Field strain of cowpea aphid, Aphis craccivora Koch, was treated by selected neonicotinoid insecticides to evaluate their toxicity and persistence against this pest in Assiut governorate, Egypt. Under faba bean field conditions, acetamiprid, imidacloprid, thiamethoxam and dinotefuran registered significantly high percent reduction of the pest at one, seven, fifteen and 21 post treatment. The residual effects of these insecticides showed that the LT50 for acetamiprid, imidacloprid, thiamethoxam and dinotefuran were 5.8, 6.2, 6.95 and 4.2 days, respectively. The application of these insecticides on the cowpea aphid under field conditions induced yield increases. The toxicity of these neonicotinide insecticides were tested against field strain of cowpea aphids using leaf-dib bioassay under field and laboratory conditions. The toxicity index showed that thiamethoxam, acetamiprid and imidacloprid have the highest aphicidal activity, with LC50s 0.60, 0.71 and 1.16 mg/L, respectively, while dinotefuran was the least toxic one with LC50 23.41 mg/L. Results of this study indicated that neonicotinoid insecticides were highly effective against cowpea aphid under field and laboratory conditions.

A population of recombinant inbred lines (RILs) produced from a cross between the cultivated durum wheat cvs. Svevo and Ciccio was used to develop near isogenic lines (NILs) for grain protein content (GPC) QTLs on chromosomes 2A, 2B, 3B, 5A and 6B. NILs were used to validate individual effects of the putative QTLs under different environmental conditions and to investigate the genetic relationship between GPC QTLs and grain yield. The results showed that the effect of the QTL located on 2AS on GPC was stable over different genetic backgrounds and different environmental conditions. Furthermore, this QTL appeared to be the most promising effect on phenotypic variation of GPC, thereby confirming its environmental stability and pointing to its appropriateness for marker assisted selection (MAS) for GPC improvement. QTLs located on 3BS, 5AL and 6BS were validated across environments, but only at single NIL for each. Validation of these QTLs in diverse genetic backgrounds and under different environmental conditions is still required to confirm their environmental stability. A weak negative relationship between GPC and grain yield was observed at a single case, indicating that different loci within the linkage groups could be involved and no strong evidence that GPC QTLs have pleiotropic effects on grain yield. Thus, it could be possible to use these results for GPC improvement without reduction in grain yield.

Bolting tendency in the facultative perennial species Beta vulgaris, which exhibits large intraspecific variation in bolting tendency, is a complex character governed by various environmental cues and multiple genetic factors. Significant variations in bolting time among annual Beta vulgaris ssp. maritima accessions were found. Three F2 populations derived from crosses between six annual beet accessions were analyzed for bolting tendency. Two populations (Bm38 and Bm49) exhibited phenotypic segregation ratios of 3:1 early-bolting and late-bolting which is expected for dominant-recessive inheritance of a monogenic trait. Phenotypic segregation ratio of the third population Bm49 was 15:1, early-bolting: late-bolting, which is expected for digenic dominant-recessive inheritance suggests the presence of a yet unidentified locus (LB2) which affects bolting time in annual Beta vulgaris.