Development of early-flowering Kabuli chickpea with compound and simple leaves D. J. Bon FIL 1 , O. Goren 2 , I. Mufradi 1 , J. Lichtenzveig 2 and S. Abbo 2,3 1 Agricultural Research Organization, Gilat Research Center, MP Negev 85280, Israel; 2 The Levi Eshkol School of Agriculture, The Hebrew University of Jerusalem, Rehovot 76100, Israel; 3 Corresponding author, E-mail: abbo@agri.huji.ac.il With 3 figures and 5 tables Received April 21, 2006/Accepted May 26, 2006 Communicated by A. Ashri Abstract Terminal drought is a major constraint to chickpea (Cicer arietinum L.) production. Autumn sowing and early flowering have been suggested as ways to benefit from the winter rains in short rainy seasons under dryland cropping. High-yielding, late-flowering, simple- leafed (slv/slv) chickpea cultivars with good field resistance to Ascochyta blight have been bred recently. Changing plant architecture, by altering leaf shape, may affect agronomic performance. As no information is available on the effect of leaf shape on phenology and seed yield, this study was aimed at: (i) introducing the simple leaf trait into an early-flowering chickpea background; (ii) comparing the grain yield of the two leaf types in early vs. late flowering backgrounds and (iii) producing breeding lines combining early flowering, large seeds and Ascochyta tolerance with both leaf types. Hybrid progeny were studied from the cross of ÔSanfordÕ (slv/slv) and ICC7344, (compound, SLV/SLV). Four early-podding, F 8 breeding lines were selected with either simple or compound leaves. In three different field experiments under dryland conditions (334–379 mm), they yielded ca. 1.4 t/ha as compared with 1.0 t/ha in the standard Israeli ÔYardenÕ on one site, but no significant differences in yield were obtained in the other two experiments. Key words: Cicer arietinum—early flowering—early podding— drought escape—leaf shape Chickpea (Cicer arietinum L.), an important food legume of the Mediterranean basin, the Middle East, East Africa and the Indian subcontinent, is mostly a dryland crop with a global mean seed yield of 0.7 t/ha (Abbo et al. 2003). In the Near East and in Mediterranean-like environments it is sown either as a rainfed winter crop or as a spring crop, in which case it relies on residual soil moisture (Abbo et al. 2003). While the yield potential of spring-sown chickpea ranges between 0.3 and 0.6 t/ha (Kumar and Abbo 2001), winter-sown crops may yield 2–4 t/ha in favourable seasons (Keatinge and Cooper 1983, Singh et al. 1997). Because of their inherent long-day requirements, most Mediterranean chickpea stocks are late flowering (Or et al. 1999, Kumar and Abbo 2001). In addition, lush vegetative growth, typical of autumn sowing, may expose dryland chickpea to high evaporative demand during the critical stage of seed filling, thereby reducing grain yield, especially under short rainy season environments (Turner et al. 2001). One possible way to overcome this problem is to breed for drought escape by early flowering and early podding (Kumar and Abbo 2001). Most chickpea cultivars have compound (Ôfern-likeÕ-wild type) leaves, also typical of many wild Cicer taxa. These compound leaves are pseudo-imparipinnate, because the ending leaflet is not in a true terminal position (Cubero 1987). Several leaf shape mutations have been described in chickpea (Ekbote 1942), and their inheritance studied (Rao et al. 1980). Among these, the recessive simple leaf trait (slv), seems to have a potential to reduce evaporative demand because of its smaller leaf area (Fig. 1), with reduced leaf area indices of slv/slv relative to compound (SLV/SLV) genotypes (unpublished results). The simple leaf trait was recently introduced into modern Ascochyta-resistant Kabuli cultivars released by the United States Department of Agriculture (USDA) breeding pro- gramme (Muehlbauer et al. 1998a,b). However, no data on the relationship between the SLV locus and agronomic performance is available. One possible way to study the association between leaf shape and agronomic traits is to compare cultivars with the different leaf types, as attempted by Gan et al. (2003). However, as pointed out by these authors, comparisons using a small number of cultivars cannot provide information on possible linkage relationships between the leaf shape gene and agronomic traits of interest. Moreover, the American simple leaf cultivars are highly photoperiod-sensitive and therefore poorly adapted to Near Eastern environments (Or et al. 1999). This prevents any meaningful comparison with conventional Mediterranean germplasm, let alone with new early-flowering types (Hovav et al. 2003). Alternatively, studies of hybrid progeny from slv/slv · SLV/SLV crosses can Fig. 1: A compound Ôfern-likeÕ (SLV/SLV) chickpea type (left), and a simple (slv/slv) leaf type (right) Plant Breeding 126, 125—129 (2007) doi: 10.1111/j.1439-0523.2007.01343.x Ó 2007 The Authors Journal compilation Ó 2007 Blackwell Verlag, Berlin www.blackwell-synergy.com