Infection of seed of subterranean clover and allied species by species of Fusarium

1980 ◽  
Vol 31 (2) ◽  
pp. 297 ◽  
Author(s):  
AW Kellock ◽  
LL Stubbs ◽  
DG Parbery
Keyword(s):  
Root Rot ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Scar Tissue ◽  
Seed Infection ◽  
Fusarium Spp ◽  
Blotting Paper ◽  
Optical Brighteners ◽  
First Time ◽  
Healthy Seed

Fusarium avenaceurn (Corda ex Fr.) Sacc. was shown for the first time to be carried in the hilum of subterranean clover (Trifolium Subterraneum L.) seed. Scanning electron microscopy and thin-section techniques showed that the fungus occurred only as dormant mycelium in parenchyma cells of funicle scar tissue. It emerged from these tissues after a 12 h incubation at 24�C and in 48 h penetrated internal parts of the seed through the hilum fissure. After 21 days on moist blotting paper, seedlings grown from infected seed developed lesions on their roots similar to those of root-rot of subterranean clover in the field. Fusarium spp. were also detected in the hilum of seeds of white (T. repens L.) and strawberry (T. fragiferum L.) clover and barrel medic (M. truncatula L.). It was demonstrated experimentally that all parts of the burr, incl~tding the funicle, became infected with F. avenaceuni when subterranean clover plants grown from healthy seed in pasteurized soil buried their burrs in soil inoculated with the fungus. Use of optical brighteners failed to trace seed infection because the compounds, although absorbed by the pathogen in culture, were not translocated.

Response of Italian elite subterranean clover genotypes to Fusarium avenaceum and Fusarium oxysporum under artificial conditions

2002 ◽  
Vol 42 (5) ◽  
pp. 557 ◽  
Author(s):  
E. Piano ◽  
L. Riccioni ◽  
L. Pecetti ◽  
A. M. Carroni ◽  
A. Porta-Puglia
Keyword(s):  
Root Rot ◽  
Disease Outbreaks ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Fusarium Spp ◽  
Seedling Vigour ◽  
Breeding Programs ◽  
Disease Response ◽  
Artificial Infestation ◽  
Growth Vigour

Breeding programs of subterranean clover in southern Europe have traditionally set low priority on selection against major pathogens, in part because there have been no major disease outbreaks in this region. However, root-rot causing fungi, such as Fusarium spp., occur frequently on other crops and can therefore also represent a threat to clover. Thus, the breeding program carried out in Sardinia, Italy, took note of this disease. This study reports the results of 2 trials carried out in 2 consecutive years following artificial infestation with Fusarium spp. The first trial included 45 genotypes, of which 37 were Sardinian lines under advanced breeding and 8 were commercial varieties. To validate the variation observed in disease response, a subset of 27 genotypes was further evaluated in the second trial. In both trials, 3 pathogen treatments were applied, in addition to a control, uninoculated treatment - F. avenaceum, F. oxysporum, and an equal mixture of both fungi. One-month-old clover seedlings were scored in all treatments for shoot-growth vigour (1-9 scale), then excavated for scoring root-rot symptoms (1-5�scale), and finally weighed after oven drying. Analysis of variance tested differences among treatments, among genotypes, and between subsp. subterraneum and brachycalycinum of Trifolium subterraneum. On the common set of genotypes to both trials, a cluster analysis was applied using, as original variables, the average disease score across the 3 inoculated treatments in the 2 trials. Confirming previous evidence, F. avenaceum proved more pathogenic than F. oxysporum. The results suggested that high seedling vigour may play a role in limiting root-rot effects, and this may also contribute to the relatively better tolerance of subsp. brachycalycinum over subsp. subterraneum observed. Despite some inconsistency of response in the 2 trials both at the treatment and genotype level, some Sardinian genotypes demonstrated a consistent level of tolerance especially in relation to the performance of the commercial varieties tested. Among them were the lines `125 brachy C', `56 sub D', `22 brachy G', `56 sub B' (=Campeda), and `19 brachy E' (=Antas).

