Studies On The Effect Of Low Temperature And Weak Light On Morphology And Physiological & Biochemical Properties Of Three-lines Hot Pepper(Capsicum Annuum L.)

Pepper is the main vegetable in the winter and spring for China. In the growth period it always suffers the diversity of low temperature and slight light in different degree. The study was carried out with the pepper of CMS system as the material, and we studied the effect of low temperature and slight light on the pepper seedling physiological and chemical traits, so as photosynthesis data. We also studied the pepper plant characteristic of anti-low temperature and slight light during the adult period using the natural low temperature and overshadow, and compared synthetically whether the ability to endure low temperature and slight light was coherent in the period of seedlings and the plant. At the same time, we studied the effect of blazing lithe after the slight light. Summarizing the relationship of the yeld system, the resume system and the crossbreed ability to anti-low temperature and slight light, so we can offer the academic gist for vegetable planting and anti-diversity breeding.1. The study on cold index of pepper CMS and the crossbreed showed: as the intimidating time increasing, the index of every material increased accordingly, but the scope was different. The index of different material was different, the index of keeping system, yeld system, the crossbreed and the resume system decreased gradually. 2. Stem diameter and plant height of the pepper seedlings increase slowly , leaves member reduce and ratio of dry weight to leaf fresh weight increase .Restorer line and the hybrid of the hot pepper had lesser symptoms in the external morphology. electrolytic leakage and MDA contents increase, the hybrid and restorer line increase slowly , restorer line were superior .Only as the increase of dealing time with the low temperature and weak light, SOD activity,POD activity and APX activity in the seedling leaves of the hot pepper increased, and then declined ; osmotic adjustment substances like Pr and soluble sugar first decreased and then increased, the content of proline showed reverse rule. During the resume stage under normal temperature, SOD and APX activity first declined and then increased; as to the activity of POD, hybrid F increased gradually, the CMS line and restorer line Showed changing trend in the shape of "V"; content of Pr declined all through; soluble sugar content first decreased and then increased; proline first increased and then decreased. Symptoms will last out long time during the resume stage under normal temperature.3. As the low temperature , weak light and time rising, the Pn and the Gs of the function leaf declined, while the Ci went up. There is great difference between the materials and dealings. When the rate of the photosynthesis dropped ,the content of CO2 between the leaf cells raised, and the decrease of the photosynthesis mainly was mainly decided by nonstomatal limitation .The Pn and Gs of the plants treated in the 15℃/10℃condition for 6 days did not recover to the formerly level, and the recovery of the plants treated in the condition of 10℃/5℃was slower. The content of chl a,chl b,chl (a+b) and chl (a/b) all declined. The decline of chl a behaved evidently, while the change of chl b was slight. We also found that the changes of chl a and b was not a simplex trend, and every index of the recover system is superior to other materials.Such indexes as Fv/Fm,ΦPSⅡ,qP,Fv′/Fm′of pepper seedlings leaves were all decreased , There is great difference between the materials and dealings. Those indexes of the grafted pepper seedlings with a better Low Temperature and weak light tolerance had lesser decreases. Those indexes have a better recovery .4. In the late autumn, the pepper was treated with overshadow, so it grew slowly or stopped growth. The outer shape changed partly and showed symptom of suffering as the temperature decreased. The chlorophyll content of different material increased differently in the initial stages, and at that time the slight light was dominant. In the later period, the content showed complicated behavior, because at that time the low temperature and slight light acted jointly. The ratio of photosynthesis descended, and as the time and intension increased, the decreasing scope of no anti-low temperature breed increased obviously. Seeing from the outer shape and the whole growth period, the suffering degree of the crossbreed and the resume system were slight, and the resume system was the excellent.In the early spring, the pepper was treated with overshadow, so the dry and green weight decreased as the intension of overshadow increased. The content of chl a, chlb and chl (a+b) of the functional leaf increased all together, and the content of different material and different dispose showed differentia. After the slight light, the photosynthesis dropped a little,and as the increase of time and intension, the scope of drop increased obviously. The daily change of photosynthesis turned to single apex from double apex, and the value debased. So and the value of Fv/Fm,ΦPSⅡ,qP,Fv′/Fm′. Under the slight light, the content of VC, soluble sugar in the fruit increased, but the content of water decreased. Modest overshadow can make the fruit characteristic increased certainly.5. Only as the increase of coercer intensity and time with the low temperature and weak light, POD activity improves in the seedling leaves of the hot pepper, but CAT activity declines, MDA content and proline content increase; SOD activity is different because of dealing with differently. Resume stage in high light, the CAT activity, SOD activity and POD activity of sterile-system display downward trend; MDA content,proline content and POD active increase . After 4 days in such a high light, SOD activity and CAT activity recover to a certain degree. Resume stage in high light, the effect on plant of extreme low temperature is more prominent than 10℃/ 10℃to be, high light bring some harm .6. The study of outer shape, growth data, leaf physiological index and photosynthesis parameter contacted the ability of anti-slow temperature and slight light. So we can conclude that the resume system was superior, the crossbreed took second place, then was the yeld, and the keeping system took the last seat. We deduced that in the CMS, the resume system and the crossbreed had close relationship, and the resume system can be chosen as father plant in the breeding.