The genus Cicer L. (Leguminosae, Cicereae) comprises 9 annual and 35 perennial species that have a centre of diversity in south-western Asia, with remote, endemic species found in Morocco and the Canary Islands (van der Maesen, 1987, Map 2.1). The genus is the member of the monogeneric tribe Cicereae Alef., subfamily Papilionoideae, family Leguminosae. It was histori- cally included in the legume tribe Vicieae Alef., but Kupicha (1977) presented detailed taxonomic evidence to support the tribal distinction of the genus from the other Vicieae genera, Vicia L., PisumL.,Lens Adans., Lathyrus L. and Vavilovia A.Fed. To this end Kupicha (1977) reinstated the monogeneric tribe Cicereae Alef. originally proposed by Alefeld (1859) and provided a detailed generic description (Kupicha, 1981). The genus was revised by van der Maesen (1972), who largely adhered to the classification of Popov (1929). The latter divided the species into 2 subgenera – Pseudononis Popov and Viciastrum Popov; 4 sections – Monocicer Popov, Chamaecicer Popov, Polycicer Popov andAcanthocicer Popov; and 14 series. The major taxonomic divisions were made on the basis of flower size, life span, growth habit, whether the plants are woody or herbaceous, and form of leaf apex, terminating in a tendril, spine or
©CAB International 2007. Chickpea Breeding and Management
14 (ed. S.S. Yadav)
This chapter reviews the taxonomy of the genus Cicer (Leguminosae, Cicereae), taking into account the 1972 revision and the 1987 update by van der Maesen, and new data available since then. Brief descrip- tions enumerate the 44 species known at present. Improved identification aids for Cicer taxa are presented: a dichotomous key and a tabular key. Infrageneric classification is discussed, on the basis of results of molecular investigations.
leaflet. The Cicer taxa present within the former Soviet Union (Popov, 1929;
Linczevski, 1948; Czrepanov, 1981) were also reviewed by Seferova (1995), who rearranged the subgeneric classification. Recently, Javadi and Yamaguchi (2004a, 2005) conducted a molecular study on 29 species of the genus, sug- gesting further adaptation of the classification above species level.
Only one of the 44 species currently recognized is cultivated on a large scale, the chickpea (Cicer arietinum L.). Today it is cultivated in 49 countries (FAO, 2006) from the Mediterranean basin to India, Ethiopia, East Africa and Mexico. It is a major pulse crop in Asia and Africa, which, combined, account for 96% of total world production. In 2004, the world production of chick- pea was 8.6 million tonnes, from 11.2 million hectares of land. These figures show that the chickpea accounts for almost 15% of the total land area used for cultivation of pulses (Singh, 1990).
There has been an increasing demand for higher-yielding, as well as dis- ease-, insect-, wilt- and drought-resistant cultivars. Chickpea breeders increas- ingly look to the wild relatives to supply genes to meet this demand, which has
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Map 2.1. ——Main areas of chickpea cultivation; --- Areas of occurrence of wild Cicer species.
resulted in definite improvement (van der Maesen et al., 2006). This interest has focused primarily on those species in the gene pools closest to the crop. Using the Harlan and de Wet (1971) gene pool concept, the chickpea gene pool may be characterized as follows:
Crop = GP1a GP1b GP2 GP3
Cicer arietinum C. echinospermum C. bijugum Other Cicer species C. judaicum
C. reticulatum C. pinnatifi dum
Thus, those in GP1b are most closely related to chickpea, with those in GP2 and GP3 more remotely related.
The threat status for Cicer species in the wild has not been systematically reviewed but six Cicer species were included in the 1997 World Conservation Union (IUCN) List of Threatened Plants (Walter and Gillett, 1998) using the pre-1994 categories: the six species, C. atlanticum,C. echinospermum,C. flori- bundum,C. graecum,C. isauricum and C. reticulatum, each being categorized as rare (R). The ecogeography and conservation status of Cicer species was recently reviewed by Hannon et al. (2001). Major international Cicer ex situ collections (see also Berger et al., 2003) are maintained by the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad, India (17,244 accessions); the International Centre for Agricultural Research in the Dry Areas (ICARDA), Aleppo, Syria (9682 accessions, 292 wild); the US Department of Agriculture, Agricultural Research Service (USDA-ARS), Western Regional Plant Introduction Station (WRPIS), Pullman, Washington (4602 accessions) (Hannon et al., 2001). There is little information available in the literature regarding in situ conservation of any wild Cicer species; although species will obviously occur in protected areas, their maintenance will not be the focus of the reserve management plan. However, Hannon et al. (2001) in their review of in situ conservation of Cicer spp. found one report of in situ conservation of one rare species in Bulgaria (Gass et al., 1996), but they report widespread actual loss of wild species habitat in the areas considered to be the centre of diversity for Cicer.
Since 1972 (only) four species have been described as new to science: C.
heterophyllum Contandriopoulos, Pamukçuoglu and Quézel (Contandriopoulos et al., 1972), C. reticulatum Ladizinsky (Ladizinsky, 1975), C. canariense A.Santos and G.P.Lewis (Santos Guerra and Lewis, 1985), which was sufficiently distinct to warrant the erection of the monospecific subgenus Stenophylloma A.Santos and G.P.Lewis, and C. luteum Rassul. and Sharip. (Rassulova and Sharipova, 1992).
In recent years collection of wild Cicer spp. has become more difficult, as uncer- tainty about the execution of new biodiversity access and benefit sharing slowed down exploration activities (van der Maesen et al., 2006). The current interest in wild relatives and addition of new taxa has resulted in improved identification aids to enable accurate identification of the currently described Cicer taxa.