The relationship of ammonia to symptom expression in apple shoots inoculated with Erwinia amylovora

1970 ◽  
Vol 48 (5) ◽  
pp. 999-1000 ◽  
Author(s):  
L. Lovrekovich ◽  
H. Lovrekovich ◽  
R. N. Goodman
Keyword(s):  
Erwinia Amylovora ◽  
Symptom Expression ◽  
Stem Tissue ◽  
Symptom Development ◽  
Apple Stem ◽  
Relationship Of ◽  
The Relationship

Apple stem tissue exposed to ammonia vapors reproduced the symptoms of fireblight. The stem tissue infected with Erwinia amylovora evolved sufficient amounts of ammonia to account for symptom development.

A comparison of three low-persistence viruses of the strawberry

1957 ◽  
Vol 8 (6) ◽  
pp. 652
Author(s):  
LL Stubbs
Keyword(s):  
Cross Protection ◽  
Mixed Infections ◽  
Fragaria Vesca ◽  
Symptom Development ◽  
Relationship Of ◽  
The Relationship ◽  
Different Levels

Three low-persistence viruses of mild, severe, and intermediate virulence, respectively, on strawberry (Fragaria vesca L.) seedlings have been isolated from Australian strawberry varieties. Studies concerned with the relationship of these viruses have shown that both the intermediate and severe types will multiply in F. vesea plants previously infected with the mild type of virus. Moreover, infection with this latter virus does not delay symptom development when the plants are inoculated with either the intermediate or severe types, and symptoms are intensified in each case. The mild and severe viruses were separated from mixed infections by serially transferring aphids (Pentatrichopus fragaefolii (Cock.)) bred on the infected plants. Separation was achieved by chance, and not as a result of different levels of persistence in the vector which the experiments were designed to exploit. In most instances both viruses were transmitted. The identity of the viruses is discussed in relation to known cross-protection phenomena.

scholarly journals Evidence for the Widespread Occurrence of Bacteria Implicated in Acute Oak Decline from Incidental Genetic Sampling

Forests ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1683
Author(s):  
Louise A. P. Gathercole ◽  
Gabriele Nocchi ◽  
Nathan Brown ◽  
Timothy L. R. Coker ◽  
William J. Plumb ◽  
...  
Keyword(s):  
Oak Decline ◽  
Symptom Development ◽  
Bacterial Genomes ◽  
Associated Bacteria ◽  
Widespread Occurrence ◽  
Genetic Sampling ◽  
Stem Lesions ◽  
Relationship Of ◽  
The Relationship ◽  
Oak Leaves

Acute Oak Decline (AOD) is complex syndrome affecting Britain’s keystone native oak species, (Quercus robur L. and Q. petraea L. (Matt.) Liebl.), in some cases causing mortality within five years of symptom development. The most distinguishable symptom is weeping stem lesions, from which four species of bacteria have been isolated: Brenneria goodwinii, Gibbsiella quercinecans, Lonsdalea britannica and Rahnella victoriana. We do not yet know where else these bacteria exist, and little is known about the relationship of the wider oak leaf microbiome (phyllosphere) to acute oak decline. Here we investigate whether incidental evidence from a large oak genome re-sequencing dataset could be used to detect these bacteria in oak foliage, and whether bacterial incidence co-varied with AOD status or location. Oak leaves and buds were sampled from 421 trees at five sites in England. Whole genomic DNA from these samples was shot-gun sequenced with short reads. Non-oak reads were extracted from these data and queried to microbial databases. Reads uniquely matching AOD-associated bacterial genomes were found to be present on trees from all five sites and included trees with active lesions, trees with historic lesions and trees without AOD symptoms. The abundance of the AOD-associated bacteria did not differ between tree health categories but did differ among sites. We conclude that the AOD-associated bacteria may be members of the normal oak microbiome, whose presence on a tree is not sufficient to cause AOD symptoms.

scholarly journals Evidence for the Widespread Occurrence of Bacteria Implicated in Acute Oak Decline from Incidental Genetic Sampling

2021 ◽  
Author(s):  
Louise Gathercole ◽  
Gabriele Nocchi ◽  
Nathan Brown ◽  
Timothy Coker ◽  
William Plumb ◽  
...  
Keyword(s):  
Oak Decline ◽  
Symptom Development ◽  
Bacterial Genomes ◽  
Associated Bacteria ◽  
Widespread Occurrence ◽  
Genetic Sampling ◽  
Stem Lesions ◽  
Relationship Of ◽  
The Relationship ◽  
Oak Leaves

