Journal of Pollination Ecology, 6(15), 2011, pp 108-117 — Short Communication — NOTES ON THE POLLINATION ECOLOGY OF THE PALM GENUS JOHANNESTEIJSMANNIA (A RECACEAE ) Y.M. Chan* and L.G. Saw Forest Biodiversity Division, Forest Research Institute Malaysia, 52109 Kepong, Selangor, Malaysia Abstract The floral biology and flower visitors of the tropical palms Johannesteijsmannia altifrons, J. magnifica and J. perakensis were investigated. We combined the data from this study with published data of J. lanceolata to give an overview of the reproductive biology and pollination system of the genus. Anthesis peaks from 0500–1100 hrs when the inflorescences are visited mainly by flies, beetles and stingless bees ( Trigona ), the last are potential pollinators. The breeding system is facultative selfing, indicating the ability of the species to reproduce in the absence of pollinators or in isolation. Keywords: reproductive biology, pollinator, breeding system, flower biology, Coryphoideae, Johannesteijsmannia INTRODUCTION The reproductive biology of J. lanceolata has been well- documented (Chan et al. 2011b): It is self-compatible, the Studies on reproductive biology and pollination ecology flowers are homogamous with diurnal anthesis and are can help to shed light on plant-pollinator relationships, visited by bees, flies and ants. For the remaining members of evolution, and also possible reasons for the persistence, the genus, such information is lacking. Thus, we extended rarity, genetic diversity or species richness of plants (e.g. the investigations into the floral biology and pollination of J. Bawa et al. 1985; Henderson 2002; Rymer et al. 2005; altifrons , J. magnifica and J. perakensis , to determine the Barfod et al. 2011). It also provides crucial information for pollinators and the breeding system. We also discuss and the conservation of threatened species (e.g. Soehartono & summarise the reproductive biology of the genus by Newton 2001; Lee et al. 2006; Ohara et al. 2006; Gargano incorporating the data from this study with published and et al. 2009). unpublished data on J. lanceolata (Chan et al. 2011b; Chan 2009). The genus Johannesteijsmannia comprises only four species, i.e., J. altifrons (Reichb.f. et Zoll) Moore, J. MATERIALS AND METHODS lanceolata J.Dransf. , J. magnifica J.Dransf. and J. perakensis J.Dransf. (Dransfield et al. 2008). All species are threatened The flowering of Johannesteijsmannia altifrons, J. by deforestation in Malaysia (Chan et al. 2011a). magnifica and J. perakensis was observed in the wild or in Uncontrolled seed harvesting for the ornamental trade may cultivation from March 2004 until March 2005. The sample also affect population regeneration in the wild (Chan & Saw size for this study was small because few palms were found 2009). Johannesteijsmannia lanceolata, J. magnifica and J. flowering during field observations. Detailed observations perakensis are endangered endemics to Peninsular Malaysia, were made on the ex-situ plants of J. altifrons (N = 6) and J. while J. altifrons is confined to southern Thailand, magnifica (N = 2) planted in the Forest Research Institute Peninsular Malaysia, Borneo and Sumatra. Malaysia (FRIM), Selangor, at 97 m.a.s. The wild population of J. magnifica grows in hill dipterocarp forest The palms usually grow in valleys (pers. obs.) but some (320–400 m.a.s.) in the Berembun Forest Reserve, Negeri populations of J. altifrons and J. perakensis are also reported Sembilan, while J. perakensis is found in lowland dipterocarp to be found on ridge tops or upper hill slopes (Dransfield forest (120 m.a.s.) in the Kledang-Saiong Forest Reserve, 1972). They occur in the understory of closed canopy forest Perak. The inflorescences and flowers were measured for and their leaves are broadly to narrowly diamond-shaped. All inflorescence length, peduncle length, flower length and species are acaulescent, except for J. perakensis which has a diameter, maximum petal width and length, and the lengths trunk of 2–4 m tall. Inflorescences are borne at the base of of stamen, pistil and style. Longitudinal and transverse the plant (for J. perakensis they are borne above the trunk), sections of mature flowers of all the species studied except and they are usually partially covered by dead leaves trapped for J. perakensis were made and examined following the in the crown. The inflorescences are interfoliar, bearing methodology in Chan & Lim (2011). Insects visiting the bisexual flowers with a three-lobed corolla and six stamens. inflorescences were observed during anthesis (shedding of pollen) in the morning, mainly ex-situ from 0700 – 1300 Received 30 June 2011, accepted 23 November 2011 hrs for at least 10 days and occasionally in-situ for J. *Corresponding author; email: [email protected] 108 December 2011 POLLINATION ECOLOGY OF JOHANNESTEIJSMANNIA 109 magnifica and J. perakensis . In the case of J. magnifica , two further elongated, curved downwards during the flowering additional observations were made in the evening (1600 and period, and emitted an odour that attracted insects. 