Overcoming the pollination barrier through artificial pollination in the Wild Nutmeg Knema attenuata (Myristicaceae), an endemic tree of the Western Ghats, India

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Murugan Govindakurup Govind
Koranapallil Bahuleyan Rameshkumar
Mathew Dan


The barrier to pollination and pollinator assemblage were investigated in Knema attenuata, a dioecious tree species endemic to the Western Ghats of India.  It occupies an intermediate canopy stratum of the low and mid-elevation wet evergreen forests.  In order to observe floral display, insect foraging and fruit development, four populations of K. attenuata were selected.  The population diagram of each population was constructed by marking one female tree as the centre and male trees available at different radii from the female tree.  Direct observations and swap net trapping were used to sample insects in the canopy during the flowering season of 2016 and 2017.  Knema attenuata exhibited generalised pollination through diverse insects: thysanopterans (thrips), coleopterans (beetles), halictid bees, and dipterans (syrphid and phorid flies), where thrips played the major role.  On analysing the floral display, it was found that the male flowers provided no rewards and thus attracted less pollinators than the female flowers.  Among the four populations studied, three showed more than 70% fruit setting and the rate of abscission in flowers and young fruits were negligible.  One population was without fruit setting and trials on artificial pollination resulted in fruit setting.  A very low frequency of seed germination was observed in natural conditions which was enhanced by a seed germinator.


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Govind, M.G., Rameshkumar, K.B. and Dan, M. 2019. Overcoming the pollination barrier through artificial pollination in the Wild Nutmeg Knema attenuata (Myristicaceae), an endemic tree of the Western Ghats, India. Journal of Threatened Taxa. 11, 12 (Sep. 2019), 14569–14575. DOI:https://doi.org/10.11609/jott.4824.11.12.14569-14575.


Armstrong, J.E. (1997). Pollination by deceit in nutmeg (Myristica insipida, Myristicaceae): floral displays and beetle activity at male and female trees. American Journal of Botany 84: 1266–1274. https://doi.org/10.2307/2446051

Armstrong, J.E. & B.A. Drummond (1986). Floral biology of Myristica Fragrans Houtt. (Myristicaceae), the nutmeg of commerce. Biotropica 18: 32–38.

Bay, D. (1995). Thermogenesis in the aroids. Aroideana 18: 32–39.

Bernhardt, P. (2000). Convergent evolution and adaptive radiation of beetle-pollinated angiosperms. Plant Systematics and Evolution 222: 293–320. https://doi.org/10.1007/978-3-7091-6306-1_16

Christenhusz, M.J.M. & J.W. Byng (2016). The number of known plants species in the world and its annual increase. Phytotaxa 261(3): 201–217. https://doi.org/10.11646/phytotaxa.261.3.1

Czabator, F. (1962). Germination value: an index combining speed and completeness of pine seed germination. Journal of forest science 8: 386–396.

Goldblatt, P., P. Bernhardt & J.C. Manning (1998). Pollination of petalloid geophytes by monkey beetles (Scarabaeidae: Rutelinae: Hopliini) in southern Africa. Annals of the Missouri Botanical Garden 85: 215–230. https://doi.org/10.2307/2992006

Gottsberger, G. (1977). Some aspects of beetle pollination in the evolution of flowering plants. Plant Systematics and Evolution 1: 211–226. https://doi.org/10.1007/978-3-7091-7076-2_14

Gottsberger, G. (1988). The reproductive biology of primitive angiosperms. Taxon 37: 630–643. https://doi.org/10.2307/1221105

Howe, H.F. & L.C. Westley (1997). Ecology of pollination and seed dispersal, pp. 262–283. In: Crawley, M.J. (ed), Plant Ecology (2nd edition). Blackwell Science, Oxford, 717pp. https://doi.org/10.1002/9781444313642.ch9

Mabberley J.D. (2018). Mabberley’ s Plant Book: A portable dictionary of plants, their classification and uses. 4th Edition. Cambridge University Press, London, 1102pp. https://doi.org/10.1017/9781316335581

Momose, K. (2005). Beetle pollination in tropical rainforests, pp. 104–110. In: Roubik, D.W., S. Sakai & A. A. Hamid (eds.). Pollination Ecology and the Rainforest- Sarawak Studies. Springer, Berlin, 307pp. https://doi.org/10.1111/j.1744-7429.1998.tb00078.x

Momose, K., T. Nagamitsu & T. Inoue (1998). Thrips cross pollination of Popowia pisocarpa (Annonaceae) in a lowland dipterocarp forest in Sarawak. Biotropica 30: 444–448.

Moog, U., B. Fiala, W. Federle & U. Maschwitz (2002). Thrips pollination of the dioecious ant plant Macaranga hullettii (Euphorbiaceae) in southeast Asia. American Journal of Botany 89: 50–59. https://doi.org/10.3732/ajb.89.1.50

Nayar, T.S., A.R. Beegam & M. Sibi (2014). Flowering Plants of the Western Ghats. Jawaharlal Nehru Tropical Botanic Garden and Research Institute, India., 1683pp.

Ravikumar, K., D.K Ved, V.R. Sankar & P.S. Udayan (2000). 100 Red Listed Medicinal Plants of Conservation Concern in Southern India. FRLHT, Bangalore, 467pp.

Seymour, R.S. & P. Schultze-Motel (1997). Heat-producing flowers. Endeavour 21(3): 125–129. https://doi.org/10.1016/S0160-9327(97)80222-0

Sharma, M.V. & J.E. Armstrong (2013). Pollination of Myristica and other nutmegs in natural populations. Tropical Conservation Science 6(5): 595–607. https://doi.org/10.1177/194008291300600502

Sharma, M.V. & K.R. Shivanna (2011). Pollinators, pollination efficiency and fruiting success in a wild nutmeg, Myristica dactyloides. Journal of Tropical Ecology 27: 405–412. https://doi.org/10.1017/S0266467411000174

Shivanna, K.R. & N.S. Rangaswamy (2012). Pollen Biology: A Laboratory Manual. Springer, Berlin, 119pp.

Vinayachandra & K.R. Chandrashekar (2014). Phenolic contents of Knema attenuata fruits and their bioactive potentials. Journal of Herbs, Spices and Medicinal Plants 20(2): 183–195. https://doi.org/10.1080/10496475.2013.848390

Vinayachandra, R. Shwetha & K.R. Chandrasekhar (2011). Larvicidal activities of Knema attenuata (Hook.f. & Thomson) Warb. (Myristicaceae) extracts against Aedes albopictus Skuse and Anopheles stephensi Liston. Parasitology Research 109(6): 1671–1676. https://doi.org/10.1007/s00436-011-2440-2

Wilde, W.J.I.O.de. (1979). New account of the genus Knema (Myristicaceae). Blumea 25: 321–478.

Williams, G.A., P. Adam & L.A. Mound (2001). Thrips (Thysanoptera) pollination in Australian subtropical rainforests, with particular reference to pollination of Wilkiea huegeliana (Monimiaceae). Journal of Natural History 35: 1–21. https://doi.org/10.1080/002229301447853

World Conservation Monitoring Centre (1998). Knema attenuata. The IUCN Red List of Threatened Species1998: e.T37122A10035137. Downloaded on 21 August 2019. https://doi.org/10.2305/IUCN.UK.1998.RLTS.T37122A10035137.en