Dimitriya S. PETKOVA, Evgeniya D. ZHEKOVA, Anna V. ILIEVA, Iliana I. IVANOVA
Abstract. Eight alfalfa genotypes were investigated at IASS “Obraztsov chiflik”–Rousse during the period 2006–2009. The objective of the study was investigation of biochemical changes in alfalfa roots, attacked by lucerne longhorn beetle (Plagionotus floralis Pall.) and root rot. Biochemical analysis of healthy roots, roots damaged by larvae of longhorn beetle, roots attacked by root rot and green mass were made. The healthy status of roots was evaluated according to the scale of Lyubenets and Shtukina (1968). A moderate negative correlation was determined between total phenols and sugars in plants damaged by longhorn beetle. The content of proteins, fiber, calcium, magnesium and total phenols in plants damaged by longhorn beetle and root rot increased compared to healthy ones and a decrease of sugars was observed. The highest number of healthy plants and high productivity were registered in Synthetic population (SP) N 7 and it could be appropriate in selection for the purposes of breeding.
Keywords: alfalfa, Plagionotus floralis, root rot, biochemistry