QUANTITATIVE TRAIT LOCI IDENTIFIED FOR ROOT TRAITS ASSOCIATED WITH DROUGHT RESISTANCE IN COMMON BEAN

Beet curly top virus, often referred to as Curly top virus (CTV), is an important virus disease of common bean in the semiarid regions of the United States, Canada, and Mexico and the only effective control is genetic resistance. Our objective was to determine if dry bean landrace G122, which lacks the Bct gene for resistance to CTV, contains novel resistance to the virus. Two populations, GT-A and GT-B, consisting of 98 F5:7 recombinant inbred lines (RILs) in total were derived from a cross between G122 and the susceptible variety Taylor Horticultural and evaluated for phenotypic response to natural CTV field infection. Genetic analyses revealed random amplified polymorphism DNA (RAPD) markers associated with a major-effect quantitative trait loci (QTL) from G122 which exhibited stable expression across 3 years in both populations. Phenotypic variation explained by the QTL in GT-A (37.6%) was greater than in GT-B (20.4%). RAPD marker Q14.973 was converted to a sequence-characterized amplified region (SCAR) and designated SQ14.973. The SCAR was used to locate the QTL on linkage group 6 of the Phaseolus core map. A survey of 74 common bean cultivars and breeding lines revealed SQ14.973 would be widely useful for marker-assisted selection of the QTL. An additional minor-effect QTL from G122 was detected on linkage group 7. G122 was determined to possess novel resistance to CTV conditioned by at least two genes, one with major the other minor effect.

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Genetic variation underlying pod size and color traits of common bean depends on quantitative trait loci with epistatic effects

Molecular Breeding ◽

10.1007/s11032-013-0008-9 ◽

2014 ◽

Vol 33 (4) ◽

pp. 939-952 ◽

Cited By ~ 10

Author(s):

Fernando J. Yuste-Lisbona ◽

Ana M. González ◽

Carmen Capel ◽

Manuel García-Alcázar ◽

Juan Capel ◽

...

Keyword(s):

Genetic Variation ◽

Quantitative Trait Loci ◽

Common Bean ◽

Quantitative Trait ◽

Epistatic Effects ◽

Color Traits ◽

Trait Loci

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Genetic Mapping Identifies Consistent Quantitative Trait Loci for Yield Traits of Rice under Greenhouse Drought Conditions

Genes ◽

10.3390/genes11010062 ◽

2020 ◽

Vol 11 (1) ◽

pp. 62

Author(s):

Niranjan Baisakh ◽

Jonalyn Yabes ◽

Andres Gutierrez ◽

Venkata Mangu ◽

Peiyong Ma ◽

...

Keyword(s):

Quantitative Trait Loci ◽

Grain Yield ◽

Drought Resistance ◽

Quantitative Trait ◽

Chromosome 1 ◽

Phenotypic Variance ◽

Yield Traits ◽

Rice Varieties ◽

Drought Tolerant ◽

Trait Loci

Improving drought resistance in crops is imperative under the prevailing erratic rainfall patterns. Drought affects the growth and yield of most modern rice varieties. Recent breeding efforts aim to incorporate drought resistance traits in rice varieties that can be suitable under alternative irrigation schemes, such as in a (semi)aerobic system, as row (furrow-irrigated) rice. The identification of quantitative trait loci (QTLs) controlling grain yield, the most important trait with high selection efficiency, can lead to the identification of markers to facilitate marker-assisted breeding of drought-resistant rice. Here, we report grain yield QTLs under greenhouse drought using an F2:3 population derived from Cocodrie (drought sensitive) × Nagina 22 (N22) (drought tolerant). Eight QTLs were identified for yield traits under drought. Grain yield QTL under drought on chromosome 1 (phenotypic variance explained (PVE) = 11.15%) co-localized with the only QTL for panicle number (PVE = 37.7%). The drought-tolerant parent N22 contributed the favorable alleles for all QTLs except qGN3.2 and qGN5.1 for grain number per panicle. Stress-responsive transcription factors, such as ethylene response factor, WD40 domain protein, zinc finger protein, and genes involved in lipid/sugar metabolism were linked to the QTLs, suggesting their possible role in drought tolerance mechanism of N22 in the background of Cocodrie, contributing to higher yield under drought.

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