ESTERASE ISOZYMES IN DOWNY MILDEW RESISTANT PEARL MILLET CYTOLINES

Abstract

Downy mildew susceptible line Tifton 23A and Tifton 23B alongwith ten other resistant near isogenic derivatives of Tift 23A showed highly polymorphic esterase isozyme banding pattern by isoelectric focussing (pH 3.5-10.0) at three stages of growth. AT D2 all resistant near isogenic lines in both the sterile and fertile backgrounds were distinctly discriminated by a band with high intensity at pI 6.1 and low intensity at pI 6.9. All resistant lines except Lll1A and Lll1B were also characterized by intense band at pI 7.3 though band intensity in 126D2A and 126D2B was quite low. Discrimination of A and B lines of every pair was easily possible at D1 and D3 stages. The effect of sterile and fertile cytoplasms and nucleocytoplasmic interaction in estarase isozyme expression alongwith the role of isozyme in growth and development has been discussed.