Elucidation of Nuclear and Organellar Genomes of Gossypium hirsutum: Furthering Studies of Species Evolution and Applications for Crop Improvement.

Jocelyn A Moore,Caryl A Chlan

doi:10.3390/biology2041224

Abstract

Plant genomes are larger and more complex than other eukaryotic organisms, due to small and large duplication events, recombination and subsequent reorganization of the genetic material. Commercially important cotton is the result of a polyploidization event between Old and New World cottons that occurred over one million years ago. Allotetraploid cotton has properties that are dramatically different from its progenitors—most notably, the presence of long, spinnable fibers. Recently, the complete genome of a New World cotton ancestral species, Gossypium raimondii, was completed. Future genome sequencing efforts are focusing on an Old World progenitor, G. arboreum. This sequence information will enable us to gain insights into the evolution of the cotton genome that may be used to understand the evolution of other plant species. The chloroplast genomes of multiple cotton species and races have been determined. This information has also been used to gain insight into the evolutionary history of cotton. Analysis of the database of nuclear and organellar sequences will facilitate the identification of potential genes of interest and subsequent development of strategies for improving cotton.

Highlights

Cotton has been cultivated by man for thousands of years
Cotton is mainly valued for its fiber, cotton by-products are used in human food and animal feed
Most of the cotton fiber produced today is a product of lint harvested from four species: two Old World diploid lines (G. herbaceum L. and G. arboreum L.) and two tetraploid lines (G. hirsutum L. and G. barbadense L.)

Summary

Introduction

Because cotton fiber has desirable properties for the production of textiles, cotton has been the subject of intense cultivation and breeding over the centuries These efforts have expanded to molecular analysis of the cotton genome and studies to determine the extent that specific genes or groups of genes contribute to the desirable properties of cotton. Most of the cotton fiber produced today is a product of lint harvested from four species: two Old World diploid lines (G. herbaceum L. and G. arboreum L.) and two tetraploid lines (G. hirsutum L. and G. barbadense L.). Genomic analysis and mapping studies will enable researchers to identify native genes or combinations of genes that confer desirable properties, such as enhanced resistance to pathogens or drought, improved fiber quality and improved nutritional composition of cottonseed. G. raimondii (whole seedling, normalized floral organs including developing embryos)

Genome Insights into Polyploidy and Evolution of Cotton

Cotton Improvement2Simple and Complex Traits

Development of New Transformation Strategies

Findings

Conclusions