Bernardello G./Публикации

From Антэкология ⋮ Anthecology
Jump to: navigation, search
Автор
АВТОР ПУБЛИКАЦИЙ 3
Bernardello G.
3
Bernardello G.
Автор антэкологических публикаций

et al. (+3)
The Botanical Review
60
Журнал с антэкологическими публикациями.

. 2001. V. 67. No. 3. P. 255–308. Статья
Ошибка: строка превышает ограничение в 5000 символов
Ошибка: строка превышает ограничение в 5000 символов
AID3428292827
Оригинал
Bernardello G.
3
Bernardello G.
Автор антэкологических публикаций

et al. (+5)
American Journal of Botany
146
Журнал с антэкологическими публикациями.
Botanical Society of America · ajb@botany.org

. 1999. V. 86. No. 6. P. 829–840. Статья
Lactoris fernandeziana, monotypic in its family, is endemic to the cloud forests of Robinson Crusoe Island. Although there has been considerable study of the relationships of Lactoris, as a rare species and as a putative primitive paleoherb, little is known of its reproductive biology. Knowledge of the latter is essential for effective conservation programs. The species is gynomonoecious. The overall proportion of flowers is ∼1 female:1 hermaphrodite. The inconspicuous semipe
ndulous green flowers, usually in mixed-gender inflorescences, do not produce rewards. Hermaphrodite flowers are herkogamous and protogynous. Pollen grains are shed from the extrorse anthers in permanent dry tetrads. There is a mean of 12879 tetrads per hermaphrodite flower. Both flower types bear an average of ∼18 ovules. The P/O (pollen/ovule) ratios imply facultative or obligate xenogamy, but hand pollinations show that Lactoris is self-compatible. No floral visitors were ever observed, but stigmata of open-pollinated flowers bore tetrads, and 64% of such styles had pollen tubes. Flowers enclosed in large mesh (1 mm) bags bore similar numbers of tetrads and pollen tubes. Thus, we conclude that Lactoris is anemophilous, a syndrome perhaps reflected by the P/O ratio. Low genetic diversity (isozymes and DNA) supports selfing and implies limited distance wind pollen dispersal. The small size of the island, the ± 1000 extant Lactoris plants, coupled with anemophily, self-compatibility, and pendant flower position, have yielded a geitonogamous system with high seed set and low genetic diversity. If inbreeding depression is expressed, it is in seed germination and seedling vigor, for Lactoris is very difficult to cultivate. For this species, effective conservation practices need to focus on habitat preservation and promotion of outcrossing.
  • AID0008889998
  • ATPR0
  • Оригинал
Galetto L.
5
Автор антэкологических публикаций

, Bernardello G.
3
Автор антэкологических публикаций

Annals of Botany
514
Журнал с антэкологическими публикациями.
Oxford University Press · office@annbot.com

. 2004. V. 94. No. 2. P. 269–280. Статья
Background and Aims. Floral nectaries and nectar features were compared between six Argentinian Ipomoea species with differences in their pollinator guilds: I. alba, I. rubriflora, I. cairica, I. hieronymi var. hieronymi, I. indica, and I. purpurea. Methods. Pollinators were recorded in natural populations. The morpho-anatomical study was carried out through scanning electron and light microscopy. Nectar sugars were identified via gas chromatography. Nectar production and the effect of its remov
al on total nectar sugar amount were determined by using sets of bagged flowers. Key Results. Hymenopterans were visitors of most species, while hummingbirds visited I. rubriflora and sphingids I. alba. All the species had a vascularized discoidal nectary surrounding the ovary base with numerous open stomata with a species-specific distribution. All nectar samples contained amino acids and sugars. Most species had sucrose-dominant nectars. Flowers lasted a few hours. Mean nectar sugar concentration throughout the lifetime of the flower ranged from 34·28 to 39·42 %, except for I. cairica (49·25 %) and I. rubriflora (25·18 %). Ipomoea alba had the highest nectar volume secreted per flower (50·12 µL), while in the other taxa it ranged from 2·42 to 12·00 µL. Nectar secretion began as soon as the flowers opened and lasted for a few hours (in I. purpurea, I. rubriflora) or it was continuous during the lifetime of the flower (in the remaining species). There was an increase of total sugar production after removals in I. cairica, I. indica and I. purpurea, whereas in I. alba and I. rubriflora removals had no effect, and in I. hieronymi there was a decrease in total sugar production. Conclusions. The chemical composition, production dynamics and removal effects of nectar could not be related to the pollinator guild of these species. Flower length was correlated with nectary size and total volume of nectar secreted, suggesting that structural constraints may play a major role in the determination of nectar traits of these species.