Interspecific hybridization to introduce useful genetic variability for pigeonpea improvement

Abstract

Pigeonpea (Cajanus cajan (L. ) Millspaugh) is an import ant grain legume grown in t ropical and subt ropical regions of t he world. Narrow genet ic base coupled wit h low levels of resist ance against import ant biot ic/ abiot ic st resses in cult ivat ed pigeonpea is t he major const raint aff ect ing it s product ion and product ivit y globally. Wild Cajanus species are t he reservoir of many import ant genes including resist ance/ t olerance t o diseases, insect ­pest s and drought , and good agronomic t rait s and can be ut ilized t o improve t he crop cult ivars, enrich variabilit y, and broaden t he genet ic base. Ut ilizat ion of wild Cajanus species has cont ribut ed f or t he development of cyt oplasmic male st erilit y (CMS) syst ems f or pigeonpea improvement . Prebreeding populat ions involving promising wild Cajanus accessions belonging t o secondary and t ert iary gene pools as donors and popular pigeonpea cult ivars as recipient s were developed f or enriching variabilit y f or pigeonpea improvement . Considerable variabilit y was observed in t hese populat ions f or morpho­agronomic t rait s and f or biot ic st resses. Two advanced backcross populat ions derived f rom wild Cajanus species are being genot yped t o ident if y QTLs associat ed wit h agronomic t rait s f or f urt her deployment in pigeonpea improvement programs. Agronomically desirable and disease resist ant int rogression lines have been ident if ied and shared wit h breeding programs f or developing new high­yielding and climat eresilient pigeonpea cult ivars wit h a broad genet ic base.