Evaluation of alfalfa germplasms for productivity and tolerance to alfalfa root longhorn beetle (Plagionotus floralis Pall.: Coleoptera, Cerambycidae)

Evgenia Zhekova

Abstract: In the period 2010-2013 a Competitive Variety Testing of six alfalfa germplasms was conducted in the experimental field of Institute of Agriculture and Seed Science ‘Obraztsov Chiflik’. In conditions of natural population density of alfalfa root longhorn beetle (Plagionotus floralis Pall.) the relative quantity of plants with root damages caused by larvae was determined as well as dry matter yield and seed yield. The aim of the research investigation was to evaluate the alfalfa germplasms for their productivity and tolerance to alfalfa root longhorn beetle with the purpose to help alfalfa breeding programs in their search for genes of high productivity and resistance to pests. The results show that three- and four-years germplasms SP–СП 08, SP–СП 08-1 and SP–VK 09 keep the lowest relative share of damages versus standard Prista 3 variety during two out of four years of investigation. This result gives a reasonable ground for continuing the investigation with them for searching of a suitable alfalfa germplasm tolerant to alfalfa root longhorn beetle. Germplasms SP–СП 08-1, SP–СП 08 and SP–СП 05 exceeded the dry matter yield of the standard variety during two out of four years of investigation and this result gives enough reason for continuing the search for creating varieties with high dry matter yield. Germplasms SP–СП 08-1 and SP–СП 09 are superior in seed yield versus the standard variety and thus they can be used as an appropriate germplasm for creating of varieties with high seed yield. Germplasm SP–СП 08-1 shows the best complex results in the conducted Competitive Variety Testing, which gives reasonable conclusion to recommend it for including in alfalfa breeding programs, directed to searching for genes of high productivity and tolerance to pests.

Keywords: alfalfa germplasm; Plagionotus floralis; productivity; root longhorn beetle; tolerance

Date published: 2017-09-13