采用离体培养结合荧光定位技术对油松花粉管生长特征和微丝骨架分布规律进行研究。结果表明:油松花粉离体萌发过程,除大量呈单一花粉管形态外,还存在异形花粉管,如具2条花粉管及分枝花粉管等;在适宜培养条件下,培养60h后萌发率趋于稳定(91%以上),培养96h后花粉管长度逐渐趋于稳定(173μm以上);异形花粉管发生频率与花粉萌发率呈极显著正相关(r=0.7867,P=0.0041),花粉管分枝发生于管伸长至89.73(±3.44)μm处;在不同形态的花粉管中均有微丝骨架正常分布,并且推动花粉管细胞核和造粉体向花粉管顶端移动;在花粉管的透明区,微丝束呈现平行于花粉管的浓密网状结构,当花粉管生长较长时,微丝束有变得稀疏的趋势。
The characteristics of pollen tube growth and microfilament distribution of Pinus tabulaeformis were studied by in vitro culture combined with fluorescence microscopic localization. The results showed the pollen germination produced a number of grains with single tube, and also some grains with hetero-tubes, such as two tubes and ramification. Under the optimal culture condition, germination rate became stable after 60 h culture (up to 91%) and the tube length stabilized after 96 h culture (up to 173 μm). The frequency of pollen grains with hetero-tubes was significantly and positively correlated with the germination rate (r=0.786 7, P=0.004 1). The tube ramification took place at 89.73(±3.44) μm of tube elongation. Microfilament cytoskeleton distributed normally in different types of tubes and brought about the tube nucleus and amyloplasts to move toward tip of tube. In transparent zone of tube, microfilament bundles formed a dense network parallel to the direction of tube elongation. However, when the tube grew long, distribution of microfilaments tended to be thin.