Varietal reaction and biochemical basis of resistance in safflower against aphid, Uroleucon compositae

Abstract

Among different varieties screened against aphids, the variety A-1 recorded the foliage drying grade 3 indicating its moderately tolerant reaction to aphid infestation which was on par with the varieties A-300 (foliage drying grade 3) and A-2 (foliage drying grade 3). The varieties PBNS-12 and Nari-6 were susceptible to aphid infestation and thus recorded the foliage drying grade of 4. Under protected condition, reducing sugars were significantly and negatively correlated with aphid population. Amino acids, total phenols and total sugars showed no significant correlation with aphid population. Total phenols correlated significantly and negatively with foliage drying grade. Under unprotected condition, amino acids correlated significantly and positively with aphid population. Reducing sugars, total sugars and total phenols correlated negatively and significantly with aphid population. Amino acids correlated significantly and positively with foliage drying grade. Reducing sugars, total sugars and total phenols correlated non-significantly with foliage drying grade. The genotypes having high concentration of amino acids viz., NARI-6, PBNS-12 recorded more infestation of aphid population. The genotypes having less concentration of reducing sugars, total phenols and total sugars viz., A-1, A-300 and A-1 recorded less aphid population and showed resistance / tolerance to aphids population.