Heritability and Genotype × Environment Interactions for Discolored Rice Kernels

Abstract

Discolored kernels are but one component of rice (Oryza sativa L.) quality that requires attention by rice breeders. Discolored kernels are most often caused by damage from rice stink bugs [Oebalus pugnax (Fabricius)] and kernel smut disease (Tilletia barclayana Bref.), but other pathogens and physiological disorders can also contribute to kernel discoloration. Our objective was to further understand the inheritance and genotype × environment (GE) interactions for discolored rice kernels to improve rice kernel quality characteristics. Thirty‐seven genotypes, representing southern U.S. rice germplasm, were evaluated for susceptibility to all causes of discolored kernels in field tests conducted during 1993 and 1994 at three Arkansas locations: Stuttgart, Tupelo, and Rohwer. Traits were inherited quantitatively, with single‐plot heritability values of 0.07, 0.18, and 0.33 for rice stink bug damage, kernel smut, and other discolorations, respectively. The GE interactions were significant for all traits. Closer inspection of the GE interaction revealed that the causes were primarily related to magnitude changes but also included genotype rank changes. The bias of GE interaction during selection could be reduced by multi‐year and multi‐location testing. Phenotypic correlations among traits were low, indicating that selection for lower levels of one trait would not adversely raise the levels of another trait. Cultivars, such as Katy, Kaybonnet, and Drew, were identified as having stable, low susceptibility to rice stink bug damage, kernel smut, and other discolorations. Although breeding for improved kernel quality traits will have certain difficulties because of low heritability, the availability of good germplasm and a proper screening program should minimize this problem.

Estimativas de parâmetros genéticos da qualidade fisiológica de sementes de genótipos de soja produzidas em diferentes regiões de Minas Gerais

“…Interações significativas têm sido freqüentemente relatadas na literatura, seja para produção de grãos, qualidade de sementes, comportamento de materiais genéticos distintos, resistência à doenças entre outras (HEGSTAD; BOLLERO;NICKELL, 1999;SOOD et al, 1999;YANG et al, 2001, LIMA et al, 2008PÁDUA et al, 2010).…”

“…Estimativas da herdabilidade ampla de características de plantas são importantes por terem relação com a seleção e quanto maior o valor estimado desse parâmetro, maior será a chance de sucesso com a seleção (STRICKBERGER, 1985;GRAVOIS;BERNHARDT, 2000).…”

Integrated pest management for sustainable rice cultivation: a holistic approach

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Research Article Estimates of genetics and phenotypics parameters for the yield and quality of soybean seeds.

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