Seed-borne Fusarium species on subterranean clover and other pasture legumes

1978 ◽  
Vol 29 (5) ◽  
pp. 975 ◽  
Author(s):  
AW Kellock ◽  
LL Stubbs ◽  
DG Parbery
Keyword(s):  
White Clover ◽  
Root Rot ◽  
Fusarium Species ◽  
Subterranean Clover ◽  
Fusarium Spp ◽  
Root Rot Disease ◽  
Pasture Legumes ◽  
Rot Disease ◽  
Clover Seed ◽  
First Time

Fusarium avenaceum (Corda ex. Fr.) Sacc. was detected for the first time on seed of strand medic (M. littoralis Rhode), lucerne (M. sativa L.), white clover (T. repens L.) and strawberry clover (T. fragiferum L.). The percentage of seed infected was 24% on medic seed, 2–3% on strawberry clover, 2–6% on white clover, and 10–14% on lucerne, compared with 1–42% on subterranean clover seed. The majority of infected seed lines were grown in the main seed-producing areas of Victoria. F. arthrosporioides Sherb., F. equiseti (Corda) Sacc., F, acuminatum Ellis & Everhart and F. culmorum (W. G. Sm.) Sacc. were isolated from subterranean clover seed for the first time, comprising between 1 and 8% of Fusarium spp. isolates, while F. oxysporum (Schlecht) and F. avenaceum comprised the remaining 55% and 35% of isolates respectively. In laboratory tests, isolates of F. avenaceum from each seed host were all strongly pathogenic on roots of subterranean clover, but there was no evidence of pathogenicity by other Fusarium spp. F. oxysporum had no effect on the severity of root rot disease either alone or in combination with F. avenaceum.

Fusarium avenaceum, a seed-borne pathogen of subterranean clover roots

1974 ◽  
Vol 25 (4) ◽  
pp. 549 ◽  
Author(s):  
DC McGee ◽  
AW Kellock
Keyword(s):  
Root Rot ◽  
Laboratory Tests ◽  
Subterranean Clover ◽  
Fusarium Avenaceum ◽  
Seed Infection ◽  
Highly Pathogenic ◽  
Infected Seed ◽  
Clover Root ◽  
First Time

Fusarium avenaceum (Corda ex Fr.) Sacc. has been shown for the first time to be a seed-borne pathogen of subterranean clover (T. subterraneum L.). In laboratory tests symptoms of subterranean clover root rot occurred on plants grown from infected seed. F. oxysporum (Schlecht.) also was seed-borne. It was only weakly pathogenic, although isolated more frequently from diseased roots than F. avenaceum. Pythium sp. was not detected on seed and rarely isolated from roots of diseased field plants, but it was highly pathogenic to subterranean clover roots in laboratory tests. F. avenaceum was detected in 81 out of 85 seed lines tested, which comprised 11 cultivars, from four Australian States. Infection with F. avenaceum occurred on up to 27% of the seed in a sample. An application of benomyl (0.63 g/kg seed) controlled seed infection.

The in vitro inhibition of Phytophthora clandestina by some rhizobia and the possible role of Rhizobium trifolii in biological control of Phytophthora root rot of subterranean clover

1999 ◽  
Vol 50 (8) ◽  
pp. 1469 ◽  
Author(s):  
S. Simpfendorfer ◽  
T. J. Harden ◽  
G. M. Murray
Keyword(s):  
Biological Control ◽  
Root Rot ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Root Disease ◽  
Rhizobium Trifolii ◽  
Biological Control Agents ◽  
Control Activity ◽  
Phytophthora Root Rot

The interaction between 29 isolates of Rhizobium and the in vitro growth of 3 strains of Phytophthora clandestina was investigated to determine the potential of these bacteria as biological control agents against root rot of subterranean clover (Trifolium subterraneum L.). The biological control activity of Rhizobium on the severity of root disease in seedlings was also investigated under glasshouse conditions. Thirteen of the 29 Rhizobium isolates caused significant reductions in the hyphal growth of the 3 P. clandestina isolates examined. Inoculation of seedlings with Rhizobium trifolii reduced the severity of root disease by 14–58% with corresponding increases in dry matter production of 20–73%. These results indicate that Rhizobium species have potential as biological control agents against the root rot of T. subterraneum seedlings caused by P. clandestina.

Occurrence of Phytophthora clandestina in Trifolium subterraneum paddocks in Australia

2001 ◽  
Vol 41 (2) ◽  
pp. 187 ◽  
Author(s):  
R. Aldaoud ◽  
W. Guppy ◽  
L. Callinan ◽  
S. F. Flett ◽  
K. A. Wratten ◽  
...  
Keyword(s):  
Western Australia ◽  
Root Rot ◽  
New South ◽  
New South Wales ◽  
South Australia ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Soil Samples ◽  
South Wales ◽  
Differential Cultivars

