Triterpenoids from the female and male flowers of Alnus sieboldiana

The major triterpenoids in both the female and male flowers of Alnus sieboldiana are a C₃₁-secodammarane-type, alnustic acid, and its 12-O-α-L-arbinofuranoside and 12-O-β-D-xylopyranoside.     

高黎贡山花卉资源与赏花旅游初探

高黎贡山有完整的生物气候垂直带谱自然景观,多种植被类型和丰富的植物资源,目前已知有种子植物2门210科1086属4303种及变种,其中有较高观赏价值的花卉达62科320属1053种,是我国花卉资源最丰富的地区之一。高黎贡山花卉资源具有种类丰富,名花众多;珍稀,濒危植物多;植物区系成分复杂,起源古老,特有植物多;垂直分布明显,四季花卉不断;形态各异,色彩绚丽等特点,是开展赏花旅游的理想地方,笔者设计3条赏花旅游线中;（1）百花岭景区;（2）大蒿坪景区;（3）大塘大树杜鹃景区。为高黎贡山开展赏花旅游提供思路。     

Flavonoids of the flowers of tamarix nilotica

The ethyl ester of kaempferol 3-O-β-D-glucuronide, the methyl and ethyl esters of quercetin 3-O-β-D-glucuronide have been isolated from an aqueous acetone extract of the flowers of Tamarix nilotica. In addition kaempferol 3-O-sulphate-7,4′-dimethyl ether and the free aglycones were isolated. The structures were established by routine methods, by FAB-MS and by ¹³C NMR spectral measurements.     

The timing of food-deceptive flowers: a commentary on Internicola et al. (2008)

A recent article presents a study of pollinator visitation behaviour that is used to evaluate the selective pressure that pollinator visitation rate might have on the timing of the production of nonrewarding flowers. Here we take issue with the conclusions of the paper that there should be selection pressure for nonrewarding flowers to be available earlier in the season in order to avoid dissimilar sympatric rewarding species. Consideration of selection pressure must take into account temporal variation in total pollinator availability, pollinator longevity and unlearned response, and the stability of plant communities over time, as well as the learned responses of individual pollinators that the original study focused on. Learning alone would not necessarily select for early flowering by nonrewarders if temporal variation in pollinator numbers is strong or naïve pollinators consistently appear throughout the flowering season. Further, we argue that early flowering could simply be a natural corollary of longevity of flowers needed to combat negative frequency‐dependent selection and low overall visitation rates by pollinators, rather than a trait that has been specifically selected to reduce temporal overlap with competing rewarding species.     

A chalcone glycoside from Acacia dealbata

A new yellow pigment isolated from the flowers of Acacia dealbata has been shown to be chalcononaringenin 2′-[O-rhamnosyl-(1→4)-xyloside] by chemical and spectroscopic methods.     

单性木兰花部综合特征及其传粉适应性

对单性木兰花部综合特征和访花昆虫种类及访花行为进行了研究,结果表明,单性木兰花冠顶端呈半合拢状,花被片之间存在间隙,只有那些能够穿过这些间隙的昆虫才能到达花内为其采粉和授粉,对访花者的要求较为苛刻。于降雨前去掉雄花和雌花花被片,使雄花雄蕊群和雌花柱头充分暴露,另外选择雄花和雌花作对照,降雨后将花取回并测定雄花花粉生活力和雌花柱头上的花粉粒。结果表明,在雨天,单性木兰花冠顶端呈半合拢状的开放方式对雄花和雌花均起到了保护作用,这种花部结构的特化是对花期持续降雨的一种生态适应。从访花昆虫种类上看,单性木兰雄花的昆虫种类是雌花的两倍,显然雄花比雌花更能吸引昆虫。     

Some pollinators do not prefer symmetrically marked or shaped daisy (Asteraceae) flowers

We noted no significant pollinator preference for symmetry in daisy (Asteraceae) flowers. Asymmetry of markings on Gorteria diffusa did not negatively affect pollinator visitation by bee-flies. Nevertheless, the flowers of this species tend to be symmetrically marked. Beetles did not discriminate against artificial daisy flowers which had petals placed in asymmetrical positions. We are sceptical about Moller's (1995) view that the symmetry of flowers is due to pollinator discrimination against asymmetrical flowers.     

