Vernalization response of wild chickpea.

• Response to low temperature during early growth in cultivated chickpea (Cicer arietinum) and its wild progenitor C. reticulatum was investigated to clarify the evolutionary processes under domestication in this crop. • Parental lines and their F and F progeny were exposed to cold treatment (4°C) for 30°d after seed imbibition and compared with controls. • Cold treatment caused a 19-d advance in flowering time in wild chickpea, but only a 3-d advance in cultivated chickpea. It also promoted apical dominance of the main stem of the wild chickpea, whereas apical dominance was constitutive in the cultivated type. F progeny showed significant genetic variation affecting the response of flowering time to low temperature. We suggest that selection against alleles conferring vernalization requirements was a major step in the evolution of cultivated chickpea. The reduced low-temperature response was fundamental both for the ancient conversion of chickpea from an autumn- to a spring-sown crop ('summer crop') in west Asia, and for its spread into the lower-latitude regions of India and east Africa. • Attempts to improve yield and/or resistance to biotic and abiotic stresses through introgression with wild chickpea species carry the risk of reintroducing vernalization sensitive alleles into the cultigen.