Research On Tolerance Of Low-temperature And Poor Light In Pepper

Abstract:By using different pepper cultivars as the research materials, the influences of low temperature on seed germination, low temperature and poor light on pepper seedlings and the effect of shading on pepper growth and yield in adult-plant stage have been studied。The results show as follows:1. The germination potential and germination index of Pepper seed decreased with the decreasing temperature,the relative germination potential and relative germination index under18℃, relative germination percentage under14℃could be used as the identification indexes of low temperature resistance,18℃could be used to identify the chilling tolerance of different varieties. The results also showed that the early-maturing had stronger ability of low temperature resistance compared with the other two varieties, and the resistance of mid-late maturity varieties are weaker; the low temperature resistance of var. acuminatum Fingern was better than other fruit type cultivars, var.grossum Sent was weaker.2. With low temperature and poor light treatment for15days, the height increment of Sujiao5and Xingshu215were lower than control. Stem diameter, dry weight and fresh weight of Sujiao5and Xingshu215were negative growth under15℃/5℃(day/night) and80μmol·m-2·s-1light treatment for5days. The leaf area growths of Sujiao5and Xingshu215are much higher than control in the same period, after15days the dry weight growth of these two varieties seedlings were significantly higher than control. When the temperature of the poor light environment was below18℃, the chlorophyll content of Sujiao5and Xingshu215decreased, but the chlorophyll contents were higher than control under suboptimal temperature and light intensity (20℃/10℃,80μmol·m-2·S-1) treatment for15days.It indicated that the influence of temperature on the chlorophyll content were greater than the weak light with the time going on.3. Analyzed the ten character indexes of different pepper varieties seedlings with factor analysis, subject function and weighted average method, the results indicated that the resistance to low temperature and poor light of Nanjing zaojiao was the best and the varieties of37-74was the weakest. The comprehensive evaluation value (D) of materials which had best resistant to low temperature and poor light was from0.742to0.765, the value (D) of materials which had stronger resistant to low temperature and poor light were in the range of0.470-0.613, and the value (D) of materials with weaker resistant were in the range of0.302-0.415, the value (D) of material with weakest resistant was less than0.302.4. The chlorophyll content, fruit number per plant and yield of shading treatments were significantly lower than control, but the leaf area was significantly larger than control. Under the shading treatments, more than85%of pepper varieties’plant height and crown diameter were greater than comparison,90%of pepper varieties’per fruit weight were lower than control. The plant height, pitch number, main stem height, crown diameter had significant negative correlation relationship with the yield of peppers, and per fruit weight was very significantly positive correlated with the yield of pepper.