Identification and genetic characterization of tobacco accessions possessing resistance to tobacco cyst nematode

Developing a flue-cured tobacco cultivar with high resistance to tobacco cyst nematode (TCN) is an important initiative in the Southern Piedmont of Virginia, where this pathogen causes severe yield losses. One hundred twenty eight lines representing a diverse geographic array of tobacco accessions, including cultivars from several types of tobacco, flue-cured-type tobacco introductions, and wild Nicotiana species were evaluated for TCN resistance under greenhouse conditions. Inheritance of TCN resistance has been reported to be closely linked or pleiotropic to inheritance of wildfire resistance. Consequently, accessions were also screened for wildfire resistance under greenhouse conditions to evaluate this relationship among a diverse group of tobacco accessions. Twenty-one accessions were identified with resistance to TCN. Response to the two pathogens was highly correlated. However, there was no relationship between resistance to the two pathogens for several accessions. 'KY 190', a fire-cured cultivar, possessed the N. longiflora source of wildfire resistance, but was found susceptible to TCN. This result seems to rule out pleiotropy and is consistent with the assertion that the two resistance genes are closely linked. six TCN resistant lines and two susceptible lines were selected and a diallel study was conducted to determine the inheritance of resistance to TCN. Additive gene action contributed significantly to inheritance of TCN resistance. Three accessions, 'Burley 64', 'Kutsaga 110', and 'Tl 1597', were determined to be the most promising parents for use in a breeding program designed to develop a flue-cured cultivar with a high level of TCN resistance.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Crop and Soil Environmental Sciences

Department dc:contributor.department

Crop and Soil Environmental Sciences

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

1995

Author dc:creator

• Hayes, Alec J.

Chair dc:contributor.committeechair

• Wilkinson, Carol A.

Committee members dc:contributor.committeemember

• Johnson, Charles S.
• Eisenback, Jonathan D.
• Buss, Glenn R.

• Globodera tabacum solanacearum
• Pseudomonas syringae tabaci
• host resistance
• diallel studies

Statement dc:rights

• In Copyright

Licence dc:rights.uri

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

Language dc:language.iso

en

Dc Identifier Other

etd-06102009-063409

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/43010