Cause and effect of quantitative characteristics on grain expansion capacity in popcorn

Abstract

RESUMO -O conhecimento do sentido e do grau de associação entre duas ou mais características pode contribuir para aumentar a eficiência na seleção de genótipos superiores. Objetivou-se com esse trabalho avaliar as correlações fenotípicas, genotípicas e ambientais, bem como os efeitos diretos e indiretos da análise de trilha para a seleção mais apropriada, via capacidade de expansão e seus componentes primários e secundários, em híbridos dialélicos de milhopipoca. Para tanto, 90 híbridos dialélicos e a testemunha (IAC 112) foram semeados em safra e safrinha em Campos dos Goytacazes -RJ, de acordo com o delineamento em blocos casualizados. As características avaliadas foram: ciclo (CO); altura da planta (AP); altura da espiga (AE); diâmetro do colmo (DC); massa de cem grãos (M100); capacidade de expansão do grão (CE); produtividade de grãos (PG); prolificidade (PR); comprimento do grão (CG), largura do grão (LG) e espessura do grão (EG). Procederam-se as análises de correlação fenotípica (r f ), genotípica (r g ) e ambiental (r a ) e após, realizou-se o desdobramento dos coeficientes de correlação simples em efeitos diretos e indiretos sobre a variável principal CE, obtidos pela análise de trilha. Os resultados demonstraram uma alta correlação genotípica negativa e significativa entre CE e PG de -0,67, evidenciando a dificuldade de obtenção de híbridos com alta CE e PG, simultaneamente. A M100 e a PG são as variáveis com maior associação, porém contrária, com capacidade de expansão. O CG e LG têm influência direta negativa e EG positiva sobre a capacidade de expansão.Palavras-chaves: Análise de trilha. Correlação. Híbridos dialélicos. Zea mays L.. ABSTRACT -Knowledge of the direction and degree of association between two or more characteristics may contribute to increase efficiency in the selection of superior genotypes. The aim of this study was to evaluate phenotypic, genotypic and environmental correlations, as well as the direct and indirect effects of path analysis, for the most suitable selection, using expansion capacity and its primary and secondary components, in diallel hybrids of popcorn. Accordingly, 90 diallel hybrids and a control (IAC 112) were planted both in and out of season in Campos dos Goytacazes, in the State of Rio de Janeiro, following a randomised block design. The characteristics under evaluation were: cycle (CO); plant height (AP); ear height (AE); stem diameter (DC); hundred grain weight (M100); grain expansion capacity (CE); Grain yield (PG); prolificacy (PR); grain length (CG), grain width (LG) and grain thickness (EG). Analysis of the phenotypic (rf), genotypic (rg) and environmental (ra) correlations were carried out, followed by breakdown of the simple correlation coefficients obtained from path analysis into their direct and indirect effects on the main variable CE. The results showed a significant high negative genotypic correlation between the EC and PG of -0.67, demonstrating the difficulty of obtaining hybrids with both a high EC and PG. The variables M100 and PG have the grea...

Evaluation of agronomic and sensory characteristics of the popcorn kernel

“…ZP 611k was ranked second according to the yield and third according to the popping volume, whereas ZP 586/1k was the third best yielding hybrid and had the second best popping volume (Table 2). Some studies indicate that there is a positive correlation between grain yield and popping volume, although non-significant and of a low magnitude (Amaral et al, 2016).The percentage of unpopped kernels was very low and it ranged from 0.66% (ZP 586/1k) to 4.57% (ZP 501k). It was even lower in comparison with the research by Soylu and Tekkanat (2007).…”

“…high-yielding popcorn hybrids usually produce low-popping volume of the flake (Rangel et al, 2011;Srdić and Pajić, 2011;Pajić et al, 2012, Cabaral et al, 2016. This poses a great challenge in popcorn breeding because certain factors favor one main trait at the expense of the other (Amaral et al, 2016). Conversely, Sweley et al (2012) found that some sensory characteristics such as popcorn texture and softness are positively correlated with the popping volume.…”

“…These traits are generally in a negative correlation, i.e. high-yielding popcorn hybrids usually produce low-popping volume of the flake (Rangel et al, 2011;Srdić and Pajić, 2011;Pajić et al, 2012, Cabaral et al, 2016. This poses a great challenge in popcorn breeding because certain factors favor one main trait at the expense of the other (Amaral et al, 2016).…”

“…On the other hand, the grain yield is positively correlated with the 1000 kernel weight, share of the soft starch and kernel size, which all decrease the popping expansion (Hallauer et al, 2010). Amaral et al (2016) suggested a traitexpanded popcorn volume per ha PV, which provides an advantageous option for the reliable acquisition of simultaneous gains in both major traits of economic interest in popcorn, i.e. grain yield and popping volume.…”

Correlação entre diversidades genéticas em genótipos de milho, obtidas em diferentes combinações de ambientes

“…Pode-se usar o conhecimento de correlações entre as características de importância econômica, uma vez que fornecer informações que auxiliem no processo de seleção de genótipos superiores (CABRAL et al, 2016).…”