Effect of genotype x environment interactions in popcorn maize yield and grain quality

Abstract

The cultivation of popcorn in Argentina has increased greatly in the last ten years: demand by the MERCOSUR countries is high, as is profitability. Nearly all Argentine production is exported since internal consumption is tiny -less than 5% of total production. «Popped corn» is produced by the explosion of the caryopsis due to the cooking temperature. Maize kernels, which are small and hard, are composed of three structural units: the pericarp, the endosperm, and the AbstractFourteen commercial popcorn maize hybrids were evaluated in a randomised block design in three locations for two years with the aim of introducing this crop into a region of the Buenos Aires province, Argentina, an area characterized by changing environmental conditions. The traits evaluated were grain yield, expansion volume, kernel width, kernel length, caryopsis roundness index, ear diameter, ear length, kernel density before expansion, expanded kernel density and prolificacy index. The interaction genotype x environment revealed environments favourable towards yield but which were simultaneously unfavourable towards expansion capacity, as well as genotypes stable for one of these variables but unstable for the other. However, some environments and genotypes were simultaneously favourable to both. Only a weak negative correlation was found between grain yield and expansion capacity, suggesting this relationship may not be very strong in these modern hybrids. Rounded grains showed higher expansion capacities, but this characteristic was negatively correlated to yield; roundness is therefore not recommended as a selection criterion. The prolificacy index correlated positively with yield but not with expansion volume, and is therefore a potential selection criterion.Key words: Zea mays L., genotype x environment interaction, expansion capacity. Resumen Interacción genético-ambiental en cultivos de maíz reventón para rendimiento y calidad del granoSe evaluaron 14 híbridos simples de maíz reventón, siguiendo un diseño de bloques al azar con tres repeticiones, en tres localidades de la provincia de Buenos Aires, Argentina, de condiciones variables en precipitación y tipo de suelo: Luján, Esteban Echeverría y Chascomús, durante dos años. Se analizaron las relaciones entre variables morfológicas, su influencia sobre rendimiento y capacidad de expansión: ancho y largo de grano, índice de redondez del cariopse, diámetro y largo de la espiga, densidad del grano sin expandir y del grano expandido e índice de prolificidad. El estudio de la interacción genético-ambiental mediante método AMMI mostró grupos de ambientes favorables para rendimiento y desfavorables para capacidad de expansión. En el caso de los genotipos se observó estabilidad para una variable e inestabilidad para la otra. No obstante, ciertos ambientes y genotipos resultaron con elevados valores para ambas variables. Se corroboró una débil correlación negativa (r = -0.16*) entre rendimiento y capacidad de expansión, sugiriendo que en los híbridos modernos tal tendencia no es tan marcada...

Genetic evaluation of popcorn families using a Bayesian approach via the independence chain algorithm

“…A genetic correlation not significantly different from zero would indicate that selecting families based on popping expansion would not have a significant effect on grain yield. This result is widely reported in the literature, for example, Arnhold et al (2009) and Broccoli and Burak (2004) confirmed that grain yield is inversely correlated (negative genetic association) with popping expansion. The Spearman correlation coefficient estimated by Munhoz et al (2009) was not significant for 96 S3 popcorn families.…”

“…The Spearman correlation coefficient estimated by Munhoz et al (2009) was not significant for 96 S3 popcorn families. Broccoli and Burak (2004) mentioned that the negative association between popping expansion and yield can affect the yield gains in simultaneous selection of a breeding population. From the genetic point of view, this phenomenon indicates that the two traits could be controlled by distinct genes.…”

Evidence of Improving Yield and Morphological Attributes via Half-Sib Family Recurrent Selection in Maize

“…[25] reported a positive correlation between ear length and grain yield. Similarly, [8] also observed positive and highly significant correlation between ear length and grain yield. [21] reported negative correlation among ear length, kernel weight and kernel rows.…”

Performance of popcorn introductions for agronomic characters, grain yield and popping qualities in the forest and derived savannah agro-ecologies of Nigeria

“…Ziegler (2001) noted that such modifications may have to do with timely planting due to the slow germination of popcorn and harvest maturity to enable optimum popping ability. Broccoli and Burak (2004) reported high significant differences (ρ ≤ 0.01) for all characters evaluated except kernel density before expansion among fourteen (14) popcorn hybrids evaluated in two years across three environments. Genotype x Environment (G x E) interaction was also observed to be significant for the two main traits (yield and expansion volume) while the relationship between grain yield and expansion volume was negative.…”