不同贮藏温度下大别山五针松花粉活力的变化

大别山五针松( Pinus dabeshanensis C. Y. Cheng et Y. W. Law)为松科( Pinaceae)松属( Pinus Linn.)植物,自然种群数量极少,目前仅发现在安徽省岳西县大王沟海拔900~1300 m阴坡和半阴坡有相对集中的分布,种群规模计200余株,且多为成年个体,林下幼苗极少,自然更新困难,为中国特有珍稀树种之一1]。大别山五针松常在每年3月份至4月份形成花芽,5月中下旬花粉成熟并散发,花粉具气囊,此时雌球花张开接受传粉,球果翌年9月成熟2]。据作者近年的调查,大别山五针松种子败育率较高,且种子质量较低,这也是该种类濒危的重要原因之一。

Change in pollen viability of Pinus dabeshanensis at different storage temperatures

By means of MTT staining method, pollen viability of Pinus dabeshanensis C. Y. Cheng et Y. W. Law stored for 1-170 d under conditions of room temperature (20 ℃-28 ℃), 4 ℃ and-20 ℃ was measured. The result shows that pollen viability of P. dabeshanensis is 95. 97% during pollen flourishing period. When storage for 7 d at different temperatures, pollen viability is still over 90%. Pollen viability decreases to 40. 33% when storage for 75 d at room temperature, while that decreases to 81. 67% and 73. 33% when storage for 75 d at 4 ℃ and -20 ℃, respectively. But when storage for 115 d at different temperatures, pollen viability is lower than 20%. It is indicated that short-term ( one month) storage at room temperature is suitable to keep pollen viability of P. dabeshanensis, but 4 ℃ is more suitable for keeping pollen viability for longer time.