TY - JOUR
T1 - Pre-pollination barriers between two sympatric Arisaema species in northern Shikoku Island, Japan
AU - Matsumoto, Tetsuya K.
AU - Miyazaki, Yuko
AU - Sueyoshi, Masahiro
AU - Senda, Yoshihiro
AU - Yamada, Kazuhiro
AU - Hirobe, Muneto
PY - 2019/1/1
Y1 - 2019/1/1
N2 - Premise: The genus Arisaema (Araceae) has rapidly diversified in Japan, and multiple species often coexist in the field. Although Japanese Arisaema species hybridize from artificial crossing, hybrid individuals are rare in mixed populations; suggesting the presence of effective pre-pollination barriers. We examined the following reproductive barriers between A. sikokianum and A. tosaense: habitat, phenology, and pollinator isolations. Methods: Habitat isolation was examined by interspecific comparisons of microhabitat conditions at a mixed site and of altitude at the sampling site of herbarium specimens. Phenological isolation was evaluated by comparing seasonal transition in apparent spathe condition and frequency of insect visitation. Pollinator isolation was examined by comparing floral visitor assemblages between the two Arisaema species. To avoid overestimation of pollinator isolation due to seasonal changes in insect assemblages, we also compared visitor assemblages between natural and late-flowering A. sikokianum, where the latter was experimentally introduced and blooming with a natural A. tosaense population. Results: Microhabitat conditions and sampling elevations of herbarium specimens overlapped between the two Arisaema species. At the population level, A. sikokianum and A. tosaense flowered for 39 and 52 days, respectively, with 13 days overlap. Insect visitation in A. sikokianum decreased before the seasonal overlap. Floral visitor assemblages differed between the two Arisaema species, while the difference between natural and late-flowering A. sikokianum was less distinct. Conclusions: Phenological and pollinator isolation contribute to reproductive isolation between the two Arisaema species and should enable the two species to coexist in this area.
AB - Premise: The genus Arisaema (Araceae) has rapidly diversified in Japan, and multiple species often coexist in the field. Although Japanese Arisaema species hybridize from artificial crossing, hybrid individuals are rare in mixed populations; suggesting the presence of effective pre-pollination barriers. We examined the following reproductive barriers between A. sikokianum and A. tosaense: habitat, phenology, and pollinator isolations. Methods: Habitat isolation was examined by interspecific comparisons of microhabitat conditions at a mixed site and of altitude at the sampling site of herbarium specimens. Phenological isolation was evaluated by comparing seasonal transition in apparent spathe condition and frequency of insect visitation. Pollinator isolation was examined by comparing floral visitor assemblages between the two Arisaema species. To avoid overestimation of pollinator isolation due to seasonal changes in insect assemblages, we also compared visitor assemblages between natural and late-flowering A. sikokianum, where the latter was experimentally introduced and blooming with a natural A. tosaense population. Results: Microhabitat conditions and sampling elevations of herbarium specimens overlapped between the two Arisaema species. At the population level, A. sikokianum and A. tosaense flowered for 39 and 52 days, respectively, with 13 days overlap. Insect visitation in A. sikokianum decreased before the seasonal overlap. Floral visitor assemblages differed between the two Arisaema species, while the difference between natural and late-flowering A. sikokianum was less distinct. Conclusions: Phenological and pollinator isolation contribute to reproductive isolation between the two Arisaema species and should enable the two species to coexist in this area.
KW - altitudinal distribution
KW - Araceae
KW - deceptive pollination
KW - flowering phenology
KW - fly pollination
KW - fungivore
KW - fungus gnat
KW - microhabitat condition
KW - rove beetle
KW - species coexistence
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U2 - 10.1002/ajb2.1389
DO - 10.1002/ajb2.1389
M3 - Article
C2 - 31729010
AN - SCOPUS:85075140236
JO - American Journal of Botany
JF - American Journal of Botany
SN - 0002-9122
ER -