Pollination of Myristica and Other Nutmegs in Natural Populations

Abstract

Field studies of several species of Myristica (Myristicaceae) have produced a more detailed understanding of the pollination and reproduction of nutmeg, which had long been wanting. Nutmegs are dioecious tropical forest trees within the order Magnoliales. Nutmegs conform to the general pattern of dioecious tropical trees; they have small, inconspicuous flowers with a pollen reward system, and interact with a guild of small, generalist insects, predominately beetles, thrips and flies. Pollen is the only obvious reward, so pollination operates by deception and foraging errors. Fluctuations in floral displays may encourage foraging errors, and beetles have been found to be sensitive and responsive to such changes in floral displays. Natural populations of nutmegs are generally malebiased, although irregular flowering can shift sex ratios from season to season. Intersexual differences in microhabitat preference were found in some, but not all nutmeg species studied. Compared to their importance and prevalence in tropical forests, the nutmeg family remains both under-studied and difficult to study. Future work should focus on aspects of nutmeg reproduction such as pollen flow and fruiting success (or seed set) that may offer conservation insights.

Niche evolution of the Neotropical tree genusOtobain the context of global biogeography of the nutmeg family, Myristicaceae

“…These seeds are important food sources for large-bodied birds, primates, and bats, which, in turn, act as seed dispersers (Russo 2003; Forget et al 2000; Moreira, Riba-Hernández, and Lobo 2017; Giraldo et al 2007; Melo et al 2009). Though pollination is less studied, the small, usually imperfect flowers are visited by various small insects including beetles, flies, and thrips in Myristica (Sharma and Armstrong 2013; Armstrong and Irvine 1989) and Virola (Jardim and Mota 2007); similarly small, generalist pollinators are likely common throughout the family. Further, their abundance in lowland forests (ter Steege et al 2006) has established Neotropical Myristicaceae an important system for understanding ecological processes that allow species coexistence in hyperdiverse communities in the western Amazon (Queensborough et al 2007a, b 2007).…”

Pollen Donor Position and Climate Factor Affecting Fruit Production of Nutmeg

“…Penyerbukan tipe ini memerlukan vektor yang membantu memindahkan serbuk sari dari bunga jantan ke bunga betina. Menurut Sharma dan Armstrong (2013), secara umum penyerbuk efektif pada ordo Myristica adalah serangga berukuran kecil, tetapi tidak menutup kemungkinan penyerbukannya dibantu juga oleh angin.…”

Sex-Specific Flowering Patterns and Demography of the Understorey Rain Forest Tree Iryanthera Hostmannii (Myristicaceae)

“…This would entail a whole suite of problems associated with the deceit pollination that occurs in Myristica, and likely Iryanthera as well [27]. Selection on reproductive structures has also been posited to explain dimorphism in canopy structure [42] and leaf size [43].…”

“…Female flowers are slightly larger and more fleshy with a single ellipsoid ovary. Pollinators of paleotropical Myristicaceae are usually small nocturnal insects such as beetles that are deceived into pollinating females, although nothing is currently known about the pollinators of Iryanthera [27]. …”

“…However, even small males produced some flowers. Given the short distances that the likely pollinators of this species move [27], as well as the understorey environment in which Iryanthera hostmannii exists, proximity to a female may be just as important as flowering intensity to ensure the successful transfer of pollen [38]. However, given the often orders-of-magnitude difference in flower number between males and females observed in multiple-ovaried flowers of species of other families [39,40,41], the difference in flower number in Iryanthera, with the single-ovaried flowers, was not that great.…”