Influence of drought conditions on BYDV infection dynamics and host defense in barley genotypes.

Francis Ghartey Anobil

Diplomová práce

Abstract:

Barley yellow dwarf virus (BYDV) an aphid-transmitted virus, represents a major economic threat to cereal production worldwide. Drought is a key environmental constraint on cereal production, and its frequency is increasing under climate change. The individual effects of these stresses on plants are well known, but their combined effect on barley growth and physiological development remains insufficiently understood. This study investigated the effects of drought on BYDV infection dynamic and plant defense mechanisms in two different winter barley varieties with contrasting resistance phenotypes. Plants were evaluated using a factorial experimental design, which included two plant types, two water treatment conditions (75% water supply and 25% water supply drought stress), and two disease states (plants infected with BYDV and plants without infection). The results were assessed using three approaches: morphological traits, quantification of BYDV titre and physiological analysis of photosynthetic performance. A significant interaction between drought and BYDV accumulation was observed, which was genotype-dependent. All three factors (genotype, water regime, and infection) significantly affected plant height, with the strongest effects observed under combined stress conditions. The susceptible cultivar LG Zoro showed a slight reduction in viral titre under drought, whereas the tolerant cultivar SY Zoomba exhibited a 2.7-fold increase in BYDV accumulation under drought, indicating partial loss of host tolerance under water deficit. OJIP fluorescence analysis showed that photosystem II efficiency was most strongly reduced under combined stress conditions. These findings demonstrate that BYDV tolerance can be compromised under drought conditions, with important implications for barley breeding and disease management in water-limited environments.

Keywords

disease resistance, combined stress, Hordeum vulgare, BYDV-PAV, water deficit, chlorophyll fluorescence, OJIP transient

Jazyk práce: angličtina

Datum vytvoření / odevzdání či podání práce: 27. 4. 2026

Obhajoba závěrečné práce

• Vedoucí: Ing. Jiban Kumar, Ph.D.
• Oponent: Tomáš Moravec, externi

Česká zemědělská univerzita v Praze

Fakulta tropického zemědělství

Magisterský studijní program:
Tropical Crop Management and Ecology