Genetic variability in progenies of Acacia nilotica (L.) ex DEL. ssp. indica (Benth.) Brenan for nitrogen fixing ability.

Nitrogen fixing abilities of 7 provenances and 21 progenies of Acacia nilotica (L.) WILLD ex DEL. ssp. indica (BENTH.) BRENAN were assessed in nitrogen free sterilized sand in chillum jars at Hisar (29°10'N Lat., 75°46'E long., 100 m alti.) in arid India. There were significant differences (P<0.05) in plant growth and their nitrogen contents between provenances. Maximum growth and nodulation occurred in Behrampur provenance and the least in that of Gurgaon and Patna. Significant variations were also observed among the progenies of each provenance. Progenies of Gurgaon provenance exhibited maximum variation. Interactions between progenies and provenances were significant (P<0.05). Overall best interaction was observed between Behrampur provenance and P 1 . Wide genetic diversity in nitrogen fixation ability of Acacia nilotica ssp. indica can be of great potential in tree improvement programes particularly selection of genotypes for nitrogen deficient soils.