杭州石荠苧(唇形科)小坚果的散布生物学研究

报道了杭州石荠（ＭｏｓｌａｈａｎｇｃｈｏｕｅｎｓｉｓＭａｔｓｕｄａ）的种子散布机制和特点，结合其它方面的研究结果，为迁地保护提供理论依据。杭州石荠小坚果的散布机制是被动弹力散布，植株、花萼和小坚果三者联合参与，风、雨、动物触动是能量来源。初级散布距离在实验条件下，在３０～３５ｃｍ的区域小坚果最多，此后，随面积的增加而减少，密度峰值出现在１０～１５ｃｍ的区间。杭州石荠的小坚果表面具旋涡状凹陷，凹陷中有细密的突起，这种结构有一定的拒水性，下沉速率小，适于以水为载体的次级散布，也具有较强的保水抗旱能力，能够确保杭州石荠在干旱的生境中世代延续。作者认为，杭州石荠的分布特性和比较特殊的生物学和生态学特点限制了居群的扩展是其濒危的重要原因。

Nutlet dispersal of Mosla hangchouensis Matsuda (Labiatae)

Mosla hangchouensis is an endangered species with a very small distributional area To find out the possible cause of distributional limitedness, nutlet dispersal of M hangchouensis was observed in three populations: Geling of Hangzhou city, Mt Wulongshan of Jiande county and Mt Huadingshan of Tiantai county, Zhejiang Province Experiment on dispersal distance was carried out at Hangzhou Botanical Gardens, Hangzhou city, Zhejiang Passive ballistic dispersal is the primary phase of dispersion followed by hydrochory as secondary phase of dispersal The nutlets are often triggered by wind, rain drops and passing animals The dispersal distance of primary phase is very limited The area of 10～15 cm away from the parent is the most densely dispersed, and very few nutlets can disperse farther than 75 cm Secondary phase of dispersion by water is more important than the first phase for population expansion, for the nutlet morphology is adaptive to being carried by water current The hydrochorious syndromes of nutlets are the sculptured surface and dense protrusions of epidermal cells Adaptation to hydrochory was confirmed by experiment of subsidence rate of nutlets on still water surface The deeper the sculpture and denser the protrusions, the slower the nutlets subside into water Both the dispersal limitations and the ecological properties restrict the expansion of this species.