Validation and Designation of Quantitative Trait Loci for Seed Protein, Seed Oil, and Seed Weight from Two Soybean Populations

Abstract

In soybean [Glycine max (L.) Merr.], there is limited and inconsistent information on the confirmation of previously reported QTL. The objectives of this study were to: (i) confirm previously reported QTL for seed protein, seed oil, and seed weight in an independent population of PI97100 × ‘Coker 237’ with the same RFLP markers and (ii) verify previously reported QTL in an independent population of ‘Young’ × PI416937 for the same seed traits using SSR markers mapped in the same region as the original RFLP markers. Each population consisted of 176 F2:4 lines and was grown in randomized complete block trials in two or three different environments. Single‐factor analysis of variance was used to verify the QTL that had significant (P ≤ 0.01) associations. In the PI97100 × Coker 237 population, two (cqProt‐001 and cqProt‐002) of four previously described QTL for seed protein, two (cqOil‐001 and cqOil‐002) of three QTL for oil content, and none of three QTL for seed weight were confirmed in the independent population. In the Young × PI416937 population, none of the three previously reported QTL for protein was confirmed. One (cqOil‐003) of three QTL for oil content and two (cqSd wt‐001 and cqSd wt‐002) of three QTL for seed weight were verified. The unconfirmed QTL may have been false positive or they may have been specific for the sample of lines used in the original populations. These results confirm the necessity of validating QTL in parallel populations before utilizing them in a plant improvement program.

QTL mapping for protein content in soybean cultivated in two tropical environments

“…According to the Soybase (2008), 76 QTL have been identified and reported as related to protein content. However, little consistency has been observed for QTL expressed in different environments or different populations (Brummer et al, 1997;Fasoula et al, 2004;Panthee et al, 2005). In the present study, this fact might be explained by the high genotype vs. environment interaction observed and by the fact that these QTL can be considered environmentally sensitive (Brummer et al, 1997).…”

“…Mapping and QTL detection studies for protein content in seeds have been reported extensively in literature (Chung et al, 2003;Fasoula et al, 2004;Hyten et al, 2004;Panthee et al, 2005). However, many reported QTL have still to be confirmed and their consistency validated (Fasoula et al, 2004).…”

“…However, many reported QTL have still to be confirmed and their consistency validated (Fasoula et al, 2004). According to Panthee et al (2005), the QTL reported with greatest consistency for protein content in soybean is located in the MLG I linkage group, close to the Satt292 microsatellite marker.…”

Associação de marcadores microssatélites com teores de óleo e proteína em soja

“…Este tipo de associação foi comum para a maioria dos QTL mapeados por Zhang et al (2004), que detectaram QTL que influenciam, ao mesmo tempo, até cinco características agronômicas distintas. Esse efeito pleiotrópico explica a correlação genética negativa existente entre os teores de óleo e proteína em soja (Fasoula et al, 2004).…”

“…Vários marcadores de locos de caracteres quantitativos (QTL) foram relatados para teores de óleo e proteína em soja (Sebolt et al, 2000;Csanádi et al, 2001;Specht et al, 2001;Chung et al, 2003;Chapman et al, 2003;Tajuddin et al, 2003;Fasoula et al, 2004;Hyten et al, 2004;Zhang et al, 2004;Panthee et al, Pesq. agropec.…”