Isolation and identification of antheridiogens in the ferns, Lygodium microphyllum and Lygodium reticulatum.

Antheridiogens in culture media of 6-week-old prothallia of two species of Schizaeaceous ferns, Lygodium microphyllum and Lygodium reticulatum, were analyzed by gas chromatography-mass spectrometry. In both species, the gibberellin A73 methyl ester (GA73-Me) was identified as the most abundant antheridiogen, and the methyl esters of GA9 and of several monohydroxy-GA73 derivatives were also detected. Since both species produced antheridiogens at a high level, they were classified into high-antheridiogen-producing ferns. The response to GA73-Me of gametophytes of both species is also discussed.     

Isozyme variation and the reproductive biology of Hydrocharis morsus-ranae L. (Hydrocharitaceae)

Electro-phoretically detectable isozyme variation was studied for 17 enzyme systems in several N American populations of the introduced aquatic plant Hydrocharis morsus-ranae and in two European populations. Twenty-nine loci were inferred from progeny, adult and turion enzyme banding patterns with 28 of these loci homozygous in all individuals studied. Malate dehydrogenase-1 (MDH-1) was the only locus which could be interpreted as multi-allelic and heterozygous. Twenty-seven of 76 seedlings assayed showed an age specific expression for an alcohol dehydrogenase locus (ADH-2) never seen in adults or turions. Since all adults sampled were phenotypically identical at all loci assayed, it is possible that only one isozyme genotype of this species is present in N America. European turion data further indicated that the populations studied were identical to N American plants sampled at all loci except EST. Therefore, although H. morsus-ranae is dioecious, outcrossing appears to involve substantial inbreeding. Connections between extensive inbreeding and the failure of effective sexual reproduction are considered.     

Parasites of the shore crab Carcinus maenas (L.): implications for reproductive potential and invasion success

The European shore crab, Carcinus maenas, is one of the most successful marine invasive species. Its success has been in part attributed to the loss of parasites, rekindling an interest in host-parasite interactions and impacts on host fitness in this crab. In the present study, we investigated C. maenas populations from Europe, South Africa and Australia for parasites, and assessed their impact on the fitness of male crabs. For the shore crab, testes weight along with success in mating competition is traded off against other life-history traits. We therefore used this parameter as an indicator both for reproductive fitness and a possible resource trade-off in response to parasite infestation. In the native range, crabs infested with Sacculina carcini showed significantly lower testes weight than uninfected crabs. However, helminth parasites did not generally cause reduced testes weights. Crab populations from South Africa and Australia were either parasitized at very low prevalences, or were completely parasite free. However, no population level effect of this parasite release was reflected in testes weight. These findings do not support a severe fitness impact of helminth parasites on C. maenas, which questions the role of parasites on its population dynamics, both in the native area and for invasive success.     

Notes on the reproductive biology ofPortulaca L. (Portulacaceae) in Nigeria

Nigerian species ofPortulaca: P. grandiflora Hooker,P. oleracea L. andP. quadrifida L. combine inbreeding, outbreeding and vegetative propagation in the wild and in the oultivation. Observations have shown that the anthers ofPortulaca species dehisces before the flower bud opens, and are usually ripe at the time the stigmas are receptive. This enhances self-fertilization.     

Octothrips lygodii sp. n. (Thysanoptera: Thripidae) damaging weedy Lygodium ferns in south-eastern Asia, with notes on other Thripidae reported from ferns

Abstract Weedy Lygodium ferns have become a serious fire hazard in Florida, introduced from the Old World Tropics. During joint CSIRO/USDA studies on potential biological control agents, a thrips species was found widely in south-eastern Asia causing severe damage to L. microphyllum . Described here as a new species, Octothrips lygodii , this is the second species of a poorly known genus that has been based on a single damaged male from Papua New Guinea. The genus is redefined, the two species distinguished, and notes given on the range of Thripidae reported from ferns worldwide.     

Host-range and cold temperature tolerance of Floracarus perrepae Knihinicki & Boczek (Acari: Eriophyidae), a potential biological-control agent of Lygodium microphyllum (Pteridophyta: Lygodiaceae)

Abstract The leaf galling eriophyid mite Floracarus perrepae is a widespread and damaging herbivore of Old World climbing fern, Lygodium microphyllum , across its native range in tropical and subtropical Asia and Australia; and was therefore selected as a candidate biological-control agent for the invasive fern in Florida, USA. The host testing of F. perrepae focused on Lygodium species from North America and the Neotropics, along with threatened or endangered ferns from Florida. Sporeling ferns were used for the initial no-choice screening and F. perrepae showed normal development on the Florida genotype of L. microphyllum with 33.0 ± 4.6 mites per marginal leaf roll gall, modest development on the North American native Lygodium palmatum with 29.0 ± 9.3 mites per roll, and minor development on six other fern species (4.0–0.3). Leaf rolls were induced only on Lygodium species and full rolls were common only on L. microphyllum . These same six non-target plant species were tested again as more mature plants in both no-choice and choice tests and F. perrepae developed only on L. microphyllum . Lethal minimum temperature and cold stress tests were also conducted on F. perrepae . These tests revealed that it would not likely establish north of USDA hardiness zone 8a (−9.5 to −12.2°C), which means it would not overlap with L. palmatum from temperate North America. Our studies conclude that F. perrepae is specific to L. microphyllum , poses little or no risk to native or cultivated ferns in North and South America, and therefore should be considered for release in Florida.     

