甜瓜種子之鹽預措對其發芽及幼苗耐鹽性之影響

The Effect of Salt Pretreatment of Seeds on their Salt Tolerance in Germination and Seedling Growth in Melon (Cucumis melo)

蜜華’與‘新世紀’甜瓜（Cucumis melo L.）種子，無預措（對照）或以18 dS．m^-1之鹽（NaCl）溶液或以海洋深層水預措72h後播種，每二天澆灌自來水（0.2 dS．m^-1）或9或13.5 dS．m^-1之鹽溶液10-15mL，然後調查種子發芽與幼苗生長情形。澆灌液之鹽濃度增加，則種子發芽率與存活率顯著降低，發芽時間增長，幼苗之鮮重、乾重、葉綠素與蛋白質含量降低，而可溶性碳水化合物與脯胺酸含量增加。但甜瓜種子經18 dS．m^-1之鹽溶液或海洋深層水預措處理後播種者，可提高在澆灌鹽溶液狀況下之發芽率，顯著縮短發芽所需時間1.7-4.7天，並增加幼苗之鮮重與乾重。鹽溶液預措對提高在鹽溶液澆灌下之種子發芽率及縮短發芽所需時間之效果，優於海洋深層水預措；而且此種差異對‘蜜華’品種特別明顯。 Seeds of 'New Century' and 'Sweetie' melon (Cucumis melo L.) were either untreated (as control) or pretreated with deep-sea water or with NaCl solution of 18 dS.m^-1 for 72 h at 20℃ before sowing. Irrigation water containing NaCl at EC value of 0.2 (control), 9, or 13.5 dS.m^-1 was applied once every 2 days; and the results of seed germination and seedling growth were investigated for 28 days. As the EC value of irrigation water increased, the seed germination rate as well as the survival percentage, fresh and dry weights, and contents of chlorophyll and protein of the seedlings declined while the time to germinate and the proline and soluble carbohydrate contents in seedlings increased. Salt pretreatment of seeds enhanced the salt tolerance of the seeds in germination and seedling growth in both cultivars. The salt pretreated seeds germinated 1.7-4.7 days earlier, had higher germination rate, and yielded seedlings with higher fresh and dry weights than untreated seeds when both were germinated under the condition of receiving high salt irrigation water. Salt (NaCl) solution pretreatment was more effective than deep-sea water pretreatment in raising germination rate and shortening the time to germinate under salt water irrigation, especially in 'Sweetie' cultivar.