<abstract xmlns="http://www.w3.org/1999/xhtml">

<p>Most commercial flue-cured tobacco cultivars contain the <italic>Rk1</italic> resistance gene, which provides resistance to races 1 and 3 of <italic>Meloidogyne incognita</italic> and race 1 of <italic>M. arenaria</italic>. A number of cultivars now possess a second root-knot resistance gene, <italic>Rk2</italic>. High soil temperatures have been associated with a breakdown of root-knot resistance genes in a number of crops. Three greenhouse trials were performed from 2014 to 2015 investigate the effect of high soil temperature on the efficacy of <italic>Rk1</italic> and/or <italic>Rk2</italic> genes in reducing parasitism by a population of <italic>M. incognita</italic> race 3. Trials were arranged in randomized complete block design in open-top growth chambers set at 25°, 30°, and 35°C. Plants were inoculated with 3,000 eggs and data were collected 35 days post-inoculation. Galling, numbers of egg masses and eggs, and reproductive index were compared across cultivar entries. Nematode reproduction was reduced at 25°C and 30°C on entries possessing <italic>Rk1</italic> and <italic>Rk1Rk2</italic> compared to the susceptible entry and the entry possessing only <italic>Rk2</italic>. However, there were often no significant differences in reproduction at 35°C between entries with <italic>Rk1</italic> and/or <italic>Rk2</italic> compared to the susceptible control, indicating an increase of root-knot nematode parasitism on resistant entries at higher temperatures. Although seasonal differences in nematode reproduction were observed among experiments, relative differences among tobacco genotypes remained generally consistent.</p>
</abstract>

Most commercial flue-cured tobacco cultivars contain the Rk1 resistance gene, which provides resistance to races 1 and 3 of Meloidogyne incognita and race 1 of M. arenaria. A number of cultivars now possess a second root-knot resistance gene, Rk2. High soil temperatures have been associated with a breakdown of root-knot resistance genes in a number of crops. Three greenhouse trials were performed from 2014 to 2015 investigate the effect of high soil temperature on the efficacy of Rk1 and/or Rk2 genes in reducing parasitism by a population of M. incognita race 3. Trials were arranged in randomized complete block design in open-top growth chambers set at 25°, 30°, and 35°C. Plants were inoculated with 3,000 eggs and data were collected 35 days post-inoculation. Galling, numbers of egg masses and eggs, and reproductive index were compared across cultivar entries. Nematode reproduction was reduced at 25°C and 30°C on entries possessing Rk1 and Rk1Rk2 compared to the susceptible entry and the entry possessing only Rk2. However, there were often no significant differences in reproduction at 35°C between entries with Rk1 and/or Rk2 compared to the susceptible control, indicating an increase of root-knot nematode parasitism on resistant entries at higher temperatures. Although seasonal differences in nematode reproduction were observed among experiments, relative differences among tobacco genotypes remained generally consistent.

Effect of Soil Temperature on Reproduction of Root-knot Nematodes in Flue-cured Tobacco with Homozygous <italic>Rk1</italic> and/or <italic>Rk2</italic> Resistance Genes

Journal of Nematology

This work is licensed under the Creative Commons Attribution 4.0 International License.

Effect of Soil Temperature on Reproduction of Root-knot Nematodes in Flue-cured Tobacco with Homozygous  and/or  Resistance Genes

Most commercial flue-cured tobacco cultivars contain the Rk1 resistance gene, which provides resistance to races 1 and 3 of Meloidogyne incognita and race 1 of...

Effect of Soil Temperature on Reproduction of Root-knot Nematodes in Flue-cured Tobacco with Homozygous Rk1 and/or Rk2 Resistance Genes

Article Category: Research Paper

Published Online: Aug 01, 2023

Page range: -

Received: Apr 08, 2022

DOI: https://doi.org/10.2478/jofnem-2023-0032

Keywords
race 3, reproductive index, plant disease loss

© 2023 Jill R. Pollok et al., published by Sciendo

This work is licensed under the Creative Commons Attribution 4.0 International License.

Effect of Soil Temperature on Reproduction of Root-knot Nematodes in Flue-cured Tobacco with Homozygous Rk1 and/or Rk2 Resistance Genes

Article Category: Research Paper

Published Online: Aug 01, 2023

Page range: -

Received: Apr 08, 2022

DOI: https://doi.org/10.2478/jofnem-2023-0032

Keywordsrace 3, reproductive index, plant disease loss

© 2023 Jill R. Pollok et al., published by Sciendo

This work is licensed under the Creative Commons Attribution 4.0 International License.

Keywords
race 3, reproductive index, plant disease loss