In 1995–96, a survey of soil samples from subterranean clover (Trifolium subterraneum L.) paddocks was conducted across Victoria, South Australia, New South Wales and Western Australia, to determine the distribution and the prevalence of races of Phytophthora clandestina (as determined by the development of root rot on differential cultivars), and the association of its occurrence with paddock variables. In all states, there was a weak but significant association between P. clandestina detected in soil samples and subsequent root rot susceptibility of differential cultivars grown in these soil samples. Phytophthora clandestina was found in 38% of the sampled sites, with a significantly lower prevalence in South Australia (27%). There were significant positive associations between P. clandestina detection and increased soil salinity (Western Australia), early growth stages of subterranean clover (Victoria), mature subterranean clover (South Australia), recently sown subterranean clover (South Australia), paddocks with higher subterranean clover content (Victoria), where herbicides were not applied (South Australia), irrigation (New South Wales and Victoria), cattle grazing (South Australia and Victoria), early sampling dates (Victoria and New South Wales), sampling shortly after the autumn break or first irrigation (Victoria), shorter soil storage time (Victoria) and farmer’s perception of root rot being present (Victoria and New South Wales). Only 29% of P. clandestina isolates could be classified under the 5 known races. Some of the unknown races were virulent on cv. Seaton Park LF (most resistant) and others were avirulent on cv. Woogenellup (most susceptible). Race 1 was significantly less prevalent in South Australia than Victoria and race 0 was significantly less prevalent in New South Wales than in South Australia and Western Australia. This study revealed extremely wide variation in the virulence of P. clandestina. The potential importance of the results on programs to breed for resistance to root rot are discussed. in South Australia.

Studies on Phytophthora clandestina, the cause of taproot rot in subterranean clover. 1. Evidence for physiological specialisation in Phytophthora clandestina

1994 ◽  
Vol 34 (8) ◽  
pp. 1125 ◽  
Author(s):  
SP Flett
Keyword(s):  
Root Rot ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Resistant Cultivar ◽  
Greenhouse Experiments ◽  
Temperate Pastures ◽  
Serious Disease

Root rot caused by Phytophthora clandestina Taylor, Pascoe & Greenhalgh is a serious disease of subterranean clover (Trifolium subterraneum), an important leguminous component of Australia's temperate pastures. Previous reports have shown that P. clandestina causes severe taproot rot in cv. Woogenellup, while cvv. Larisa and Trikkala remain highly resistant. In this study, 3 greenhouse experiments were conducted to determine the effects of P. clandestina isolates collected between 1983 and 1990 on different subterranean clover cultivars. Woogenellup was consistently susceptible while Meteora was less affected by all isolates tested. Trikkala, a previously known root rot resistant cultivar, was as susceptible as Woogenellup when tested with a recently collected isolate from Katamatite, northern Victoria. This study provides the first evidence for variation in virulence between isolates of P. clandestina and for physiological specialisation in this species.

Mass rearing Halotydeus destructor (Tucker) (Acari : Penthaleidae) for use in summer screening of Trifolium subterraneum (L.) for mite resistance

1997 ◽  
Vol 37 (3) ◽  
pp. 343 ◽  
Author(s):  
D. J. Thackray ◽  
T. J. Ridsdill-Smith ◽  
D. J. Gillespie
Keyword(s):  
Subterranean Clover ◽  
Soil Surface ◽  
Trifolium Subterraneum ◽  
Mass Rearing ◽  
Screening Tests ◽  
Common Vetch ◽  
Halotydeus Destructor ◽  
Natural Pasture ◽  
Redlegged Earth Mite ◽  
First Time

Summary. Controlled environment experiments were conducted to establish some of the requirements for successful mass rearing of Halotydeus destructor (redlegged earth mite). Numbers of mites reared on Vicia sativa (common vetch) cv. Blanchefleur grown alone or on a mixture of vetch with Trifolium subterraneum (subterranean clover) cv. Goulburn, were significantly higher than those on subterranean clover or Arctotheca calendula (capeweed) alone. Populations reared on vetch grown in a sandy soil were significantly higher than those reared on vetch grown in a loamy soil, pure sand or pure loam. Covering the soil surface with a natural pasture mulch increased mite numbers compared with leaving the soil bare or placing plant pots inside ventilated cages. Subsequent changes in rearing methodology produced enough mites to enable summer screening of subterranean clover lines for resistance to H. destructorfor the first time. Over 20 000 mites can be produced from vetch at one time for screening tests throughout the year.

Fusarium root rot complex in soybean: Molecular characterization, trichothecene formation and cross-pathogenicity.

