lsolates of Rhizoctonia solani from Camelina sativa (L) CRTZ were differentiated using inoculation and biochemical methods.
lsolates of Rhizoctonia solani from Camelina sativa (L) CRTZ were differentiated using inoculation and biochemical methods. M. Henneken, L. Fo1ler, V.H.Paul Universitat-Gesamthochule Paderborn Frachberiech Agwirtschaft, Luebecker Ring 2, D 59494 Soest, Germany Background and objectives Camelia sativa (L) CRTZ (false flax) is an old culture crop cultivated since about 2000 b.C. fts potential as a renewable oilseed crop was recognized in the 20th century. One major aspect of a modem culture crop is to afford smal argronomic input like disease control, fertilization and soil management. To reach this aim it is required to breed for disease resistance to emerge healthy plants. Further studies [1] discovered the production of phytoalexins whitch cause resistance to Aiternaria spp and probably to other diseases, tao ' Still there are diseases on C. sativa that need to be taken seriously. To breed for disease resisttnce in C. sativa cultivars practical inoculation methods are needed to distinguist between susceptibility of cultivars C. sativa and between different isolates of the corresponding pathogens. In the presented study two infection methods were established to inoculate C. sativa with Rhizoctonia solani. Differentiation of ten C. saliva cultivars and eight isolates of Rhizoctonia so)ani was carryed out. Additional biochemical investigations to differentiate the isolates of Rhizoctonia solani were carried out. Materials and Methodes Eight isolates of Rhizoctonia solani were isolated from field plots of C. sativa at seven locations in Germany and Poland. The first inoculation method was a quick-agar-test system (QATS) to test the susceptibility of C. sativa cultivars to Rhizoctonia solani. Rhizoctonia solani isolates were grown on PDA (Potato Dextrose Agar) for 3 days. Then C. sabva seeds were added to the surface. After germination the susceptibility was assessed (1 not susceptible; 5 high susceptible). For the second inoculation method Rhizoctonia solani was grown on PDA. For 8 days. The fungal cultures were then mixed with substratum (sand 1 peat 1 : 3) and C. saliva was sown into this mixture. Germination occurred in a climatic chamber (stable conditiones). The assessments of disease symptoms were carried out at the 4 -6 leaf stage. The biochemical differerdiation of the Rhizoctonia soiani isolates was carried out using the usual methods. Results and concausions The available C. sativa cultivars showed no differences in susceptibility to Rhizoctonia solani but there were some differences in the aggressiveness of the isolates of Rhizoctonia solani. The obtained results from biochemical investigations were compared with the results of the two develped inoculation methods used. 5 Rhizoctonia solani isolates can similary be differentiated based upon the biochemical and infections methodes used, while the other 3 can not. References.. [ 1] Tewari JP, PS Bains, 1991: Carnelina sativa phyt oalexins (cametexin and rnethoxycarnelexin) provide resistance against Altemavia brassicae Canadian Journal of Plant Pathology, Voilume 13, p. 274