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A cytological study on Ophrys (Orchidaceae) in Italy: New evidence and the importance of polyploidy

Turco, A., D'Emerico, S., Medagli, P., Albano, A.
Plant biosystems 2015 v.149 no.1 pp. 24-30
Ophrys, chromosome number, karyotyping, metacentric chromosomes, tetraploidy, triploidy, Italy, Sardinia
This paper presents a cytological study of two recently described species of Ophrys from the Apulia region, which is one of the most important diversification centres of the genus. The basic chromosome number was x = 18 for the two species. Ophrys peucetiae Lozito, D'Emerico, Medagli & Turco has the karyotype 2 n = 2 x = 36: 24 m+12 sm, and O. pseudomelena Turco, Medagli & D'Emerico has 2 n = 2 x = 36: 30 m+6 sm. As observed in the O. fusca group, in O. pseudomelena , metacentric chromosomes predominate over submetacentric ones. In contrast, Ophrys peucetiae has a more evolved character, as seen in the standard karyotype of O. fuciflora s.l. On average, Ophrys peucetiae exhibited a more asymmetrical karyotype than O. pseudomelena . Variations in morphology and size in chromosome pair 1 were observed within both species. Studies on chromosome numbers in Ophrys taxa from Apulia and Sardinia revealed triploidy in Ophrys morisii (Martelli) Soò and tetraploidy in O. apulica (O. Danesch & E. Danesch) O. Danesch & E. Danesch and O. forestieri (Rchb. f.) Lojac. (= O. lupercalis Devillers Tersch. & Devillers). The significance of the results is discussed in relation to previous information for this genus.