Study on Pollen Germination of Michelia crassipes, M.calcicolaand Their F₁ Hybrids

Pollen germination of Michelia crassipes,M.calcicola and their F₁ hybrids were observed for providing the data for new cultivars selecting from the F₁ hybrids.The results revealed that fresh pollen of both M.crassipes and M.calcicola had high germination percentage of more than 90%.Fresh pollen of the F₁ hybrids was less vigorous than their parents,and the germination percentage varied from 38% to 79%,with an average of 57.7%.Temperature of 25℃ was optimum for pollen germination of the parents and their F₁ hybrids.The higher temperature could prevent pollen tube elongation and induce the top burst of the pollen tube.The fresh pollen of the parents and most of the F₁ hybrids germinated well and had higher germination percentage in sucrose concentrations of 100 g/L and 150 g/L.Pollen stored under-20℃ for one year were more sensitive to the sucrose concentration than fresh pollen.Two-tube pollen was examined in in-vitro cultured pollen of parents and the F₁ hybrids.Safranin could effectively dye and cause a death of the pollen cultured in the liquid medium,which is helpful with statistics of pollen germination.