Blooming and Fruiting Habits,Microspore Genesis and Development of Male Gametes of Trigonobalanus doichangensis

Trigonobalanus doichangensis may flower when its height is about 4 meters,and the starting date of blooming is slightly different among populations or population’s micro-climatic habitants.In general,the plants in the higher altitude and further north latitude may have an earlier starting date of blooming.But the duration of blooming and fruiting is mostly from October until next May,and this phonological character is obviously different in comparing with that of other fagaceous species within the same populations.Observations on the microspore genesis and the development of male gametes in T.doichangensis revealed that the anther is 4-sporangiate and its anther wall formation conforms to the dicotyledonous type.And also the tapetum is of the glandular type and its most cells are 2-nucleate,and cytokinesis at meiosis of microspore mother cells is simultaneous and tetrads are tetrahedral,occasionally decussate.Besides,mature pollen grains are 2-celled.Therefore,it can be concluded that microspore genesis and development of male gametes in T.doichangensis are normal,and they are not the factors caused the lower rate of fructification.