#gymnosperm

A fertile branch at three meters high was chosen from a 25-year-old Ginkgo biloba male tree for this investigation. The tree was examined daily to record the suitable time of mature yellow catkins (male cone), which was in April 2023. Pollen grains from the mid catkin from the nine fertile nodes beside those collected from the four Earths directions have been examined carefully by both the light and Scanning electron microscopes. Element contents have been investigated within the different pollen stages. The data obtained revealed that most of the investigated pollen pheno-characters showed highly significant differences between the catkin developmental stages and in between the different positions in each catkin stage, except within few characters. Despite the state of differences recorded within the different positions of the catkins there were highly significant differences between the different nine stages of the catkin position. This investigation showed that G. biloba trees growing in Alexandria city are adapted to the city climate and release their pollen grains gradually to ensure successful pollination. The microsporangia mature gradually; accordingly, their pollen grains are in different developmental and hydrolytic states. The obtained results proved the high adaptation processes which are shown in both the phenol-morphological states beside their mineral contents of the G. biloba pollen grains.

A fertile branch at three meters high was chosen from a 25-year-old Ginkgo biloba male tree for this investigation. The tree was examined daily to record the suitable time of mature yellow catkins (male cone), which was in April 2023. Pollen grains from the mid catkin from the nine fertile nodes beside those collected from the four Earths directions have been examined carefully by both the light and Scanning electron microscopes. Element contents have been investigated within the different pollen stages. The data obtained revealed that most of the investigated pollen pheno-characters showed highly significant differences between the catkin developmental stages and in between the different positions in each catkin stage, except within few characters. Despite the state of differences recorded within the different positions of the catkins there were highly significant differences between the different nine stages of the catkin position. This investigation showed that G. biloba trees growing in Alexandria city are adapted to the city climate and release their pollen grains gradually to ensure successful pollination. The microsporangia mature gradually; accordingly, their pollen grains are in different developmental and hydrolytic states. The obtained results proved the high adaptation processes which are shown in both the phenol-morphological states beside their mineral contents of the G. biloba pollen grains.