, number of seeds per pod, 50-seed weight, and grain yield, indicating the occurrence of both additive and nonadditive genetic effects. The best strategy to be adopted is the use of BRS Campeiro, FT Soberano and BRSMG-Talismã cultivars in common bean breeding programs involving selection. The most promising combinations were 'IPR Uirapuru' x 'IAC Tybatã', 'IPR Uirapuru' x 'FT Soberano', 'BRS Campeiro' x 'IPR Juriti', and 'BRS Campeiro' x 'IAC Tybatã'. The parents of these hybrids presented high estimates of specific combining abilities. Hybridization of cultivars belonging to distinguished commercial groups propitiates higher heterosis values in the segregant population.Index terms: Phaseolus vulgaris, additive effects, diallel analysis, interpopulational breeding, intrapopulational breeding, nonadditive effects. Capacidade combinatória e heterose em cultivares de feijoeiro-comumResumo -O objetivo deste trabalho foi determinar a capacidade combinatória e a heterose, quanto à produtividade de grãos e aos componentes de rendimento, em híbridos derivados dos cruzamentos dialélicos entre as cultivares BRSMG-Talismã, IPR Uirapuru, FT Soberano, BRS Campeiro, IAC Tybatã, e IPR Juriti. Quinze híbridos foram gerados a partir dos cruzamentos dialélicos, sem os recíprocos. As capacidades de combinação geral e específica foram significativas em relação à altura de planta, ao número de vagens por planta, número de sementes por planta, número de sementes por vagem, peso médio de 50 sementes e à produção de grãos, e indicaram a ocorrência de efeitos aditivos e não aditivos. A melhor estratégia a ser adotada em programas de melhoramento que envolvam seleção é o uso das cultivares BRS Campeiro, FT Soberano e BRSMG-Talismã. As combinações mais promissoras foram 'IPR Uirapuru' x 'IAC Tybatã', 'IPR Uirapuru' x 'FT Soberano', 'BRS Campeiro' x 'IPR Juriti' e 'BRS Campeiro' x 'IAC Tybatã'. Os parentais destes híbridos apresentaram elevadas estimativas de capacidade específica de combinação. A hibridização de cultivares pertencentes a grupos comerciais distintos propicia maiores valores de heterose.Termos para indexação: Phaseolus vulgaris, efeitos aditivos, análise dialélica, melhoramento interpopulacional, melhoramento intrapopulacional, efeitos não aditivos.

RESUMO. Seis variedades de milho pipoca (Amarela, Roxa, Branca, Rosa-claro, Beija-flor e Viç osa), Zea mays L. (Poaceae), seus 15 hí bridos F 1's e 15 hí bridos F 1's recí procos foram avaliados em um delineamento em blocos ao acaso, com trê s repetiç õ es, instalado em Viç osa, nos anos agrí colas 90/91 e 91/92, e Visconde do Rio Branco, em 91/92. Avaliaram-se os seguintes caracteres: altura da planta, altura da espiga, peso de grã os e capacidade de expansã o. A variedade Viç osa foi indicada para ser usada em hí bridos ou como fonte de linhagens para uso em programas de melhoramento intra ou interpopulacionais. O hí brido Viç osa x Roxa mostrou-se o mais desejá vel considerando rendimento e capacidade de expansã o. As combinaç õ es Viç osa com Roxa e Rosa-claro com Beija-flor foram indicadas para iniciar programa de seleç ã o recorrente recí proca, uma vez que foram as que mais se complementaram em relaç ã o ao peso de grã os e capacidade de expansã o. Nestes programas, atenç ã o especial deve ser dada à capacidade de expansã o, que é a caracterí stica mais limitante nestes hí bridos. Apesar de haver evidê ncia de efeitos recí procos para todos os caracteres, verificou-se pouca importâ ncia dos mesmos. Palavras-chave: Zea mays L, rendimento, capacidade de expansã o.ABSTRACT. Diallel analysis of the combining ability of popcorn cultivars. A study of six improved varieties of popcorn ('Amarela', 'Roxa', 'Branca', 'Rosa-claro', 'Beija-flor' and 'Viç osa'), Zea mays L. (Poaceae), and their fifteen hybrids F1 was carried out in Viç osa, in the agricultural years of 90/91 and 91/92, and Visconde do Rio Branco, in 91/92. The traits evaluated were plant height, ear corn height, yield and popping expansion, in order to indicate the best strategies for joint improvement of all characters. The 'Viç osa' variety was indicated to be used in hybrids or inbred lines development in intra or interpopulation improvement methods. 'Viç osa x Roxa' hybrid showed best results when considering yield and popping expansion. The combinations 'Viç osa' with 'Roxa' and 'Rosa-claro' with 'Beija-flor' were recommended to begin reciprocal recurrent selection program, because they were complementary in relation to yield and popping expansion. In these programs, more attention must be given to popping expansion, because its seems to be the biggest problem in hybrids. The reciprocal effects were not important for any trait.

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The cultivars, AB 136 and G 2333 both

Soybean cultivars with "plasticity" traits, such as good branching ability, ensure compensation of gaps in planting. The cultivar INT7100 IPRO provides excellent branching ability and plant architecture, facilitating control of pests and diseases, and it contains the biotechnology INTACTA RR2 PRO®. It is resistant to stem canker, brown stem rot, and bacterial blight.

The objective of this study was to evaluate of the genetic similarity among 129 sugarcane clones. For that, it was evaluated the number of stalks per plot, the average mass of the stalks, the mass of 10 stalks, the medium brix and the brix production in kilograms for each plot. The data were analyzed through several Canonic Variables and Tocher method using the Mahalanobis (D 2 ii') distance. The results obtained by Tocher method and graphic dispersion shown that the most dissimilar clone was TUC77519. On the other hand, the most similar clones were RB 975056 and RB 915006. The number of stalks per plot (NSP) and the brix production per kilograms per plot (BKP) were characteristics that most contributed most for the genetic variability.