Abstract:

The effects of liquid culture medium composition, temperature, pH value on Populus simonii×P.nigra pollen germination were investigated with in vitro culture. The results were as follows: First, sucrose,H₃BO₃ and CaCl₂ could promote pollen germination and tube growth within a certain concentration range in single factorial experiments, but they would inhibit germination beyond the concentration range. Similar responses also held for temperature and pH value. Second, the effects of sucrose, H₃BO₃, CaCl₂, temperature and pH value were extremely remarkable in orthogonal design experiment. The optimal culture medium was 150 g · L^-1 sucrose + 20 mg ·L^-1 H₃BO₃ + 40 mg ·L^-1 CaCl₂, and in the medium the rate of pollen germination was up to 46.23%under the conditions of 21 ℃ and pH 6.0, with healthy pollen tube. Third, cytological observations exhibited P. simonii×P. nigra mature pollen was a bicellular pollen and pollen germination rate gradually increased and tube was growing with culture time.

Key words: Populus simonii×, P. nigra, pollen, in vitro germination, liquid culture medium, germination rate