Identifying donors of reduced ethylene biosynthesis among apple-tree accessions in the genetic collection of the Federal Altai Scientific Center of Agro-Biotechnologies using the MD-ACO1 and MD-ACS1 molecular markers
Abstract
Background. Obtaining highly winter-hardy apple-tree genotypes with a long fruit shelf life is a key goal for breeders, especially for Siberia’s harsh climate. Despite the availability of cultivars with reduced ethylene biosynthesis (‘Fuji’ or ‘Gala’), their utilization in northern regions is restricted by their low winter hardiness. Thus, identifying regional genotypes with low ethylene production is crucial for breeding programs aimed at improving the fruit storage potential without losing cold tolerance. Materials and methods. Genetic polymorphism of the Md‑ACS1 and Md‑ACO1 genes (ethylene biosynthesis enzymes) was studied in 34 apple accessions from the genetic collection of the Federal Altai Scientific Center of Agro-Biotechnologies (Barnaul). Total DNA was extracted using a commercial Diamond DNA Plant kit (Altaibiotech, Russia) per the manufacturer’s protocol. PCR amplification used specific primers targeting the Md‑ACS1 and Md‑ACO1 gene regions. Results. Analyzing the Md‑ACO1 allelic polymorphism revealed an uneven genotype distribution: the heterozygous genotype 1/2 prevailed, accounting for 100% of the accessions, while homozygous genotypes were absent. Conversely, Md‑ACS1 showed predominance of the homozygous genotype 1/1 (91.4%), while heterozygous 1/2 was rare (8.6%), and homozygous 2/2 was not detected. Conclusion. Identifying genotypes with allelic configurations linked to reduced ethylene biosynthesis is an important breeding step. Cvs. ‘Altayskoye Purpurovoye’, ‘Altayskoye Yubileynoye’, ‘Mantet’, and ‘Wealthy’, and the open‑pollinated seedling Со‑99‑2981 (all featuring the Md‑ACS1 genotype 1/2) are recommended for further research and breeding. These accessions hold potential for developing highly winter-hardy apple-tree cultivars with extended post‑harvest fruit shelf life, thereby improving apple production in Siberia and other northern regions with extreme climate conditions.