摘要
2012年通过对狭域特有植物瘤果三宝木的分布、群落、个体生长及繁殖特征进行了调查，据此分析其濒危原因，并进行了扦插试验。结果表明，瘤果三宝木分布区域十分狭窄，集中分布在海拔470—500m的元江干热河谷普漂段1km范围内；花单性，雌雄同株，雌雄比为1：2，传粉昆虫主要是蚁类和蝇类；平均坐果率23．98％，平均结籽率16．68％；观察脱落后的种子发现，未完全发育种子数（41．95％）〉霉变种子数（32．76％）〉虫蛀种子数（16．09％）〉完好种子数（9．2％），瘤果三宝木产生有效种子的比例较低。其有性繁殖能力和无性繁殖能力都较弱，实生苗比例约3．8％，以根孽为主的无性繁殖率约0．96％，具有萌枝植株的比例达96．2％，种群多样性依靠萌枝来维持。扦插试验表明，瘤果三宝木可通过扦插扩繁。对其濒危原因分析表明，生境干旱、高温和干扰程度大是造成瘤果三宝木濒危的外因；种群分布区狭窄、生态幅度小、结实少、成苗率低、种群扩展受限是导致其濒危的内在因素。
Distribution, community and individual growth, breeding characteristics of narrow domain and endan- gered plant Trigonostemon tuberculatus were investigated in 2012, and its endangered causes were analyzed. The results showed that the distribution zone of T. tuberculatus was very narrow and mainly distributed within the eleva- tion of 360 - 520 m and the scope of 1 km in Yuanjiang dry-hot valleys. Flowers unisexual, monoecious, male and female ratio was 1 to 2. Ants and flies were the main pollinators. Average fruit-set rate was 23.98 % and seed rate was 23.98 %. The observation on dropped seeds found that not fully developed seeds （41.95 % ） 〉 mildew seeds （32.76 % ） 〉 bug eatted seeds （16.09 % ） 〉 intact seeds （9.2 % ）, the proportion of effective seeds was low. Sexual and asexual reproduction abilities were both weak, the seeding rate was 3.8 % , and asexual reproduction was root sprouts with low probability of 0.96 %. The plants with sprout accounted for 96. 12 % on which the pop- ulation relied to maintain. The cutting experiment showed that T. tuberculatus can be propagated by cuttings. En- dangered reasons analysis showed that drought habitat, high temperature and high disturbance are the exterior fac- tors, while narrow population distribution, small ecological amplitude, fruit-less, low stocking percent and limited population expansion are external factor.
出处
《西部林业科学》
CAS
北大核心
2013年第5期69-74,共6页
Journal of West China Forestry Science
基金
西南林业大学科技创新资金资助(项目编号1202)
西南林业大学植物学重点学科建设项目资助
关键词
濒危植物
瘤果三宝木
种群特征
繁殖特性
致危因素
endangered plant
Trigonostemon tuberculatus
population
reproductive characteristics
endangered factor
