Esterase Profile in Distinguishing Inbreeds F1 And Backcross Hybrids in Indian Major Carps

Abstract

Esterase was surveyed in four different tissues namely skeletal muscle, heart, liver and kidney obtained from two Indian major carps viz.., rohu (Labeo rohita) and catla (Catla catla) pair crossed F1 hybrids of catla (y) x rohu (6), and back crossed hybrid progenies of (catla x rohu) (?) x catla (J) (BC1C) and of (catla x rohu) (?) x rohu (6) (BC1R). The enzyme was found to be highly polymorphic in different tissues of the inbred as well as in hybrids. Detailed scanning of different activity zones in the zymograms revealed that amidst 15 bands, band numbers 4 and 12 of liver and kidney tissues were found to be common in both the inbreeds and hybrids were probably characteristics bands to these two species and their hybrid progenies. Band 4 of rohu and 6/7 of catla were diagnostic bands of pure rohu and catla, respectively, regardless of the nature of the tissue. However, both the bands were present in F 1 hybrid and BC1C backcross progenies only. Another backcross i.e. BC1R could not manifest shared bandings of the parents perhaps because of cleavage into or fusion with other sister esterase isomorphs through homo- or hetero-polymerization. Only band 4 was found to be present across all the tissues in BC 1R renders its demarcation difficult from rohu inbreed. However, band 9 and 13 of liver in BC1R can distinguishit from F1and inbreeds. They are likely to be instrumental in distinguishing inbreeds from hybrids reliably. The mean pair wise similarity (S) based on esterase profile, between the parents (catla and rohu) and the developed progenies (F, hybrids, BC1C and BC1R) showed BC1C was genetically more diverse than the F 1hybrids and BC1R for esterase which may be used in carp breeding and improvement programme if it is found to be tightly linked with any characters of economic importance.