scholarly journals Screening for Resistance to Pythium Root Rot among Twenty-three Caladium Cultivars

2005 ◽  
Vol 15 (3) ◽  
pp. 631-634 ◽  
Author(s):  
Zhanao Deng ◽  
Brent K. Harbaugh ◽  
Rick O. Kelly ◽  
Teresa Seijo ◽  
Robert J. McGovern
Keyword(s):  
Root Rot ◽  
Tuber Yield ◽  
Sources Of Resistance ◽  
Aesthetic Value ◽  
Pythium Root Rot ◽  
Landscape Plants ◽  
Tuber Production ◽  
Commercial Cultivars ◽  
Loss Severity ◽  
Pot Plant

Caladiums (Caladium ×hortulanum) are widely grown as pot or landscape plants for their attractive leaves. Pythium root rot (Pythium myriotylum) is one of the most damaging diseases in caladium, severely reducing plant growth, aesthetic value, and tuber yield. Twenty-three commercial cultivars were inoculated with three aggressive isolates of P. myriotylum and evaluated for their resistance to root rot. Three cultivars, `Apple Blossom', `Blizzard', and `Etta Moore', were found to have a moderate level of resistance (partial resistance) to pythium root rot. The rest of these cultivars were susceptible or highly susceptible to Pythium infection, losing up to 94% of their root tissue to rotting within 10 days after inoculation. Data indicated a linear relationship between root rot severity and leaf loss severity on Pythium-inoculated plants and highlight the importance of controlling pythium root rot in caladium pot plant and tuber production. Comparison of some recent releases with their parents for pythium root rot resistance suggests the potential of developing new resistant caladium cultivars using the identified sources of resistance.

scholarly journals Pythium Root Rot Resistance in Commercial Caladium Cultivars

HortScience ◽  
2005 ◽  
Vol 40 (3) ◽  
pp. 549-552 ◽  
Author(s):  
Zhanao Deng ◽  
Brent K. Harbaugh ◽  
Rick O. Kelly ◽  
Teresa Seijo ◽  
Robert J. McGovern
Keyword(s):  
Root Rot ◽  
Tuber Yield ◽  
Integrated Control ◽  
Ornamental Plants ◽  
Aesthetic Value ◽  
Pythium Root Rot ◽  
Yield Information ◽  
Loss Severity ◽  
Highly Virulent ◽  
Potential Use

Caladiums (Caladium ×hortulanum) are popular ornamental plants widely grown for their bright colorful leaves. Pythium root rot, caused by Pythium myriotylum, is one of the few soil-borne diseases in caladium that dramatically reduces plant growth, aesthetic value, and tuber yield. Information on the reaction of caladium cultivars to P. myriotylum is not available, but would be valuable for integrated control of this disease and for breeding new resistant cultivars. Three Pythium isolates obtained from decaying roots of plants collected from a field production site and two greenhouses were evaluated for pathogenicity and potential use in experiments to screen commercial caladium cultivars for resistance. All three isolates were found to be highly virulent; they were able to cause obvious root rotting within 3 to 5 days and severe root rotting and leaf losses on susceptible cultivars within 10 days after inoculation. Nineteen major commercial cultivars were evaluated for their resistance to these isolates. Fifteen of the cultivars were susceptible or highly susceptible to Pythium infection. Four widely grown cultivars, `Candidum', `Candidum Jr.', `Frieda Hemple', and `White Christmas', were found to have a moderate level of resistance (partial resistance) to pythium root rot. Pythium infection also caused leaf discoloration, epinasty, wilting, and collapse. Regression analyses revealed a linear relationship between the root rot and leaf loss severity on Pythium-inoculated plants.

scholarly journals Resistance of Nineteen Major Caladium Commercial Cultivars to Pythium Root Rot

EDIS ◽  
1969 ◽  
Vol 2005 (3) ◽  
Author(s):  
Zhanao Deng ◽  
Brent K. Harbaugh ◽  
Richard O. Kelly ◽  
Teresa Seijo ◽  
Robert J. McGovern
Keyword(s):  
Root Rot ◽  
Integrated Management ◽  
Ornamental Plants ◽  
Control Measures ◽  
Publication Date ◽  
Aesthetic Value ◽  
Resistance Level ◽  
University Of Florida ◽  
Pythium Root Rot ◽  
Commercial Cultivars