Acute Oak Decline (AOD) is complex syndrome affecting Britain’s keystone native oak species, (Quercus robur L. and Q. petraea L. (Matt.) Liebl.), in some cases causing mortality within five years of symptom development. The most distinguishable symptom is weeping stem lesions, from which four species of bacteria have been isolated: Brenneria goodwinii, Gibbsiella quercinecans, Lonsdalea britannica and Rahnella victoriana. We do not yet know where else these bacteria exist, and little is known about the relationship of the wider oak leaf microbiome (phyllosphere) to acute oak decline. Here we investigate whether incidental evidence from a large oak genome re-sequencing dataset could be used to detect these bacteria in oak foliage, and whether bacterial incidence co-varied with AOD status or location. Oak leaves and buds were sampled from 421 trees at five sites in England. Whole genomic DNA from these samples was shot-gun sequenced with short reads. Non-oak reads were extracted from these data and queried to microbial databases. Reads uniquely matching AOD-associated bacterial genomes were found to be present on trees from all five sites and included trees with active lesions, trees with historic lesions and trees without AOD symptoms. The abundance of the AOD-associated bacteria did not differ between tree health categories but did differ among sites. We conclude that the AOD-associated bacteria may be members of the normal oak microbiome, whose presence on a tree is not sufficient to cause AOD symptoms.

scholarly journals Relationship of Pink Pigmentation in Rose Petals and Botrytis cinerea

2020 ◽  
Vol 21 (2) ◽  
pp. 152-156
Author(s):  
Melissa Muñoz ◽  
James E. Faust ◽  
William C. Bridges ◽  
Guido Schnabel
Keyword(s):  
Botrytis Cinerea ◽  
Culture Media ◽  
Scientific Evidence ◽  
Rosa Hybrida ◽  
Symptom Development ◽  
Commercial Grower ◽  
Rose Petals ◽  
Relationship Of ◽  
The Relationship

Pink pigmentation on rose (Rosa × hybrida) petals in the form of round spots or irregular-shaped discoloration has been associated with Botrytis cinerea infection, but scientific evidence has been lacking to support this hypothesis. The unfounded association between pink pigmentation and Botrytis blight has been sufficient to warrant rejection of international shipments during inspection at the ports of entry. The objective of this research was to evaluate the relationship between pink pigmentation symptoms on rose petals and B. cinerea infection. Four shipments of ‘Vendela’ and ‘Brighton’ roses were received from a commercial grower. Intact rose flowers and detached petals were assessed separately, and symptom development and Botrytis blight incidence were evaluated. In addition, tissue pieces with and without pink pigmentation were placed in culture media to determine the frequency of B. cinerea isolation. Results showed that Botrytis blight incidence in whole flowers and petals of cut roses with and without pink pigmentations was not significantly different. B. cinerea was not isolated more frequently from pink-pigmented tissue compared with tissues lacking pink pigmentation. These results show that pink pigmentation in the form of round spots or irregular-shaped discoloration along the petal margins is not associated with B. cinerea infections.

scholarly journals The Role of Autumn Infections in the Progression of Fire Blight Symptoms in Perennial Pear Branches

Plant Disease ◽  
2003 ◽  
Vol 87 (9) ◽  
pp. 1077-1082 ◽  
Author(s):  
D. Blachinsky ◽  
D. Shtienberg ◽  
D. Oppenheim ◽  
M. Zilberstaine ◽  
S. Levi ◽  
...  
Keyword(s):  
Fire Blight ◽  
Shoot Growth ◽  
Erwinia Amylovora ◽  
Symptom Expression ◽  
Host Phenology ◽  
Final Length ◽  
Symptom Progression ◽  
In Fire ◽  
The Relationship

The role of autumn infections in the progression of fire blight (caused by Erwinia amylovora) symptoms in perennial pear branches was studied in orchard-grown trees in Israel. The extent of symptom progression and the final length of fire blight cankers in perennial branches were variably affected by the vigor of the trees and the season of infection. Following spring infections, when all trees supported active shoot growth, fire blight symptoms progressed more rapidly and to longer distances in trees that exhibited high vigor (i.e., with numerous annual shoots on most terminal branches) than in low-vigor trees (i.e., few or no annual shoots on terminal branches). Irrespective of the vigor of the trees, the progression of fire blight symptoms in perennial branches ceased between mid-May and mid-July, and only a small proportion (0 to 14.2%) of the infections had invaded main limbs or trunks of trees. Progression of fire blight symptoms following autumn infections was related to the preceding summer (August to No-vember) shoot regrowth: in trees in which the shoots did not restore their growth in the summer, the rate of symptom progression in perennial branches was higher in trees with a low vigor than in those with a high vigor, whereas for those with summer regrowth the relationship between rates of symptom expression was reversed. Irrespective of the vigor group and of whether there was summer regrowth, symptoms in perennial branches continued to progress through the winter until the following spring. Most of the autumn infections (50 to 78.5%) that developed in susceptible trees had invaded main limbs or trunks of trees. The results of this study indicate that factors related to host phenology and physiology, rather than factors related to environmental influences (such as temperature), govern the extent, rate, and duration of fire blight progression in perennial pear branches. Furthermore, it turned out that autumn infections play a substantial role in fire blight epidemiology in Israel.

