燃烧高温下松树球果鳞片对种子的保护

The Protection of Pine Cones Scales to Seed under Burning High Temperature

为了探讨在野火燃烧下松树球果鳞片对种子的保护作用,通过模拟野火的不同燃烧程度,设置不同燃烧处理水平:400℃+3 min、500℃+3 min、500℃+5 min、500℃+7 min、600℃+3 min、600℃+5 min、常温对照等。球果分为云南松大球果(PB表示)、云南松小球果(PS表示)、地盘松(PP表示)。结果显示:在燃烧时间3 min下,3种不同大小的球果内的种子,其萌发率、萌发势、萌发指数和萌发历时都随着燃烧温度的升高显著降低(P<0.05),而萌发时滞则是随燃烧温度升高而升高;在600℃+3 min下,云南松大球果种子仍有萌发,而云南松小球果和地盘松球果种子已无萌发;种子的萌发率随着燃烧时间的增加而下降的更为剧烈,在5 min下完全无种子萌发;10 d幼苗的生长随着燃烧温度的升高先增高后降低,生长量大小顺序为:PB>PS>PP。研究结果表明,球果鳞片对其内种子有重要的保护作用,球果越大,球果鳞片厚度越厚,球果鳞片的降温保护效果越明显,保护能力越强。

In order to explore the protective effect of pine cone scales on seeds under wildfire burning,different burning treatment levels were set by simulating the different burning levels of wildfires:400℃+3 min,500℃+3 min,500℃+5 min,500℃+7 min,600℃+3 min,600℃+5 min and normal control.Cones are divided into large cones of Pinus yunnanensis var.yunnanensis(PB indicated),small cones of P.yunnanensis var.yunnanensis(PS indicated),cones of P.yunnanensis var.pygmaea(PP indicated).The results showed that the germination percentage,germination potential,germination index and germination duration of the seeds in the three cones of different sizes under the burning time of 3 min decreased significantly with the increase of burning temperature(P<0.05);but germination Time delay increases as the combustion temperature increases.At 600℃+3 min,the seeds of large cones of P.yunnanensis var.yunnanensis still germinated,but the seeds of small cones of P.yunnanensis var.yunnanensis and cones of P.yunnanensis var.pygmaea had no germination.The seed germination rate decreased more drastically with the increase of burning time,and there was no seed germination in 5 minutes.The growth of 10 d seedlings increased first and then decreased with the increase of combustion temperature,the growth amount was:PB>PS>PP.Cone scales have an important protective effect on its inner seeds;the larger the cone,the thicker the thickness of the cone scales,the more obvious the cooling protection effect of the cone and the stronger the protection ability.