scholarly journals Effects of some commercial products on root and crown rot caused by Phytophthora cactorum in apple cultivation

2021 ◽  
Keyword(s):  
Crown Rot ◽  
Phytophthora Cactorum ◽  
Commercial Products ◽  
Root And Crown Rot

scholarly journals Resistance to Phytophthora Species among Rootstocks for Cultivated Prunus Species

HortScience ◽  
2017 ◽  
Vol 52 (11) ◽  
pp. 1471-1476 ◽  
Author(s):  
Gregory T. Browne
Keyword(s):  
Root Rot ◽  
Phytophthora Species ◽  
Crown Rot ◽  
Phytophthora Cactorum ◽  
Prunus Species ◽  
Phytophthora Megasperma ◽  
Soil Flooding ◽  
Root And Crown Rot ◽  
Crown And Root Rot ◽  
Multiple Species

Many species of Phytophthora de Bary are important pathogens of cultivated Prunus L. species worldwide, often invading the trees via their rootstocks. In a series of greenhouse trials, resistance to Phytophthora was tested in new and standard rootstocks for cultivated stone fruits, including almond. Successive sets of the rootstocks, propagated as hardwood cuttings or via micropropagation, were transplanted into either noninfested potting soil or potting soil infested with Phytophthora cactorum (Lebert & Cohn) J. Schöt., Phytophthora citricola Sawada, Phytophthora megasperma Drechs, or Phytophthora niederhauserii Z.G. Abad & J.A. Abad. Soil flooding was included in all trials to facilitate pathogen infection. In some trials, soil flooding treatments were varied to examine their effects on the rootstocks in both the absence and presence of Phytophthora. Two to 3 months after transplanting, resistance to the pathogens was assessed based on the severity of root and crown rot. ‘Hansen 536’ was consistently more susceptible than ‘Lovell’, ‘Nemaguard’, ‘Atlas’, ‘Viking’, ‘Citation’, and ‘Marianna 2624’ to root and/or crown rot caused by P. cactorum, P. citricola, and P. megasperma. By contrast, susceptibility to P. niederhauserii was similarly high among all eight tested genotypes of peach, four genotypes of peach × almond, two genotypes of (almond × peach) × peach, and one genotype of plum × almond. Most plum hybrids were highly and consistently resistant to crown rot caused by P. niederhauserii, but only ‘Marianna 2624’ was highly resistant to both crown and root rot caused by all of the Phytophthora species. The results indicate that there is a broad tendency for susceptibility of peach × almond rootstocks and a broad tendency for resistance of plum hybrid rootstocks to multiple species of Phytophthora.

Root and crown rot of strawberry caused by Pythium helicoides and its distribution in strawberry production areas of Japan

2014 ◽  
Vol 80 (5) ◽  
pp. 423-429 ◽  
Author(s):  
Yasushi Ishiguro ◽  
Kayoko Otsubo ◽  
Hideki Watanabe ◽  
Mikihiko Suzuki ◽  
Kiichi Nakayama ◽  
...  
Keyword(s):  
Crown Rot ◽  
Root And Crown Rot ◽  
Pythium Helicoides ◽  
Production Areas

scholarly journals PhytophthoraSpecies Are Common on Nursery Stock Grown for Restoration and Revegetation Purposes in California

Plant Disease ◽  
2019 ◽  
Vol 103 (3) ◽  
pp. 448-455 ◽  
Author(s):  
S. Rooney-Latham ◽  
C. L. Blomquist ◽  
K. L. Kosta ◽  
Y. Y. Gou ◽  
P. W. Woods
Keyword(s):  
North America ◽  
Phytophthora Species ◽  
Molecular Techniques ◽  
Crown Rot ◽  
Native Plant ◽  
Nursery Stock ◽  
Plant Nursery ◽  
Root And Crown Rot ◽  
Symptomatic Tissue ◽  
First Time

