Biochemical studies of canola plant resistance against aphids

Integrated Pest Management (IPM) is very helpful for the studies of Aphids on canola plants. Biochemical studies of canola plant resistance for its serious pests, among one of them is aphid, 16 genotypes of canola were studied at growth chamber and farmer field. Some important plant chemicals were extracted from plant leaves, and affected plants parts attacked by aphids and population of aphids in various canola cultivars were counted.  Aphids per leaf area of young plants were highly correlated with aphids on mature plants.  This suggests that aphids-resistant varieties for mature canola plants may also be arrange for baby leaf production. Concentration of Sucrose from young plants was correlated with aphids per leaf (r = 0.733, p = 0.01) and nymphs per plant (r = 0.793, p = 0.01), suggesting that low sucrose content could be used as a marker for early screening or selection for aphids resistance.  Aphids and nymphs population were negatively associated with contents of flavonoids (r = -0.564, p = 0.05) chlorogenic acid (r = -0.600, p = 0.05) while nymphs per plant were negatively associated with concentrations of chlorogenic acid (r = -0.590, p = 0.05) flavonoid (r = -0.699, p = 0.01), implying a role of phenolics and rutin (r = -0.605, p = 0.05) in the aphid resistance.  Total number of apterous aphids including Myzus persicae, per plant weight was correlated with contents of b-carotene (r = 0.823, p = 0.01), chlorophyll (r = 0.741, p = 0.01), lutein (r = 0.830, p = 0.01), and glucose (r = -0.769, p = 0.01) protein (r = 0.894, p = 0.01) of young canola plants, which could provide as early marker of aphid resistance.

Keywords; Resistance mechanism, role of chemicals in plant resistance against insects.