Agronomic potential of genebank landrace elite accessions for common bean genetic breeding

Plant breeding efficiency relies mainly on genetic diversity and selection to release new cultivars. This study aimed to identify landraces with favorable characteristics that can be used as parents of segregating populations in common bean (Phaseolus vulgaris L.) breeding programs. Firstly, ten bean genotypes were selected because they showed promising agronomic performance, and the following seven adaptive traits of four commercial bean cultivars were evaluated: i) plant height; ii) diameter of the stem; iii) height of the insertion of the first pod; iv) pod number per plant; v) grain number per pod; vi) weight of a thousand grains and vii) grain yield. The accessions BAF 07, BAF 44, and BAF 45 are promising in terms of increasing plant height, and accession BAF 01, in terms of reducing plant height. The accession BAF 07 was also the most promising in terms of a plant ideotype that combines higher plant height, maximum height of the insertion of the first pod, and increment in grain yield. Moreover, the selection can be made between and within accessions, because genetic variability is also present within landraces.

Agronomic potential of genebank landrace elite accessions for common bean genetic breeding

Plant breeding efficiency relies mainly on genetic diversity and selection to release new cultivars. This study aimed to identify landraces with favorable characteristics that can be used as parents of segregating populations in common bean (Phaseolus vulgaris L.) breeding programs. Firstly, ten bean genotypes were selected because they showed promising agronomic performance, and the following seven adaptive traits of four commercial bean cultivars were evaluated: i) plant height; ii) diameter of the stem; iii) height of the insertion of the first pod; iv) pod number per plant; v) grain number per pod; vi) weight of a thousand grains and vii) grain yield. The accessions BAF 07, BAF 44, and BAF 45 are promising in terms of increasing plant height, and accession BAF 01, in terms of reducing plant height. The accession BAF 07 was also the most promising in terms of a plant ideotype that combines higher plant height, maximum height of the insertion of the first pod, and increment in grain yield. Moreover, the selection can be made between and within accessions, because genetic variability is also present within landraces.(AU)

Correlação fenotípica entre componentes do rendimento de grãos de feijão comum (Phaseolus vulgaris L. ) / Phenotypic correlation between yield components of common bean (Phaseolus vulgaris L. )

O objetivo deste trabalho foi identificar qual é o componente principal do rendimento de grãos de feijão comum que apresenta menor sensibilidade ao efeito do ambiente, e que propicia maior consistência na expressão dos resultados, quando avaliados em diferentes locais. Os dados experimentais utilizados nas análises são provenientes de Ensaio de Valor cultivo e Uso (VCU) conduzidos nos municípios de Lages e de Chapecó. Os caracteres observados foram estande final de plantas; número de legumes por planta; número de grãos por legume; massa de 1.000 grãos e rendimento total de grãos em kg ha-1. O delineamento experimental utilizado foi o de blocos ao acaso, com quatro repetições. As estimativas das correlações fenotípicas foram obtidas pelo método proposto por STEEL e TORRIE e particionadas em efeitos diretos e indiretos mediante a análise de trilha. Correlação inversa foi obtida para os caracteres massa de 1.000 grãos e número de grão por legume, revelando que os mesmos devem ser selecionados conjuntamente para obter ganho no caráter rendimento de grãos. Quando a seleção tem por objetivo aumentar o rendimento de grãos, para as condições ambientais de Chapecó a característica massa de 1.000 grãos pode ser utilizada, enquanto que em Lages o mais apropriado é utilizar o caractere número de legume por planta, pois apresentam consistência e estabilidade no desdobramento dos coeficientes de trilha.

This study aimed to identify which is the main component of grain yield of bean that that shows less sensitivity effect of the environment, and provides greater consistency in the expression of results when evaluated in different environments. Experimental data used in the analysis are derived from test of Cultivate and Use Value (VCU) conducted in Lages SC and Chapecó SC, South of Brazil. The characters observed were the final stand of plants, number of pods per plant; number of grains per pod, seed mass (g 1000 seed-1) and grain yield (kg ha-1). The experiment was conducted in a randomized block design, with four replications. Estimates of phenotypic correlations were obtained by the method proposed by STEEL and TORRIE and partitioned into direct and indirect effects through path analysis.The inverse correlation was obtained for the characters of seed mass and grain number per pod, revealing that they should be selected together to obtain gains in the yield character. When the selection is aimed at grain production, for Chapecó-SC the characteristic of seed mass can be used, where as in Lages-SC the character number of grains per pod is more appropriate. Characters seed mass and number of vegetable per pod showed high stability during the unfolding of the path coefficients, showing that they can be used in selecting genotypes with higher grain yield in different environments.

Uso ou abuso em testes de comparações de média: conhecimento científico ou empírico? / Use or abuse in mean comparison tests: scientific or empiric knowledge?

O objetivo deste trabalho foi identificar quais os principais erros e acertos na aplicação de testes de comparação de médias em trabalhos científicos, demonstrando alternativas viáveis no sentido de aumentar a imparcialidade dos resultados obtidos pelos pesquisadores. Um dos maiores desafios do pesquisador é a interpretação dos resultados de forma fidedigna. Apesar da preocupação com a análise dos dados, muitas vezes pode ser observado certo descaso com a interpretação dos resultados, em que a aplicação incorreta de testes estatísticos pode levar à divulgação de informações pouco confiáveis. Foram revisados 226 trabalhos científicos publicados na revista Ciência Rural de 2002 a 2006, somente na área de Fitotecnia, sendo utilizados 148 trabalhos para discussão. A maioria dos trabalhos que estudaram mais de um fator foram classificados como incorretos (72 por cento) devido ao abuso dos testes de comparações de médias. Por outro lado, 4 e 24 por cento foram classificados como parcialmente corretos e corretos, respectivamente.(AU)

The objective of this research was to verify which are the main mistakes and the successes in the application of mean comparison tests in scientific studies, demonstrating viable alternatives in the sense of increasing the impartiality of the results obtained by researchers. One of the researcher's largest challenges is the interpretation of the obtained results in a trustworthy way. In spite of the concern of most researchers with the data analysis, many times certain disregard is observed in the interpretation of the results. Thus, the incorrect application of statistical tests leads the researchers to publish information not completely reliable. One hundred and forty-eight papers dealing with one or more than one factor were evaluated. All of them are related to the crop production major area, published from 2002 to 2006, in the 'Ciência Rural', a Brazilian scientific journal. Most of the studies (72 percent) were classified as incorrect due to the abuse of means comparison tests. In addition, only 4 percent and 24 percent were classified respectively as partially correct and correct.(AU)