Radiosensitivity of different ploidy pollen in poplar and its application

Through investigahon on germinating rate and process of unreduced diploidy Pollen and monoploid pollen in Populus tomentosa × P. alba and P. tomentosa, it was proved that there were defferent radiosensihvities to ~60Co r-ray among different ploidy Pollen, i. e. the radiosensitivity of monoploidy Pollen was two bines higher than diploidy pollen. To overcome the problems of late germination and poor compatibility of diploidy pollen during fertilization, a certain dose of radiation can be applied to shmulating the diploidy pollen germination, meanwhile to restrain of kill some monoploidy pollen based on their different radiosensitilities. Therefore the rate of germination and faster germinating process of diploidy pollen on stigmas can be increased relatively to certain extent The efficiency of radiation was proved by breeding practice. In the hybidization of (P. alba ×p.glandulosa) × (P. tomentosa × P. bolleana), 3.8% of triploid could be produced by 1470 rad treatment while no triploid is examined in the control. 12.9% of triploids were produced by the treatment of 1680 rad from the above cross.