Agronomic performance of diploid inbred potatoes and their F1 hybrid potatoes

Phenotypic uniformity and tuber yield are fundamental concerns in diploid inbred-based F 1 hybrid breeding in potatoes. We evaluated the agronomic traits of 22 hybrid families grown in small and large pots and the field. These families were derived from crosses of heterozygous × heterozygous, homozygous × heterozygous, and homozygous × homozygous parents using highly homozygous plants of Solanum phureja , S. chacoense , and tenth selfed generation plants derived from an interspecific hybrid. Genetic variability was estimated using genome-wide single nucleotide polymorphism (SNP) markers. Hybrid populations from homozygous × homozygous parents exhibited the highest phenotypic and genetic uniformity levels. Hybrid vigor in hybrids of homozygous × homozygous parents was tremendously enormous for fecundity and growth (up to 2877.5% and 8153.6%, respectively) and moderately large for tuber yield (158.2 to 230.7%). SNP-based genome-wide percent heterozygosity ranged from 28.7 to 44.3% for heterozygous parents and 14.4 to 44.8% for hybrid populations. The heterozygosity was correlated most highly with tuber size ( r = 0.691–0.684) and negatively with tuber number ( r = − 0.518), resulting in a positive correlation with tuber yield ( r = 0.498). Since the heterozygosity of 2 x Atlantic was the second highest (44.3%), its hybrid population produced a high yield in the field (925.6 g/plant) close to the yield of tetraploid potatoes. Thus, yield potential can be predicted by the genome-wide percent heterozygosity, possibly because many genetic factors collectively contributing to yield are located across the potato genome, and their accumulated heterotic effects can be represented as the genome-wide percent heterozygosity.