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

<p>Chemical controls for root-knot nematodes are increasingly restricted due to environmental and human health concerns. Host resistance to these nematodes is key to flue-cured tobacco production in Virginia. Resistance to <italic>Meloidogyne incognita</italic> races 1 and 3, and race 1 of <italic>M. arenaria</italic> is imparted by the gene <italic>Rk1,</italic> which is widely available in commercial flue-cured tobacco. <italic>Rk2</italic> imparts increased resistance to <italic>M. javanica</italic> when stacked with <italic>Rk1</italic> and is becoming commercially available. The efficacy of <italic>Rk2</italic> against <italic>M. arenaria</italic> race 2, which is increasingly prevalent in Virginia, is unclear. Greenhouse trials were conducted in 2017 to determine how potential resistance derived from <italic>N. repanda</italic> compares to the root-knot nematode resistance afforded by <italic>Rk1</italic> and <italic>Rk2</italic>. Trials were arranged in a completely randomized block design and included an entry with traits derived from <italic>N. repanda</italic>, a susceptible entry and entries possessing <italic>Rk1</italic> and/or <italic>Rk2</italic>. Data collected after 60 days included percent root galling, egg mass counts, and egg counts. Root galling and reproduction were significantly lower on the entry possessing traits derived from <italic>N. repanda</italic> relative to other entries, suggesting that the <italic>N. repanda</italic> species may hold a novel source of root-knot nematode resistance for commercial flue-cured tobacco cultivars.</p>
</abstract>

Chemical controls for root-knot nematodes are increasingly restricted due to environmental and human health concerns. Host resistance to these nematodes is key to flue-cured tobacco production in Virginia. Resistance to Meloidogyne incognita races 1 and 3, and race 1 of M. arenaria is imparted by the gene Rk1, which is widely available in commercial flue-cured tobacco. Rk2 imparts increased resistance to M. javanica when stacked with Rk1 and is becoming commercially available. The efficacy of Rk2 against M. arenaria race 2, which is increasingly prevalent in Virginia, is unclear. Greenhouse trials were conducted in 2017 to determine how potential resistance derived from N. repanda compares to the root-knot nematode resistance afforded by Rk1 and Rk2. Trials were arranged in a completely randomized block design and included an entry with traits derived from N. repanda, a susceptible entry and entries possessing Rk1 and/or Rk2. Data collected after 60 days included percent root galling, egg mass counts, and egg counts. Root galling and reproduction were significantly lower on the entry possessing traits derived from N. repanda relative to other entries, suggesting that the N. repanda species may hold a novel source of root-knot nematode resistance for commercial flue-cured tobacco cultivars.

<article-title xml:lang="en">Reproduction of <italic>Meloidogyne arenaria</italic> race 2 on flue-cured tobacco with putative resistance derived from <italic>Nicotiana repanda</italic>


Journal of Nematology

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

Reproduction of  race 2 on flue-cured tobacco with putative resistance derived from 


Chemical controls for root-knot nematodes are increasingly restricted due to environmental and human health concerns. Host resistance to these nematodes is key...

		Root % galling
		June-August		September-November
Genotype	Entry	Blackstone	Blacksburg	Blackstone	Blacksburg
rk1rk2	Hicks	42.5bc	42.5ab	45.0a	54.0a
Rk1rk2	K326	45.0bc	56.3ab	51.7a	21.0b
rk1Rk2	T-15-1-1	53.8abc	71.3a	36.7ab	21.0b
Rk1Rk2	CC 13	60.0ab	41.3ab	20.0ab	27.0b
Rk1Rk2	STNCB 2-28	67.5a	55.0ab	36.7ab	16.0bc
Rk1Rk2	BAG 29-15-3-32-1	40.0c	36.3b	20.0ab	15.0bc
N. repanda	81-R-617A	20.0d	37.5b	3.7b	6.2c

		June-August		September-November
Genotype	Entry	Blackstone	Blacksburg	Blackstone	Blacksburg
Egg masses per gram of root
rk1rk2	Hicks	64ab	38b	51a	21a
Rk1rk2	K326	90a	41b	45a	22a
rk1Rk2	T-15-1-1	83a	86ab	17a	15ab
Rk1Rk2	CC 13	89a	98ab	38a	9bc
Rk1Rk2	STNCB 2-28	65a	126a	24a	10bc
Rk1Rk2	BAG 29-15-3-32-1	67a	60ab	16ab	15ab
N. repanda	81-R-617A	30b	60ab	6b	5c
Eggs per gram of root
rk1rk2	Hicks	5,697ab	9,938ab	2,907a	439ab
Rk1rk2	K326	11,612a	2,728c	1,488a	596a
rk1Rk2	T-15-1-1	6,585ab	4,613c	965a	596a
Rk1Rk2	CC 13	9,071a	8,311ab	1,197a	170b
Rk1Rk2	STNCB 2-28	6,656ab	13,568a	904a	294ab
Rk1Rk2	BAG 29-15-3-32-1	5,215ab	7,354ab	946a	268ab
N. repanda	81-R-617A	3,988b	5,381abc	17b	54c
Reproductive index ^**
rk1rk2	Hicks	37.9a	3.9c	6.9a	2.1ab
Rk1rk2	K326	40.5a	2.3c	4.6a	3.0a
rk1Rk2	T-15-1-1	33.4a	6.9bc	3.8a	2.7a
Rk1Rk2	CC 13	64.0a	22.9ab	5.5a	0.9c
Rk1Rk2	STNCB 2-28	45.1a	26.7a	2.9ab	1.2bc
Rk1Rk2	BAG 29-15-3-32-1	36.3a	15.4abc	3.6a	1.1bc
N. repanda	81-R-617A	29.3a	6.3bc	0.0b	0.3d

Reproduction of Meloidogyne arenaria race 2 on flue-cured tobacco with putative resistance derived from Nicotiana repanda

Publié en ligne: 19 juil. 2021

Pages: 1 - 9

DOI: https://doi.org/10.21307/jofnem-2021-064

Mots clés
Flue-cured tobacco, Resistance, Management

© 2021 Noah Adamo et al., published by Sciendo.

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

Root galling of flue-cured tobacco entries by Meloidogyne arenaria race 2 in greenhouse pot tests in 2017*.

Egg masses and eggs per gram of root, as well as reproductive indices of Meloidogyne arenaria race 2 on flue-cured tobacco entries in greenhouse pot tests in 2017*.

Reproduction of Meloidogyne arenaria race 2 on flue-cured tobacco with putative resistance derived from Nicotiana repanda

Publié en ligne: 19 juil. 2021

Pages: 1 - 9

DOI: https://doi.org/10.21307/jofnem-2021-064

Mots clésFlue-cured tobacco, Resistance, Management

© 2021 Noah Adamo et al., published by Sciendo.

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

Root galling of flue-cured tobacco entries by Meloidogyne arenaria race 2 in greenhouse pot tests in 2017*.

Egg masses and eggs per gram of root, as well as reproductive indices of Meloidogyne arenaria race 2 on flue-cured tobacco entries in greenhouse pot tests in 2017*.

Mots clés
Flue-cured tobacco, Resistance, Management