ABSTRACT In the present study it is hypothesized that the germplasm of popcorn of tropical regions shows resistance to FAW, and the multivariate analysis can characterize the main traits of this resistance. Thus, the aim of this study was to identify key traits used to select fall armyworm resistance in popcorn by using factor and cluster analyses. Sixteen biological traits were evaluated at larval and pupae stages: total number of armyworm, time larval period, final mass of caterpillars, total mass of caterpillars, mean mass of caterpillars, pupae period, mass of pupae and some indices used to evaluate the food consumed by the caterpillars. Multicollinearity diagnosis, factor and canonical analysis, and the genetic divergence among the genotypes were performed to implement multivariate analysis. The groups were established according to Mojena (1977). After multicollinearity test, only five traits were retained for further analysis. The factor analysis divided the five traits into two factors: the first factor included time larval period, metabolized food and mass of pupae; the second was composed of total number of armyworm and stool mass. Unweighted Pair Group Method with Arithmetic Mean (UPGMA) grouped the eighteen genotypes in three clusters. The present study provides insights of popcorn resistance to fall armyworm, and the multivariate analytical approach used here is directly applicable to any species and set of traits exhibiting correlation.

RESUMO O número de cultivares de milho doce adaptada às condições climáticas e com características agronômicas recomendadas para o mercado brasileiro ainda é restrito. Assim, objetivou-se investigar as capacidades de combinações gerais e específicas em relação ao rendimento de grãos (GY) e teor de sólidos solúveis totais (TSS) de sete linhagens de milho doce (su1) e oito linhagens de milho super-doce (sh2) pela análise de cruzamentos dialélicos. Para TSS, as linhagens SC6 e SC7 de milho doce, e SSC7 e SSC8 de milho super-doce apresentaram valores superiores para capacidade geral de combinação. Para rendimento de grãos, as linhagens SC1 e SC2 de milho doce, e SSC4 e SSC6 apresentaram valores superiores para capacidade geral de combinação. TSS em milho doce, os híbridos 4x6 e 1x7 apresentaram as estimativas Ŝijsuperiores em todos os ambientes avaliados. Para GY, o híbrido 5x7 foi o mais relevante pois apresentou amais alta estimativa Ŝij na grande maioria dos ambientes. Além disso, os híbridos 1x4, 3x4 e 1x7 destacaram-se com valores positivos em todos os ambientes. Em milho super-doce, os híbridos 2x8, 3x6 e 5x6 devem ser selecionados como os mais promissores para ambos os caracteres (TSS e GY), pois apresentaram estimativas Ŝij positivas e altas nos seis ambientes.

ABSTRACT The number of sweet corn cultivars adapted to the climatic conditions and with agronomic traits recommended to the Brazilian market is still limited. Thus, the aim was to investigate the general and specific combining ability (GCA and SCA, respectively) in relation to the grain yield (GY) and total soluble solid (TSS) contents of seven lines of sweet corn (su1) and eight lines of supersweet corn (sh2) by diallel crosses. For TSS, the inbred lines SC6 and SC7 of sweet corn, and SSC7 and SSC8 of supersweet corn showed higher GCA effect. For GY, the inbred lines SC1 and SC2 of sweet corn and SSC4 and SSC6 of supersweet corn showed higher GCA effect. For TSS in sweet corn, the hybrids '4 × 6' and '1 × 7' showed the superior Ŝij estimates across all evaluated environments. For GY, the hybrid '5 × 7' was the most relevant because it showed higher Ŝij estimates in most of the evaluated environments. Additionally, the hybrids '1 × 4', '3 × 4', and '1 × 7' showed positive Ŝij values across all environments. In supersweet corn, the hybrids '2 × 8', '3 × 6', and '5 × 6' should be selected as the most promising for both traits (TSS and GY), because they presented positive and high Ŝij estimates across the six environments.

RESUMO: O trabalho teve por objetivo avaliar a depressão por endogamia e os componentes genéticos de médias em sete híbridos e em duas variedades de polinização aberta para uso como milho verde, para seleção de genótipos visando à formação de populações-base para a extração de linhagens. Para a realização do estudo, foi instalado um experimento no município de Sabáudia - PR, no ano agrícola de 2014/15. O experimento foi delineado em blocos completos ao acaso, com quatro repetições, em arranjo de parcelas subdivididas, com as gerações de endogamia e os diferentes genótipos ocupando as parcelas e as subparcelas, respectivamente. As maiores estimativas de dominância e de depressão endogâmica foram observadas na produtividade de espigas empalhadas e comerciais. Os efeitos aditivos foram mais expressivos na herança do comprimento e do diâmetro de espigas comerciais. Os genótipos AM811, Cativerde 02 e AG4051 apresentaram maiores probabilidades no sucesso de extração de linhagens destinadas à produtividade e qualidade de milho verde.

ABSTRACT: This study aimed to evaluate the inbreeding depression and average genetic components in seven hybrids and two open pollinated cultivars for green corn production, as well as to select the best genotypes in order to obtain base populations for inbred lines extraction. The experiment was carried out in a randomized complete block design with four replications, in a split plot design, with inbreeding levels arranged in the plots and the different genotypes distributed over the subplots, in the municipality of Sabáudia - PR, during the 2014/15 crop season. Higher values of dominance and inbreeding depression were observed for yield of both unhusked and commercial ears. Higher additive effects were detected on length and diameter of commercial ears. The genotypes AM811, Cativerde 02 and AG4051 showed greater probability of obtaining highly productive and higher quality green corn inbred lines.