Salinity Tolerance in F1 Hybrids of Pigeonpea and a Tolerant Wild Relative

Abstract

Salinity in soil or water presents a stress condition to crop plants that is of increasing importance in the sustainability and stability of crop production in the semiarid regions of the world. This study determined the potential for genetic introgression of salinity tolerance from a wild relative, Atylosia albicans (W. & A.) Benth., to cultivated pigeonpea, Cajanus cajan (L.) Millse. A sand culture system was used to grow the salt‐tolerant A. albicans, salt‐sensitive C. cajan, and their F1 hybrids at various precisely maintained salinity levels. The results demonstrated the feasibility of transferring salinity tolerance from A. albicans to C. cajan. The high level of salinity tolerance in A. albicans was expressed as a dominant genetic factor in both the reciprocal F1 hybrids of this species and C. cajan. The physiological attributes conferring salinity tolerance in A. albicans and the F1 hybrids include Na and Cl retention in the roots and limited translocation to the shoots, high K selectivity, and maintenance of transpiration rate under saline conditions.