Genetic effects on seed quality in diallel crosses of popcorn

Juliana Saltires Santos,Henrique Duarte Vieira,Pablo Diego Silva Cabral,Antonio Teixeira Do Amaral Júnior,Messias Gonzaga Pereira,Ismael Lourenço De Jesus Freitas

doi:10.1590/s1413-70542013000600003

Juliana Saltires Santos, Henrique Duarte Vieira + Show 4 more

Open Access

https://doi.org/10.1590/s1413-70542013000600003

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Abstract

The failure to obtain the ideal stand is one of the causes of decreased crop yields, in this sense it is important to investigate the genetic effects related to seed quality. The aim of this study was to measure the general combining ability (GCA), the specific combining ability (SCA) and the reciprocal effects (RE) for popcorn seed quality in addition to evaluate the association between germination and vigor tests with field emergencein order to identify hybrids with better germination and vigour. Ten inbred lines were evaluated using a complete diallel cross with reciprocals. Seed quality was measured by germination tests (GT) and by modified cold vigour tests (MCV). In the GT, the numbers of strong normal seedlings (SNS), weak normal (WNS), abnormal (AS) and ungerminated seeds (UGS) were counted. In the MCV, the numbers of normal seedlings (NPC), abnormal (ASC) and ungerminated seeds (UGSC) were counted, and the plants' dry matter (DM) was measured. Analysis of variance for GCA, SCA and RE were significant for all variables. The quadratic components for SCA were higher than those for GCA for the SNS, AS, UGS, ASC and UGSC traits, which indicates higher significance for the non-additive effects. The most favourable GCA estimates, were found in lines P3 and L70. The best hybrids were P1xL70, P3xP6 and P8xL70. The RE results showed that L70 and P3 should be used as the female parent in the P1xL70 and P3xP6 hybrid crosses, respectively. The MCV was the test that was most strongly correlated with field emergence, with a magnitude of 0.667.

Highlights

One of the primary causes of reduced yield per unit area for most cultivated varieties of plants is unsuccessful stand establishment that is the result of crops with substandard populations (MARCOS FILHO, 2005)
The effects of the general combining ability (GCA), specific combining ability (SCA) and reciprocal effects (RE) were significant for all evaluated traits, which indicates that additive, non-additive and maternal effects are involved in the genetic control of these traits
The estimates of quadratic components associated to GCA, SCA and RE indicated that non-additive effects had a greater impact on WNS, abnormal seedlings (AS), ungerminated seeds (UGS), ASC and UGSC than additive effects

Summary

Introduction

One of the primary causes of reduced yield per unit area for most cultivated varieties of plants is unsuccessful stand establishment that is the result of crops with substandard populations (MARCOS FILHO, 2005). It is essential to investigate the nature of the genetic effects that affect the seed quality traits and the effects of different genetic structures in populations in the field with respect to germination and vigour (TEKRONY; EGLI, 1991). Seed quality may be defined as the sum of the genetic, physical, physiological and health-related traits that affect the plant’s ability to perform vital functions; it is characterised by germination and vigour (POPINIGIS, 1985). Vigour tests are performed to complement data obtained from germination tests and to detect significant differences in seed quality in lots with similar germination rates (MARCOS FILHO, 2005). Of the various vigour tests used for maize growth, the modified cold test is the most recommended because of its strong correlation with plant emergence in the field (MCDONALD, 1975; MOLINA; IRIGON; ZONTA, 1987; TEKRONY; EGLI; WICKAM, 1989; BARROS et al, 1999)

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