ISHS Acta Horticulturae 808: II International Symposium on Tomato Diseases
SCREENING TOMATO VARIETIES FOR THEIR BACTERIAL WILT RESISTANCE OVER SEASONS IN NORTHEAST THAILAND |
| Authors: | S. Techawongstien, P. Thummabenjapone, H. Bolkan |
| Keywords: | Ralstonia solanacearum, combined analysis, bacterial wilt resistant tomato |
| Abstract:
To identify resistance germplasm and test the stability of resistance to bacterial wilt disease of tomatoes caused by Ralstonia solanacearum, two experiments were conducted at the experimental field of Khon Kaen University, Thailand. The trials were conducted in the rainy season (May-September, 2005), and during the cool season (October, 2005-Febuary, 2006). Randomized complete block design was used in each trial. Tomato plants were screened in concrete blocks inoculated with high level of bacterial inoculums (107-108 cfu of R. solanacearum mixed- populations per 1 g of soil). The level of disease severity was recorded by following the AVRDC (1990) protocol, and yield performances of each tomato line were statistically analyzed. Ten lines of tomato received from Campbell Research and Development, Davis, California, USA and 10 lines from Khon Kaen University were screened in the rainy season trial. The varieties HW7996 (resistant) and VF134-1-2 (susceptible) were used as controls. Four tomato lines, A2-10-3-1, A4-7-1-1-5, X12207B-5, and X12207B-4-2 with resistant or moderated resistant to bacterial wilt (<30% of wilt intensity); and 10 lines from Campbell Research and Development were selected and screened in the second trial during the cool season. The results showed that three tomato lines, A4-7-1-1-5, THBW104, and THBW109 carried high levels of bacterial wilt resistances (20 % of wilt intensity) and good fruit yield performances (>1200 g/plant). Using over seasons combined analysis of 6 tested tomato varieties; the similarity trends of bacterial wilt resistance and yield performance were obtained. A4-7-1-1-5 line showed the best stability, followed by X12207B-5, X12207B-4-2, and A2-10-3-1 for bacterial wilt resistance and good yield performances. Therefore, A4-7-1-1-5, THBW104 and THBW109 should be considered good materials in a breeding program for bacterial wilt resistance development. | |
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