Abstract
It is of significance to discover genes related to fiber quality and yield traits and tightly linked markers for marker-assisted selection (MAS) in cotton breeding. In this study, 188 F8 recombinant inbred lines (RILs), derived from a intraspecific cross between HS46 and MARCABUCAG8US-1-88 were genotyped by the cotton 63K single nucleotide polymorphism (SNP) assay. Field trials were conducted in Sanya, Hainan Province, during the 2014–2015 cropping seasons under standard conditions. Results revealed significant differences (P < 0.05) among RILs, environments and replications for fiber quality and yield traits. Broad-sense heritabilities of all traits including fiber length, fiber uniformity, micronaire, fiber elongation, fiber strength, boll weight, and lint percentage ranged from 0.26 to 0.66. A 1784.28 cM (centimorgans) linkage map, harboring 2618 polymorphic SNP markers, was constructed, which had 0.68 cM per marker density. Seventy-one quantitative trait locus (QTLs) for fiber quality and yield traits were detected on 21 chromosomes, explaining 4.70∼32.28% phenotypic variance, in which 16 were identified as stable QTLs across two environments. Meanwhile, 12 certain regions were investigated to be involved in the control of one (hotspot) or more (cluster) traits, mainly focused on Chr05, Chr09, Chr10, Chr14, Chr19, and Chr20. Nineteen pairs of epistatic QTLs (e-QTLs) were identified, of which two pairs involved in two additive QTLs. These additive QTLs, e-QTLs, and QTL clusters were tightly linked to SNP markers, which may serve as target regions for map-based cloning, gene discovery, and MAS in cotton breeding.
Highlights
The Gossypium genus is the most important source of natural textile fiber
The aims of this study were to identifying stable quantitative trait locus (QTLs) for fiber quality and yield traits and their tightly linked single nucleotide polymorphism (SNP) markers for Marker-assisted selection (MAS) in upland cotton breeding
2618 polymorphic SNP markers from a 63K SNP assay (HulseKemp et al, 2015) were used to construct a relative high-density genetic map for 188 recombinant inbred lines (RILs) derived from the combination of HS46/MARCABUCAG8US-1-88
Summary
The Gossypium genus is the most important source of natural textile fiber It consists of 50 species approximately, including four cultivated species, G. arboreum, G. herbaceum, G. hirsutum, and G. barbadense. Developing new cotton cultivars with superior fiber quality and high yields are immense to meet the demand of textile industry demand and to maintain the profitability of cotton for its growers. The intraspecific genetic maps of upland cotton have been constructed to detect QTLs for fiber quality and yield traits (Zhang et al, 2003, 2009; Shen et al, 2006; Wang et al, 2006, 2015b; Qin et al, 2008; Wu et al, 2008; Sun et al, 2011; Liang et al, 2013; Tan et al, 2014; Islam et al, 2015; Zhang Z. et al, 2015). It is necessary to develop new type of markers which can enable mapping upland cotton populations to obtain high polymorphism
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