| Abstract: | Two seed lots of lettuce (Lactuca sativa L.) cv. Krolowa Majowych were primed in polyethylene glycol (PEG) 8000 at -1.25MPa for 7 days in dark at 20℃. Two fungicide treatments combined with PEG were used to control fungi: 1) Funaben T (0.1%) and Apron 35 SD (0.02%) were added to -1.25 MPa PEG solution (PEG+F); 2) After seed priming and drying,Funaben T was mixed at 5 g kg-1 and Apron 35 SD at 1 g kg-1 of seeds (PEG then F dust). PEG, PEG+F and PEG then F dust treatments reduced significantly thermodormancy and increased the seed germination at 35℃ in both lots. PEG then F dust treatment had the best effect on reducing seed thermodormancy at 35℃, and increased seed germination to 64.5% in lot 1 and 72.0% in lot 2 compared to 0 in untreated. PEG and PEG then F dust treatments have accelerated germination speed at 20 and 15℃ in both lots. There was a significant reduction in seed infestation in which the seeds were treated with PEG+F and PEG then F dust compared to untreated seeds and PEG primed seeds. PEG priming enhanced seed infestation considerably by Alternaria alternata, Penicillium spp., Rhizopus spp. and Ulocladium spp. Mycological analysis showed higher frequency of Alternaria alternata and Ulocladium spp. in untreated seeds at 20℃. Priming in combination with fungicides significantly alleviated the infestation of fungi, especially Alternaria alternata infestation. |
