Molecular Biology and Genetics

Electronic Journal of Biotechnology ISSN: 0717-3458 Vol. 12 No. 2, Issue of April 15, 2009
© 2009 by Pontificia Universidad Católica de Valparaíso -- Chile Received August 2, 2008 / Accepted November 3, 2008
DOI: 10.2225/vol12-issue2-fulltext-13
RESEARCH ARTICLE

Identification of QTLs for pod and kernel traits in cultivated peanut by bulked segregant analysis

Michael Gomez Selvaraj
Department of Plant and Soil Science
Texas Tech University
Lubbock, TX 79409, USA

Manivannan Narayana
Department of Oilseeds
Tamil Nadu Agricultural University
Coimbatore - 641 003, India

A. Michael Schubert
AgriLife Research
Texas A&M System
1102 East FM 1294
Lubbock TX 79403, USA 

Jamie L. Ayers
AgriLife Research
Texas A&M System
1102 East FM 1294
Lubbock, TX 79403, USA

Michael R. Baring
AgriLife Research
Texas A&M System
College Station, TX 77843, USA

Mark D. Burow*
AgriLife Research
Texas A&M System and
Department of Plant and Soil Science
Texas Tech University
1102 East FM 1294
Lubbock, TX 79403, USA
E-mail: mburow@tamu.edu

*Corresponding author

Keywords: maturity, oil quantity, quality, SSR markers.

Abbreviations:

100PodWgt: 100-Pod weight
100SdWgt: 100-Seed weight
BSA: bulked segregant analysis
NPodsPlt: number of pods per plant
NSdsPlt: number of seeds per plant
OilCon: oil content
PCR: polymerase chain reaction
PltWtg: plant weight
PodCons: pod constriction
PodLen: pod length
PodWid: pod width
QTL: quantitative trait loci
RAPD: random amplified polymorphic DNA
RFLP: restriction fragment length polymorphism
RIL: recombinant inbred line
SdLen: seed length
SdWid: seed width
SSR: simple sequence repeat

Abstract   Full Text

Bulked segregant analysis was used to identify simple sequence repeat (SSR) markers associated with pod and kernel traits in cultivated peanut, to permit rapid selection of superior quality genotypes in the breeding program. SSR markers linked to pod and kernel traits were identified in two DNA pools (high and low), which were established using selected F2:6 recombinant individuals resulting from a cultivated cross between a runner (Tamrun OL01) and a Spanish (BSS 56) peanut. To identify quantitative trait loci (QTLs) for pod and kernel-related traits, parents were screened initially with 112 SSR primer pairs. The survey revealed 8.9% polymorphism between parents. Of ten SSR primer pairs distinguishing the parents, five (PM375, PM36, PM45, pPGPseq8D9, and Ah-041) were associated with differences between bulks for seed length, pod length, number of pods per plant, 100-seed weight, maturity, or oil content. Association was confirmed by analysis of segregation among 88 F2:6 individuals in the RIL population. Phenotypic means associated with markers for three traits differed by more than 40%, indicating the presence of QTLs with major effects for number of pods per plant, plant weight, and pod maturity. The SSR markers can be used for marker assisted selection for quality and yield improvement in peanut. To the best of our knowledge, this is the first report on the identification of SSR markers linked to pod - and kernel- related traits in cultivated peanut.

Supported by UNESCO / MIRCEN network