The potential of South African indigenous plants for the international cut flower trade

A broad review is presented of recent developments in the commercialization of southern Africa indigenous flora for the cut flower trade, including potted flowers and foliages (“greens”). The botany, horticultural traits and potential for commercialization of several indigenous plants have been reported in several publications. The contribution of species indigenous and/or endemic to southern Africa in the development of cut flower crop plants is widely acknowledged. These include what is known in the trade as gladiolus, freesia, gerbera, ornithogalum, clivia, agapanthus, strelitzia, plumbago and protea. Despite the wealth of South African flower bulb species, relatively few have become commercially important in the international bulb industry. Trade figures on the international markets also reflect the importance of a few species of southern African origin. The development of new research tools are contributing to the commercialization of South African plants, although propagation, cultivation and post-harvest handling need to be improved. A list of commercially relevant southern African cut flowers (including those used for fresh flowers, dried flowers, foliage and potted flowers) is presented, together with a subjective evaluation of several genera and species with perceived potential for the development of new crops for the florist trade. It is concluded that research should be focused on potential markets rather than on preconceived product concepts. A special national effort is required to maximize the opportunities presented by the rich diversity of the flora and to develop an internationally competitive cut flower industry.     

Fossil palm flowers in Dominican and Baltic amber

Five palm flowers in Dominican amber and one in Baltic amber are described or characterized. Palaeoraphe dominicana gen. et sp. nov. in the subtribe Livistoninae, is described from one perfect flower in Dominican amber. Roystonea palaea sp. nov. is described from one staminate and one pistillate flower in Dominican amber. Three other palm flowers, two perfect flowers from Dominican amber and one staminate flower from Baltic amber, are briefly characterized and figured.  © 2002 The Linnean Society of London, Botanical Journal of the Linnean Society , 2002, 139 , 361–367.     

γ射线紫外线镰刀菌产生玉米赤霉烯酮毒素的影响

锭刀菌(Fusarium)经γ射线、紫外线辐射诱变后,接种于大米培养基中.经10℃低温产毒培养.采用薄层层析方法定性定量分析培养物中的镀刀菌毒素—玉米赤霉烯酮(zearalenone简称ZEA).结果表明:不同菌株对诱变剂的反应不同.产毒菌株NF5232、NF5946在较大剂量γ射线处理后,ZEA产量显著增加,但其产生的色素量下降.或者用紫外线处理,仍然产生ZEA.不产毒菌株NF6127、NF6123、NP6138和HD—002,经γ射线或紫外线处理后仍不产生ZEA.由此可知镰刀菌产生ZEA毒素的能力是相对稳定的,其产毒机制是由菌株本身的遗传特性决定的,一定剂量的γ射线可使低产毒菌株变为高产毒菌株.     

Floral sex ratios and gynomonoecy in Aster (Asteraceae)

Gynomonoecy is the sexual system in which female and bisexual flowers occur on the same plant. This system has received little attention despite the considerable work on other plant sexual systems in the past few decades. Our study examines one hypothesized advantage of having two flower types on a plant, namely that this arrangement permits flexibility in allocation of resources to male and female reproductive functions. We examined 16 species of Aster (Asteraceae), a genus of gynomonoecious, perennial herbs. Plants in this genus produce heads consisting of a whorl of female flowers around a cluster of bisexual flowers. Among field-grown plants we found no evidence that plant size, date, position of heads, rainfall, or shade influenced the proportion of female flowers. A series of greenhouse experiments likewise revealed no large or consistent effects of light, nutrients, or position of heads on the proportion of ray flowers. While floral ratios proved very stable in the face of environmental and physiological variables, they exhibited significant variation among plants and among sibships in most species. We conclude that the presence of two flower types in gynomonoecious asters is not advantageous in permitting flexibility in allocation of resources to male and female functions. We believe that the advantage of the female flowers in aster heads lies either in reducing pollen-pistil interference or in attracting pollinators.     

