scholarly journals Transformation of American Chestnut (Castanea dentata (Marsh.) Borkh) Using RITA® Temporary Immersion Bioreactors and We Vitro Containers

Forests ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1196
Author(s):  
Linda McGuigan ◽  
Patrícia Fernandes ◽  
Allison Oakes ◽  
Kristen Stewart ◽  
William Powell
Keyword(s):  
Liquid Medium ◽  
Phytophthora Cinnamomi ◽  
The United States ◽  
Pathogen Resistance ◽  
Cryphonectria Parasitica ◽  
Castanea Dentata ◽  
American Chestnut ◽  
Antifungal Protein ◽  
Semisolid Medium ◽  
Temporary Immersion

American chestnut (Castanea dentata (Marsh.) Borkh) was almost completely wiped out by the fungal pathogen, Cryphonectria parasitica (Murrill) M.E. Barr. Another invasive pathogen, Phytophthora cinnamomi Rands, is devastating American chestnuts in the southern region of the United States. An alternative approach for controlling these pathogens is to use genetic engineering or gene editing. We successfully transformed American chestnut with a detoxifying enzyme, oxalate oxidase, to enhance blight tolerance and more recently with the Cast_Gnk2-like gene, which encodes for an antifungal protein, to be tested for P. cinnamomi putative tolerance. Eight somatic embryo lines were transformed using three methods of selection: semisolid medium in Petri plates, liquid medium in RITA® temporary immersion bioreactors, or liquid medium in We Vitro containers. No significant differences were found between the treatments. These methods will allow for further testing of transgenes and the development of enhanced pathogen resistance in chestnut. It can serve as a model for other tree species threatened by invasive pests and pathogens.

scholarly journals Resistance toPhytophthora cinnamomiin American Chestnut (Castanea dentata) Backcross Populations that Descended from Two Chinese Chestnut (Castanea mollissima) Sources of Resistance

Plant Disease ◽  
2019 ◽  
Vol 103 (7) ◽  
pp. 1631-1641 ◽  
Author(s):  
Jared W. Westbrook ◽  
Joseph B. James ◽  
Paul H. Sisco ◽  
John Frampton ◽  
Sunny Lucas ◽  
...  
Keyword(s):  
Phytophthora Cinnamomi ◽  
Seedling Survival ◽  
Cryphonectria Parasitica ◽  
Castanea Dentata ◽  
American Chestnut ◽  
Chestnut Blight ◽  
Sources Of Resistance ◽  
Backcross Population ◽  
Chinese Chestnut ◽  
Root Health

Restoration of American chestnut (Castanea dentata) depends on combining resistance to both the chestnut blight fungus (Cryphonectria parasitica) and Phytophthora cinnamomi, which causes Phytophthora root rot, in a diverse population of C. dentata. Over a 14-year period (2004 to 2017), survival and root health of American chestnut backcross seedlings after inoculation with P. cinnamomi were compared among 28 BC3, 66 BC4, and 389 BC3F3families that descended from two BC1trees (Clapper and Graves) with different Chinese chestnut grandparents. The 5% most resistant Graves BC3F3families survived P. cinnamomi infection at rates of 75 to 100% but had mean root health scores that were intermediate between resistant Chinese chestnut and susceptible American chestnut families. Within Graves BC3F3families, seedling survival was greater than survival of Graves BC3and BC4families and was not genetically correlated with chestnut blight canker severity. Only low to intermediate resistance to P. cinnamomi was detected among backcross descendants from the Clapper tree. Results suggest that major-effect resistance alleles were inherited by descendants from the Graves tree, that intercrossing backcross trees enhances progeny resistance to P. cinnamomi, and that alleles for resistance to P. cinnamomi and C. parasitica are not linked. To combine resistance to both C. parasitica and P. cinnamomi, a diverse Graves backcross population will be screened for resistance to P. cinnamomi, survivors bred with trees selected for resistance to C. parasitica, and progeny selected for resistance to both pathogens will be intercrossed.

scholarly journals REMNANT AMERICAN CHESTNUT (CASTANEA DENTATA (MARSH.) BORKH.; FAGACEAE) IN UPLAND FORESTS OF NORTHWESTERN NEW YORK

2016 ◽  
Author(s):  
Robert G. Laport
Keyword(s):  
New York ◽  
The United States ◽  
Cryphonectria Parasitica ◽  
Castanea Dentata ◽  
American Chestnut ◽  
Hardwood Species ◽  
Forested Areas ◽  
Identification And Characterization ◽  
Historical Range

AbstractThe American chestnut (Castanea dentata [Marsh.] Borkh.; Fagaceae) was an historically important hardwood species in eastern deciduous forests of the United States and Canada prior to being nearly eradicated by chestnut blight (Cryphonectria parasitica (Murr.) Barr). Several remnant populations have been identified persisting across fragmented parts of the historical range. The identification and characterization of remnant C. dentata populations is important for breeding and conservation efforts, as they may represent potential genetic sources of local adaptation or blight resistance, but much of the historical range remains unsurveyed. Here, I report the locations, blight infection status, and reproductive status of remnant American chestnut in upland forested areas of western New York, finding several reproductive/potentially reproductive trees.