Caladiums (Caladium xhortulanum) are popular ornamental plants widely grown for their bright colorful leaves. Pythium root rot, caused by P. myriotylum, is one of the few soil-borne diseases in caladium that can dramatically reduce plant growth, aesthetic value, and tuber yield. Identification and use of disease-resistant cultivars has proven to be an important and economically viable strategy for integrated management of major diseases in crops and for reducing the use of pesticides. This strategy will be particularly useful for caladiums in the landscape and home gardens, because in such cases choices of root rot control measures are limited. However, information on the resistance level of commercial caladium cultivars has been lacking. This document is ENH996, one of a series of the Environmental Horticulture Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Original publication date December 2, 2004.  ENH996/EP251: Resistance of Nineteen Major Caladium Commercial Cultivars to Pythium Root Rot (ufl.edu)

scholarly journals Evaluation of Caladium Cultivars for Resistance to Pythium Root Rot

HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 772E-773 ◽  
Author(s):  
Zhanao Deng* ◽  
Brent K. Harbaugh ◽  
Rick Kelly ◽  
Teresa Seijo ◽  
Robert J. McGovern
Keyword(s):  
Root Rot ◽  
Plant Production ◽  
Higher Plant ◽  
Pythium Root Rot ◽  
Tuber Production ◽  
Commercial Cultivars ◽  
Greenhouse Plant ◽  
Growing Conditions ◽  
Spore Densities ◽  
Highly Virulent

Caladiums (Caladium × hortulanum) are widely grown for their bright colorful leaves. Pythium root rot, caused primarily by P. myriotylum, is one of the most important diseases in caladiums. This disease can dramatically reduce plant growth, impact plant aesthetical value, and lower tuber yield. Pythium infection in the roots may also lead to subsequent entry of Fusarium into tubers resulting in tuber rot. There has been a strong interest in the tuber production and greenhouse plant production industries to identify cultivars that are resistant or tolerant to Pythium. However, few studies have been conducted since the pathogen was identified, and little information is available regarding the existence of any possible resistance in commercial cultivars. Pythium isolates were made from diseased plants collected from different sites; their pathogenicity was confirmed using tissue culture-derived plants. Procedures were developed for oogonia spore production, inoculation, and disease severity assessment. Nineteen major commercial cultivars were inoculated at two spore densities and then maintained in greenhouses under growing conditions favorable for root rotting. Plant appearance, leaf characteristics and severity of root rotting were evaluated 2-3 times after inoculation. Observations indicated that the isolates were highly virulent. They induced visible root rot within 3-5 days, and caused a complete loss of the root system and plant death for some cultivars within 2-3 weeks after inoculation. Several cultivars, including `Candidum' and `Frieda Hemple' which are widely grown cultivars, had much less root rot, higher plant survival, and seemed to have moderate levels of resistance.

scholarly journals Screening for Resistance to Pythium Root Rot among Twenty-three Caladium Cultivars

EDIS ◽  
2019 ◽  
Vol 2005 (11) ◽  
Author(s):  
Zhanao Deng ◽  
Brent K. Harbaugh ◽  
Rick O. Kelly ◽  
Teresa Seijo ◽  
Robert J. McGovern
Keyword(s):  
Root Rot ◽  
Integrated Management ◽  
Cooperative Extension Service ◽  
Publication Date ◽  
University Of Florida ◽  
Resistant Cultivars ◽  
Evaluation Procedures ◽  
Pythium Root Rot ◽  
Commercial Cultivars ◽  
Screening For Resistance

