| Summary: | Grafting is a valuable tool for managing problems of tomato soil-borne pathogens and pests, but often generates unpredictable effects on crop yield and product quality. To observe these rootstocks-induced changes, experimental designs including many rootstock-scion combinations are required. To this end, a greenhouse experiment was conducted on 63 graft combinations, involving seven cherry tomato scions grouped in large, medium and small-fruited, and eight rootstocks with different genetic backgrounds (crosses between <i>Solanum lycopersicum</i> and <i>S. habrochaites</i> or <i>S. peruvianum</i> or <i>S. pimpinellifolium</i>, plus an intraspecific hybrid), using ungrafted controls. The response of the graft partners was firstly analyzed individually using the environmental variance (σ<sup>2</sup><sub>E</sub>), then by grouping them by classes. When analyzed individually, the scion genotype influenced fruit <i>L*</i>, <i>b*</i>, shape index, total soluble solids (TSS) and its ratio with tritatable acidity (TSS/TA), whereas plant growth and yield were unpredictable. After clustering the graft partners, some of these responses were attributable to the imposed classes. The <i>S. habrochaites</i>-derived hybrids maximized plant biomass, unlike the <i>S. pimpinellifolium</i> ones. Both classes reduced fruit biomass in small- and medium-fruited scions (by 11 and 14%, respectively). The <i>S. habrochaites</i> and <i>S. peruvianum</i> hybrids reduced <i>a*</i> and TSS, whereas promoted TA. L-ascorbic acid was reduced by grafting (from −23 to −45%), in the <i>S. pimpinellifolium</i> group too, indicating, even in low vigor rootstocks, a dilution effect worsening this nutraceutical trait of tomatoes.
|
|---|