Ex situ conservation of American chestnut (Castanea dentata (Marsh.) Borkh.) and butternut (Juglans cinerea L.), a review

2000 ◽  
Vol 76 (5) ◽  
pp. 765-774 ◽  
Author(s):  
Ken McIlwrick ◽  
S. Wetzel ◽  
T. Beardmore ◽  
K. Forbes
Keyword(s):  
Genetic Information ◽  
Ex Situ Conservation ◽  
In Situ Conservation ◽  
Cryphonectria Parasitica ◽  
Castanea Dentata ◽  
American Chestnut ◽  
Ex Situ ◽  
Juglans Cinerea ◽  
Research Areas

Two tree species native to North America, American chestnut (Castanea dentata (Marsh.) Borkh.) and butternut (Juglans cinerea L.), which have experienced rapid declines in their populations due to similar stressors (disease and changes in land use), are used as examples of how these species would benefit from ex situ conservation efforts. Current and past ex situ and in situ conservation efforts for these species are discussed and the focus of this review is on two key research areas: 1) what needs to be preserved (genetic information) and 2) how to preserve these trees or germplasm. Key words: butternut, American chestnut, Cryphonectria parasitica, Sirococcus clavigignenti-juglandacearum, ex situ conservation

scholarly journals First Report of Ectomycorrhizal Fungus, Laccaria ochropurpurea, Associated with Castanea dentata (American Chestnut) Roots in a Mixed-Species Plantation

2019 ◽  
Vol 20 (3) ◽  
pp. 140-141
Author(s):  
Morgan V. Ritzi ◽  
Stephen D. Russell ◽  
M. Catherine Aime ◽  
Gordon G. McNickle
Keyword(s):  
Cryphonectria Parasitica ◽  
Ectomycorrhizal Fungus ◽  
Castanea Dentata ◽  
American Chestnut ◽  
Fungal Colonization ◽  
Root Tips ◽  
Mixed Species ◽  
Plant Host ◽  
Mutualistic Association ◽  
Direct Confirmation

American chestnut (Castanea dentata) is critically endangered by chestnut blight caused by Cryphonectria parasitica. Beneficial interactions with mutualistic ectomycorrhizae sometimes confer resistance to pathogens; however, little is known about the mycorrhizal partners of American chestnut. Basidiocarps of Laccaria ochropurpurea were observed in a 10-year-old American chestnut plantation. The identity of the species was confirmed utilizing the nuclear ribosomal internal transcribed spacer. In spring 2018, root fragments were excised from beneath three American chestnut trees in three separate plots where basidiocarps were observed. Root tips with evidence of mycorrhizal fungal colonization were pooled, extracted, and sequenced to confirm both the plant host and mycorrhizal associates. To our knowledge, this is the first direct confirmation of American chestnut roots associated with L. ochropurpurea. We suggest further studies to investigate whether this association is common, whether it confers any disease resistance, and if this mutualistic association could be employed in restoration efforts of the American chestnut.

scholarly journals Facilitation of American Chestnut (Castanea dentata) Seedling Establishment byPinus virginianain Mine Restoration

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Jenise M. Bauman ◽  
Carolyn H. Keiffer ◽  
Shiv Hiremath
Keyword(s):  
Root Colonization ◽  
Its Region ◽  
The United States ◽  
Forest Edge ◽  
Castanea Dentata ◽  
American Chestnut ◽  
Facilitative Effect ◽  
Growth And Survival ◽  
Abandoned Coal Mine ◽  
Mine Restoration

This study evaluated the influence of planting sites on the establishment and ectomycorrhizal (ECM) colonization of American chestnut (Castanea denetata(Marsh.) Borkh.) on an abandoned coal mine in an Appalachian region of the United States. Root morphotyping and sequencing of the fungal internal transcribed spacer (ITS) region were used to identify the ECM species associated with the chestnut seedlings. Germination, survival, ECM root colonization, and growth were assessed in three habitats: forest edge, center (plots without vegetation), and pine plots (a 10-year-old planting ofPinus virginiana). Seedlings in pine plots had higher survival (38%) than the other plot types (center 9% and forest edge 5%;P=0.007). Chestnuts found colonized by ECM within the pine plots were larger (P=0.02), contributed by a larger root system (P=0.03). Forest edge and pine plots had more ECM roots than seedlings in center plots (P=0.04). ITS fungal sequences and morphotypes found among chestnut and pine matchedScleroderma, Thelephora,andPisolithussuggesting these two plant species shared ECM symbionts. Results indicated that the presence ofP. virginianahad a greater facilitative effect on growth and survival of chestnut seedlings.

