Studies On The Morphological And Physiological Indexes Of Heat Resistance In Petunia Hybrida Vilm

Petunia (Petunia hybrida Vilm.)is an important ornamental plant which is fond of being cultivated at warm place full of sunlight, unable to bear torridity, flood and frost.Aiming at industrialization and scale-up of Petunia, and providing the convicing data for the future breeding job, three screened petunia varietiesâ…¢1-4 ,â…¦2-4 and Iâ… 1-4 were chosen as experimental materials in this study, their morphological and physiological parameters were measured at florescence and seedling stage by field investigation and temperature artificial imitation method, and the mechanism of heat resistance was discussed. This research provides theoretical basis to ascertain heat resistance parameters at florescence and seedling stage.The results show as follows:1. At high temeperature, there are significant differences among the heat injury index of three varieties,â… 1-4 <â…¦2-4<â…¢1-4.â…¢1-4 is most heat-tolerant whileâ… 1-4 is not. This result accords with the field observation.2. Petunia variety with higher resistance to heat stress has more flower numbers at high temperature.3. The LRWC of Petunia variety with lower resistance to heat stress is lower than that of other petunia varities.4. Under high temperature stress, the leaf electrolytic leakage of petunia with lower resistance to heat stress is observed high.5. At high temperature, Chl content of the petunia with higher resistance to heat stress is observed high.6. Leaf MDA content of petunia with higher resistance to heat stress is observed low either at high or normal temperature. The higher the temperature is, the more remarkable the trend is.7. Leaf O2.-content of petunia with higher resistance to heat stress is observed lower than that of heat sensitive variety, either at high or normal temperature.8. Leaf pro content amplitude of petunia with higher resistance to heat stress is observed higher than that of petunia with lower resistance to heat stress. There is no significant difference among the leaf pro content of petunia varieties at florescence.9. The higher the heat resistance of petunia is, the higher the POD activity is.10. Descending rate of root vitality of petunia variety with higher resistance to heat stress is significantly lower than that of petunia with lower resistance to heat stress. 11. The result carrying out that petunia heat resistance is complicacy for multiple-factor controls, the Correlation and Correlation analysis on various physiology index is indicated.