The Actinidiaceae, formerly called Dilleniaceae, comprise about 300 tree and shrub species within four genera. Fruits are either hard dehiscent capsules, or are fleshy and berry-like and indehiscent as is the case in Actinidia, the only genus in this family for which information is provided here on seed dormancy and germination.
ACTINIDIA
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A. arguta |
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A. chinensis Planch. |
kiwifruit, Chinese gooseberry, yangtao |
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A. kolomikta |
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I. Evidence of dormancy
Germination of A. Chinensis seeds is generally poor and erratic and can be a considerable problem for growers (2,5), although there are reports where seeds were germinated without difficulty (1,4). After-ripening for three months is unable to promote the subsequent germination of seeds at constant temperatures (5).
II. Germination regimes for non-dormant seeds
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III. Unsuccessful dormancy-breaking treatments
A. chinensis
Constant temperatures: 21°C (2,3); 4.5°-26.5°C (5) Pre-chill: 4.5°C, 2w, germinate at 4.5°-26.5°C (5); 4°C, 37d, germinate at 20°C (3)
IV. Partly-successful dormancy-breaking treatments
A. chinensis
Alternating temperatures: 21°/10°C, 10°/21°C (16h/8h) (2,3); 4.5°/21°C, 10°/21°C, 15.5°/21°C, 26.5°/21°C (16h/8h) (5)
Pre-chill: 4°C, 37d (2,3); 4.5°C, 5w (5); 4.5°C, 4-12w, germinate at 10°-26.5°C (5); 4°C, 37d, then GA3, pre-applied, 24h, 10-500 ppm (2)
GA3: pre-applied, 24h, 10, 100, 500, 2500 ppm (2); pre-applied, 6-25h, 2000 ppm (2); pre-applied, 6,23,25h, 5000 ppm, then pre-dry, 24h (2); pre-applied, 6-23h, 2000 ppm (3); pre-applied, 6,23h, 5000 ppm (3)
A. kolomikta
Pre-chill: 3°-5°C, 5m (6)
GA3: 500 ppm (6); 500 ppm, plus kinetin, 50 ppm
(6)
V. Successful dormancy-breaking treatments
A. arguta
Scarification: abrade with sharp sand (7); file or nick seed coat (7)
A. chinensis
Pre-chill: 4.5°C, 2-12w, germinate at 10°/21°C (16h/8h) (5); 4°C, 37d, then GA3, pre-applied, 24h, 2500 ppm, germinate at 21°/10°C (16h/8h) (2)
GA3: pre-applied, 17h, 5000 ppm, germinate at 21°/10°C (16h/8h) (2); pre-applied, 17h, 5000 ppm, germinate at 21°C (3); pre-applied, 17-24h, 2500 ppm (3)
A. kolomikta
Scarification: abrade with sharp sand (7); file or nick seed coat (7)
VI. Comment
The germination of seeds of A. chinensis is promoted greatly by alternating temperatures (2,3,5). Thermoperiod appears to be relatively unimportant - 10°/21°C being equally promotory at both 16h/8h and 8h/16h cycles (2). The regime 4.5°/21°C (16h/8h) is, however, superior to 10°/21°C (16h/8h) (5). Alternating temperatures alone generally provide insufficient stimulus to promote the germination of all dormant seeds (2,3,5). Pre-chill and gibberellin treatments also promote germination (1,2,3,5). Consequently the following combined procedure has been suggested: pre-chill, 3°-5°C, for 37 days, then pre-treat in 2500 ppm GA3 for 24 hours (on filter paper in petri dishes) and subsequently test for germination at 21°/10°C (16h/8h) (2). Whilst this is satisfactory it might be worth investigating whether testing at 5°/20°C (16h/8h) could enable the pre-chill period, and thus the total test period, to be reduced.
VII. References
1. Bailey, F.L. (1961). Chinese gooseberries, their culture and uses. New Zealand Department of Agriculture, Bulletin 349.
2. Lawes, G.S. and Anderson, D.R. (1980). Influence of temperature and gibberellic acid on kiwifruit (Actinidia chinensis) seed germination. New Zealand Journal of Experimental Agriculture, 8, 277-280.
3. Lawes, G.S. and Sim, B.L. (1980). An analysis of factors affecting the propagation of kiwifruit. Orchardist of New Zealand, 53, 88 -90.
4. Rivals, P. (1964). Notes biologiques et culturales sur 1'Actinidia de chine (Actinidia sinensis Planchon). Journal d'Agriculture Tropicale et de Botanique Appliquee, 11, 75-83.
5. Smith, R.L. and Toy, S.J. (1967). Effects of stratification and alternating temperatures on seed germination of the Chinese gooseberry, Actinidia chinensis Planch. Proceedings of the American Society for Horticultural Science, 90, 409-412.
6. Kolotova, G.K. and Nikolaeva, M.G. (1981). [Effect of stratification and phytohormones on seed germination of Schisandra chinensis and Actinidia kolomikta.] Rastitel'nye Resursy, 17 (4), 544-550. (From Seed Abstracts, 1982, 5, 1584.)
7. Riley, J.M. (1981). Growing rare fruit from seed. California Rare Fruit Growers Yearbook, 13, 1-47.
