Articles
RESISTANCE OF CAPSICUM CHINENSE LINES TO TOMATO SPOTTED WILT VIRUS ISOLATES FROM LOUISIANA, USA, AND INHERITANCE OF RESISTANCE
Article number
431_34
Pages
393 – 401
Language
Abstract
Resistance to tomato spotted wilt virus (TSWV) has been identified in three Capsicum chinense lines (PI 152225, PI 159236, and AVRDC C00943). The two PI lines were homogeneous in their reactions to TSWV that formed necrotic local lesions on inoculated leaves; however, 3–5% of the plants developed systemic necrosis.
Most plants of C00943 developed necrotic lesions, but this was followed by systemic necrosis in about 75% of the plants.
Progeny from two single plant selections of this line (C00943A and C00943B) responded to TSWV in the same way as the two PI lines.
A single atypical isolate (TSWV-LA4) from a tomato plant at Lakeland, Louisiana caused systemic mosaic in these resistance sources.
From a collection of 61 Louisiana TSWV isolates made in 1993, two additional atypical isolates (Calhoun 5 from tomato and RRTFT2 via thrips collected from Ranunculus spp.) were found that overcame the resistance in all three of the C. chinense lines.
The three atypical TSWV isolates and all other TSWV isolates recovered from Louisiana to date have reacted strongly to TSWV-L antisera in enzyme-linked immunosorbant assay (ELISA) tests.
This suggests that the atypical isolates from Louisiana are TSWV and not, as has been reported from Brazil, other tospoviruses that overcome resistance in PI 159236. Genetic studies were conducted to determine inheritance of resistance and allelism of inheritance of resistance from PI 152225 and PI 159236. Results indicate that a single dominant gene is responsible for inheritance and that the same gene for resistance occurs in both lines.
Most plants of C00943 developed necrotic lesions, but this was followed by systemic necrosis in about 75% of the plants.
Progeny from two single plant selections of this line (C00943A and C00943B) responded to TSWV in the same way as the two PI lines.
A single atypical isolate (TSWV-LA4) from a tomato plant at Lakeland, Louisiana caused systemic mosaic in these resistance sources.
From a collection of 61 Louisiana TSWV isolates made in 1993, two additional atypical isolates (Calhoun 5 from tomato and RRTFT2 via thrips collected from Ranunculus spp.) were found that overcame the resistance in all three of the C. chinense lines.
The three atypical TSWV isolates and all other TSWV isolates recovered from Louisiana to date have reacted strongly to TSWV-L antisera in enzyme-linked immunosorbant assay (ELISA) tests.
This suggests that the atypical isolates from Louisiana are TSWV and not, as has been reported from Brazil, other tospoviruses that overcome resistance in PI 159236. Genetic studies were conducted to determine inheritance of resistance and allelism of inheritance of resistance from PI 152225 and PI 159236. Results indicate that a single dominant gene is responsible for inheritance and that the same gene for resistance occurs in both lines.
Authors
L.L. Black, H.A. Hobbs, D.S. Kammerlohr
Keywords
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