A tetracyclic triterpenoid from Musa paradisiaca

The structure of a new tetracyclic triterpene isolated from the flowers of Musa paradisiaca was determined as (24R)-4α,14α,24-trimethyl-5α-cholesta-8,25(27)-dien-3β-ol.     

Scanning Electron Microscopic Studies on the Development of the Organs of Litchi Flower

The pattern of development of the floral parts of litchi (Litchi chinensis Sonn.) flower was followed using scanning electron microscopy. Before making scanning electron microscopic observations, specimens were tannin-osmium impregnated and critical point dried. In the bisexual flower, floral organogenesis starts with the formation of protrusions near the floral apex. The two to three protrusions present at the apical region of the floral apex later expand and fuse to form the ovary. At the upper middle region of the ovary another protrusion develops which later becomes the style and the stigma. When the flower matures the tip of the style not only splits but also becomes twisted. On the upper side of the stigma there are numerous papillate cells. These cells are covered with mucilage when fully mature. The development of the filament and anther begins a little bit earlier than the gynoecium. The first sign of androecium development begins when protrusions start to develop around the floral apex. Each litchi flower possesses 6 to 10 anthers. In addition to forming bisexual flowers, litchi also produces a large number of male and female unisexal flowers. But under the scanning electron microscope it is very difficult to distinguish accurately between male and female flowers, because both flowers invariably give rise to some poorly developed organs of the opposite sex. Thus it seems that all flowers in litchi are potentially bisexual and only at the final stage of development (i.e. about 50 days after floral initiation) sex organs fail to develop properly in some flowers.     

Apigenin 7-glucoside diacetates in ligulate flowers of Matricaria chamomilla

From ligulate flowers of Matricaria chamomilla was isolated a mixture of apigenin 7-O-β-glucoside diacetates, which was shown to be based on (2″, 3″)- and (3″, 4″)-diacetates.     

Evolution of funnel-revolver flowers and ornithophily in nasa (loasaceae)

Floral morphology, distribution, and flower visitors for 60 taxa of Nasa are investigated and compared to molecular trees inferred both from a combined marker analysis (ITS1 and trnL (UAA)) and from a single marker (ITS1). Flowers conform to two different floral types: Firstly, "tilt-revolver flowers", with spreading to reflexed, white to yellow petals and small, brightly coloured floral scales contrasting with the petals and firmly enclosing the nectar (Saccatae and Carunculatae); secondly, "funnel-revolver flowers", with half-erect to erect, orange to red petals and floral scales not contrasting with the petals, or enclosed in the corolla, and nectar freely accessible by funnel-shaped floral scales ( Alatae, Grandiflorae, and N. venezuelensis species group). Phylogenetic analysis shows that "tilt-revolver flowers" represent the plesiomorphic condition by outgroup comparison. The two groups with tilt-revolver flowers in Nasa are not monophyletic ( Saccatae are paraphyletic, Carunculatae are polyphyletic). Most Saccatae fall into two monophyletic assemblages, the N. poissoniana species group and the N. triphylla species group. The remainder of Saccatae group either with Grandiflorae ( N. insignis species group) or with Alatae ( N. laxa species group). The clades retrieved in the molecular analysis contradict the traditional classification, but are congruent with vegetative morphology, details of the flower morphology, and biogeography. "Funnel-revolver flowers" represent the derived condition, but molecular data suggest a convergent development (at least twice independently), since the corresponding species do not constitute a monophyletic group. "Tilt-revolver flowers" are visited and pollinated by bees (especially Colletidae), whereas "funnel-revolver flowers" are mostly visited by hummingbirds. The transition from melittophily to ornithophily may have been the license for the colonization of, and the diversification in, both cloud forest and high Andean habitats.     