Pythium root rot, caused by Pythium myriotylum (Ridings and Hartman, 1976), is a very damaging disease to caladium plants (Caladium x hortulanum). Use of disease-resistant cultivars has been an effective and economically viable strategy for integrated management of major diseases in numerous crops. This strategy could be used to control pythium root rot in caladium if resistant cultivars could be identified or developed. In an evaluation of 19 major commercial cultivars, 'Candidum', 'Candidum Jr.', 'Frieda Hemple', and 'White Christmas' were found to have a moderate level of resistance to Pythium. To find more resistant cultivars, twenty-three additional commercial cultivars were screened using the same Pythium isolates, inoculation and evaluation procedures as described earlier (Deng et al. 2004). This document is ENH1008, one of a series of the Environmental Horticulture Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Original publication date September 27, 2005. ENH1008/EP259: Screening for Resistance to Pythium Root Rot among Twenty-three Caladium Cultivars (ufl.edu)

scholarly journals Immunological characteristics of winter wheat varieties to the main pathogens in the right-bank Forest Steppe

2021 ◽  
Vol 29 ◽  
pp. 74-81
Author(s):  
L. Golosna ◽  
O. G. Afanasieva ◽  
O.V. Shevchuk ◽  
L.O. Kucherova ◽  
I.S. Shvets ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Winter Wheat ◽  
Root Rot ◽  
Tan Spot ◽  
High Plasticity ◽  
Common Bunt ◽  
Sources Of Resistance ◽  
Wheat Varieties ◽  
Group Resistance ◽  
Winter Wheat Varieties

Aim. To determine the resistance of winter wheat varieties to the main pathogens, to establish their stability and plasticity, to identify perspective sources of resistance. Methods. Laboratory – production of inoculum of pathogens; field – artificial inoculation,, assessment of variety stability; statistical calculation of disease severity, indicators of stability and plasticity. Results. In 2015–2017, the resistance of 43 varieties of winter wheat to the main pathogens of leaf diseases, common bunt and root rots was assessed. Resistance to powdery mildew was found in 32 varieties, tan spot – in 2, root rot – in 3, hard smut – in 2 varieties. Six varieties of winter wheat were characterized by group resistance. Varieties that combine high plasticity and stability of the sign of disease resistance have been identified. Conclusions. Valuable sources of resistance are winter wheat varieties with group resistance to common bunt and powdery mildew – Tradytsiia Odeska and Kurs; powdery mildew and tan spot – Nasnaga and Zolotonozhka; powdery mildew and root rot – Nezabudka and Shchedrist kyivska.Keywords: resistance, winter wheat, diseases, plasticity, stability.

scholarly journals Identification of Pisum sativum Germ Plasm with Resistance to Root Rot Caused by Multiple Strains of Aphanomyces euteiches

Plant Disease ◽  
1999 ◽  
Vol 83 (1) ◽  
pp. 51-54 ◽  
Author(s):  
D. K. Malvick ◽  
J. A. Percich
Keyword(s):  
Pisum Sativum ◽  
Root Rot ◽  
Plant Introduction ◽  
Aphanomyces Euteiches ◽  
Sources Of Resistance ◽  
Breeding Programs ◽  
Pea Seedlings ◽  
Biomass Loss ◽  
Serious Disease ◽  
Multiple Strains

Aphanomyces root rot is a serious disease of pea (Pisum sativum), and additional sources of resistance are needed for development of disease-resistant cultivars. Accessions (n = 123) from the P. sativum Plant Introduction (PI) collection with the highest relative levels of resistance to one strain of Aphanomyces euteiches were previously identified from among approximately 2,500 accessions evaluated. The chosen 123 accessions were evaluated in this study for resistance to root rot caused by multiple strains of this pathogen. Five strains representing different US geographical locations and pathogenicity characteristics were used to evaluate pea seedlings in a greenhouse. Disease severity (DS) and percent loss of fresh biomass (inoculated vs. non-inoculated plants) were determined 15 days after inoculation. Significant differences (P = 0.05) in levels of DS and biomass loss (BL) occurred among the accessions after inoculation individually with the five strains. The relative rank of accessions based on DS and BL varied with the strain of A. euteiches used for inoculations. The 20 accessions with the lowest DS after inoculation with each strain were identified. Based on lowest DS, two accessions were among the 20 identified with all five individual strains, and four other accessions were among the 20 identified with four of the five strains. The results suggest that the P. sativum PI collection contains useful accessions for breeding programs aimed at developing pea varieties with resistance to A. euteiches.

