Submitted to: Arabidopsis Research International Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 7/25/1995
Publication Date: N/A
Technical Abstract: To identify different responses to tobacco ringspot virus (TRSV), 97 Arabidopis ecotypes were inoculated with TRSV and examined visually for symptoms and by ELISA to measure virus accumulation. All of the Arabidopsis ecotypes screened were susceptible to TRSV and displayed a range of symptoms. Plants from the most sensitive ecotypes died ten days after inoculation while those from the most tolerant ecotypes did not show any visible symptoms. Four ecotypes were selected for further study based on their differential reaction to TRSV. Infected plants of ecotypes Col-0 and Col-0 gll flowered and produced seed like non-infected plants, while those of ecotypes Estland and H55 both died before producing seeds. Seeds were collected from infected plants and germinated to determine the seed transmission rate by visual symptom evaluation and by ELISA. Only 5 plants (3%) out of 160 Col-0 plants accumulated virus as detected by ELISA. While a seed transmission rate of 80-90% was observed from infected F1 plants from reciprocal crosses between ecotypes H55 and Col-0. Serological studies indicated that in all four ecotypes the virus accumulated at essentially the same rate and to the same levels. F1 populations from reciprocal crosses of ecotypes Estland and Col-0, and ecotypes Col-0 g11 and H55 indicated that the tolerance gene was controlled by the nuclear genome. A segregation ratio of 1 tolerant:2 intermediate:1 sensitive was observed in F2 plants from both crosses indicating that tolerance to TRSV was controlled by a single locus and the tolerance gene was incompletely dominant with the sensitive gene.