长白山区6种杜鹃花属植物种子形态及萌发特性

Seed morphology and germinating characteristics of 6 Rhododendron species from Changbai Mountains

选择长白山区6种杜鹃花属植物种子进行形态及萌发特性观察。结果表明:6种杜鹃花属植物种子呈椭圆、矩圆、卵形等形态,种子极为细小,且种间差异极显著,以迎红杜鹃(Rhododendron mucronulatum)种子千粒重最重(0.111 2g),苞叶杜鹃(R.redowskianum)最轻(0.022 3g);种皮吸水性良好;萌发时滞最短为毛毡杜鹃(R.conferi-tissmum)7d,最长为苞叶杜鹃12d;发芽率、发芽势、发芽指数以迎红杜鹃(83.33%、50.00%、35.68%)和兴安杜鹃(R.dauricum)(80.67%、47.33%、35.41%)最高,毛毡杜鹃次之,牛皮杜鹃(R.aureum)和小叶杜鹃(R.parvifolium)较低,苞叶杜鹃最低,仅为2.500%、1.167%和0.334%,4类间差异显著。

Seed morphology and germinating characteristics were studied in six Rhododendron species from Changbai Mountains.The results showed that the seed shape of six species were nearly elliptic,oblong,or ovate.The seed of the six species were very small,and the 1 000-seed weight showed significant differences.The 1 000-seed weight of R.mucronulatum was the biggest,0.112 g,while that of R.redowskianum was the smallest,0.022 3 g.The all the water-absorbing of 6 species seeds was very good.Time to onset of germination of R.conferitissmum was the shortest,7 d,while that of R.redowskianum was the longest,12 d.The 6 Rhododendron species were divided into four broad categories according to the germination rate(GR),germination energy(GE) and germination index(GI): R.mucronulatum and R.dauricum were the highest,with 83.33% and 80.67% GR,50.00% and 47.33% GE,35.68% and 35.41% GI respectively;those of R.conferitissmum were the second;those of R.aureum and R.parvifolium were the third,and that of R.redowskianum was the lowest(2.500%,1.167%,0.334%,individually),the four broad categories had significant difference.