Studies On Reproductive Biological Characteristics Of Ceratoides (Tourn.) Gagnebin

The thesis studied on the reproductive biological characteristics of Ceratoides. The contents were composed of the phonological periods, the flowering habits, the set seed characteristic, the organ flower and seed isoenzyme multiplicity, the nutritive peculiarity of seed, the ecological characteristic of seed, and the abortive mechanism of seed as well.They were from June to August, and longer, in the flowering phases of the Ceratoides. In C.arborescens and ecotype of C.arborescens, they meet each other in the flowering phase of female and male flower, others were not, and first female flower, male flower later. The flowering time of the day arrived maximum peak during 7:00~11:00.There were differences between species and ecotype in the seed set of Ceratoides. The seed set rate existed obvious differences between xenogamy and geitonogamy. In the same year, different sampling date, in the same material, different position, seed set rate existed obvious differences. In the same material, seed set rate existed obvious differences between 3 years plant and 5 years plant. Appropriate fertilizing could improve seed set rate in Ceratoides. Accumulation of N, P, K and sugar was increased during seed-filling stage in Ceratoides. But in the different nutritive composition and plant, accumulation of them was different. The correlation was very obvious between female flower, N content and seed set rate, others weren,t. It indicated that N was one of the fundamental factors in the influence factor of seed set rate. The Phytohormone was increased during seed-filling stage. Esterase isozyme, peroxidase isozyme activities were enhanced. In addition to C.ewersmannia, relative activity of esterase isozyme depended on its relative intensity and number. The others, esterase isozyme produced special isozyme except ecotype of C.arborescens, peroxidase isozyme of all didn,t, and its relative isozyme activity was only related to its relative intensity. Esterase isozyme and peroxidase isozyme of male flower was abundant. Research indicated that the reasons of abortion seed were as follows. Firstly, poor nitrogen nutrition level. Secondly, longer flowering phase. Thirdly, lower seed set rate in geitonogamy plant.