1700 hrs) and one after rain at night (2200 hr) in FRIM to Depending on the species, the odour varies from faintly sour check for night visitors. To determine potential pollinators, to strongly fermented sweet and sour (Tab. 2). There was no we carried out additional observations and sampled floral common trend in flowering sequence of the inflorescence in visitors of J. lanceolata (N plant = 3) in FRIM, for three the genus, except that flowering within the cincinnus is days from 0830 to 1230 hrs in September 2011. The asynchronous as in most other palms with sympodial flower captured insects were checked for pollen load under a 40× clusters. The genus also shows consistency in having diurnal dissecting microscope. Pollen grains were removed with anthesis. In general, flowers open in the morning with forceps, dispersed onto a drop of 70% alcohol on a anthesis peaking between 0500 and 1100 hrs (in one microscope slide and cross-checked with pollen grains from observation, J. altifrons began anthesis at 0200 hr, and later flowers of J. lanceolata under a light microscope. All peaked from 0430 hr onwards). Each inflorescence lasts 7– captured insects were identified and deposited in the 14 days. Anthesis occurs 30–60 minutes after the flowers Entomology Unit, FRIM. have opened except in J. lanceolata where it is initiated immediately when the petals have just separated. Flowers are Pollen to ovule ratios (total number of pollen grains: fully open after 1–2 hours. No nectar is produced as the total number of ovules per flower) for J. magnifica were gynoecium is dry, and no nectaries were seen in anatomical calculated according to Chan et al. (2011b). In one sections of flowers of J. lanceolata, J. magnifica and J. inflorescence, pollen viability was determined by the ‘sitting altifrons . The flowering rate (or anthesis) in an inflorescence drop culture’ method (Shivanna & Rangaswamy 1992, for declines or ceases by noon or sometimes by the evening. The details see Chan et al. 2011b). Effervescence of stigmatic flowering intensity (mean number of open flowers per tissues of flowers aged 0, 5 and 24 hrs in a 3% hydrogen inflorescence per day) at peak was estimated at 396 and peroxide aqueous solution was used as an indicator of 3152 for J. lanceolata and J. altifrons respectively (Chan, receptivity in accordance with Carrington et al. (2003). unpubl. data). The pollen is viable for one day (mean RESULTS AND DISCUSSION percentage germination of fresh pollen, 6 and 24 hrs after anthesis for J. magnifica was 69, 20 and 0.8 respectively, Floral biology present study). Johannesteijsmannia magnifica flowered in-situ in March One day after anthesis, anthers have little pollen left and 2004 and 2005, and flowered ex-situ in October 2004 and the stigma, style and filaments start turning brown. The March 2005. Peak flowering for J. perakensis occurred in flowers close on the second day after anthesis and turn March–April, followed by a smaller peak in October– brown on the third day. In this study, the stigmas of newly December. The cultivated plants of J. altifrons flowered opened flowers ( J. magnifica and J. altifrons ) before or at continuously from June 2004 until the end of observation anthesis, showed limited effervescence activity when period. The floral morphology and behaviour of the species studied are given and compared with those of Johannesteijsmannia lanceolata (data from Chan et al. 2011b) in Tabs. 1 and 2. All species have cream-coloured flowers and floral parts of similar size, but are different in inflorescence size and structure (branching order, Fig. 1, Tab. 1). The inflorescence size and structure of J. altifrons and J. perakensis are similar, while that of J. magnifica is somewhat intermediate in the genus, and J. lanceolata has the smallest inflorescence with only one order of branching. The first three have highly floriferous comb-like inflorescences. The mean number of flowers per inflorescence for J. lanceolata was 2442 (Chan et al. 2011b) whereas for J. altifrons , it was estimated at 9515 (SD 1571, N = 2, present study). The petals of all species are more or less flat, triangular, bluntly acute, smooth and 0.3-0.5 mm thick (present study), except for that of J. lanceolata which is thicker, shorter and papillate on the outer surface (Chan 2009). The inflorescence development in all species was very similar to that of J. lanceolata (Chan et al. 2011b). After the prophyll had emerged from the leaf