Transmission of Bacterial Wilt of Alfalfa By Ditylenchus Dipsaci (Kühn)

Abstract

Corynebacterium insidiosum was transmitted by Ditylenchus dipsaci into alfalfa crown buds resulting in increased incidence of bacterial wilt in a wilt-susceptible variety. Plant nematodes and related soil forms are frequently members of plant disease complexes. They can, according to Steiner (1953), act as initiators, cooperators, synergists, and aggravators of disease and should therefore be considered important components of a complex biotic community. Plant parasitic nematodes provide avenues of entry for plant parasitic micro

Nematodes as vectors of bacterial and fungal plant pathogens

“…insidiosum (McCulloch) Davis et al 1984 (= Corynebacterium insidiosum), which causes bacterial wilt in alfalfa, is transmitted by the nematode Ditylenchus dipsaci Kuhn into alfalfa crown buds resulting in increased incidence of bacterial wilt. Studies of Hawn (1963Hawn ( , 1971 provided evidence of transmission of the bacterial cells by D. dipsaci. Hawn (1963) found frequent association of C. michiganense subsp.…”

“…Studies of Hawn (1963Hawn ( , 1971 provided evidence of transmission of the bacterial cells by D. dipsaci. Hawn (1963) found frequent association of C. michiganense subsp. insidiosum and D. dipsaci in the same alfalfa stands in southern Alberta, Canada.…”

“…A glasshouse study on the effect of D. dipsaci on the initiation and development of bacterial wilt in alfalfa showed that D. dipsaci acted as transmitting agent and carried C. michiganense subsp. insidiosum into the crown bud and placed in the conducive infection court (Hawn, 1963). It was believed that C. michiganense subsp.…”

“…insidiosum was carried on the body of the nematodes. The possibility of internal transmission within the body of the nematodes was discounted because the lumen diameter of adult males and females was too narrow to allow ingestion of mature bacterial cells and surface-disinfected nematodes in artificial culture remained free of bacterial growth (Hawn, 1963). Hawn (1971) demonstrated that numerous bacterial cells adhered to the cuticle of nematodes exposed to the wilt bacteria suspension.…”

Synergistic damage by interactions between Ditylenchus dipsaci and Rhizoctonia solani (AG 2–2IIIB) on sugar beet

“…The fungus R. solani is also part of 18 separate disease complexes which involve a diversity in genera of plant parasitic nematodes (Evans & Haydock 1993). In addition, Ditylenchus dipsaci can cause a disease complex involving two fungal pathogens and some bacterial diseases (Metcalfe 1940, Hawn 1963, Vrain 1987, Griffin 1992. Damage on sugar beet infected with SBN can increase due to secondary infection of soil-borne root rotting diseases (bacterial and fungal; Niere & Schlang 2006).Plant damage under combined attack by nematodes and root-rot fungi can result in synergistic, antagonistic, or additive effects (Evans & Haydock 1993).…”