A Karyotypic Study on Manglietia (Magnoliaceae) from China

Twenty species of Manglietia and one species of Manglietiastrum from China are cytologically investigated, of which 12 are reported for the first time. All the studied species are diploid (2n = 38). Chromosomes are medium-small to small with gradually decreased sizes. The interphase nucleus and the prophase chromosomes of all species are categorized as the complex chromocenter type and the interstitial type respectively. Karyotype is mainly of 2B or in rare condition, 2A or 1A. The metacentric (m) and submetacentric (sm) chromosomes are found to form the main part of chromosome complement while the subtelocentric (st) chromosomes were rare or absent. It seems that karyotypic variation at the diploid level is the predominant feature of chromosome evolution in Manglietia. Nevertheless, karyomorphological differences are disordered and show no significant correlation with the morphological variation and the circumscription of the sampled taxa.