CYTOPLASMIC ULTRASTRUCTURE AND DOWNY MILDEW RESISTANCE IN PEARL MILLET

Abstract

In pearl millet, cytoplasmic diversitywas studied using electron microscopy atthree growth stages of male sterile and fertile lines which represented susceptible control, Tifton 23, and five other downy mildew resistant/immune lines. Structural superiority of the resistant lines over susceptible control was evident, particularly for the following attributes: polyribosomal density, granum density, mode of phenolic generation, mechanism for cytoplasmic compartmentalisation, organization of grana and stroma in chloroplast and shape of plasma membrane. This has been discussed as a possible criterion for selecting lines resistant to downy mildew.