Micro-Mel and Mini-Mel short life cycle dwarf lines with Solanum anguivi introgressions as the first model varieties for eggplant research and breeding, with potential ornamental applications

Eggplant ( Solanum melongena ) research has been hindered by the lack of suitable model plants. The development of Micro-Mel and Mini-Mel, two short-cycle dwarf model lines with introgressions from the wild relative Solanum anguivi , represents a breakthrough in eggplant research. Both lines were characterized using 30 phenotypic descriptors and compared to their parental lines and Micro-Tom. Micro-Mel has determinate growth, early flowering (41.0 days post-transplantation), and physiological fruit maturity at 103.7 days. Mini-Mel is around 3 cm taller, with indeterminate growth, later flowering (57.2 days) and fruit maturity (114.7 days), with a more conventional architecture. Both are significantly shorter than other dwarf eggplants (30 cm at 50 days), reaching only 6.83 cm and 7.93 cm at 60 days. Micro-Mel and Mini-Mel complete three and two and a half full seed-to-seed cycles per year, respectively. Their compact size makes them ideal for space-limited environments, controlled growth chambers, speed breeding, and urban or ornamental horticulture. Whole-genome sequencing (23X coverage) identified 179,653 SNPs between the parental lines, revealing heterozygosity rates of 0.00098% (Micro-Mel) and 0.00123% (Mini-Mel). Micro-Mel and Mini-Mel have 8.50% and 10.79% of their genomes introgressed from S. anguivi , respectively, including 18 shared introgressions. Notably, three orthologues of dwarfism-related genes in tomato ( SlDREB1, SlER, and SlSERK1 ) were identified within these introgressions. The compact, short-cycle nature of Micro-Mel and Mini-Mel accelerates breeding and supports research in genetics, physiology, and cultivar development, while their miniature stature and abundant flowering and fruiting confer them clear ornamental potential.