Cultural Growth Patterns and Incompatibility Reactions in Diaporthe and Phomopsis Populations

Abstract

Comparative studies were carried out with cultures isolated from Phomopsis condiomata and/or Diaporthe ascomata found on naturally‐infected living stems or on overwintered stem fragments of Arctium lappa L., Helianthus annuus L., Glycine max (L.) Merr., and Xanthium italicum Moretti, growing in or nearby the same fields in Vojvodina. Results underscored the heterogeneity of the Phomopsis anamorphs in the D. arctii (Lasch) Trav, complex, Intra‐specific vegetative incompatibility groups were distinguished among Phomopsis and/or Diaporthe populations from A. lappa. More than one phytopathogenic Phomopsis and/or Diaporthe species were identified on X. italicum. P. longicolla Hobbs was isolated for the first time in Yugoslavia from soybean stem debris. The holomorph Diaporthe (Phomopsis) helianthi Muntanola‐ Cvetkovic, Mihaljcevic et Petrov showed distinguishing characteristics with respect to other congeneric fungi.

Differential Growth Inhibition of Diaporthe and Phomopsis Isolates by the Metabolic Activity of Five Actinomycetes

“…However, the A and B groups, based on the sensitivity of the fungal cultures, subsisted with D. arctii and the isolates from soybean in group A, and D. helianthi in group B. These results support the division of the fungal isolates into the groups A and B on the basis of cultural characteristic features that were discussed in a previous paper ( Muntañola‐Cvetkovi;ć et al, 1996).…”

“…They were collected in Vojvodina, Yugoslavia, in different seasons and sites during a period of 8 years. Fifty‐five fungal cultures were tested, for which the same codes were used as in another paper ( Muntañola‐Cvetković et al, 1996). Host plants and fungal isolates are listed in Table 1.…”

“…This study is a follow‐up of another already published ( Muntañola‐Cvetković et al, 1996) intended to obtain further insights into the relationships between Diaporthe arctii (Lasch) Nitschke, Diaporthe helianthi Muntañola‐Cvetković, Mihaljčević & Petrov and other Diaporthe and Phomopsis species that colonize cultivated plants and weeds growing in the same region. It deals with the reactions of 55 cultures, isolated from Diaporthe perithecia and Phomopsis pycnidia found on diverse host plants, toward the activity of five actinomycetes obtained as fortuitous contaminants of the plates during the routine laboratory procedures for isolating plant pathogenic fungi from field material.…”

Plasmid distribution in European Diaporthe helianthi isolates

“…First epidemiological analysis revealed different incidence levels of the disease, the stem canker, which occurred on the host based on geographic location: heavy damages were reported in the former Yugoslavia [42] and in France [21], whereas in Italy the pathogen is only sporadically found, in spite of conducive climatic conditions [24,43]. Previous investigations were aimed at D. helianthi intraspecific variability and were based on morpho-physiological, biological and genetic characters [26,27], host cultivars/pathogen isolates interaction [28], molecular genotypic and phenotypic features [29]. These studies all examined populations within the Diaporthe/Phomopsis helianthi complex from countries where the disease caused heavy damages.…”

“…Intraspecific variability has been previously displayed by different D. helianthi isolates, which have been studied by several approaches. In the early 1980s, Yugoslavian D. helianthi isolates have been screened for morphological, biological and epidemiological differences [25]; then European populations have been analysed for morphophysiological and genetic characters [26,27]. The interaction between French D. helianthi isolates and varyingly susceptible sunflower cultivars has been investigated [28].…”