The Relationship of Pleural Pressure to Symptom Development During Therapeutic Thoracentesis

CHEST Journal ◽  
2006 ◽  
Vol 129 (6) ◽  
pp. 1556-1560 ◽  
Author(s):  
David Feller-Kopman ◽  
Allan Walkey ◽  
David Berkowitz ◽  
Armin Ernst
Keyword(s):  
Pleural Pressure ◽  
Symptom Development ◽  
Relationship Of ◽  
The Relationship

The relationship of the scleractinian corals to the rugose corals

Paleobiology ◽  
1980 ◽  
Vol 6 (02) ◽  
pp. 146-160 ◽  
Author(s):  
William A. Oliver
Keyword(s):  
Critical Points ◽  
Scleractinian Corals ◽  
Convincing Evidence ◽  
Early Triassic ◽  
Rugose Corals ◽  
History Of ◽  
The Subject ◽  
Relationship Of ◽  
The Relationship ◽  
Biologic Factors

The Mesozoic-Cenozoic coral Order Scleractinia has been suggested to have originated or evolved (1) by direct descent from the Paleozoic Order Rugosa or (2) by the development of a skeleton in members of one of the anemone groups that probably have existed throughout Phanerozoic time. In spite of much work on the subject, advocates of the direct descent hypothesis have failed to find convincing evidence of this relationship. Critical points are:(1) Rugosan septal insertion is serial; Scleractinian insertion is cyclic; no intermediate stages have been demonstrated. Apparent intermediates are Scleractinia having bilateral cyclic insertion or teratological Rugosa.(2) There is convincing evidence that the skeletons of many Rugosa were calcitic and none are known to be or to have been aragonitic. In contrast, the skeletons of all living Scleractinia are aragonitic and there is evidence that fossil Scleractinia were aragonitic also. The mineralogic difference is almost certainly due to intrinsic biologic factors.(3) No early Triassic corals of either group are known. This fact is not compelling (by itself) but is important in connection with points 1 and 2, because, given direct descent, both changes took place during this only stage in the history of the two groups in which there are no known corals.

Skeletal elements of crinoid echinoderms: High-resolution structural and microanalytical results

1983 ◽  
Vol 41 ◽  
pp. 194-195
Author(s):  
D. F. Blake ◽  
L. F. Allard ◽  
D. R. Peacor
Keyword(s):  
High Resolution ◽  
Marine Invertebrates ◽  
Sea Urchins ◽  
Structural Features ◽  
Sea Stars ◽  
High Resolution Tem ◽  
Relationship Of ◽  
The Relationship ◽  
Insight Into

Echinodermata is a phylum of marine invertebrates which has been extant since Cambrian time (c.a. 500 m.y. before the present). Modern examples of echinoderms include sea urchins, sea stars, and sea lilies (crinoids). The endoskeletons of echinoderms are composed of plates or ossicles (Fig. 1) which are with few exceptions, porous, single crystals of high-magnesian calcite. Despite their single crystal nature, fracture surfaces do not exhibit the near-perfect {10.4} cleavage characteristic of inorganic calcite. This paradoxical mix of biogenic and inorganic features has prompted much recent work on echinoderm skeletal crystallography. Furthermore, fossil echinoderm hard parts comprise a volumetrically significant portion of some marine limestones sequences. The ultrastructural and microchemical characterization of modern skeletal material should lend insight into: 1). The nature of the biogenic processes involved, for example, the relationship of Mg heterogeneity to morphological and structural features in modern echinoderm material, and 2). The nature of the diagenetic changes undergone by their ancient, fossilized counterparts. In this study, high resolution TEM (HRTEM), high voltage TEM (HVTEM), and STEM microanalysis are used to characterize tha ultrastructural and microchemical composition of skeletal elements of the modern crinoid Neocrinus blakei.

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