Evidence that Castanea Dentata Persists on Xeric, Mid-Elevation Sites in the Southern Appalachians

2017 ◽  
Vol 133 (1-2) ◽  
pp. 23-31 ◽  
Author(s):  
W. Henry Mcnab
Keyword(s):  
North Carolina ◽  
Tree Species ◽  
Phytophthora Cinnamomi ◽  
Model Performance ◽  
Root Systems ◽  
Cryphonectria Parasitica ◽  
Castanea Dentata ◽  
Northern Red Oak ◽  
Yellow Poplar ◽  
Biological Variables

Abstract:  Castanea dentata (American chestnut) persists today in the southern Appalachian forests of North Carolina as sparsely occurring sprouting root systems. The introduction of two exotic fungal diseases into North America, root rot (Phytophthora cinnamomi) in the early 1800s and chestnut blight (Cryphonectria parasitica) in the early 1900s, eliminated C. dentata as a dominant canopy species. Identifying and understanding the characteristics of sites where C. dentata persists could offer insights for management and restoration. Using a regional forest inventory and analysis (FIA) database, I studied the ecology of C. dentata on 831 forested sample plots in 21 mountainous counties of western North Carolina. The purpose of my study was to determine if the presence of C. dentata was associated with common topographic variables and the co-occurrence of other tree species that could be used in a regression model for evaluation of sites for potential management activities. I found that C. dentata occurred on only 3.5% of the sample plots. Its presence was directly associated with elevation >900 m, positively related to the co-occurring species Quercus prinus (chestnut oak) and Q. rubra (northern red oak), and negatively related to Liriodendron tulipifera (yellow-poplar). Logistic regression revealed poor performance of formulations with multiple significant biological variables (i.e., tree species) because of multicollinearity effects with elevation. Good model performance was achieved with a two-variable formulation using elevation and a weighted averages score derived from direct gradient analysis and ordination of moisture affinities of the 30 tree species in the study plots. An explanation for the effect of elevation on occurrence of C. dentata on sites >900 m is unknown, but the arborescent species scores suggest probable xeric to subxeric plot moisture regimes. Limitations of the FIA data for my study were many including few plots with C. dentata, lack of plot soil characteristics and history of disturbance from fire. Results from my study may have application to rank forest sites for investigation of biological control of C. parasitica through hypovirulence and for identifying stands for application of silvicultural practices to reduce environmental stress and increase survival of existing root systems.

scholarly journals Chestnut Breeding in the United States for Disease and Insect Resistance

Plant Disease ◽  
2012 ◽  
Vol 96 (10) ◽  
pp. 1392-1403 ◽  
Author(s):  
Sandra L. Anagnostakis
Keyword(s):  
United States ◽  
Phytophthora Cinnamomi ◽  
Single Species ◽  
The United States ◽  
Cryphonectria Parasitica ◽  
Southern United States ◽  
Native Range ◽  
European Chestnut ◽  
Cultivar Selection ◽  
Nut Production

The genus Castanea (family Fagaceae) is found in north temperate climates around the world, and is highly prized in many different cultures for its nutritious nuts and valuable timber. Selection for larger, better-tasting nuts has been ongoing in Asia and Europe for centuries. Early trade routes moved European chestnut trees (C. sativa) west of their native range (in the Caucasus mountains), and the Romans then moved them across their empire to provide support posts for grapevines, as well as for the nuts. Cultivar selection in Turkey, Italy, Spain, and Portugal has been extensive, and regional favorites developed. The many uses of the wood of American chestnut made this “all purpose” tree extremely valuable in its native range in North America. Nut production was important as a food source for rural families and many species of birds and animals. The other American species in the genus Castanea are classed as chinquapins, and may be divided into several or lumped as a single species. The small nuts from these trees and bushes serve primarily as mast for wildlife. Two serious diseases of chestnut trees changed the direction of chestnut research in the United States. Ink disease, caused by the root pathogen Phytophthora cinnamomi, was discovered to be the cause of widespread death of chestnuts and chinquapins in the southern United States, which had been observed since about 1850. This imported pathogen probably came into the southern United States before 1824. The second chestnut disaster was the introduction of chestnut blight disease, which was first found in the United States in 1904. The pathogen causing the lethal cankers is an Ascomycete now known as Cryphonectria parasitica. The longest continuing chestnut breeding program in the United States is in Connecticut.

Sign in / Sign up

Export Citation Format

Share Document