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In 2017 in Kenya, we collected leaves from tomato plants with leaf curling. The leaves were infected with a begomovirus that was most similar to tomato leaf curl Uganda virus (ToLCUV-[UG:Iga:05]). Neither DNA-B nor satellite DNAs were detected. Recombination analyses indicated the virus was a chimera of tomato leaf curl Madagascar virus (ToLCMGV-Ats[MG:Tol:01]) and ToLCUV-[UG:Iga:05] (minor and major parents, respectively). An infectious clone induced symptoms on tomato, Nicotiana benthamiana, N. tabacum, and African nightshade. This is the first report describing the molecular characterization of tomato leaf curl disease in Kenya. GenBank/ENA/DDBJ accession number for the ToLCUV-[KE:Kia:17] sequences: LC437667.

The production of African nightshade is below its potential due to a lack of superior varieties. The development of varieties through breeding programmes has been initiated in order to supply farmers with quality seeds. However, systematic studies on the agronomic performance of African nightshade germplasm have been started only recently, and publications in this area are very scarce. In this study, we analysed morphological traits relevant for the agronomic performance of 54 entries comprising two species: Solanum villosum and S. scabrum. In addition, AFLP markers and newly developed SSR markers were used to assess genetic diversity and differentiation in the African nightshade entries. An analysis of molecular variance showed higher variation within than among entries. A cluster analysis grouped the entries into two clusters representing the two species. The analysis of agronomic traits revealed significant differences among entries. The genetic diversity of the released cultivars and accessions was comparable to but lower than that of the local cultivars. Additionally, the local cultivars had higher allelic richness and a larger number of unique alleles than did the developed cultivars and could serve as a useful gene pool for future breeding of superior germplasm.

The tomato red spider mite Tetranychus evansi Baker & Pritchard is a serious pest of solanaceous plants worldwide. Management of this oligophagous pest in African nightshades has been a challenge to smallholder African farmers due to its high reproductive rate and rapid development of resistance to synthetic pesticides. The aim of the present study was to determine the influence of leaf trichomes on T. evansi by comparing its fecundity and movement on the leaf surfaces of five African nightshade species, namely Solanum sarrachoides Sendter, S. villosum Miller, S. tarderemotum Bitter, S. americanum Miller and S. scabrum Miller. Data were recorded in the laboratory at 23 ± 1°C, 50–70% relative humidity and a 12 h light:12 h dark photoperiod for the effect of trichome type and density of the abaxial leaf surface on mite fecundity. Distances travelled by mites on the leaf surface from the edge of a thumbtack pin inserted on the leaf were also recorded. Different trichomes, glandular and non-glandular types, were identified. There was a significant negative correlation of fecundity and distance walked by mites with the density of glandular trichomes. Significantly fewer eggs were laid on S. sarrachoides in comparison with the other Solanum species. The distance walked by mites was also significantly shorter in this species, indicating that higher densities of glandular trichomes interfere with mite movements. These results suggest that African nightshade genotypes differ in their levels of resistance to T. evansi, which is partially associated with differences in trichome types and their densities.

The effect of five African nightshade (Solanum sp.) species on the biological and demographic parameters of the tomato spider mite, Tetranychus evansi Baker and Pritchard, was examined in the laboratory at 25 +/- 1 degrees C, 70-80% RH and 12L:12D photoperiod. Duration of each development stage, reproduction rate, longevity, intrinsic rate of natural increase (r (m)), and doubling time (DT) of the tomato spider mite on the five nightshade species were calculated. The results indicated that S. villosum, S. scabrum, S. tarderemotum and S. americanum are more suitable for T. evansi due to a shorter developmental period, longer adult longevity, higher reproduction and intrinsic rate of natural increase ranging between 0.180 and 0.196 females/female/day compared with S. sarrachoides which cannot support T. evansi populations as the r (m) (-0.063 females/female/day) and DT were negative on this host. Differences in developmental time and life table parameters among the other host plants were not significant.