Phytophthora tentaculata was detected for the first time in North America in 2012 in a nursery on sticky monkeyflower plant (Diplacus aurantiacus) and again in 2014 on outplanted native plants. At that time, this species was listed as a federally actionable and reportable pathogen by the USDA. As a result of these detections, California native plant nurseries were surveyed to determine the prevalence of Phytophthora species on native plant nursery stock. A total of 402 samples were collected from 26 different native plant nurseries in California between 2014 and 2016. Sampling focused on plants with symptoms of root and crown rot. Symptomatic tissue was collected and tested by immunoassay, culture, and molecular techniques (PCR). Identifications were made using sequences from the internal transcribed spacer (ITS) rDNA region, a portion of the trnM-trnP-trnM, or the atp9-nad9 mitochondrial regions. Phytophthora was confirmed from 149 of the 402 samples (37%), and from plants in 22 different host families. P. tentaculata was the most frequently detected species in our survey, followed by P. cactorum and members of the P. cryptogea complex. Other species include P. cambivora, P. cinnamomi, P. citricola, P. hedraiandra, P. megasperma, P. multivora, P. nicotianae, P. niederhauserii, P. parvispora, P. pini, P. plurivora, and P. riparia. A few Phytophthora sequences generated from mitochondrial regions could not be assigned to a species. Although this survey was limited to a relatively small number of California native plant nurseries, Phytophthora species were detected from three quarters of them (77%). In addition to sticky monkeyflower, P. tentaculata was detected from seven other hosts, expanding the number of associated hosts. During this survey, P. parvispora was detected for the first time in North America from symptomatic crowns and roots of the nonnative Mexican orange blossom (Choisya ternata). Pathogenicity of P. parvispora and P. nicotianae was confirmed on this host. These findings document the widespread occurrence of Phytophthora spp. in native plant nurseries and highlight the potential risks associated with outplanting infested nursery-grown stock into residential gardens and wildlands.

scholarly journals First Report of Neopestalotiopsis clavispora Causing Root and Crown Rot on Strawberry in Italy

Plant Disease ◽  
2019 ◽  
Vol 103 (11) ◽  
pp. 2959-2959 ◽  
Author(s):  
G. Gilardi ◽  
F. Bergeretti ◽  
M. L. Gullino ◽  
A. Garibaldi
Keyword(s):  
Crown Rot ◽  
First Report ◽  
Root And Crown Rot

scholarly journals Genetic Determinants of Wheat Resistance to Common Root Rot (Spot Blotch), Fusarium Crown Rot, and Sharp Eyespot

2020 ◽  
Author(s):  
Jun Su ◽  
Jiaojie Zhao ◽  
Shuqing Zhao ◽  
Mengyu Li ◽  
Xiaofeng Shang ◽  
...  
Keyword(s):  
Root Rot ◽  
Spot Blotch ◽  
Crown Rot ◽  
Genetic Determinants ◽  
Common Root ◽  
Fusarium Crown Rot ◽  
Common Root Rot ◽  
Sharp Eyespot ◽  
Root And Crown Rot ◽  
Moderate Resistance

Due to the field soil changes, high density planting, and straw-returning methods, wheat common root rot (spot blotch), Fusarium crown rot (FCR), and sharp eyespot have become severe threatens to global wheat productions. Only a few wheat genotypes show moderate resistance to these root and crown rot fungal diseases, and the genetic determinants of wheat resistance to these devastating diseases have been poorly understood. This review summarizes the recent progress of genetic studies on wheat resistance to common root rot, Fusarium crown rot, and sharp eyespot. Wheat germplasms with relative higher resistance are highlighted and genetic loci controlling the resistance to each of the disease are summarized.

scholarly journals First report of crown rot of Photinia fraseri caused by Phytophthora cactorum

2006 ◽  
Vol 55 (4) ◽  
pp. 573-573 ◽  
Author(s):  
A. M. Vettraino ◽  
L. Antonacci ◽  
L. Flamini ◽  
P. Nipoti ◽  
E. Rossini ◽  
...  
Keyword(s):  
Crown Rot ◽  
Phytophthora Cactorum ◽  
First Report

scholarly journals Fusarium Root and Crown Rot: A Disease of Container-Grown Hostas

