不同温度对迷人杜鹃种子萌发与幼苗生长及生理特性的影响

Seed Germination,Seedling Growth and Physiological Characteristics of Rhododendron agastum under Different Temperatures

该研究利用实验室不同恒温和变温控制试验,考察了不同温度[恒温(15℃、25℃、35℃)和变温(25℃/15℃、30℃/20℃,高温12 h,低温12 h)]处理对迷人杜鹃种子萌发、幼苗形态指标和生理生化指标的影响,探讨温度对迷人杜鹃种子萌发和幼苗生长的影响机制。结果表明:(1)迷人杜鹃种子在25℃/15℃变温条件下萌发率(87.69%)和萌发指数(8.65)均最高。(2)25℃/15℃变温有利于迷人杜鹃幼苗的地径、苗高、平均根长和萌枝数的增加,以及根、茎、叶生物量的积累。(3)25℃/15℃变温处理下幼苗叶片的总叶绿素、可溶性糖和可溶性蛋白含量最高,而MDA含量、CAT活性和SOD活性较低。研究认为,迷人杜鹃种子萌发和幼苗生长的最适宜温度条件为25℃/15℃(昼/夜),而在高温(35℃)和低温(15℃)环境下均会受到显著抑制。

The effects of temperature on seed germination,seedling morphological and physiologicalbiochemical indexes were studied by different constant temperatures(15℃,25℃,35℃)and variable temperatures(25℃/15℃,30℃/20℃,high and low temperature for 12 h respectively)controlled experiments in laboratory.This paper also discussed the influencing mechanism of temperature on seed germination and seedling growth of Rhododendron agastum.The results showed that:(1)the condition of variable temperature 25℃/15℃,the seed germination rate(87.69%)and exponential value(8.65)was the highest.(2)The variable temperature 25℃/15℃is beneficial for ground diameter,seedling height,average root length and twig increase,and biomass accumulation of roots,stems and leaves of R.agastum.(3)After the seedling leaves was treated at variable temperatures 25℃/15℃,the total leaf chlorophyll,soluble sugar and soluble protein contents were the highest,while the MDA content,CAT activity and SOD activity was lower.The research showed thatthe optimum temperature for seed germination and seedling growth of R.agastum was 25℃/15℃(day/night).The growth was significantly inhibited at high temperature(35℃)and low temperature(15℃).