Status of the Global Cotton Germplasm Resources

Abstract

The cultivated Gossypium spp. (cotton) represents the single most important, natural fiber crop in the world. In addition to its fiber, the oil and protein portion of the cottonseed also represents significant economic value. To protect the worldwide economic value of cotton fiber and cotton byproducts, coordinated efforts to collect and maintain cotton genetic resources have increased over the last 100 yr. The classified genetic resources of cotton are extensive and include five tetraploid species in the primary gene pool, 20 diploid species in the secondary gene pool, and 25 diploid species in the tertiary gene pool. This report provides information on the status and contents of eight major cotton germplasm collections present across the world. Based on the findings of this report, a number of classified Gossypium species are not maintained in these collections, and several are underrepresented and vulnerable to extinction. This report presents several critical challenges and opportunities facing international efforts to enhance and preserve the world's Gossypium genetic resources. Multinational communication and collaboration are essential to protect, secure, and evaluate the global cotton germplasm resources. Without global, collaborative efforts, the rarest and most unique cotton germplasm resources are vulnerable to extinction.

Mapping genomic loci for cotton plant architecture, yield components, and fiber properties in an interspecific (Gossypium hirsutum L. × G. barbadense L.) RIL population

“…The genus of Gossypium (cotton) consists of at least 45 diploid and 5 allotetraploid species grouped into nine genome types with the designations A, B, C, D, E, F, G, K, and AD (Campbell et al 2010;Fryxell 1979;Percival et al 1999;Wendel et al 2009). The AD-genome tetraploid cottons originated from the hybridization between A-genome and D-genome diploid cottons approximately 1-2 million years ago (MYA) (Beasley 1940;Cronn et al 1999;Wendel and Cronn 2003).…”

“…3-79). Using the single nonparametric and MQM QTL model mapping procedures, we detected 428 putative loci in the 159 genomic regions that confer 24 cotton traits in three diverse production environments [College Station F&B Road (FB), TX; Brazos 1 3 G. herbaceum L. (A 1 ) and G. arboreum L. (A 2 ), and two tetraploid species (2n = 4X = 52) from the New World, G. hirsutum L. (AD 1 ) and G. barbadense L. (AD 2 ), are cultivated to produce the world's leading natural fiber and the second most important oilseed crop (Campbell et al 2010;Kantartzi et al 2009;Lee 1984;Ulloa et al 2013;Wendel et al 1992;Percy et al 2014). The complexity of Gossypium genomes has afforded research opportunities on the evolution and diversity among diploid (Ma et al 2010) and allotetraploid species (Brubaker et al 1999;Jiang et al 1998;Paterson et al 2012).…”

Development of a core set of SSR markers for the characterization of Gossypium germplasm

“…The Gossypium genus has about 50 species, including the four domesticated species (G. arboreum L., G. barbadense L., G. herbaceum L., and G. hirsutum L.), that embody considerable genetic diversity across a wide geographic range covering most tropical and subtropical regions of the world (Percival et al 1999;Wendel and Cronn 2003;Campbell et al 2010). Based on pairing relationships of 13 chromosomes, the diploid Gossypium species are grouped into A through G and K genomes (Endrizzi et al 1985;Stewart 1994).…”

Optimal use of SSR markers for varietal identification of upland cotton

“…Wild cotton comprises 45 diploid and 5 tetraploid species (Campbell et al, 2010), of which four have been independently domesticated in four different regions worldwide. Gossypium hirsutum L., one of the tetraploid species, is classified into seven different races: one wild and six domesticated (Lacape et al, 2007).…”

“…Gossypium hirsutum L., one of the tetraploid species, is classified into seven different races: one wild and six domesticated (Lacape et al, 2007). The G. hirsutum race latifolium Hutch., or upland cotton, is economically the most important one and, besides being broadly adapted, is also the main fiber crop (Campbell et al, 2010). However, there is evidence that cotton genetic diversity has been declining in breeding programs (Paterson et al, 2004), which can also lead to a reduction in yield gain through breeding, since diversity is required for selection (Campbell et al, 2010).…”