Distyly and floral morphology of Psychotria cephalophora (Rubiaceae) on the oceanic Lanyu (Orchid) Island, Taiwan

Abstract

BackgroundPsychotria cephalophora Merr. (Rubiaceae), a shrub in oceanic islands of Taiwan and the Philippines, appears to be distylous, but distyly is usually rare on oceanic islands. To elucidate the functional breeding system of P. cephalophora can improve our understanding of plant reproductive ecology on oceanic islands.ResultsField investigations on Lanyu (Orchid Island) off the coast of southeastern Taiwan revealed the flowers to be distylous with short (S)- and long (L)-styled morphs, with only one morph per individual. Laboratory observations revealed that both morphs had stainable pollen grains and indicated dimorphism in stigmatic papillae and pollen size. In hand pollination experiments, the pollen tubes reached the base of the style in intermorph crossing, whereas they rarely penetrated stylar tissue in intramorph crossing and selfing. Open pollinated S- and L-styled flowers produced fruit.ConclusionsThe results indicate that the breeding system of P. cephalophora is morphologically and functionally distylous.Electronic supplementary materialThe online version of this article (doi:10.1186/s40529-015-0091-9) contains supplementary material, which is available to authorized users.

Risk of genetic vulnerability and aspects of the reproductive biology of Psychotria ipecacuanha (Rubiaceae), a threatened medicinal plant species of Brazilian forests

“…Longer stigma lobes in the short-styled morph may receive higher amounts of pollen than long-styled stigma in lobes (Barrett 2000). The different lengths of stigma lobes of the floral morphs of P. ipecacuanha confirms observations in other populations of the same species of the Atlantic Forest (Rossi et al 2005), and other species such P. carthagenensis (Koch et al 2010) and P. cephalophora (Watanabe et al 2015).…”

“…Isoplethy in P. ipecacuanha has been recorded (Rossi et al 2005), in natural populations of the Atlantic Forest in Minas Gerais and Rio de Janeiro and is consistent with the results of the present study. For the genus Psychotria, isoplethy was also recorded in other distylous species such as P. tenuinervis (Virillo et al 2007), P. brachypoda (Fonseca et al 2008), P. carthagenensis (Koch et al 2010;Faria et al 2012); P. hastisepala (Silva & Vieira 2015), P. elata (Silva & Segura 2015), P. cephalophora (Watanabe et al 2015), and P. deflexa (Matias et al 2016).…”

Comparison of Sample Preparation Techniques for Inspection of Leaf Epidermises Using Light Microscopy and Scanning Electronic Microscopy

“…It was reported that t-butanol is equivalent or sometimes superior to CPD (Inoué and Osatake, 1988;Baskin et al, 2014). The t-butanol freeze-drying method is commonly used to prepare biological SEM samples in Japan (Kaneko et al, 1990;Tuji, 2000;Watanabe et al, 2015), China (Xin et al, 2012), and other regions (El Sharaby et al, 2012). Methanol is reported to be a better fixative than glutaraldehyde and FAA when preparing SEM samples (Neinhuis and Edelmann, 1996;Pathan et al, 2010;Talbot and White, 2013b).…”

Is heterostyly rare on oceanic islands?

“…2007 ; Sugawara et al . 2013 , 2014 ; Watanabe et al 2014 a , b , 2015 ). Hawaiian Psychotria is one of the well-known examples of dioecy derived from distyly ( Vuilleumier 1967 ; Beach and Bawa 1980 ; Muenchow and Grebus 1989 ; Barrett 1992 ).…”

“…Geography is also important for understanding colonization and reproduction of heterostylous species on oceanic islands. Watanabe et al . (2015) reported distyly in P. cephalophora from oceanic Lanyu Island, which is only 60 km away from the south of Taiwan, but has never been connected to it.…”