Quantitative Trait Locus Analysis and Identification of Candidate Genes for Micronaire in an Interspecific Backcross Inbred Line Population of Gossypium hirsutum × Gossypium barbadense

Cotton is the most important fiber crop and provides indispensable natural fibers for the textile industry. Micronaire (MIC) is determined by fiber fineness and maturity and is an important component of fiber quality. Gossypium barbadense L. possesses long, strong and fine fibers, while upland cotton (Gossypium hirsutum L.) is high yielding with high MIC and widely cultivated worldwide. To identify quantitative trait loci (QTLs) and candidate genes for MIC in G. barbadense, a population of 250 backcross inbred lines (BILs), developed from an interspecific cross of upland cotton CRI36 × Egyptian cotton (G. barbadense) Hai7124, was evaluated in 9 replicated field tests. Based on a high-density genetic map with 7709 genotyping-by-sequencing (GBS)-based single-nucleotide polymorphism (SNP) markers, 25 MIC QTLs were identified, including 12 previously described QTLs and 13 new QTLs. Importantly, two stable MIC QTLs (qMIC-D03-2 on D03 and qMIC-D08-1 on D08) were identified. Of a total of 338 genes identified within the two QTL regions, eight candidate genes with differential expression between TM-1 and Hai7124 were identified. Our research provides valuable information for improving MIC in cotton breeding.

Development and Characterization of SSR Markers in the Gossypium Barbadense Genome

BackgroundThe fiber quality and resistance traits of Gossypium barbadense are considerably better than that of other Gossypium species. Simple sequence repeats (SSRs) are user friendly, low cost markers widely used in genetic studies. However, most SSRs have been developed from G. hirsutum, G. arboreum, and G. raimondii; no genome-wide SSRs have been developed from G. barbadense.The de novo sequences of G. barbadense cv. Xinhai21 were utilized to develop SSR markers and scanned to detect SSRs using the MIcroSAtellite (http://pgrc.ipk-gatersleben.de/misa/) identification tool. And then in silico PCR analysis was conducted to evaluate these primers polymorphism in five Gossypium species.ResultsIn total, 85,582 SSRs were identified with different motifs. 153,560 primer pairs were successfully designed for 73,419 SSRs. In silico analysis, we found that 8,466 primer pairs of 3,288 SSRs yielded one product (monomorphic) simultaneously in five Gossypium species. two Gossypium species (30 G. hirsutum and 27 G. barbadense accessions) were successfully separated by 300 primer pairs with the polymorphism information content (PIC) ranging from 0.00 to 0.93. ConclusionThese newly developed SSR markers will be helpful for the construction of genetic linkage maps, genetic diversity analyses, QTL mapping, and molecular breeding of Gossypium species.

Gossypium barbadense: revaloración y sustentabilidad

El ensayo aborda la problemática del algodón nativo de color peruano y su uso en la elaboración de productos artesanales que no logran competir con el algodón comercial. Pese a ello las familias de las comunidades productoras, ven en el algodón una extensión cultural a mantener vigente, siendo esto insuficiente para su valorización. El objetivo es proponer la revaloración del algodón, a partir de la comunicación de sus virtudes genéticas, el beneficio ambiental en su producción y la innovación en diseño hacia el mercado contemporáneo, procurando que su esencia precolombina potencie el desarrollo económico de las comunidades productoras dentro del marco de la sustentabilidad e identidad.