Small stem assay for chestnut blight resistance in segregating half-sib and full-sib families of F2 and backcross hybrid chestnut trees

Chestnut breeders routinely screen hybrid chestnut seedling progeny for resistance to chestnut blight in an orchard setting – a process that takes five to seven years. A novel technique that allows for screening in the first and second growing season is known as a small stem assay. We screened 110 first-backcross seedlings and 98 third-backcross seedlings in a completely randomized design in 2017 (Gentner 2018). In 2018, an additional 391 F2 hybrid chestnut seedlings were screened in a randomized complete block design. All seedlings were inoculated with the chestnut blight causal organism Cryphonectria parasitica when stem diameters were greater than 4mm. The 2017 trial recorded the day on which the plant wilted, during both the 2017 and 2018 trial, canker length was measured and recorded. The 2017 trial gave insight to the rate at which different seed types wilted and the 2018 trial selected the very best of the F2s.

Grantor dc:publisher

University of Tennessee at Chattanooga

Author dc:creator

• Miller, Margaret Joyce

Contributors dc:contributor

• Craddock, J. Hill
• Shaw, Joey; Barbosa, Jose
• College of Arts and Sciences

• American chestnut
• Chinese chestnut
• Plant bioassay
• Trees -- Breeding

Licence

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language

English, eng

Repository record dc:identifier

https://scholar.utc.edu/theses/663

OAI identifier oai:identifier

oai:scholar.utc.edu:theses-1824