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The efficiency of using monosomic alien addition lines (MAALs) to introgress agronomical traits of interest carried by wild diploid Gossypium species into the main cultivated cotton species G. hirsutum depends on the opportunities of confronting the alien chromosome with the recipient background genome at each generation and on the occurrence of translocations and homoeologous recombinations. The selfed-progeny of five MAALs of G. australe in G. hirsutum was screened with SSR markers to determine the transmission frequency of the alien chromosome and monitor its integrity. Three MAALs revealed a transmission frequency significantly lower than the expected ratio and one MAAL presented an exclusive transmission of the additional chromosome. In these four MAAL the alien chromosome was transmitted almost unaltered. With the fifth MAAL the alien chromosome was normally transmitted but was altered in half of the plants carrying it. In one MAAL, normally carrying brown fiber, the emergence of some plants carrying white and brown fiber revealed the somatic elimination of the additional chromosome. The loss of this chromosome seems to be triggered by its deletion.

In order to select genotypes of Gossypium hirsutum genetically balanced and expressing the low-gossypol seed & high-gossypol plant trait introgressed from the Australian wild diploid species G. sturtianum, the [(G. hirsutum × G. raimondii)² × G. sturtianum] triple hybrid was backcrossed to G. hirsutum and autopollinated to produce backcross and selfed progenies. Two hundred and six mapped SSR markers of G. hirsutum were used to monitor the introgression of SSR alleles specific to G. sturtianum and G. raimondii in the selected progenies. A high level of heterozygosity, varying from 25 to 100%, was observed for all G. sturtianum-specific SSR markers conserved in the most advanced progenies. These results indicate the existence of segregation distortion factors that are associated with the genes controlling the researched trait. This study represents a starting point to map the genes involved in the expression of the trait and better understand its genetic determinism.