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United States Department of Agriculture

Agricultural Research Service

Title: Heat Stability of Root-Knot Nematode Resistance in Bell Pepper

Authors
item Thies, Judy
item Fery, Richard

Submitted to: Pepper National Conference Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: November 5, 1998
Publication Date: N/A

Technical Abstract: Heat stability of the N gene that confers resistance to the southern root-knot nematode, Meloidogyne incognita in pepper (Capsicum annuum), was determined in growth chambers. Responses of resistant bell pepper cultivars 'Charleston Belle' and 'Carolina Wonder' (homozygous for the N gene) and their respective susceptible recurrent backcross parents, 'Keystone Resistant Giant' and 'Yolo Wonder B' to M. incognita were compared at 24 C, 28 C, and 32 C. Reproduction of M. incognita and root galling increased (P less than 0.05) for all cultivars as temperature increased. Responses of the resistant cultivars to increased temperatures were less dramatic than responses of the susceptible cultivars. Both 'Charleston Belle' and 'Carolina Wonder' exhibited a partial loss of resistance at 28 C and 32 C. Reproduction of M. incognita was minimal on the resistant cultivars at 24 C, but increased at higher temperatures. However, at 32 C reproduction of M. incognita on the resistant cultivars was only 20% that of the susceptible cultivars and root gall indices were within the range considered moderately resistant. Unlike the susceptible cultivars, the shoot dry weights of the resistant cultivars were not suppressed at 32 C. This suggests that 'Charleston Belle' and 'Carolina Wonder' are somewhat resistant to M. incognita at high soil temperatures. Although our results indicate that a partial loss of resistance to M. incognita occurred in 'Charleston Belle' and 'Carolina Wonder' under high soil temperatures, root-knot nematode resistant bell pepper cultivars may be a useful component of cropping systems designed to manage M. incognita in hot climates.

Last Modified: 7/31/2014