不同遮阴环境下木奶果幼苗生长与生理生化的响应  

Growth,physiological and biochemical response of Baccaurea ramiflora Lour.seedlings to different shading environments

作　　者：黄河腾 黄剑坚 陈杰 陈玉娟[1] 管东生[1] HUANG He-teng;HUANG Jian-jian;CHEN Jie;CHEN Yu-juan;GUAN Dong-sheng(School of Environmental Science and Engineering,Sun Yat-Sen University,Guangzhou 510275,China;Three Ridge Mountain Forest Park Management Of-fice of Zhanjiang,Zhanjiang 524012,Guangdong,China)

机构地区：[1]中山大学环境科学与工程学院,广州510275 [2]湛江市三岭山森林公园管理处,广东湛江524012

出　　处：《生态学杂志》2020年第5期1538-1547,共10页Chinese Journal of Ecology

基　　金：广东省林业科技创新项目(2018KJCX023);国家自然科学基金项目(31500521)资助。

摘　　要：木奶果是一种在幼苗期和成熟期对光适应性不同的热带乔木树种。研究不同遮阴环境下木奶果幼苗的生长及生理响应机制,以明确木奶果幼苗生长的适宜光照环境范围,对木奶果的苗木栽培及生态应用意义重大。本试验设置了5个处理,即CK(无遮阴),S3(遮光率45.3%)、S4(遮光率69.2%)、S6(遮光率80.0%)和S8(遮光率90.2%),观测停扣山和谢鞋山种源的木奶果幼苗4个月后的生长生理变化情况。结果显示:随着遮阴强度的加大,木奶果幼苗的叶面积与光合色素含量一直上升;叶绿素a/b值和过氧化氢酶(CAT)活性一直下降;丙二醛含量在S6前先呈下降趋势,而后稍有上升;株高和地径增长量先升后降,相对电导率、脯氨酸(Pro)与可溶性糖(Ss)含量则表现为先降后升。强光环境下,木奶果幼苗通过增加类胡萝卜素相对含量与CAT活性,以减缓膜脂过氧化损害;弱光环境下,木奶果幼苗通过增加叶面积与光合色素含量提高光能利用率。Pro与Ss则作为综合调节物,调节渗透压,以减轻强光与弱光带来的细胞膜胁迫压力。其中,停扣山与谢鞋山种源分别在S6与S4处理下Pro与Ss含量达最低值且株高与地径增长量达最高值。表明幼苗期的木奶果具有阴生植物的特性,强光或重度遮阴都会在一定程度上抑制其生长。停扣山种源木奶果幼苗比谢鞋山种源更耐阴,反映了其种源地长期光强环境差异的影响。Baccaurea ramiflora Lour.is a native tropical tree species with different light adaptability at seedling stage and maturity stage.Clarifying the growth,physiological and biochemical response mechanisms of B.ramiflora seedlings to different shading environments can help determine the suitable light environment for seedling growth,which is of great significance for cultivation and ecological application.Five shading treatments were set up,including CK(natural light),S3(shading rate of 45.3%),S4(shading rate of 69.2%),S6(shading rate of 80.0%)and S8(shading rate of 90.2%).Growth and physiological changes of seedlings from Tingkou Mountain and Xiexie Mountain were measured after four months of treatment.With the increases in shading,leaf area and photosynthetic pigment content of B.ramiflora seedlings increased,while chlorophyll a/b value and catalase(CAT)activity decreased.Malondialdehyde content decreased firstly when shading rate was≤S6,and then slightly increased in S8.Plant height and ground diameter firstly increased and then decreased,while electrical conductivity,proline(Pro)and soluble sugar(Ss)contents firstly decreased and then increased.Under strong light conditions,B.ramiflora seedlings eliminated membrane lipid peroxidation by increasing CAT activity and the relative content of carotenoids.Under low light conditions,seedlings increased light energy utilization by enhancing leaf area and photosynthetic pigment content.Pro and Ss,as comprehensive regulatory substances,could alleviate cell membrane stress caused by strong light and weak light by changing osmotic pressure.Pro and Ss contents of seedlings from Tingkou Mountain and Xiexie Mountain were the lowest under the treatments of S6 and S4,respectively,while the increase of plant height and ground diameter was the highest under the treatments of S6 and S4,respectively.Our results indicated that B.ramiflora at seedling stage exhibited the characteristics of shading plants.In other words,strong light or heavy shading will inhibit its growth.The seedlin

关 键 词：光照 抗逆性指标 苗木生长 光适应 种源 

分 类 号：S792.99[农业科学—林木遗传育种]