Abstract:

It was studied that the effects of low temperature stress on production traits and associated physiological characters of three cultivars of peppers (Capsicum annuum L.). The aims were to reveal the relationship between flower bud differentiation and cold tolerance of three cultivars. The experiment was conducted in three production variety of Capsicum in Guangzhou, under low temperature treatment by gradient cooling in the stage of flower bud differentiation stage. The results showed that low temperature stress could cause the first flowering node downward, the duration of flower narrowed, and the number of fruit setting of plant and the single fruit weight and single plant yield decreased. Decreasing the number of fruit setting of plant was a key factor that induced the decrease of single plant yield. The physiological index such as Chlorophyll relative content as well as the activities of SOD and POD decreased, however the relative conductivity, the Pro, the contents of MDA and soluble sugar concentration increased. The growth and development with associated physiological characters of pepper were affected seriously with low temperature treatments during flower and fruit stage. The lower temperature treated, the more serious stress showed on pepper yield during flower and fruit stage, however, different varieties of pepper responded differently to low temperature. ‘Zhongjiaosihao’ (sweet pepper) showed the most tolerant ability. Hence, ‘Honglong’ revealed most sensitive to low temperature among 3 tested varieties. Pepper didn’t stop growing even under 13℃/3℃ during flower and fruit stage, this result was different with reported references, and more detailed researches should be conducted to discover the lowest temperature pepper could tolerance in the future.