100(3)_str35

 

ISSN 1392-3196 / e-ISSN 2335-8947
Zemdirbyste-Agriculture, vol. 100, No. 3 (2013), p. 277–282
DOI  10.13080/z-a.2013.100.035

Impact of the short-term mild and severe ozone treatments on the potato spindle tuber viroid-infected tomato (Lycopersicon esculentum Mill.)

Asta ABRAITIENĖ, Raselė GIRGŽDIENĖ

Abstract

This study was the first attempt to find out if the phenotypic plant response to the short-term ozone exposure might be altered by the presence of systemic viroid infection in plants. Model pathosystem used in these experiments was formed from the tomato (Lycopersicon esculentum Mill.) cv. ‘Micro-Tom’ and potato spindle tuber viroid. Viroid-infected plants were exposed to chronic, acute and extreme ozone treatments in order to find out if the elevated concentration of ozone could have any significant impact on the pathogenicity and spread of sub-viral pathogen. The results revealed that phenotypic alterations caused by the presence of viroid infection in plants were highly dependent on the dose of ozone received by plants. Only slight yellowing of the plant top leaves was detected in plants exposed to 80 ppb of ozone for 8 hours. No significant differences between viroid-inoculated and uninoculated plants were observed in the phenotypic appearance as well as in plant growth after application of this treatment suggesting that naturally occurring single short-term peaks of elevated ozone concentration could have no significant impact on viroid and host interaction. There were no significant differences observed in the degree of visible ozone injury between viroid-inoculated and uninoculated plants just after the short-term acute (400 ppb × 6 h) and extreme (300 ppb × 13 h) ozone treatments were applied. However, in the end of the growth period clearly expressed differences in plant growth, degree of defoliation and the regeneration capacity were revealed between viroid-inoculated and uninoculated plants submitted to these treatments, indicating that pathogenicity of potato spindle tuber viroid could be altered by the exposure of inoculated plants to the severe ozone stress.

Key words: pathogenicity, potato spindle tuber viroid, short-term ozone treatment.

Full text:  100_3_str35.pdf