毛舞花姜花器官的发生与发育

通过扫描电镜观察了毛舞花姜(Globba barthei Gagne p.)的花序及花器官的发生与发育。3枚萼片原基首先于花顶连续发生,随后花顶的中心凹陷形成环状原基,环状原基进一步分化形成三枚花瓣—雄蕊共同原基,并在花顶的中心形成花杯。共同原基分化形成花瓣和三枚内轮雄蕊,紧接着外轮雄蕊在花杯的顶点发生。远轴的两枚内轮雄蕊延伸生长并相互融合形成了唇瓣,近轴的一枚形成了可育雄蕊;近轴的两枚外轮雄蕊发育形成了成熟花结构中的侧生退化雄蕊,而远轴的一枚缺失。近轴的两枚外轮雄蕊原基起始的同时,3枚心皮原基也在中心花杯的内侧发生而后与外轮雄蕊相间排列。对毛舞花姜花序的发生和发育的观察发现,在花序轴的头几片初级苞片中产生的是珠芽原基而非蝎尾状小花序原基,其形态特征类似于早期的蝎尾状小花序原基,由此推测珠芽很可能是蝎尾状小花序的变异。

Inflorescence and Flower Development of Globba barthei (Zingiberaceae)

Inflorescence of Globba barthei is a thyrse.Primary bracts are initiated in a spiral phyllotactic pattern on the inflorescence apex.Cincinnus primordia are initiated in the axils of primary bracts.These promordia develop secondary bracts and floral primordia.The floral primordium continues to enlarge and produce a ring primordium.Sepals are initiated sequentially from the rounded corner of the primordium.The ring primordium separates three common primordium surrounding a central cavity.The adaxial common primordium is the first to separate.This primordium divides transversely and produces petal and fertile stamen.The remaining two common primordium transversely separate and produce respectively a petal and a petaloid.As the flower developing,the cavity of the floral cup becomes triangular.The angles of this triangle are the sites of outer androecial primordium.The abaxial androecia forms slightly earlier than the two adaxial ones,and then this primordium ceases growth soon.The two posterior primordia continue growth to produce the lateral petaloid staminodes.During this stage,gynoecia initiate from the floral cup and continue to fuse and develop into style and stigma.In addition,Initiation of the bulbil primordium is observed at base of inflorescence axis during the early floral development.The bulbil primordium initiates in the axil of primary bract.The evolutionary significance of six androecia is discussed.