| Pepper (Capsicum annuum L) originated in Mexico and Peruof tropical rain forest regionof Central and South American, pepper is widely popular vegetable crops. Pepper was thermophilic vegetable but unthermostable. In recent years, the"greenhouse effect"and increasing global temperatures continue to rised. Difficulty of pepper over-summering increased.Plant growth and development was severely affected. Causing resistance reduced,growth potential weakend, leading to quality decreased. The high temperature more and more becomes one of the important restrictive factors in the course of vegetables growth. The study conducted the seed germination experiment of different types of pepper varieties at hign temperature and screened varieties that presented the most different heat resistance. And then it studied the effects of high temperature stress and glutathione on heat resistance-related seedling morphology, physiological and biochemical characteristics of pepper seedling. In oder to it can explore change of physical and chemical indicators under high temperature.and heating injury prevention and control. To pepper breeding and study of heat-Resistant mechanism provides theoretical basis and references.1.High temperature treatment inhibited the germination of popper seeds after the eight vatitieties were placed at 35℃and 40℃. The germination rata germination force and germination index growth rate of the radicles were followed. 40℃was the optimal temperature for detecting heat resistance of kidney varieties by high temperature germination.Two varieties were tested by high temperature germination to have the most different heat resistance;the one with the strongest hest resistance was"B34"and the other weakest heat resistance was"B6"and medium heat resistance was"P78".2.Two heat-resistant seedlings of different pepper varieties were placed in 25℃,35℃,40℃. treatment respectively 0d,1 d,3 d,5d,7d was sampled, with the temperature and time increased, the seedlings morphological indicators of change and stress level of negative correlation. Under high temperature stress, plant height and root lengthof twovarieties are significantdifference. Comparing with the control,thermo-sensitive Cultivars more reducer than Themo-tolerant Cultivars.3. Along with the coercion temperature and coercion levels increase, heat injury index increased, water content of plant decreased, bound water /free water ratio reduced, At the same temperature conditions, heat injury index of heat-resistant varietiesig nificantly lower the thermal variety, ratio of bound water / free water lower than the heat-sensitive species. 4. High temperature treatment significantly inhibited the germination of pepper pollen Viability. Under 35℃,40℃temperature treatment.comparing with the control pollen viability of the five pepper varieties in the senate trialwas decreased. In the same temperature, using medium pollen higher than TTC. Compareing with the control, with increasing temperature, pollen viability gradually decreased. at 40℃condition pollen viability of the two species showed significant differences. It can effectively distinguished the heat-resistant of pepper varieties. In 42℃condition, viability of vitro pollen was significantly lower than the pollen viability of flower.5. In the high temperature stress, change of MDA and Proline content in was positively Correlated. MDAandProlinecontenincreased, Solubleproteinandchlorophyllcontent decreased gradually, root activity and POD activity increased at short time and then decreased in the longer stress time, These phenomena were more evident in thermo-sensitive cultivar than in themo-tolerant cultivar.6. After pepper seedlings were treated with glutathione. The pepper seedlings got heat resistances significantly enhanced. Glutathione presentend favorable effect in increasing heat resistance of pepper by its spraying at the concentration of 40mg·L -1 .
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