Rhizoctonia crown and root rot of the pasture legume, sulla (Hedysarum coronarium)

Abstract

Abstract. Rhizoctonia solani AG-2-2 was isolated from wilting and dying plants of sulla (Hedysarum coronarium), which is currently being assessed in eastern and southern Australia for its potential as a pasture and forage legume. Infected plants in the field had extensive rotting of the taproot, lateral roots and crown. Koch's postulates were fulfilled using three inoculation methods. The disease may pose a considerable threat to the potential use of H. coronarium in the dryland, grazing farming systems of Australia, with resistance offering the most viable option for minimising its impact.A P 0 3 0 9 3 R h i z o c t o n i a c r o w n a n d r o o t r o t o f s u l l a M . J . Ry l e y e t a l .

Medicago truncatula as a model host for studying legume infecting Rhizoctonia solani and identification of a locus affecting resistance to root canker

“…). These observations are consistent with the symptoms described for the R. solani ZG1‐1 (AG8) isolate infecting canola (Khangura et al ., ) and R. solani AG2‐2 isolates infecting the pasture legume Hedysarum coronarium (Ryley et al ., ).…”

Cross-pathogenicity of Rhizoctonia solani strains on pasture legumes in pasture-crop rotations

“…While R. solani ZG4 (AG2-2) has been reported to cause hypocotyl rot on legumes (Sweetingham et al 1986) and soybean (Glycine max [L.] Merr.) (Fenille et al 2004), AG2-2 has been reported causing crown and root rot of H. coronarium in Queensland, Australia (Ryley et al 2004), root rot of subterranean clover (Wong and Sivasithamparam 1985;MacNish et al 1994 (Sumner 1985); wheat (T. aestivum) and barley (Furgal-Wegrzycka et al 1998); and several grasses (Haygood and Martin 1990;Herr and Fulton 1995).…”

“…(You et al 1999;Barbetti et al 2006) and more recently has been reported to cause severe root disease on several newly introduced legume species including Hedysarum sp. (Ryley et al 2004). This marked increase in root rots affecting pasture legumes in recent years, including diseases caused by R. solani, may be related to the increasing frequency of the leguminous host in the rotation system in recent years, leading to enrichment of pathogens of legumes in pasture-crop rotations.…”

“…Hence it is not surprising that root rot diseases play an important role in these regions on annual pasture productivity and persistence and can be caused by one or more of different fungal pathogens including species of Pythium, Phytophthora, Fusarium and Rhizoctonia (Wong et al 1985a;Barbetti et al 1986). Rhizoctonia solani causes root disease on many plant species worldwide including wheat (Triticum) (Roget 1995), oil-seed Brassica (Khangura et al 1999;Klein-Gebbinck and Woods 2002), pasture legumes (Barbetti et al 1986;Ryley et al 2004), tomato (Lycopersicum esculentum Miller) (Berta et al 2005), soybean (Glycine) (Dorrance et al 2003) and lupin (Kumar et al 2002;Chang et al 2005). This pathogen causes root rots of T. subterraneum (Wong et al 1985b;Barbetti et al 1986), annual Medicago spp.…”