Screening tomato cultivars for high beta -carotene and bacterial wilt resistance.

摘要

To improve tomato cultivars for high beta -carotene with bacterial wilt resistance, tomato cultivars reported to have high beta -carotene and/or bacterial wilt resistance were evaluated. Thirty tomato cultivars were evaluated for high beta -carotene under open field and plastic-net house during dry season (October 2008-Febuary 2009). The level of beta -carotene and fruit yield were recorded and combined for analysis. The best cultivar code number 106 showed the highest values in both of beta -carotene ('CLN2585A' and 'Lukullus') and fruit yield under both conditions compared to the control cultivars ('Thubtimdang' and 'Thomas'). For bacterial wilt resistance screening, 32 cultivars were evaluated during dry season (October 2008-Febuary 2009), and 12 selected cultivars were evaluated during the rainy season (May-September, 2009), compared to the resistant ('Hawaii 7996') and susceptible ('VF134-1-2') cultivars. The seedlings were transplanted into infested soil in concrete blocks with artificial inoculation of mix 13 isolates of Ralstonia solanacearum. During dry season, the cultivars of code number 222, 223, 225 and 226 gave the highest fruit yield and resistant to bacterial wilt, and were similar to 'Hawaii 7996'. However, no resistant cultivars were detected under the rainy season, even though 'Hawaii 7996' showed moderate susceptibility.