Biotech Today: An International Journal of Biological Sciences

Fifteen maize genotypes were screened for their tolerance against flooding stress by cup method. On the basis of survival of the seedlings, the genotypes were characterized as tolerant, moderate and susceptible to the stress condition. SDS-PAGE analysis of selected genotypes revealed certain unique polypeptide bands in roots of stressed samples (68.0, 70.0 and 85.0 kDa) indicating the synthesis of some new proteins under stress conditions which implies the synthesis of anaerobiosis induced anaerobically-induced proteins (ANPs) in the maize seedlings.. Presence of 85kDa was observed exclusively in the roots of tolerant genotypes which suggest the presence of differential protein expression in tolerant genotypes in comparison to susceptible ones. Genetic diversity using RAPD markers revealed three clusters. All the susceptible genotypes were found in cluster III while moderate and tolerant genotypes in cluster I and II and were more closely related to each other. Among the twenty gene specific markers used, only five gave the positive results and correspond to Zea mays sucrose synthase gene. The absence of amplification was observed in some of the flood susceptible (PMH2 and LM13) and moderately susceptible (Paras and CM140) genotypes, whereas in all flood tolerant genotypes, the gene was present and were well amplified. Present investigation revealed potential markers for screening of tolerant genotypes against flooding stress.