Karyotypic studies in Arachis hypogaea L. varieties

The karyotypes of nine Arachis hypogaea accessions, including two botanical varieties of subspecies hypogaea and four of subspecies fastigiata, were analyzed. Varieties aequatoriana and peruviana were studied for the first time. The mean chromosome length showed that variety hirsuta is distinctive when compared with the others because it is the shortest; besides, significant intravarietal differences exist within variety hypogaea, but not between subspecies. The karyotypes are highly symmetric since metacentric chromosomes are the most frequent. A pair of satellites was observed in all the accessions in mitotic metaphases, this feature was useful to differentiate groups. These data suggest that all Arachis accessions present a very similar chromosomal complement and support the hypothesis of a monophyletic origin.