Dipartimento di Biologia Applicata, Universita degli Studi di Perugia, Borgo XX Giugno, 06100 Perugia, Italy.
Genome. 2009 Nov;52(11):919-25. doi: 10.1139/g09-068.
Ficus carica (2n = 26) is one of the oldest fruit trees of the Mediterranean basin. Recently there has been increasing interest in this species, in particular for questions related to germplasm such as genetic diversity and cultivar identification. This study was undertaken to gain more knowledge of F. carica cytogenetics and provide data useful for the characterization of its germplasm. Karyomorphological analysis and physical mapping of 18S-25S and 5S rRNA genes by the FISH technique contributed to defining the basic traits of the chromosome complement of F. carica. However, the most interesting result was the discovery of triploid (2n = 39) cytotypes of the cultivated common fig. This result demonstrates the importance of cytogenetic investigations in studies of fig germplasm and emphasizes the role of cross-fertilization as a source of variability not only in wild populations but also in cultivated forms. The results of pollen analysis suggest spontaneous sexual polyploidization as a possible origin of triploid cytotypes. Further studies are necessary to clarify the origin and effective spreading of polyploidy, the presence of other ploidy levels, and their distribution in wild and cultivated forms.
软枣猕猴桃（2n=26）是地中海盆地最古老的果树之一。最近，人们对该物种越来越感兴趣，特别是对与种质资源相关的问题，如遗传多样性和品种鉴定。本研究旨在深入了解软枣猕猴桃的细胞遗传学，并为其种质资源的特征提供有用的数据。通过 FISH 技术的核型形态分析和 18S-25S 和 5S rRNA 基因的物理作图，有助于确定软枣猕猴桃染色体组的基本特征。然而，最有趣的结果是发现了栽培普通无花果的三倍体（2n=39）细胞型。这一结果证明了细胞遗传学研究在无花果种质资源研究中的重要性，并强调了异花授粉作为变异源的作用，不仅在野生种群中，而且在栽培形式中也是如此。花粉分析的结果表明，自发的有性多倍化可能是三倍体细胞型的起源。需要进一步的研究来阐明多倍体的起源和有效扩散，以及其他倍性水平的存在及其在野生和栽培形式中的分布。
