Barley Yellow Dwarf Virus Effects on Cereal Plant Growth and Transpiration

Abstract

ABSTRACTLittle is known about how changes in root system characteristics caused by barley yellow dwarf virus (BYDV) infection affect transpiration in cereal plants. Objectives of these greenhouse studies were to elucidate virus infection effects on plant growth and apparent transpiration rate in oats (Avena sativa L. ‘Coast Black’) and barley (Hordeum vulgare L. ‘Robust’). Seedlings were infested at the first leaf stage (13 d after planting) with viruliferous (BYDV) or nonviruliferous bird cherry oat aphids (Rhopalosiphum padi L.) for 48 h. Aphids were removed and plants grown for an additional 26 d. Root and shoot dry weights, root‐to‐shoot weight ratio, leaf blade dry weight, leaf blade area, and apparent transpiration rate were measured. Data were subjected to ANOVA analysis. Viral disease symptoms, such as reduced tiller number, stunting, leaf chlorosis, and reddening, were more pronounced in oats than in barley. Virus infection decreased root dry weight by 88% in oats and 35% in barley, reduced root‐to‐shoot ratio by 65% in oats and 36% in barley, decreased leaf blade area by 75% in oats and 36% in barley, and reduced apparent transpiration by 73% in oats and 33% in barley. Thus, BYDV infection caused significant reductions in growth and water movement through the transpiration stream to a greater extent in oats than in barley, indicating that Coast Black oats was sensitive to BYDV infection whereas Robust barley was considerably more tolerant.