Plant Disease ◽  
2000 ◽  
Vol 84 (9) ◽  
pp. 980-988 ◽  
Author(s):  
B. Wang ◽  
S. N. Jeffers
Keyword(s):  
South Carolina ◽  
Crown Rot ◽  
Undescribed Species ◽  
Fresh Weight ◽  
Fusarium Spp ◽  
Disease Symptoms ◽  
Leaf Yellowing ◽  
Oat Seeds ◽  
Root And Crown Rot ◽  
Fusarium Sp

A previously unreported disease was observed on 11 cultivars of container-grown hosta plants at five wholesale nurseries in South Carolina between 1997 and 1999. Symptoms included leaf yellowing, plant stunting, rotting of and vascular discoloration in roots, and necrosis in the crowns. Fusarium spp. consistently were isolated from symptomatic hosta plants. Four species were recovered: F. solani, F. oxysporum, F. proliferatum, and an undescribed species designated Fusarium sp.; F. solani and Fusarium sp. were recovered most frequently. To demonstrate pathogenicity, four methods were used to inoculate hosta plants with representative isolates of F. solani, F. oxysporum, and Fusarium sp. Two types of inoculum, colonized oat seeds and conidium suspensions, were used to inoculate wounded and nonwounded plants. Disease symptoms occurred consistently only on hosta plants inoculated by dipping wounded roots and crowns into suspensions of conidia. Symptoms were most severe on plants inoculated with Fusarium sp. and much less severe on plants inoculated with F. solani or F. oxysporum. Disease severity increased and fresh weight of inoculated plants decreased when the concentration of inoculum of Fusarium sp. was increased over the range of 1 × 103 to 1 × 107 conidia per ml. Isolates of Fusarium sp., F. solani, and F. oxysporum varied in virulence when Hosta ‘Francee’ plants were inoculated. This study demonstrated that Fusarium root and crown rot of container-grown hostas is caused primarily by Fusarium sp. but that it also can be caused by F. solani and F. oxysporum. Fusarium sp. appears to be taxonomically distinct from other species, and its identity currently is under investigation.

STUDIES OF CROWN ROT OF APPLE TREES

1942 ◽  
Vol 20c (9) ◽  
pp. 457-490 ◽  
Author(s):  
Maurice F. Welsh
Keyword(s):  
Soil Moisture ◽  
Apple Tree ◽  
Disease Incidence ◽  
Antagonistic Effect ◽  
Crown Rot ◽  
Phytophthora Cactorum ◽  
Additional Information ◽  
Two Factors ◽  
Below Ground ◽  
Old Trees

The form of apple tree crown rot that occurs in the irrigated orchards of British Columbia is confined to the below-ground bark tissues of the tree. It has been encountered in trees of all ages and of all the commercial varieties.Proof is given that this crown rot is caused by the fungus Phytophthora cactorum (L. & C.) Schroet. Typical symptoms of the disease have been reproduced in over 200 trees of various ages as a result of their inoculation with this fungus. Isolation has been possible only from the margins of active lesions, and has proved difficult even from these tissues. There is evidence that the activity of P. cactorum is inhibited in rotted tissues by the antagonistic effect of one or more secondary organisms.The influence of soil moisture and temperature on disease incidence has been studied by field observations and by the inoculation of two-year—old trees under controlled conditions in Wisconsin tank equipment in the greenhouse. The effects of these two factors seem to be interrelated, with the highest incidence of disease in an almost saturated soil at the highest temperature imposed, 32 °C. The influence of soil moisture is exerted particularly in the subsoil, rather than in the locus of crown rot attack.Certain varieties of apple have been found to vary in their resistance to crown rot. Deep wounds have proved necessary to allow entry of the fungus into bark tissues.The additional information now available is being utilized in a search for improved means of combating the disease.

scholarly journals Meristem culture for the elimination of the strawberry crown rot pathogen Phytophthora cactorum

2011 ◽  
Vol 1 (3) ◽  
pp. 129-136 ◽  
Author(s):  
A.B. Whitehouse ◽  
C.L. Govan ◽  
K.J. Hammond ◽  
D.J. Sargent ◽  
D.W. Simpson
Keyword(s):  
Crown Rot ◽  
Meristem Culture ◽  
Phytophthora Cactorum
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