This year, we evaluated the appearance of 5 heat-resistant and 1 heat-intolerant tomato lines in the high-temperature period and the normal cultivation period, confirmed their heat-resistance based on the growth of flower vessels in the high temperature period, and compared the difference in vegetative growth appearance between the high-temperature period and the normal cultivation period. The results show, there were heat-resistant The mesophyll thickness, chlorophyll content and vascular bundle size of the strains were less than the two cultivation periods. There was no significant correlation between the heatresistant strains and the heat-labile strains. The number of stomata per unit area was higher in the normal cultivation stage and all were significantly higher than heat-resistant strains.

▲Fig.1. Floral fertility assessment of tomato.		▲Fig.2. Trait investigation of heat resistant in tomato: the proportion of vascular bundles; number of pores.
▲Fig.3. The number of stomata per unit area of the tested varieties in spring cropping and autumn cropping in 2022