Abstract
In order to investigate the effects of different exogenous hormones on the dormancy and germination of lettuce seeds, this paper soaks the lettuce seeds in ACC, GA, CaCl2 and SNP solutions with different concentrations, respectively, observes the quantity of lettuce seeds germinated, calculates the germination rate, and analyzes the optimum concentrations to break the period of dormancy and promote the germination of seeds to increase the germination rate of seeds. Through the observation of lettuce seeds soaked with ACC, GA, calcium chloride and SNP in different time periods, it is found that ACC, GA, calcium chloride and SNP solutions can all promote the germination of lettuce seeds. Lettuce falls within the Lactuca genus, the Asteraceae family. It likes cold climate and the suitable temperature for growth is 15-20°C. If the temperature exceeds 25°C, the high temperature in the leafy head will cause the necrosis and rot and poor growth of interior leaves (Song et al., 2013). The temperature for germination of seeds ranges between 15-20°C. If the temperature is higher than 25°C, the seed coat will not be able to absorb water, affecting the germination (Li et al., 2012). When lettuce is sowed in summer, it needs to be treated at a low temperature. After being soaked, it should be placed in the refrigerator freezer to accelerate germination and should not be sowed until the sprout turns white. Lettuce is rich in protein, sugar, vitamins, minerals and other nutrients. It is popular among consumers due to its crisp texture, fresh taste and fragrance and rich nutrition (Hu and Zhan, 2014). Few research has been conducted on the effects of exogenous hormones on the germination rate of lettuce seeds. This study takes lettuce seeds from the same source as the test material and conducts tests on the germination rate of lettuce seeds, trying to explore the effects of ACC, GA, CaCl2 and SNP solutions with different concentrations on the germination rate of lettuce seeds so as to improve the germination rate.
