College of Horticulture, Kerala Agricultural University, Vellanikkara, Thrissure - 680 656, India.
The non preference mechanism of aphid resistance was evidenced under free choice conditions of migration and settling on cowpea. The tender most shoot tips of the resistant cowpea lines were densely pubescent with mixed types of trichomes. Anatomical studies showed that lignification of the schlerenchymatous pericycle was more in susceptible lines, indicating that resistance is more of physiological nature rather than anatomical. The resistant lines had more reducing sugars but less nonreducing sugars and total sugars but, protein, total nitrogen, phosphorus and potassium contents did not differ among resistant and susceptible lines.
