Genetic effects on seed quality in diallel crosses of popcorn

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. Index terms:General and specific combining ability, maternal effect, germination and vigour. RESUMOO insucesso na obtenção do estande ideal é uma das causas da diminuição do rendimento das culturas. Nesse sentido, tornase importante investigar os efeitos gênicos relacionados à qualidade de sementes. No presente trabalho objetivou-se avaliar a capacidade geral (CGC) e específica (CEC) de combinação e o efeito recíproco (ER) da qualidade de sementes de milho-pipoca e a correlação entre os testes de germinação e de vigor com a emergência no campo, visando à obtenção de híbridos com maior germinação e vigor. Avaliaram-se dez linhagens em cruzamento dialélico completo, com recíprocos. A qualidade das sementes foi avaliada por meio dos testes de germinação (TG), computando-se plântulas normais fortes (PNft) e fracas (PNfr), anormais (PA) e sementes não germinadas (SNG) e pelos testes de vigor de frio modificado (TFM), foram avaliadas plântulas normais (PNF) e anormais (PAF) e sementes não germinadas (SNGF) e pela matéria seca das plântulas (MS). De acordo com a análise de variância a CGC, a CEC e o ER foram significativos para todas as variáveis. Os componentes quadráticos relacionados aos efeitos de CEC foram maiores que os relacionados com a CGC para as características PNfr, PA, SNG, PAF e SNGF, indicando a maior significância dos efeitos não-aditivos. As estimativas mais favoráveis para CGC, foram expressas pelas linhagens P3 e L70. As melhores combinações híbridas: P1xL70,...

Combining Ability and Heterosis of Maize Genotypes under Water Stress during Seed Germination and Seedling Emergence

“…The importance of nonadditive effects in traits related to physiological quality of maize seeds were also reported by Gomes et al (2000b), Mortele et al (2011), andCabral et al (2013). The higher estimates of s 2 ŝ for EMERG and NSR suggest that lines from Groups 1 and 2 have contrasting favorable alleles in locus with nonadditive effects for these two traits.…”

“…The higher estimates of s 2 ŝ for EMERG and NSR suggest that lines from Groups 1 and 2 have contrasting favorable alleles in locus with nonadditive effects for these two traits. The importance of nonadditive effects in traits related to physiological quality of maize seeds were also reported by Gomes et al (2000b), Mortele et al (2011), andCabral et al (2013).…”

“…The occurrence of reciprocal effects controlling seed physiological quality and seedling performance was reported by Gomes et al (2000b) for SL and RL on maize seedlings; Hoecker et al (2006) observed reciprocal effect for root density in maize hybrids; and Mortele et al (2011), Cabral et al (2013, and Oliveira et al (2015) reported the occurrence of reciprocal effects on the quality of seeds. These results suggest that it is important to choose which line will be used as female parent to obtain maize hybrids with better performance for seed quality or seedling traits related to tolerance to water stress.…”

Gene effects from Bipolaris maydis incidence and severity on popcorn

“…Among them, it is worth mentioning Rangel et al (2007) and Vieira et al (2009). On the other hand, Pinto et al (2007), Pajic et al (2008), Silva et al (2010), Viana et al (2011), Vieira et al (2011, Moterle et al (2012) and Cabral et al (2013) stand out when it comes to studies providing information about the diallel cross between popcorn lines.…”

Diallel analysis of corn for special use as corn grits: determining the main genetic effects for corn gritting ability

“…Moterle et al (2012) studied combining ability for seed quality in nine popcorn strains in a complete diallel without reciprocals, and observed that the estimates of GCA and SCA were significant for germination, first count, accelerated aging, modified cold, electrical conductivity, seedling emergence in sand, speed of emergence, and emergence rate. Cabral et al (2013), in studying the genetic effects of seed quality in diallel in popcorn, found that there was genetic variability for seed quality between strains, where there was a non-additive genetic effect for predominant seed quality, and that there was a prononuced reciprocal effect for seed quality in popcorn, necessitating early indication of male and female parents in crosses.…”