V. Jarosik et al., THE INFLUENCE OF PLANTING LOCATION, PLANT-GROWTH STAGE AND CULTIVARS ON MICROFLORA OF WINTER-WHEAT ROOTS, Microbiological research, 151(2), 1996, pp. 177-182
The occurrence of parasitic and saprophytic microflora on roots of eig
ht winter wheat cultivars was recorded at seven plant experimental sta
tions with different climatic and soil conditions during four plant gr
owth stages. The rates of recovery for pathogenic and sprophytic micro
organisms were negatively correlated, and the negative correlations be
came larger as the crop matured. Similarities were noted between the r
atios of pathogen to saprophyte recovery in spring samplings as well a
s between the root assays in early summer and early autumn. In spring,
recovery of pathogenic Fusarium spp. was negatively correlated with r
ecovery of saprophytic Trichoderma spp., and recovery of pathogenic Al
ternaria spp. with saprophytic spp. of Trichoderma and Epicoccum. In s
ummer and autumn, a negative relationship was found among saprophytic
sterile fungi, saprophytic Mucor spp. and pathogenic Fusarium spp. Dif
ferences among recovery ratios were found for the various plant breedi
ng stations but not among individual cultivars. The average rates of r
ecovery for pathogenic microorganisms thus depended on planting locati
on and plant growth stage but the recovery ratios did not depend on cu
ltivars. It suggests a stronger influence of these environmental compo
nents than cultivars on pathogen recovery rates. Mutual interactions a
mong microflora species, planting conditions, and plant development wi
ll strongly influence field resistance to pathogens.