APETALA1 and SEPALLATA3 interact to promote flower development

In Arabidopsis, the closely related APETALA1 (AP1) and CAULIFLOWER (CAL) MADS-box genes share overlapping roles in promoting flower meristem identity. Later in flower development, the AP1 gene is required for normal development of sepals and petals. Studies of MADS-domain proteins in diverse species have shown that they often function as heterodimers or in larger ternary complexes, suggesting that additional proteins may interact with AP1 and CAL during flower development. To identify proteins that may interact with AP1 and CAL, we used the yeast two-hybrid assay. Among the five MADS-box genes identified in this screen, the SEPALLATA3 (SEP3) gene was chosen for further study. Mutations in the SEP3 gene, as well as SEP3 antisense plants that have a reduction in SEP3 RNA, display phenotypes that closely resemble intermediate alleles of AP1. Furthermore, the early flowering phenotype of plants constitutively expressing AP1 is significantly enhanced by constitutive SEP3 expression. Taken together, these studies suggest that SEP3 interacts with AP1 to promote normal flower development.     

Ethylene production by young Aranda orchid flowers and buds

A high rate of ethylene production was observed in buds and young flowers of Aranda orchid, which increased with bud growth, reaching a high value in half-opened flower. This was followed by a gradual decline but it increased again when the flowers showed sign of senescence. Aminooxylacetic acid (AOA) inhibited ethylene production and bud expansion of Aranda buds.     

表油菜素内酯对月季切花保鲜作用的研究

本文初步探讨了表油菜素内酯（epiBR）对瓶插月季切花的保鲜作用。与对照（蒸馏水）和基本液（2％蔗糖＋500mgL-1柠檬酸＋250mgL-8-羟基喹啉＋25mgAgNO3）相比,经epiBR处理（基本液＋0．1mgL-1epiBR）的月季切花花枝坚挺,蓝变延迟,瓶插寿命延长1-1.5倍。测定有关生理指标表明,epiBR处理对月季切花瓶插花枝前期鲜重的增加及后期的保持有明显作用。并显著延缓花瓣和叶片质膜相对透性的增加,还能使瓶插前期花瓣还原糖含量增加。epiBR处理对花瓣蛋白质和叶片叶绿素含量变化无明显影响,而对花瓣花青素水平下降有轻微的促进作用。     

Discovery of Bisexual Flowers in Pterocarya Stenoptera C. DC.

This paper reports the bisexual structure of the flowers of Pterocarya stenoptera. The bisexual flowers are borne at the end of a leafy shoot of the current year in many-flowered terminal pendulous catkins. They have the same structure as the general female ones. Each flower grows in the axil of a bract, with a pair of bracteoles and four small perianths. Each flower has two or three carpels in the centre of the flower, and upon them there are two or three styles with stigmas on the inner face. They differ from the general female ones in that each of them contains 4-6 stamens, forming a single whorl. The stamens alternates with, or is opposite to, the perianth elements. Sometimes they contain 8 (-10) stamens, forming two whorls, with 6 in the outer whorl and 2 (-4) in the inner whorl, and in this case the pistil in the bisexual flower of terminal catkins often becomes a rudiment. It is interesting that we have also found bisexual flowers in another tree, which are borne in lateral male catkins. They have the same structure as general male ones, and the pistils are often represented by a rudiment. Manning (1940) points out that some female flowers of Pterocarya stenoptera and P. fraxinifolia occasionally have stamens ( ? ) opposite the sepals. In P. stenoptera we have found that both the stamens and the stigmas of bisexual flowers are functional. They are capable of producing functional fruits. This is the same case as in Myrica Gale described by Davey and Gibson (1917). Rendle (1952) points out that in the male flowers of Platycarya the pistils often appeared as a rudiment. He considers, however, the male flowers derived from the bisexual flowers with an indefinite number of stamens. The rudimentary pistils of lateral male catkins in P. stenoptera we found are just the same as the ones found in Platycarya by Rendle. The discovery of the bisexual flowers in P. stenoptera may prove that the unisexual flowers of the present-day Juglandaceae are derived from ancestors with bisexual flowers.This tends to support the hypothesis that Cycadicae is the possible ancestor of the angiosperms.