DISTRIBUTION, BIOLOGICAL CHARACTERISTICS AND MOLECULAR IDENTIFICATION OF POTATO AUCUBA MOSAIC VIRUS (PAMV) IN THE KASHKADARYA REGION

Abstract

Potato aucuba mosaic virus (PAMV) is one of the significant phytopathogens negatively affecting potato yield and seed quality. The present study was devoted to a comprehensive investigation of the distribution, biological characteristics, and serological and molecular identification of PAMV in the Qarshi, Koson, Kitob, Shahrisabz, and Yakkabog districts of the Kashkadarya region.

A total of 100 symptomatic samples were collected under field conditions and analyzed using the DAS-ELISA method. The overall infection rate was 25%. The highest incidence was recorded in Kitob district (35%), whereas the lowest was observed in Shahrisabz district (15%).

Mechanical inoculation resulted in local necrotic lesions in Chenopodium amaranticolor and systemic mosaic symptoms in Nicotiana benthamiana, confirming active viral replication. RT-PCR analysis revealed a 750 bp fragment corresponding to the coat protein gene, with a 92% agreement between serological and molecular results.

Evaluation of physiological responses of potato cultivars demonstrated a strong negative correlation between ascorbic acid content and symptom severity (r = −0.76; p < 0.05), suggesting that the antioxidant system may play a crucial role in virus resistance.

Additionally, potential mixed infections were observed in certain areas, indicating that synergistic interactions between PAMV and other Potexviruses or Potyviruses may increase epidemiological risk. The findings provide the first comprehensive characterization of PAMV under Uzbek agro-ecological conditions and contribute to the scientific basis for healthy seed production and selection of virus-resistant cultivars.

Keywords

Potato aucuba mosaic virus, PAMV, potato virus, Potexvirus, DAS-ELISA, RT-PCR, epidemiology, Kashkadarya region, ascorbic acid, virus resistance, mixed infection, molecular diagnostics.