• Development of Long-Term Protective Technology for Vegetable Crop Seed Treatment

    Bacterial fruit blotch (BFB) of cucurbits is a significant global disease affecting cucurbitaceous crops. The pathogen of BFB, Acidovorax citrulli (Acit), can spread through rainwater, irrigation water, and seeds/seedlings. Applying antibiotics is one of the main methods for controlling BFB in cucurbits. This project tested the optimal conditions for seed treatment by using four coating agents of methylcellulose, sodium alginate, xanthan gum and gum arabic combined with five chemical bactericides of streptomycin, validamycin A, oxolinic acid, kasugamycin and Tiviant (fosetyl-aluminium + isotianil). The results showed that kasugamycin treatments at 10X, 20X, and 50X levels exhibited the best antibacterial activity, but kasugamycin negatively delayed cucurbit seed germination and reduced germination rate. While oxolinic acid treatments at 10X, 20X, and 50X levels and streptomycin treatments at 20X and 50X levels showed slightly less antibacterial activity than kasugamycin, they had no negative impact on the final germination rate of cucurbit seeds.

• Development of Seed Treatment Technology for High Temperature Adaptation and Long-Term Storage

    For seeds with good intrinsic germination capacity, at optimal temperatures (20℃, 25℃), the germination potential is already fully realized, and additional osmotic priming treatments do not provide significant benefits. The only exception is the 'Red Sun' variety, which has a naturally lower germination capacity, where seed priming still showed an enhancing effect on the germination rate. At 30℃, H₂0₂ priming treatment effectively promotes the germination rate of the 'Golden Jumbo' and 'Red Sun' onion varieties, while 10 mM Betaine treatment simultaneously enhances the germination rate of the '706' variety. The '708' variety, on the other hand, exhibits inherently higher temperature tolerance at 30℃.Under the high-temperature stress of 35℃, germination is inhibited across all onion varieties, and the '708' variety shows particularly high sensitivity to 35℃. However, 20 mM Betaine treatment can simultaneously boost the germination rates of the '706' and '708' varieties, though it is unable to fully counteract the inhibition caused by the high-temperature stress. Storage trial results indicate that H₂0₂ priming does not compromise the post-storage germination rate within a six-month period. The effects of Betaine treatments on storage have not yet been experimentally verified this year and require future testing.

▲Figure 1. Daily germination of cucumber seeds treated with methylcellulose and different fungicides.

▲Figure 2. A three-factor variable analysis of the effects of conditioning treatment (unconditioned CK, conditioned CK with H2O, H2O2, and spermidine), different germination temperatures (20, 25, 30, and 35°C), and different storage times (0, 3, and 6 months) on the Golden Diamond onion variety.