Plant Diversity ›› 2006, Vol. 28 ›› Issue (06): 631-638.

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The Light-Sensitivity of Germination of Ficus benjamina var. nuda (Moraceae) Seeds and Its Ecological Significance

WANG Xue, SONG Song-Quan   

  1. Xishuangbanna Tropical Botanical Garden , Chinese Academy of Sciences
  • Received:2006-01-16 Online:2006-12-25 Published:2006-12-25
  • Contact: SONG Song-Quan

Abstract: In this paper , Ficus benjamina L . var . nuda seeds were used as experimental materials, effects of temperature, light , phytohormone ( gibberellin , 6-benzyladenine and ethylene ) , nitrogenous compounds ( sodium nitroprusside,
nitrate , and nitrite ) on seed germination were studied , and ecological significance of light in seed germination was discussed. Under alternating photoperiod (14 h light , 10 h dark , 12μmol m- 2 s - 1 ) , final germination percentage of seeds was 87. 5% , 100% , 100% , 100% , 98% , 89% and 100% , respectively, at 15℃ , 20℃ , 25℃ , 30℃ , 35℃ , 40℃ and 30℃􊄯20℃ , mean germination time of seeds was 34 . 7 d , 16 . 3 d , 5. 6 d , 4 .8 d , 6 . 4 d , 9 d and 6 .3 d , respectively. Germination percentage of seeds which were incubated for 35 d at 15℃ , 20℃ , 25℃ , 30℃ , 35℃ , 40℃ , 30℃􊄯20℃ and dark was zero , and these seeds rapidly germinated after addition of alternating photoperiod . Light intensity of 0 . 5 - 20μmol m- 2 s - 1 markedly increased final germination percentage of seeds . However , different light intensity influenced
hardly final germination percentage of seeds, but altered germination rate of seeds . Under photoperiod of 24 h , final germination percentage of seeds notably increased with increasing length of light duration . The seeds treated for 24 h ,36 h , and 48 h by continuous light could germinate at subsequent dark. Different concentrations of exogenous gibberellin, 6-benzyladenine, ethylene, sodium nitroprusside , nitrate and nitrite could not replace light and not accelerate seed germination, and these seeds rapidly gained germinablity after addition of alternating photoperiod . Germination behavior of F. enjamina L . var . nuda seeds was closely related to long-term adaptation for tropical forest .

Key words: Ficus benjamina var. nuda seeds