Among four varieties of Indian mustard, Sarson T42 was found more susceptible than Lahi T9 to infection by Cuscuta reflexa, whereas Varuna-59 and Rai Pusa Bold showed no apparent response. The infection by Cuscuta resulted in decrease in oil content of Sarson T42 and Lahi T9 by 84 and 36% per plant, respectively. A significant increase in free fatty acids and free sterols and decrease in total neutral glycerides of oil were also observed. The alteration in lipase activity induced by Cuscuta infestation was dependent on the developmental stage of seed. Although total fatty acid content decreased insignficantly, the fatty acid composition of oil showed appreciable differences upon infection. The percentage unsaturation of fatty acids in Sarson T42 and Lahi T9 was decreased by 23 and 12%, respectively, on infection by Cuscuta. Conclusively, in addition to a decrease in oil content, the quality (composition) of the oil of susceptible mustard varieties becomes poorer upon infection by Cuscuta.
