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Identification of peanut ( Arachis hypogaea) chromosomes using a fluorescence in situ hybridization system reveals multiple hybridization events during tetraploid peanut formation
Author(s) -
Zhang Laining,
Yang Xiaoyu,
Tian Li,
Chen Lei,
Yu Weichang
Publication year - 2016
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/nph.13999
Subject(s) - arachis hypogaea , biology , arachis , karyotype , ploidy , fluorescence in situ hybridization , chromosome , genome , bacterial artificial chromosome , genetics , in situ hybridization , cytogenetics , botany , gene , gene expression
Summary The cultivated peanut Arachis hypogaea ( AABB ) is thought to have originated from the hybridization of Arachis duranensis ( AA ) and Arachis ipaënsis ( BB ) followed by spontaneous chromosome doubling. In this study, we cloned and analyzed chromosome markers from cultivated peanut and its wild relatives. A fluorescence in situ hybridization ( FISH )‐based karyotyping cocktail was developed with which to study the karyotypes and chromosome evolution of peanut and its wild relatives. Karyotypes were constructed in cultivated peanut and its two putative progenitors using our FISH ‐based karyotyping system. Comparative karyotyping analysis revealed that chromosome organization was highly conserved in cultivated peanut and its two putative progenitors, especially in the B genome chromosomes. However, variations existed between A. duranensis and the A genome chromosomes in cultivated peanut, especially for the distribution of the interstitial telomere repeats ( ITR s). A search of additional A. duranensis varieties from different geographic regions revealed both numeric and positional variations of ITR s, which were similar to the variations in tetraploid peanut varieties. The results provide evidence for the origin of cultivated peanut from the two diploid ancestors, and also suggest that multiple hybridization events of A. ipaënsis with different varieties of A. duranensis may have occurred during the origination of peanut.