Fungi and Gram‐negative bacteria as soilborne minor pathogens of goat's rue (Galega orientalis Lam.)

Abstract

Fungi and Gram-negative bacteria were isolated from inside the roots of fieldgrown goat's rue (Galega orientalis). Fungi were isolated from three plants out of a total of 45 tested. Two multinuclear Rhizoctonia solani isolates were identified to the anastomosis group 5 ( R . solani AG-5-Gal) using pairings with known AG test cultures. One fungal isolate was identified to Phoma chrysanthernicola. Gram-negative bacteria were isolated from three plants out of 25 tested. They were identified using classical methods, the BIOLOG identification system based on the utilisation of 95 different carbon sources, and the MIDI system for the analysis of whole cell fatty acids. The two latter systems were computer-associated and utilised an extensive reference library of isolates. One bacterial isolate was identified as Enterobacter agglomerans and two isolates as Pseudomonas marginalis.R. solani AG-5-Gal reduced the emergence of Lupinus luteus, L . polyphyllus and french bean (Phaseolus vulgaris) and the growth of broad bean (Viciafaba), L. luteus and french bean, but did not cause obvious damage in goat's rue and pea (Pisum satiuum). However, R. solani AG-5-Gal was re-isolated from the roots of all the test plant species following inoculation. P. chrysanthemicola reduced the emergence of L. polyphyllus and the growth of goat's rue, french bean and broad bean, and it was re-isolated from all of the test plant species (except for french bean) following inoculation.All the bacteria reduced the emergence of french bean, but not that of goat's rue and pea, when applied to the soil. When the roots were dipped into bacterial suspension, all the bacteria damaged french bean and L . polyphyllus. Additionally, P. marginalis JV3 damaged goat's rue and red clover. The pathogenicity of the fungi and bacteria were not changed when they were doubleinoculated in pairs, except for R. solani AG-5-Gal and P. marginalis JV2 which reduced the emergence of goat's rue when inoculated together but not when inoculated separately.

Alterations in growth of tissue‐cultured tansy (Tanacetum vulgare L.) treated with antibiotics

“…Delphinium, Gerbera, Hosta and Iris (Leifert, Waites & Nicholas, 1989), Galega orientalis Lam. (Valkonen et al, 1993), Cynara scolymus L. (Peiialver et al, 1994) and Mentha (Buckley et al, 1995). Several studies have shown that bacteria can colonise the vascular tissue (e.g.…”

“…Several studies have shown that bacteria can colonise the vascular tissue (e.g. Gardner et al, 1982;van Doorn et al, 1991;Whitesides & Spotts, 1991;Valkonen et al, 1993) where they can be translocated (Whitesides & Spotts, 1991). Because growth medium used for plants may not be optimal for bacterial growth or may even inhibit the growth (Leifert et al, 1994), endophytically growing bacteria can remain undetected for a long time and over several subcultures of internodal cuttings or shoot tips.…”

“…This is particularly problematic when explants are taken from perennial field grown plants (Peiialver, Durn-Vila & Lopez, 1994;Savela & Uosukainen, 1994;Keskitalo, Kanerva & Pehu, 1995). Perennial species often have endophytic microflora which are non-pathogenic under natural growth conditions (Gardner, Feldman & Zablotowicz, 1982;van Doorn, de Stigter, de Witte & Boekestein, 1991;Valkonen, von Heiroth & Savela, 1993), but which under a change of environmental conditions, e.g., the transfer of plants to in vitro culture, can alter the host-microbe interaction and can become pathogenic (Leben, 1972;Misaghi & Donndelinger, 1990;Peiialver et al, 1994). The *Corresponding author.…”

Resistance to six viruses in the legume goat's rue {Galega orientalis Lam.)

“…1986), physiological stress such as nutritional imbalance, high temperature and water deficiency (Duffus. 1977;Lindstrom, Sarsa, Polkunen & Kansanen, 1985) or certain bacteria and fungi infecting the roots of goat's rue in the field (Valkonen, von Heiroth & Savela, 1993).…”

Formation of canker lesions on stems and black scurf on tubers in experimentally inoculated potato plants by isolates of AG2-1, AG3 and AG5 of Rhizoctonia solani: a pilot study and literature review

“…These findings are consistent with higher host species-specificity or host-dependency on potato exhibited by AG3 and a putatively lower ability of AG3 to survive as a saprophyte than other AGs , Sumner 1996. For example, AG5 and AG2-1 isolates occur in a broader range of crops and are important pathogens in legumes and turfgrass, and brassicas, respectively , Sneh et al 1991, Valkonen et al 1993. However, black scurf on seed potatoes AG3 is considered as the most important dispersal and survival mechanism of AG3 (van Emden et al 1966, Cubeta and Vilgalys 1997, Ceresini et al 2002) relatively short-living soilborne inoculum.…”