Tansley review No. 110 - Numerical and physical properties of orchid seeds and their biological implications

被引:448
作者
Arditti, J [1 ]
Ghani, AKA
机构
[1] Univ Calif Irvine, Dept Dev & Cell Biol, Irvine, CA 92697 USA
[2] Univ Kebangsaan Malaysia, Dept Bot, Bangi 43600, Selangor, Malaysia
关键词
orchids; orchid seeds; orchid dispersal; dust seeds; seed floatation; seed production; seed size; seed numbers;
D O I
10.1046/j.1469-8137.2000.00587.x
中图分类号
Q94 [植物学];
学科分类号
071001 ;
摘要
Orchid seeds are very small, extremely light and produced in great numbers. Most range in length from c. 0.05 to 6.0 mm, with the difference between the longest and shortest known seeds in the family being 120-fold. The 'widest' seed at 0.9 mm is 90-fold wider than the 'thinnest' one, which measures 0.01 mm (because orchid seeds are tubular or balloon-like,'wide' and 'thin' actually refer to diameter). Known seed weights extend from 0.31 mu g to 24 mu g (a 78-fold difference). Recorded numbers of seeds per fruit are as high as 4000 000 and as low as 20-50 (80000-200000-fold difference). Testae are usually transparent, with outer cell walls that may be smooth or reticulated. Ultrasonic treatments enhance germination, which suggests that the testae can be restrictive. Embryos are even smaller: their volume is substantially smaller than that of the testa. As a result, orchid seeds have large internal air spaces that render them balloon-like. They can float in the air for long periods, a property that facilitates long-distance dispersal. The difficult-to-wet outer surfaces of the testa and large internal air spaces enable the seeds to float on water for prolonged periods. This facilitates distribution through tree effluates and/or small run-off rivulets that may follow rains. Due to their size and characteristics, orchid seeds may also be transported in and on land animals and birds (in fur, feathers or hair, mud on feet, and perhaps also following ingestion).
引用
收藏
页码:367 / 421
页数:55
相关论文
共 204 条
[1]  
Ackerman JD., 1994, C 14 WORLD ORCH C LO
[2]  
AMES O, 1948, ORCHIDS RETROSPECT
[3]  
AMES O, 1922, ORCHID REV, V30, P229
[4]  
AMES O, 1922, RHODORA, V24, P37
[5]  
Ames Oakes, 1946, AMER ORCHID SOC BULL, V14, P355
[6]  
ANDO T, 1990, P NAG INT ORCH SHOW, P108
[7]  
[Anonymous], 1983, KRAKATAU 1883 VOLCAN
[8]  
[Anonymous], 1936, Samenkeimung der Orchideen
[9]  
Ardila A, 1990, J NEUROLINGUIST, V5, P1
[10]   FACTORS AFFECTING GERMINATION OF ORCHID SEEDS [J].
ARDITTI, J .
BOTANICAL REVIEW, 1967, 33 (01) :1-&