Artificial pollination of Metasequoia glyptostroboides?

The artificial pollination method of Metasequoia glyptostroboides is as follows: Metasequoia glyptostroboides flowers are unisexual, monoecious, male cones from green to yellow, select a single plant with strong tree body and more inflorescences, pick branched inflorescences for indoor culture, and collect pollen. Cut the flower branch into about 20 cm, cut the base into a horizontal section, tie a bundle every 20 to 30 branches, and align the base of the branch, attach a ball of defatted cotton balls soaked in nutrient solution on the branch section, which is wrapped in plastic paper (to prevent the evaporation of nutrient solution), hang the bundled inflorescences indoors, lay white glossy paper under it to receive pollen, and inject appropriate amount of nutrient solution into defatted cotton balls with syringes every 6 to 8 hours. The method of controlling indoor air temperature was adopted to adjust the development rate of inflorescence, so that the pollen time of male inflorescence was consistent with the development of external female flowers. Before pollination, a small bundle of male flowers is placed in a dry and clean plastic bag to shake, that is, a large amount of pollen is released. After the artificial pollination mother tree was selected, the development of female flowers was observed in order to select the best pollination time, and pollination was carried out when most of the female flowers opened and the germ ball spit out pollination drops. The collected pollen is mixed with 50 grams of talc powder every 5 to 10 grams, packed in silk or fine nylon cloth bags, tied to the end of the long rod, and shaken inside and outside the selected mother tree crown to achieve the purpose of pollination.