Systematic study of Onobrychis shahpurensis (Fabaceae) in Iran, with the description of O. neychalanensis sp. nov.

Abstract

The study of morphology, meiotic behavior, chromosome number and pollen morphology of different populations of Onobrychis shahpurensis Rech. f. (O. sect. Onobrychis) was undertaken to evaluate and determine the variation and circumscription of this species in Iran. All populations were found to be diploid with 2n=2x=14, consistent with the previously proposed base number x=7 for the species. Almost all the populations displayed regular bivalent pairing and chromosome segregation at meiosis. However, some meiotic abnormalities were observed including various degrees of sticky chromosomes with laggards and bridges in anaphase to telophase, fragmented chromosomes in metaphase I, asynchronous nucleus in metaphase II and cytomixis. In addition, Onobrychis neychalanensis Ranjbar, Hadadi & Karamian, a new diploid species (2n=2x=14), belonging to the same section and morhologically similar to O. shahpurensis, but restricted to the northern Khalil-Kuh mountain, northwest Iran, is described and illustrated. © 2011 The Authors.