吉首蒲儿根的繁育系统及克隆构型  

Breeding System and Clonal Architecture of Sinosenecio jishouensis

作　　者：张洁[1,2] 陈功锡[1] 徐亮[1] 邓涛[3] 周建军[2] 张代贵[1,2] 孟明明[2] 

机构地区：[1]吉首大学/植物资源保护与利用湖南省高校重点实验室,湖南吉首416000 [2]吉首大学生物资源与环境科学学院,湖南吉首416000 [3]中国科学院昆明植物研究所东亚植物多样性与生物地理学重点实验室,昆明650201

出　　处：《西北植物学报》2015年第5期948-956,共9页Acta Botanica Boreali-Occidentalia Sinica

基　　金：国家自然科学基金(30770157);湖南省重点学科建设项目(JSU0713Z21)

摘　　要：吉首蒲儿根是分布于武陵山区的稀有植物,通过观察其花部特征和开花进程,检测花粉活力、柱头可授性以及套袋实验对其繁育系统进行了研究,并根据地下根茎构筑型、形态特征和地下根茎间的夹角分析了其克隆构型。结果显示：（1）吉首蒲儿根种群花期一般为45-50d,有不明显的二次开花现象,单株花期为10-22d,单个头状花序花期约为3-5d;散粉时柱头高于花药筒,形成花冠、药筒、柱头三者在空间上的分离。（2）吉首蒲儿根的杂交指数为5,P/O值为3 188,繁育类型属于专性异交,异花授粉为主,部分自交亲和,需要传粉者。（3）吉首蒲儿根地上平均含有3.61个分株和4.74个根茎数,根茎间的分枝角度以30°为主,地下根茎构筑型归属于密集型,根状茎断裂是由于组织破碎引起的。研究认为,为适应特殊的峡谷生境,吉首蒲儿根形成了独特的适应策略,先以克隆繁殖来占据生境中的有利地位,后通过＂集中开花模式＂、雌雄异熟、产生大量花粉等方式来提高异交率,以获得高质量的种子来拓展生境。Sinosenecio jishouensis D.G.Zhang,Y.Liu Q.E.Yang is a Critically Endangered（CR）species which is only distributed in Wuling Mountain areas.The breeding system of S.jishouensis was researched by observing floral morphology and dynamic,testing pollen viability and stigma receptivity,and bagging experiments.Clonal architecture was studied by field investigation and laboratory analysis：architectural form of rhizomes,configuration characteristics of rhizomes,and branching angle between rhizomes.The result shows that：（1）the flowering period of the S.jishouensis population lasted about 45-50 days and with inconspicuous second blooming.The life span of individual plant was usually about 10-22 days.For a single capitulum,it could last 3-5days.The stigma was obviously higher than the canister when pollen dissemination.As a result,there is a spatial isolation of corolla,anther canister and stigma with in the same floret.（2）The out-crossing index and pollen-ovule ratio of S.jishouensis were 5and 3 188,respectively.The breeding system is obligate xenogamy,predominant in cross-pollination and fruit setting is depended on pollinators of this species.（3）The ramets and rhizomes per clone of S.jishouensis averaged 3.61 and 4.74,respectively.Branching angle between rhizomes usually was 30°.The architectural form rhizomes of its spe-cies belongs to phalanx system for the branch distance of rhizomes is short,and the rhizome rupture is the result of the tissue piecing.Unique adaptive strategy had been formed for adapting to the special habitat.S.jishouensis used clonal reproduction to occupy habitats at first,and then took various measures to enhance cross-pollination rate for producing high-quality of seeds,such as mass-flowering,dichogamy,generating a large number of pollens etc.

关 键 词：吉首蒲儿根 繁育系统 克隆构型 特殊生境 适应 

分 类 号：Q944.4[生物学—植物学] Q944.2