Pollen development and floral morphology of Populus pseudo-simonii

Abstract

Pollen development and floral morphology of Populus pseudo-simonii were investigated by stain-squashing and anatomical techniques. It took approximately 16 days for the pollen to develop from pollen mother cells to mature pollen in the greenhouse. Meiosis of pollen mother cells was regularly applied and completed by a process of simultaneous cytokinesis. Pollen development was considerably asynchronous. The meiotic division was initiated at the bulgy middle position of the flower bud and proceeded towards the tip and base of the bud. The number and size of the nucleoli varied during pollen development and at most eight nucleoli formed in each daughter nucleus at the meiotic telophase, suggesting a paleopolyploid origin of the genus Populus. An association between floral morphology and pollen development was found and the ratio of width to length of flower buds or catkins presented an S-shaped curve related to pollen development as a function of time. The investigation on the pollen development and floral morphology of P. pseudo-simonii is important for further cross breeding programs of the section Tacamahaca.

High temperature-induced production of unreduced pollen and its cytological effects in Populus

“…37 ). In the high temperature-treated samples, however, there were many abnormalities that occurred in meiosis.…”

“…In the control samples, the microsporocytes underwent normal meiosis (see Wang et al . 37 ). In the high temperature-treated samples, however, there were many abnormalities that occurred in meiosis.…”

“…37 . Briefly, the pollen samples were hydrated for 1 h and fixed with 4% paraformaldehyde for 45 min.…”

“…As previously described by Wang et al . 37 , the floral morphology and the colour of anthers were used for preliminary determination of pollen development. The meiotic stage of microsporocytes was observed using the 1% acetocarmine squash method.…”

“…Mature pollen samples were stained to observe the vegetative and generative nuclei as described by Wang et al . 37 . Briefly, the pollen samples were hydrated for 1 h and fixed with 4% paraformaldehyde for 45 min.…”