Studies On The Reproductive Biology Of Musella Lasiocarpa

Musella lasiocarpa,which is a kind of perennial herbaceous and big-sized tuf, is also a developing Chinese famous flower attached to Musaceae. There is only one species in the genera and particularly distributes in China. Its habitat usually is mountain slop at the elevation of 1 500-2 500 Km in the middle and at the west of Yunnan province. In order to continue the further study on breeding new varieties, sex allocation and flower fertility,biological characteristics,mating system and embryo development were investigated. The results were summarized as follows:1. sex allocation and flower fertility: There were three kinds of flowers of a inflorescence:female flower,neutroflower and functional male flower. We called the flower of which stigma and style were functional while there was no ovule in the ovary functional male flower. Only female flowers had fecundity. Musella lasiocarpa was a species of monoecism and dichogamy.According to different standards, It was protogyny,interfloral dichogamy,incomplete dichogamy and one-cycle synchronous dichogamy. The florescence was from february to september in warm-house. The stigma and bract began to sear at the sixth day after anthesis for female flowers and fifth day for the neuter and functional male flowers.2. biological characteristics:The color of stem,bract and back of leafstalk of yellow-bract plants was green while that of red-bract plants was red. There was no differences between the pollen shape of red-bract plants and yellow-bract plants. There is no obviously differences in fruit size,seeds number of each fruit and the weight of 100 seeds between red-bract and yellow-bract plants while the differences of 10 inflorescence characters and clone reproduction were obviously. The ability of clone reproduction of yellow-bract ones was stronger than red-bract ones. For the red-bract plants, the size of ground level had significantly positive correlation to the size of inflorescence.There was no significant change of the embryo size.3. mating system:The stigma of 1-2days after anthesis,pollen of 2 days after anthesis of yellow-bract plants and 3 days after anthesis of red-bract plants should be used during the hybridization experiment. 4℃was the best way to store pollen and the storage time must be less than 10 days. There was self-compatibility and no parthenogenesis in Musella lasiocarpa. The hybridization experiment was carried out between yellow-bract and red-bract plants and the hybrid was obtained.They had certain reproduction affinity.4. embryo development:Megasporogenesis and the formation of female gametophyte :The ovule was anatropous and bitegminous,crassinucellate and tenuinucellate.The micropyle was formed by both the inner and the outer integuments.The development of the embryo sac conformed to the Polygonum type.Microsporogenesis and the formation of male gametophyte:The anther was tetrasporangiate and its wall developed conforming to the basic type.The cytokinesis of the microspore mother cell in meiosis was of the successive type.The microspore tetrads were"T",linear,isobilateral and tetrahedral shape.