EVALUATION OF CROP RESISTANCE TO AQUEOUS OIL POLLUTION

Root and shoot tolerance indices and photosynthesis characteristics (CO2-dependent-O2 evolution; H2O→MV electron transport; whole-leaf photosynthesis by infrared gas analyzer) indicated that ADT-36 and CR-1009 rice varieties were more tolerant than other varieties (IR-50, IR-20, and Ponni). Vigna varieties (T-9 and Krishna) were most susceptible to aqueous oil pollution. Since the oil-polluted soil contained a potentially toxic concentration of cadmium, tolerant (ADT-36) and susceptible (IR-50) varieties of Oryza were further analyzed for cadmium-binding components. Higher accumulations of cadmium were found in the roots than in the leaves of both rice varieties. Cadmium is associated with proteins of about 50,000 and 33,000-dalton in molecular mass, of which the 33-kdalton protein was significantly induced only in ADT-36. It is suggested by the present study that the ADT-36 rice variety is most tolerant to aqueous oil pollution, as evidenced by higher STI (shoot tolerance index) and RTI (root tolerance index) values, induction of Cd-binding proteins, and comparatively normal photosynthesis rates. © 1990 Humana Press Inc.