Effects Of Soil Water Stress On The Physiology And Biochemistry And Stomatal Parameter Of Lactvca Sativa

In this paper,'quan nian lettuce' and'hong run lettuce'were used as the experimental materials. Physiology and biochemistry and stomatal parameters of lettuce under soil water stress were studied. The main results are as follows:1 Relative water content and chlorophyll total content of leaves in the two varieties reduced significantly during stress treatment compared with that of control. Relative water content and chlorophyll total content in'hong run lettuce' decreased less than that of'quan nian lettuce'. The results showed that'hong run lettuce'had stronger drought tolerance than'quan nian lettuce'.2 Proline, soluble sugar and MDA content of leaves in the two varieties increased significantly compared with the control after treatment. Proline and MDA content of leaves in'hong run lettuce'increased less than that of'quan nian lettuce'.The results showed that'hong run lettuce'had stronger drought tolerance than'quan nian lettuce'.3 There was no significant difference in stomatal density on the upper and lower epidermis between different stress treatments and the control in'quan nian lettuce'. There was also no significant difference in stomatal density on the lower epidermis between stress treatments and the control in'hong run lettuce'.But there was significant difference in stomatal density on the upper epidermis between stress treatments and the control in'hong run lettuce'.'Hong run lettuce' stomatal density on the upper and lower epidermis was smaller than that of'quan nian lettuce'in different treatments.4 There was no significant difference in stomatal apparatus length on the upper and lower epidermis between stress treatments and the control in'quan nian lettuce'and'hong run lettuce'. The study also found that stomatal apparatus length on the upper and lower epidermis of'quan nian lettuce'leaves was larger than that of 'hong run lettuce'in the same treatment.