Effect of phosphorus deficiency in wheat on the infection of roots by Gaeumannomyces graminis var. tritici

1988 ◽  
Vol 39 (4) ◽  
pp. 541 ◽  
Author(s):  
RF Brennan
Keyword(s):  
Phosphorus Deficiency ◽  
Root Systems ◽  
Gaeumannomyces Graminis ◽  
Nodal Roots ◽  
Nodal Root ◽  
Seminal Roots ◽  
Phosphorus Status ◽  
Gaeumannomyces Graminis Var Tritici ◽  
P Supply ◽  
Take All

Wheat was grown in a slightly acidic grey sand at six levels of phosphorus, in the presence or absence of take-all inoculum in a glasshouse experiment. The incidence and severity of take-all was related to the phosphorus supply and the phosphorus status of wheat.Plants grown without P were more severely infected by take-all than those grown at adequate levels of phosphorus. The percentage of both nodal and seminal roots infected by take-all declined as the level of P was increased. The percentage of seminal roots infected was reduced from 35% to 13.7% by increasing the supply of phosphorus from levels severely deficient to those adequate for plant growth. Infection in nodal roots was reduced from 24% to 2.3% as the P supply increased. In both the seminal and nodal root systems, increasing the P supply decreased the length of proximal lesions (closest to seed) and increased the length of root between the crown and the proximal lesions.

Effect of nitrogen and phosphorus deficiency in wheat on the infection of roots by Gaeumannomyces graminis var. tritici

1989 ◽  
Vol 40 (3) ◽  
pp. 489 ◽  
Author(s):  
RF Brennan
Keyword(s):  
Root System ◽  
Phosphorus Deficiency ◽  
Gaeumannomyces Graminis ◽  
Nitrogen And Phosphorus ◽  
Nodal Roots ◽  
Proximal Lesion ◽  
Nodal Root ◽  
Seminal Roots ◽  
Four Levels ◽  
Take All

Wheat was grown in a slightly acid grey sand at six levels of phosphorus and four levels of nitrogen, in the presence and absence of inoculum of Gaeurnannomyces graminis tritici (Ggt) in a glasshouse experiment. Adequate nutrition of N (400 mg/pot) and P (100 mg/pot) for wheat plants was required to overcome take-all of wheat grown for 46 days. Severely N and P deficient plants had 60% of their seminal and nodal roots infected by take-all. As the plants responded to increasing levels of N and P, the percentage of infected nodal and seminal roots steadily declined to 0% and 10% for each root system respectively at luxury levels of P and adequate N. In both the seminal and nodal root system, increasing the N and P supply decreased the length of proximal lesions (closest to seed) and increased the length of the root between the crown and the proximal lesion. The seminal root system was more severely infected with take-all than the nodal root system.

Effect of copper deficiency in wheat on the infection of roots by Gaeumannomyces graminis var. tritici

1984 ◽  
Vol 35 (6) ◽  
pp. 735 ◽  
Author(s):  
MJ Wood ◽  
AD Robson
Keyword(s):  
Plant Growth ◽  
Copper Deficiency ◽  
Gaeumannomyces Graminis ◽  
Fresh Weight ◽  
Nodal Roots ◽  
Copper Status ◽  
Seminal Roots ◽  
Effect Of Copper ◽  
Gaeumannomyces Graminis Var Tritici ◽  
Take All

Wheat was grown in a soil at five levels of copper (ranging from levels deficient, to those luxurious, for plant growth), in the presence or absence of introduced take-all inoculum (oat kernels colonized by Gaeumannomyces graminis var. tritica). The incidence and severity of take-all were related to the copper supply and hence the copper status of the wheat. Plants grown without applied copper were more severely infected by take-all than were those grown with an adequate or luxurious supply of copper. The number of lesions per gram fresh weight of roots was reduced from 6.5 to 2.4 by increasing the copper supply from that severely deficient, to that adequate for plant growth. In seminal roots, increasing the copper supply from levels severely deficient to those adequate or luxurious for plant growth, decreased the length of proximal lesions (those closest to the seed). By contrast, in nodal roots, a similar increase in copper supply had no effect on the length of proximal lesions, but increased the length of uninfected root between the crown and proximal lesions. In both seminal and nodal roots, copper supply did not affect the intensity of lesions.

