Construction of cytogenetic map of Gossypium herbaceum chromosome 1 and its integration with genetic maps

BACKGROUND: Cytogenetic map can provide not only information of the genome structure, but also can build a solid foundation for genetic research. With the developments of molecular and cytogenetic studies in cotton (Gossypium), the construction of cytogenetic map is becoming more and more imperative. RESULTS: A cytogenetic map of chromosome 1 (A(1)01) of Gossypium herbaceum (A(1)) which includes 10 bacterial artificial chromosome (BAC) clones was constructed by using fluorescent in situ hybridization (FISH). Meanwhile, comparison and analysis were made for the cytogenetic map of chromosome 1 (A(1)01) of G. herbaceum with four genetic linkage maps of chromosome 1 (A(h)01) of G. hirsutum ((AD)(1)) and one genetic linkage map of chromosome 1 of (A(1)01) G. arboreum (A(2)). The 10 BAC clones were also used to be localized on G. raimondii (D(5)) chromosome 1 (D(5)01), and 2 of them showed clear unique hybridized signals. Furthermore, these 2 BAC clones were also shown localized on chromosome 1 of both A sub-genome and D sub-genome of G. hirsutum. CONCLUSION: The comparison of the cytogenetic map with genetic linkage maps showed that most of the identified marker-tagged BAC clones appearing same orders in different maps except three markers showing different positions, which might indicate chromosomal segmental rearrangements. The positions of the 2 BAC clones which were localized on A(h)01 and D(h)01 chromosomes were almost the same as that on A(1)01 and D(5)01 chromosomes. The corresponding anchored SSR markers of these 2 BAC clones were firstly found to be localized on chromosome D(5)01 (D(h)01) as they were not seen mapped like this in any genetic map reported.