2021 ◽  
Author(s):  
Mohamed Hafez ◽  
Ahmed Abdelmagid ◽  
Reem Aboukhaddour ◽  
Lorne R. Adam ◽  
Fouad Daayf
Keyword(s):  
Root Rot ◽  
Fusarium Species ◽  
Molecular Diagnostic ◽  
Soybean Seeds ◽  
Head Blight ◽  
Fusarium Spp ◽  
Fusarium Root Rot ◽  
Yield And Quality ◽  
Fusarium Pathogens ◽  
First Time

Soybean is threatened by many pathogens that negatively affect this crop's yield and quality, e.g., different Fusarium species that cause wilting and root rot diseases. Fusarium root rot (FRR) in soybean can be caused by F. graminearum and other Fusarium spp. that are associated with Fusarium head blight (FHB) in cereals. Therefore, it was important to enquire whether Fusarium pathogens from soybean can cause disease in wheat, and vice versa. Here, we investigated the Fusarium root rot complex in Manitoba (Canada) from symptomatic plants, using both culture- and molecular-based methods. We developed a molecular diagnostic toolkit to detect and differentiate between several Fusarium spp. involved in FHB and FRR, then we evaluated cross-pathogenicity of selected Fusarium isolates collected from soybean and wheat, and the results indicate that isolates recovered from one host can infect the other host. Trichothecene production by selected Fusarium spp. was also analyzed chemically using LC-MS in both soybean (root) and wheat (spike) tissues. Trichothecenes were also analyzed in soybean seeds from plants with FRR to check the potentiality of trichothecene translocation from infected roots to the seeds. All of the tested Fusarium isolates were capable of producing trichothecenes in wheat spikes and soybean roots, but no trichothecenes were detected in soybean seeds. This study provided evidence, for the first time, that trichothecenes were produced by several Fusarium spp. (F. cerealis, F. culmorum and F. sporotrichioides) during FRR development in soybean.

Phytophthora clandestina. [Descriptions of Fungi and Bacteria].

1991 ◽  
Author(s):  
G. Hall
Keyword(s):  
Geographical Distribution ◽  
Plant Pathogen ◽  
Root Rot ◽  
Dry Matter ◽  
Subterranean Clover ◽  
Soil Surface ◽  
Trifolium Subterraneum ◽  
Moist Soil

Abstract A description is provided for Phytophthora clandestina. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Trifolium subterraneum. DISEASE: Root rot of subterranean clover; a facultatively necrotrophic plant pathogen. In field plants, black necrotic lesions develop 1-4 cm below the soil surface extending into the stele and causing orange-brown to brown tissue discoloration. Dry matter can be reduced by 71% (69, 5030). GEOGRAPHICAL DISTRIBUTION: Australasia & Oceania; Australia (NSW, WA, Vic.) TRANSMISSION: Presumably by zoospores released in moist soil. Oospores may act as perennating structures.

The pathogenicity of Fusarium avenaceum to wheat and legumes and its association with crop rotations

1974 ◽  
Vol 14 (69) ◽  
pp. 572 ◽  
Author(s):  
JF Kollmorgen
Keyword(s):  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Dry Weight ◽  
Crop Rotations ◽  
Fusarium Avenaceum ◽  
Wheat Roots ◽  
Barrel Medic ◽  
Wheat Pasture ◽  
Wheat Stubble ◽  
First Time

Studies were made of the pathogenicity of Fusarium avenaceum (Fr.) Sacc. to wheat (Triticum aestivum), subterranean clover (Trifolium subterraneum) and barrel medic (Medicago truncatula var. truncatula), and of the effects of crop rotation on field populations of the fungus. F. avenaceum reduced emergence and dry weight of wheat, subterranean clover, and barrel medic seedlings. Infection reduced the height of both legumes but not the height or yield of wheat. The fungus caused a greater reduction in dry weight and height in barrel medic than in subterranean clover. Barrel medic is recorded as a host of F. avenaceum for the first time. The fungus was isolated from the roots of seedlings and from 0.3 per cent of a commercial seed sample. When this infected seed was sown in wheat stubble in crop rotations of fallow-wheat (stubble burnt), fallow-wheat and fallow-wheat-pasture-pasture its incidence in seed increased to 5.2, 6.0 and 10 per cent, respectively Studies on the effects of rotations on the incidence of F. avenaceum in wheat roots and wheat soil demonstrated a relation between crop sequence and population levels of the fungus. F. avenaceum was more prevalent in fallow-wheat-pasture than fallow-wheat.

Sign in / Sign up

Export Citation Format

Share Document