Evolutionary Participatory Selection for Organic Heterogeneous Material: A Case Study with Ox-Heart Tomato in Italy

Abstract

Cultivars specifically adapted to organic agriculture are lacking in most crops, and tomato is no exception. Evolutionary-participatory breeding (EPB) combines the adaptive ability of evolutionary populations with farmers’ selection, thus representing a cost-effective strategy for the development of novel organic heterogeneous material, as introduced by the European regulation on organic agriculture (EU) 2018/848. An F4 ox-heart tomato composite cross population (CCP), derived from a half-diallel cross of four local varieties chosen for their superior performance under organic conditions, was submitted to both natural and farmers’ selection on three organic farms and at one research station in Italy. During field days held at each location before harvest, farmers visually scored 400 plants, all of which were carried forward to develop the natural selection (NS) population, while the 20 best ranking plants were chosen to develop the farmers’ selection (FS). After two cycles of selection (2018 and 2019), one NS and one FS population were obtained at each location. After this two-year selection process, in 2020, the eight populations (four NS and four FS), were evaluated in a randomised complete block trial in the four locations of selection and evolution. Four local varieties chosen by farmers and two modern varieties (one open pollinated variety and one F1 hybrid) were added as controls. The ANOVA showed significant differences among entries for all traits. Entry-by-location interactions were larger than the genetic effect for the overall evaluation, yield at first harvest, total yield and percentage of marketable yield. This confirms the importance of decentralising selection when seeking to develop specifically adapted varieties and/or populations. Evidence was observed of the effectiveness of participatory selection for improving the yield at first harvest, with a slight trade-off effect for the total yield and plant vigour.