Inoculation test were conducted four years (1985 to 1988) to determine the degree of resistance of 46 varieties and new breeds of peas to the complex of soil pathogens and to the fungus Mycospharella pinodes. The resistance to the complex of root diseases was studied in micro-plot trials by sowing of the tested material in the provocative field with strongly infested soil (plot of area 2 m2 four replications). Inoculation tests infested with Mycosphaerella pinodes were treated with the spraying of conidial suspensions (plots of 2 m2, four replications, two inoculations in the growing season). In root diseases the highest share exhibited the fungi Pythium ultimum, Rhizoctonia solani, Fusarium solani, Aphanomyces euteiches, Verticillium albo-atrum and Fusarium oxysporum. The range of pathogens changed in dependence on the year (Tab. I). The results obtained correspond to the data in foreign literature (B u r k e et al., 1974; C v e t k o v a et al., 1983; K o t o v a, 1979, 1984). Health and the seed yield of the tested set of peas was markedly affected by the complex of root diseases. The highest resistance (Tab. II) to the complex of root diseases manifested the selected strains (KM-01, KM-02, KM-03), genetic sources of resistance (De 2707, Garfield) and some field peas (Tyla, Arvika). The most susceptible varieties were as follows: Progreta, Legenda, Gratas and Mihan. The seed yield of resistant strains was higher in infested soil by more than 150% in comparison with the control variety Bohatyr. The comparison of the yields obtained with commercial peas varieties with the resistant strains indicates an existance of large reserves in the sphere of resistant breeding of peas to diseases. The resistant strains were even better, as to the resistance is concerned, than the American gene resource of complex resistance, the variety Garfield, and reached the comparable level of resistance with the line De 2707. In inoculation tests conducted with the fungus Mycosphaerella pinodes (Tab. III), varietal differences were succeeded to determine solely in an intensity of pathogen transfer to the harvest seeds. No differences were found in intensity of leaf and pod infestations. The poorest transfer of pathogen on the harvested seeds (up to 8%) was found in the varieties Bohatyr, Dukat and Junak. The highest transfer (above 22%) was found in the varieties Perf. Freezer, Regent, Golf, Sentinel, Belinda, Aster, Ruga and Maxi. A higher degree of resistance was not confirmed in the leafless forms of peas (type Solara) (infestation of the harvested seeds for 19.2%). The resistance of strains gained (KM-01, KM-02, KM-03) is satisfactory to the fungus Mycosphaerella pinodes, though not of such a degree as at variety Bohatyr. A high relative resistance of the variety Bohatyr is presented also from abroad (N a s i r, H o p p e., 1988). Pea breeding for high resistance to the entire complex of pathogens is very difficult and complicated. Gene resources of high resistance are not know. There is only limited number of resources available of relatively higher level of resistance, providing the resistance of 40 to 50% in very strongly infective medium. The relative resistance obtained is usually non-stable and shows a fluctuation in particular years (S h e h a t a et al., 1982).
