Meiotic chromosome number and behaviour of Onobrychis avajensis (Fabaceae): a new species from western Iran

Abstract

Background and aims -The present study is focused on the cytogenetic and morphological criteria allowing to distinguish a new taxon from Onobrychis sect. Heliobrychis. This section is the largest section in O. subg. Sisyrosema represented with 21 species in Iran. The new species belongs to the O. subsect. Boissierianae characterized by perennial plants with well-developed stems and O. andalanica group with uniformely yellow corolla. Methods -The morphological features and meiotic chromosome number and behaviour were studied in O. avajensis Ranjbar. Key results -The novelty Onobrychis avajensis Ranjbar, endemic to Iran, is described and illustrated from two collections from a single locality between Avaj and Abgram in Qazvin Province in the west Zagros. It is closely related to O. andalanica Bornm. but differs from it in a few morphological characters. In addition, meiotic chromosome number and behaviour were studied in O. avajensis. This report is the first cytogenetic analysis of this taxon. O. avajensis is a diploid plant and possesses 2n = 2x = 16 chromosomes, consistent with the proposed base number of x = 8. The general meiotic behaviour of the species was regular, with bivalent pairing and normal chromosome segregation at meiosis. Meiotic abnormalities were observed included a varying degree of sticky chromosomes with laggards, precocious division of centromeres in metaphase I, bridges in anaphase I and multipolar cells in telophase II. Conclusion -Morphological features support the separation of Onobrychis avajensis Ranjbar as a new species.

An overview on cytogenetics of the genusOnobrychis(Fabaceae) with special reference toO.sect.Hymenobrychisfrom Iran

“…A summary of their cytological features is given in Table 2, and the chromosomes are illustrated in Ranjbar et al 2010c;Ranjbar et al 2010d;Ranjbar et al 2009a.…”

“…From these and other reports (e.g. Fedorov 1969;Goldblatt 1981aGoldblatt , 1981bGoldblatt , 1984Goldblatt , 1985Goldblatt , 1988Romano et al 1987;Goldblatt and Johnson 1991;Diaz-Lifante et al 1992;Tamas 2006;Ranjbar et al 2009aRanjbar et al , 2010Hesamzadeh Hejazi and Ziaei Nasab 2010;Ranjbar et al 2010c;Ranjbar et al 2010d;Ranjbar et al 2010f;Arslan et al 2012) it is evident that the chromosome count is known for just over a quarter of the species. Two basic chromosome numbers (x = 7 and x = 8) and three ploidy levels (2n = 2x = 14, 2n = 4x = 28, 2n = 8x = 56 and 2n = 2x = 16, 2n = 4x = 32) are present in the genus Onobrychis.…”

Iranian Onobrychis carduchorum (Fabaceae) populations: morphology, ecology and phylogeography

“…These eleven populations represent the only known O. carduchorum populations in Iran (based on over ten years of extensive studies of the genus Onobrychis in Iran: e.g. Karamian et al 2010a, Ranjbar et al 2004, 2009a, 2009b, 2010c, 2010d, 2010e, 2011, Toluei et al 2010. The specimens were prepared according to established herbarium techniques and voucher specimens were deposited in the herbarium of Bu-Ali-Sina University (BASU).…”

“…in Iran (e.g. Ranjbar et al 2004, 2009a, 2009b, 2010c, 2010d, 2010e, Toluei et al 2010, the present investigation was carried out to provide for the first time a detailed taxonomic, morphological, genetic and ecogeographical characterization of O. carduchorum in Iran and to test whether different populations of O. carduchorum are differentiated with respect to the corresponding environmental conditions. Because of lack of information about the Iranian range of this species, we here present a description of this species in Iran and compare it to information derived from occurrences of the species in other countries.…”

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

“…The taxonomy of the genus continues to be subject of much confusion, mainly because of different approaches to species delimitation, resulting in varying numbers of recognized species (Boissier 1872, Širjaev 1925, Hedge 1970, Ball 1978, Duman and Vural 1990, Aktoklu 2001. Recently some new taxa of the genus have been described from Iran (Ranjbar et al 2004(Ranjbar et al , 2007(Ranjbar et al , 2009b(Ranjbar et al , 2010a.…”