Strain Variation in Tolerance of Water Stress by Idriella(Microdochium)bolleyi, a Biocontrol Agent of Cereal Root and Stem Base Pathogens

1994 ◽  
Vol 4 (2) ◽  
pp. 239-249 ◽  
Author(s):  
L. I. Douglas ◽  
J. W. Deacon
Keyword(s):  
Water Stress ◽  
Biocontrol Agent ◽  
Strain Variation ◽  
Stem Base ◽  
Microdochium Bolleyi ◽  
Cereal Root

Improving water stress tolerance of the biocontrol yeastCandida sakegrown in molasses-based media by physiological manipulation

2001 ◽  
Vol 47 (2) ◽  
pp. 123-129 ◽  
Author(s):  
M Abadias ◽  
N Teixidó ◽  
J Usall ◽  
I Viñas ◽  
N Magan
Keyword(s):  
Polyethylene Glycol ◽  
Water Stress ◽  
Amino Acid ◽  
Cell Viability ◽  
Stress Tolerance ◽  
Biocontrol Agent ◽  
Compatible Solutes ◽  
Intracellular Concentration ◽  
Water Stress Tolerance ◽  
Candida Sake

The biocontrol agent Candida sake was cultured on either an unmodified molasses-based medium (water activity, aw0.996) or on water stressed media produced by the addition of glycerol, glucose, NaCl, sorbitol, or proline to 0.98, and 0.96 awfor 24, 48, and 72 h, to study their impact on subsequent cell viability, and on concentrations of endogenous sugars (trehalose and glucose) and polyols (glycerol, erythritol, arabitol, and mannitol). The viability of cells of different ages cultured on these media was evaluated on NYDA medium with freely available water (aw0.995), and on medium modified with polyethylene glycol to aw0.95. Regardless of solute used, viable counts of cells grown on molasses-based medium (aw0.98) were equal to or higher than those obtained from the medium with water freely available. The amino acid proline stimulated growth at 10% concentration. In contrast, water stress induced by addition of NaCl, glucose, or sorbitol at aw0.96 caused a significant reduction in viable counts. Older cultures were more resistant to water stress. Glycerol and arabitol were the main solutes accumulated by C. sake cells in response to lowered aw. Intracellular concentration of these polyols depended more on the solute used to adjust the awthan on the awitself. Candida sake was more resistant to water stress with higher intracellular concentration of glycerol and erythritol.Key words: compatible solutes, polyols, sugars, improved viability, formulation.

scholarly journals Mycoflora of rhizomes and roots of Elytrigia repens a potential inoculum source for takeall in wheat

2004 ◽  
Vol 57 ◽  
pp. 59-66
Author(s):  
S.F. Chng ◽  
M.G. Cromey ◽  
R.C. Butler
Keyword(s):  
Biological Control ◽  
Biocontrol Agent ◽  
Gaeumannomyces Graminis ◽  
Inoculum Source ◽  
Elytrigia Repens ◽  
Microdochium Bolleyi ◽  
Gaeumannomyces Graminis Var Tritici

Elytrigia repens is a host of the wheat takeall pathogen Gaeumannomyces graminis var tritici (Ggt) While E repens does not suffer substantial damage from infection by Ggt rhizomes and roots of this plant are potential carriers of Ggt and the infested residues are likely to provide sources of inoculum for wheat The mycoflora of rhizomes and roots of E repens collected from three arable cropping sites over six sampling occasions were examined The possible causes of root and rhizome lesions and fungi that might provide a level of biological control of Ggt in E repens were identified Ggt was not always associated with lesions and other fungi may also cause lesions on E repens Most Ggt was isolated from E repens collected from an area where severe takeall infection had previously been observed in wheat Microdochium bolleyi cooccurred most frequently with Ggt and the potential of M bolleyi as a biocontrol agent for takeall is discussed

Biscogniauxia (Hypoxylon) Canker or Dieback in Trees

EDIS ◽  
2017 ◽  
Vol 2017 (6) ◽  
Author(s):  
Claudia Paez ◽  
Jason A. Smith
Keyword(s):  
Water Stress ◽  
Tree Species ◽  
Soil Compaction ◽  
Urban Areas ◽  
Root Disease ◽  
Poor Health ◽  
Green Spaces ◽  
Opportunistic Pathogens ◽  
Wide Range ◽  
Quercus Spp

Biscogniauxia canker or dieback (formerly called Hypoxylon canker or dieback) is a common contributor to poor health and decay in a wide range of tree species (Balbalian & Henn 2014). This disease is caused by several species of fungi in the genus Biscogniauxia (formerly Hypoxylon). B. atropunctata or B. mediterranea are usually the species found on Quercus spp. and other hosts in Florida, affecting trees growing in many different habitats, such as forests, parks, green spaces and urban areas (McBride & Appel, 2009).  Typically, species of Biscogniauxia are opportunistic pathogens that do not affect healthy and vigorous trees; some species are more virulent than others. However, once they infect trees under stress (water stress, root disease, soil compaction, construction damage etc.) they can quickly colonize the host. Once a tree is infected and fruiting structures of the fungus are evident, the tree is not likely to survive especially if the infection is in the tree's trunk (Anderson et al., 1995).

Citrus Irrigation Management

EDIS ◽  
2017 ◽  
Vol 2017 (5) ◽  
Author(s):  
Davie Mayeso Kadyampakeni ◽  
Kelly T. Morgan ◽  
Mongi Zekri ◽  
Rhuanito Ferrarezi ◽  
Arnold Schumann ◽  
...  
Keyword(s):  
Water Stress ◽  
Physiological Activity ◽  
Irrigation Management ◽  
Fruit Size ◽  
Irrigation Scheduling ◽  
Leaf Expansion ◽  
Tree Canopy ◽  
Limiting Factor ◽  
Irrigation Frequency ◽  
Citrus Production

Water is a limiting factor in Florida citrus production during the majority of the year because of the low water holding capacity of sandy soils resulting from low clay and the non-uniform distribution of the rainfall. In Florida, the major portion of rainfall comes in June through September. However, rainfall is scarce during the dry period from February through May, which coincides with the critical stages of bloom, leaf expansion, fruit set, and fruit enlargement. Irrigation is practiced to provide water when rainfall is not sufficient or timely to meet water needs. Proper irrigation scheduling is the application of water to crops only when needed and only in the amounts needed; that is, determining when to irrigate and how much water to apply. With proper irrigation scheduling, yield will not be limited by water stress. With citrus greening (HLB), irrigation scheduling is becoming more important and critical and growers cannot afford water stress or water excess. Any degree of water stress or imbalance can produce a deleterious change in physiological activity of growth and production of citrus trees.  The number of fruit, fruit size, and tree canopy are reduced and premature fruit drop is increased with water stress.  Extension growth in shoots and roots and leaf expansion are all negatively impacted by water stress. Other benefits of proper irrigation scheduling include reduced loss of nutrients from leaching as a result of excess water applications and reduced pollution of groundwater or surface waters from the leaching of nutrients. Recent studies have shown that for HLB-affected trees, irrigation frequency should increase and irrigation amounts should decrease to minimize water stress from drought stress or water excess, while ensuring optimal water availability in the rootzone at all times.

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