S14 - Session P5 - Diagnosis of bacterial wilt in tomato genetic resources using OJIP parameters

Authors: Yu Kyoung Shin *, Shiva Ram Bhandari, Jae Woo Song, Myeong-Cheoul Cho, Eun Young Yang, Yul Kyun Ahn, Indeok Hwang, Jun Gu Lee

This research was performed to select the OJIP to discriminate the bacterial wilt caused by Ralstonia solanacearum in tomato genetic resources seedlings. Forty-five tomato genetic resources (sensitive and resistant to bacterial wilt) were used in this study. At first, eighteen days old seedlings at 3-4 leaf stage grown in greenhouse were brought to the laboratory, and acclimatized under fluorescent light conditions (Philips TLD32W/865RS) at 230 +- 10 μmol/m 2 /s (PPFD) at 14/10h (day/night) for three days. The seedlings were inoculated by direct injection of the 10 mL of bacterial suspension (1 × 10 8 CFU/mL) into the root, and grown under the similar light conditions for three days. The daily temperature and humidity were maintained at 24/18 ℃ (day/night) and 60%, respectively, during the experimental period. OJIP were monitored for 0, 24, 48, 72, 96, and 120 h with 24 h-interval. Several parameters identified through OJIP analysis were decreased significantly in almost of the sensitive genetic resources with increasing inoculation time. In addition, with an increasing time after inoculation in sensitive genetic resources, symptoms of wilting appeared in almost of the genetic resources. Parameters including F0 and PIABS showed a higher decrement with the longer inoculation time than other parameters, and can be considered as suitable OJIP parameters for the diagnosis of bacterial wilt in tomato seedlings. [This study was supported by the National Institute of Horticultural & Herbal Science, Rural Development Administration, Korea (PJ01356102)].