Colonization of lateral, seminal and adventitious roots of wheat by the take-all fungus, Gaeumannomyces graminis var. tritici

1980 ◽  
Vol 94 (2) ◽  
pp. 325-329 ◽  
Author(s):  
C. A. Gilligan
Keyword(s):  
Adventitious Roots ◽  
Lateral Roots ◽  
Initial Period ◽  
Hyphal Growth ◽  
Gaeumannomyces Graminis ◽  
Rate Of Growth ◽  
Direct Inoculation ◽  
Seminal Roots ◽  
Gaeumannomyces Graminis Var Tritici ◽  
Take All

SummaryProgressive colonization of adventitious, seminal and lateral roots of wheat by Gaeumannomyces graminis var. triticiwas monitored for 18 days after direct inoculation of roots. Adventitious roots supported greater colonization by superficial runner hyphae above and below inoculation sites than did seminal roots due to more rapid establishment of colonization. Subsequent rates of superficial runner hyphal growth along the two types of root were not significantly different. In contrast with seminal and lateral roots, adventitious roots did not show any dark stelar discoloration during the period of observation. Both the rate of growth of superficial runner hyphae and of advance of dark stelar discoloration were substantially slower on lateral roots than on seminal roots. After an initial period of equal growth above and below inoculation sites, superficial runner hyphae grew more slowly below than above these sites on all three types of root.

scholarly journals Isolation, Characterization, and Sensitivity to 2,4-Diacetylphloroglucinol of Isolates of Phialophora spp. from Washington Wheat Fields

2010 ◽  
Vol 100 (5) ◽  
pp. 404-414 ◽  
Author(s):  
Youn-Sig Kwak ◽  
Peter A. H. M. Bakker ◽  
Debora C. M. Glandorf ◽  
Jennifer T. Rice ◽  
Timothy C. Paulitz ◽  
...  
Keyword(s):  
Sequence Comparison ◽  
Phylogenetic Trees ◽  
Washington State ◽  
Gaeumannomyces Graminis ◽  
Wild Oat ◽  
Genetic Characteristics ◽  
Oat Cultivars ◽  
Eastern Washington ◽  
Gaeumannomyces Graminis Var Tritici ◽  
Take All

Dark pigmented fungi of the Gaeumannomyces–Phialophora complex were isolated from the roots of wheat grown in fields in eastern Washington State. These fungi were identified as Phialophora spp. on the basis of morphological and genetic characteristics. The isolates produced lobed hyphopodia on wheat coleoptiles, phialides, and hyaline phialospores. Sequence comparison of internal transcribed spacer regions indicated that the Phialophora isolates were clearly separated from other Gaeumannomyces spp. Primers AV1 and AV3 amplified 1.3-kb portions of an avenacinase-like gene in the Phialophora isolates. Phylogenetic trees of the avenacinase-like gene in the Phialophora spp. also clearly separated them from other Gaeumannomyces spp. The Phialophora isolates were moderately virulent on wheat and barley and produced confined black lesions on the roots of wild oat and two oat cultivars. Among isolates tested for their sensitivity to 2,4-diacetylphloroglucinol (2,4-DAPG), the 90% effective dose values were 11.9 to 48.2 μg ml–1. A representative Phialophora isolate reduced the severity of take-all on wheat caused by two different isolates of Gaeumannomyces graminis var. tritici. To our knowledge, this study provides the first report of an avenacinase-like gene in Phialophora spp. and demonstrated that the fungus is significantly less sensitive to 2,4-DAPG than G. graminis var. tritici.

Gaeumannomyces graminis var. tritici. [Descriptions of Fungi and Bacteria].

1973 ◽  
Author(s):  
J. Walker
Keyword(s):  
Geographical Distribution ◽  
Root Hairs ◽  
Seed Transmission ◽  
Gaeumannomyces Graminis ◽  
Root Infection ◽  
Root Death ◽  
Meristematic Region ◽  
Germ Tubes ◽  
Gaeumannomyces Graminis Var Tritici ◽  
Take All

Abstract A description is provided for Gaeumannomyces graminis var. tritici. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Gramineae, especially Triticum, Hordeum, Secale, Agropyron and several other grass genera and, more rarely, Sorghum and Zea; also recorded from the roots of plants in other families. DISEASE: Take-all of cereals and grasses (also referred to as deadheads or whiteheads, pietin and pied noir (France), Schwarzbeinigkeit and Ophiobolus Fusskrankheit (Germany), Ophiobolusvoetziekt (Netherlands) and others). Root infection is favoured by soil temperature from 12-20°C (Butler, 1961). Ascospore germ tubes penetrate root hairs and the epidermis in the meristematic region (Weste, 1972) leading to plugging of xylem and root death. GEOGRAPHICAL DISTRIBUTION: (CMI Map 334, ed. 3, 1972). Widespread, especially in temperate zones. Africa; Asia (India, Iran, Japan, USSR): Australasia and Oceania; Europe; North America (Canada, USA); South America (Argentina, Brazil, Chile, Colombia, Uruguay). TRANSMISSION: In soil on infected organic fragments, as runner hyphae on roots of cereals and grasses and, under special conditions, by ascospores. Seed transmission very doubtful (47, 3058).

Sign in / Sign up

Export Citation Format

Share Document