Compensation studies on the tomato landrace ‘Tomataki Santorinis’
The attributes of yield and yield stability of two coexisting lines within the old landrace of small-sizedtomatoes ‘Tomataki Santorinis’, i.e., ‘Genuine Santorinis’ (‘G’-line) and ‘Traditional Santorinis’ (‘T’-line)were defined, quantifying the interaction of the lines with the environment. The experiments wereconducted in parallel at two environments: (a) two-year intra-selection experiments in situ (islandof Santorini) under traditional agronomic management, (b) two-year evaluation experiments ex situ(Agricultural Research Center of Northern Greece) under the usual ‘farmer’s technique’, and (c) finalcomparative trials of selected entries of each line with the source material in situ and ex situ. Especially,for the attributes of yield, the number and the weight of early and total fruits were measured. Addi-tionally, descriptive (fruit ribbing and shape) and qualitative (total soluble solids, total solids and pH)characteristics were recorded. In the in situ environment, genetic variance for yield components wasmedium to high for ‘G’-line and zero to low for ‘T’-line. In the ex situ environment, the genetic variancewas high for ‘G’-line and low for ‘T’-line. Ranking of yield components, between the two environments,showed significant correlations of ‘G’-line and ‘T’-line in situ. Ex situ, the ‘T’-line performed similarly,while the ‘G’-line showed reduced association between phenotypic and genotypic performance. Thecomparative trials showed significant difference between selected entries and source material solely forthe ‘G’-line, revealing different compensation profiles of the lines’ adaptive ability. The ‘G’-line profilerevealed productivity, efficiency to direct selection and specific adaptability. The ‘T’-line profile revealedlower productivity, high homogeneity and broad adaptation. These profiles permit breeders to developtwo distinctive types of the landrace, either as a Protected Designation of Origin (PDO) cultivar or as a line.