Reação de genótipos de soja do programa de melhoramento da Universidade Federal de Uberlândia ao fitonematóide Heterodera glycines raça 3

Abstract

Soybean (Glycine max (L) Merril) is an ancient plant, and its origin and history are hard to establish. The occurrence of diseases in this culture is one of the major limiting factors to high yields. Resistant soybean cultivars are the most effective tool available for soybean cyst nematode management. This study evaluated the reaction of soybean genotypes from UFU s breeding program to the plant nematode Heterodera glycines race 3. The trials were done in a greenhouse of the Instituto de Ciências Agrárias da Universidade Federal de Uberlândia. The experimental design was completely randomized with 25 treatments (twenty four soybean genotypes from UFU and the cultivar MG/BR 46 Conquista , as a control) with eight repetitions. The genotypes were seeded on Styrofoam trays, with one seed per cell; subsequently, the seedlings were transplanted to 1-L clay pots containing a mixture of sand and soil (2:1), previously fumigated with methyl bromide. The trail was done with one plant per pot, inoculated with 4000 nematode eggs. The evaluation was done 35 days after the inoculation. The root system was gently washed to remove the females, and the soil was processed for female and cyst extraction. Among the 24 genotypes evaluated, UFU 502 was moderately susceptible to Heterodera glycines race 3 while UFU 510, UFU 504 and UFU 512 were highly susceptible to the soybean cyst nematode. All other lines were susceptible.