Elargissement de la base génétique de la principale espèce de cotonnier cultivé Gossypium hirsutum L. par la création et l'exploitation de lignées monosomiques d'addition

Abstract

Genetic broadening of the main cultivated cotton species Gossypium hirsutum L. by creation and exploitation of monosomic alien addition lines. The genus Gossypium is composed of about forty wild diploïd species that constitute an important reservoir of interesting genes for the genetic improvement of Gossypium hirsutum L., the main cultivated cotton species. Creation of monosomic alien addition lines (MAAL), made up of plants having in addition to the chromosome set of the cultivated species one wild species' supernumerary chromosome, is an interesting way to exploit this diversity. Numerous constraints limit the creation of MAAL, among them the most important is doubtless the production of first generation derivatives from pentaploids obtained by backcrossing G. hirsutum with bispecific hexaploid hybrids made of the cultivated species tetraploid genome and the genome of a donor diploid species. Raising this impediment by appropriate techniques allows to develop MAAL offering the possibility to introgress finely traits of interest from diploid species and to better understand genomic relationships between species in the genus Gossypium. Identification and exploitation of these MAAL have been for a long time based on not very reliable morphological characteristics and on the use of classical cytogenetic techniques, very heavy to implement. Nowadays, the exploitation of MAAL benefits from the great advances registered in molecular biology through the development of DNA markers and molecular cytogenetics. These progresses make of MAAL a promising way for the genetic improvement of the main cultivated cotton species.

Keywords

• Cotton
• genetic improvement
• Gossypium hirsutum L.
• interspecific hybridization
• monosomic alien addition line
• wild diploid species