Identification of metalaxyl and ethaboxam insensitive Pythium sylvaticum pathogenic to pulse crops in Montana, USA.

2021 ◽  
Author(s):  
Lipi Parikh ◽  
Swarnalatha Moparthi ◽  
Frankie Crutcher ◽  
Mary Burrows
Keyword(s):  
Root Rot ◽  
Damping Off ◽  
Management Options ◽  
Fungicide Sensitivity ◽  
Root Rots ◽  
Pulse Crops ◽  
Pythium Root Rot ◽  
Pythium Sylvaticum ◽  
Potential Pathogenicity

Pythium root rot and damping-off caused by Pythium spp. are important diseases of pulse crops. In a 2016 pathogen survey from dry pea growing fields in Montana, along with commonly known causal agents P. ultimum and P. irregulare, an isolate identified as P. sylvaticum (LPPY17) was isolated from the rhizosphere of a diseased pea plant collected from Valley County, MT. Root rots and damping-off caused by P. sylvaticum have not previously been reported for chickpea, pea, and lentil crops. The isolate LPPY17 was tested for fungicide resistance in vitro, and results indicated a reduced sensitivity to metalaxyl and ethaboxam containing fungicides. LPPY17 was also tested for pathogenicity on chickpea, pea, and lentil seedlings in the greenhouse, and the results from the study revealed LPPY17 is capable of causing both root rots and damping off. Due to the potential pathogenicity and reduced fungicide sensitivity of this species, in the future it will be important to monitor for P. sylvaticum in pulse root rot surveys and diagnostics, as management options may be different from other common Pythium spp.

STUDIES ON BROWNING ROOT ROT OF CEREALS: VI. FURTHER CONTRIBUTIONS ON THE EFFECTS OF VARIOUS SOIL AMENDMENTS ON THE INCIDENCE OF THE DISEASE IN WHEAT

1940 ◽  
Vol 18c (6) ◽  
pp. 240-257 ◽  
Author(s):  
T. C. Vanterpool
Keyword(s):  
Root Rot ◽  
Nutrient Deficiencies ◽  
Sweet Clover ◽  
Poor Growth ◽  
Prairie Soils ◽  
Pythium Root Rot ◽  
The Poor ◽  
Copper Manganese ◽  
Supplemental Nutrients ◽  
Severe Leaf

Further work has substantiated earlier findings that phosphatic fertilizers and farm manure will give adequate control of Pythium root rot of wheat in infested prairie soils. The improvement in growth resulting from these amendments is considered to be due to the production of a larger number of quicker growing roots which lessens the chances for infection and leaves more roots healthy, though the same percentage may be affected as in diseased plants showing severe leaf discolorations. Experiments have failed to indicate that the phosphatic materials increase resistance appreciably. Nitrogenous materials when applied singly had virtually no effect on growth, but once ample phosphorus was added, further nitrogen applications gave substantially greater increases than phosphate alone. Phosphorus is apparently the chief limiting element. No difference was found in preliminary tests in the phosphate-fixing power of browning and normal soils. Typical browning soils responded irregularly to small applications of boron, copper, manganese, or zinc, but were not found to be seriously lacking in these elements. Moderate benefits resulted from heavy applications of gypsum and of sulphur. Browning soil was found also to be deficient in phosphate for non-cereals such as alfalfa, buckwheat, carrots, flax, lettuce, and sweet clover. These crops were not attacked by the Pythium spp. pathogenic to cereals. Consequently the poor growth of the non-cereals in browning soil appears to be due to nutrient deficiencies, while the poor growth of cereals is due to both root-destroying fungi and nutrient deficiencies. In both instances phosphorus is probably the chief limiting element. Ground cereal straw, sweet clover hay, and weed hay amendments gave moderate increases m the growth of wheat. No consistent differences were found in the carbon-nitrogen ratios of browning and normal soils. The results as a whole suggest that two of the most practicable means of meeting the browning root-rot situation are, firstly, to supply supplemental nutrients in the form of artificial fertilizers, and secondly, to add organic residues or farm manure regularly to fields subject to the disease.

Sign in / Sign up

Export Citation Format

Share Document