Dynamic changes in carotenoid and flavonoid content and relative water content (RWC) by corn leaf aphid infestation on sorghum

Abstract

Sorghum is truly a versatile crop that can be grown as a grain, forage or sweet crop. Sorghum is one of the top five cereal crops in the world. Small bluish green colored, corn leaf aphids (Rhopalosiphum maidis(Fitch)) (Aphididae: Hemiptera) begin feasting early in a plant's development, feeding on the whorls of corn.The quantification of leaf pigmentcarotenoid indicated a significant loss in medium (200 aphids/plant) and high (300 aphids/plant) infestation compared to control.The per cent reduction of these pigment ranged between 10 to 40, respectively. On the contrary, the flavonoid content increased significantly in medium (200 aphids/plant) and high (300 aphids/plant) infestation.The relative water content (RWC) ranged between 89.3±1.20 to 87.2±1.21%, the per cent of reduction varying between 5.03 to 2.31 at different levels of infestation. The pigment loss was greater at high densities than the water loss.