Location: Crop Germplasm ResearchTitle: Introgression genetics and breeding between Upland and Pima cotton: a review) Author
Submitted to: Euphytica
Publication Type: Peer reviewed journal
Publication Acceptance Date: 3/1/2014
Publication Date: 3/18/2014
Citation: Zhang, J., Percy, R.G., McCarty Jr, J.C. 2014. Introgression genetics and breeding between Upland and Pima cotton: A review. Euphytica. 198:1-12. Interpretive Summary: It is generally accepted that the genetic variability necessary to continue improving upland cotton (Gossypium hirsutum L.) has been significantly reduced by the breeding process. One means of restoring genetic variability to upland cotton is to import useful variability from the G. barbadense species by means of hybridization. This strategy has been pursued for over a century with varying levels of success. Barriers to greater success have included hybrid breakdown, hybrid sterility and selective elimination of genes. This article reviews successful transfer or creation of useful variation between the two species involving qualitatively inherited traits, chromosome substitutions, quantitatively inherited traits, and heterotic responses. The article demonstrates the need and benefits of continued hybridization efforts between the two species.
Technical Abstract: The narrow genetic base of elite Upland cotton (Gossypium hirsutum L.) germplasm has been a significant impediment to sustained progress in the development of cotton cultivars to meet the needs of growers and industry in the recent years. The prospect of widening the genetic base of Upland cotton by accessing the genetic diversity and fiber quality of Pima cotton (G. barbadense L.) has encouraged interspecific hybridization and introgression efforts for the past century. However, success is limited due mainly to genetic barriers between the two species in the forms of divergent gene regulatory systems, accumulated gene mutations, gene order rearrangements and cryptic chromosomal structure differences that have resulted in hybrid breakdown, hybrid sterility and selective elimination of genes. The objective of this paper is to provide a mini-review in interspecific hybridization between Upland and Pima cotton relevant to breeding under the following sections: (1) qualitative genetics; (2) cytogenetic stocks; (3) quantitative genetics; (4) heterosis, and (5) introgression breeding. Case studies of successful examples are provided.