環境因子影響萵苣種子發芽之檢討

A Review on the Influence of Environmental Factors on Lettuce Seed Germination

水分能影響萵苣種子的發芽率及發芽勢，也影響種子對光線之敏感性。氧氣為萵苣種子發芽所必需，無空氣時會引起種子休眠。萵苣種子在溫度0℃至25℃均可發芽，唯溫度低發芽愈慢，但低溫能打破種子休眠，並能代替光線促進種子發芽；高溫時引起種子休眠或促進種子對光線發生敏感，對光線之敏感性依品種而巽；係由Phytochrome色素所控制；溫度、水分、氣體、及化學物質均能影響或代替光線對種子發芽產生之作用。抑制物質或促進物質均能影響萵苣種子之發芽。

1. The moisture supplied to lettuce seed may affect both the germination percentage and germination rate Imbibition of water is also an improtant factor influencing germination of light-sensitive seeds. 2. Oxygen is necessary for lettuce seed germination. Anaerobic condition will induce dormancy. 3. Lettuce seeds wilt germinate at a temperature range of 0℃ to 25℃ The lower the temperature, the slower germination rate Low temperature can break lettuce seed dormancy or replace the light requirement for germination. High temperature on the other hand, can induce dormancy or light requirement for germination. 4. Some varieties of lettuce seeds require to promote germination, but some do not. Temperature, far-red, moisture, gas, and chemicals can affect or replace the light requirement for germination in spite of whether it is related to phytochrome or not. 5. There are some inhibitors and promoters which have been tested for lettuce seed germination.