| 要旨トップ | 目次 | 日本生態学会第65回全国大会 (2018年3月、札幌) 講演要旨
ESJ65 Abstract


一般講演(口頭発表) E02-01  (Oral presentation)

Green greenhouse for fruit development of an annual androdioecious liana Schizopepon bryoniifolius and its relationship with sex ratio

Nagaoka, Nobuyuki(Yamagata Nature Park), Naoe, Shoji(FFPRI), Takano, Yu(Yamagata Nature Park), *SAKAI, Shoko(Kyoto University)

Plant leaves rarely play a major role in reproduction. In this study, we report a phenomenon in which overlapping leaves enclose flowers and fruits possibly to protect against cold. Schizopepon bryoniifolius (Cucurbitaceae) is an androdioecious scandent annual commonly inhabits the edge of deciduous forests on the foot of mountains in Japan. From late August to September, males form conspicuous racemose or paniculate inflorescences with many flowers, while hermaphrodites produce small solitary flowers in the axils of leaves. Early in the flowering season, hermaphrodite flowers are spatially separated from each other due to long internodes. In contrast, later flowers are packed together on a dwarf shoot with very short internodes. Very late in the flowering season leaves grow to enclose these flowers and fruits. We found that enclosing leaves were larger in colder sites at higher altitudes. Under solar radiation, temperature inside an enclosure was up to 4.6°C higher than ambient temperature. Besides, removal of enclosing leaves negatively affected fruit growth. On the other hand, enclosure may have an adverse effect on outcrossing. The negative correlation between the male ratios and altitude reported in a previous study may be related with higher proportions of selfing enclosed flowers at cooler sites.


日本生態学会