Morphological and Biochemical Responses of Three Durum Wheat Varieties to Aphid (Rhopalosiphum maidis) Infestation

Abstract

Aphids cause biotic stress and vector diseases. However, wheat’s morphological and biochemical responses to aphid infestation are poorly studied. Our study evaluated the varietal behavior of durum wheat (Triticum durum Desf) against Rhopalosiphum maidis (Homoptera: Aphididae) in laboratory conditions. We studied morphological trait variation (plant height [HP], flag leaf area [SFDF], leaf area [SF], spike length [LE], and beard length [LB]) and biochemical characteristics (chlorophyll, soluble sugars, and proline contents) of three varieties in Algeria: MBB, BOU, and GTA. MBB is the least affected, with a 13.34 % infestation rate. The heaviest infestation occurs during the heading stage. All morphological factors decreased in length or surface between control and infested samples. ANOVA showed significant variations for HP, LE, SFDF, and SF but not LB. Biochemical parameters decrease in GTA. In MBB, chlorophyll and soluble sugars decrease while proline increases. For BOU, soluble sugars decrease while chlorophyll and proline increase. Only soluble sugars showed a significant statistical variation between control and infested plants. HP is affected by aphid infestation, which is of higher significance for MBB. Proline content is affected in BOU and GTA. There is no significant variation between aphid infestation and chlorophyll, soluble sugars, and proline levels for MBB. The effect of R. maidis infestation is less important on MBB. HP, SFDF, SF, and LE are morphological selection criteria for R. maidis infestation resistance. Proline is a biochemical selection criterion. Genetic and molecular analyses are required to identify genes for programs that enhance durum wheat’s resistance to R. maidis infestations.