海金沙的化学成分和药理活性研究进展

海金沙是海金沙科海金沙属多年生蕨类植物,在我国广东、海南、江苏、浙江等地广泛分布。海金沙含有黄酮类化合物、酚酸及其糖苷类化合物及三萜类化合物等多种生物活性成分,具有利胆、防治结石、抗氧化、抗茵等多种药理活性。对海金沙的化学成分和药理活性做了综述,以便更好地对其进行开发利用。     

The reproductive biology of the genusBaldellia (Alismataceae)

The reproductive biology of the genusBaldellia was studied under cultivation and in nature.B. ranunculoides subsp.repens is self-incompatible whereasB. ranunculoides subsp.ranunculoides andB. alpestris are self-compatible. Bud-pollination occurs in theB. alpestris. Self-incompatibility correlates with the production of fewer, larger, more showy flowers, higher pollen production (but reduced pollen grain size), fewer carpels and smaller seeds. Resource allocation to sexual reproduction is inversely correlated with the degree of vegetative growth.B. ranunculoides subsp.repens produces more ramets than subsp.ranunculoides, which reproduces mainly by seeds.B. alpestris is intermediate between the two since it is self-compatible, produces fewer, larger seed than subsp.ranunculoides and is also able to propagate by vegetative means.     

海金沙胚胎发育的研究

利用石蜡切片法研究了海金沙胚胎发育过程。合子的第一次分裂面垂直于颈卵器的长轴,产生两个相等的子细胞,靠近颈卵器颈部的营养器官原始细胞和远离颈部的基足原始细胞。前者发育成子代孢子体的营养器官,后者发育成基足。胚胎在32细胞阶段后,第一叶顶端细胞与第一根顶端细胞几乎同时发生。第一叶突出帽状体之后,由第一叶基部保留下来的茎干顶端细胞产生第二叶。据营养器官的形态结构判断,在海金沙胚胎发育中最早出现的营养器官是叶和根。     

The effects of white fluorescent light,far-red light,darkness, and moisture on spore germination of Lygodium heterodoxum (Schizaeaceae)

Spores of Lygodium heterodoxum Kunze were stored in dry and fully water-imbibed conditions in darkness at 23–25 C. Spores stored in dry conditions lose viability faster than those stored fully water-imbibed. After 1 year, less than 1% of the spores stored in dry condition germinated, while about 40% of the stored water-imbibed spores still germinated. The spores do not germinate in darkness, but they do germinate under white and far-red light.     

Floral and reproductive biology of Drosophyllum lusitanicum (L.) Link (Droseraceae)

We studied the floral and reproductive biology of Drosophyllym lusitanicum (Droseraceae), a species endemic to the western Iberian Peninsula and northwest Morocco. Flowering lasted from March to August, peaking in April. The species is clearly homogamous, with pollen germination and stigma receptivity occurring even in preanthesis. This was reflected in the high rates of fruit set and seed set in bagged inflorescences. Fructification did not differ significantly between different pollination treatments, although we did find differences between some treatments in the numbers of viable seeds per flower and fruit. However, seed weight did not differ significantly. The importance of self-pollination over cross-pollination was also supported by the low percentages of fructification (24.67%) after emasculation and open pollination. Metameric deviations were seen in flowers, although this abnormality was not translated as any reproductive benefit or disadvantage (fructification, number or weight of seeds) in comparison with normal flowers.     

Vulnerability and determinants of reproductive success in the narrow endemic Antirrhinum microphyllum (Scrophulariaceae)

The breeding system and flowering phenology of the narrow endemic Antirrhinum microphyllum (Scrophulariaceae) were studied in order to assess the main factors affecting female reproductive success and to identify existing or potential threats to the viability of its populations. Hand-pollination experiments showed that A. microphyllum is an allogamous self-incompatible species. In both populations studied, the flowering season was 4 mo long and mean flowering duration per plant was about 1 mo. Peak flower production took place between mid-April and mid-May and overlapped with the period of activity of the main pollinator, Rhodanthidium sticticum (Megachilidae). Estimated mean number of seeds produced per plant was 9391, showing that population viability is not presently limited by seed output. The study of the direct and indirect effects of plant size, phenological traits (first flowering date, flowering duration, and flowering synchrony), and distance to neighbor plants on reproductive success was performed using structural equation modeling (SEM). In both populations, number of flowers and plant size were the main factors that determined the total number of fruits produced by a plant. First flowering date and flowering synchrony also affected fruit production. Multisample comparison of path coefficients for the two populations rejected the possibility that reproductive patterns could be described by one single model.     

The taxonomy, reproductive biology and economic potential of Parkia (Leguminosae: Mimosoideae) in Africa and Madagascar

The taxonomy, reproductive biology and economic potential of Parkia (Leguminosae: Mimosoideae) in Africa and Madagascar. Three species of the pantropical woody genus Parkia are recognized from continental Africa (including São Tomé), P. biglobosa, P. bicolor and P.filicoidea. A fourth species, P. madagascariensis , is confined to Madagascar. All have capitula of similar structure although details of shape vary. Relatives sharing this capitulum structure occur in the Far East and the Neotropics. Patterns of infraspecific variation are described for the mainland species. Parkia biglobosa shows clinal variation in several leaf characters and P. clappertoniana must be regarded as synonymous. Parkia bicolor shows geographical variation especially in capitulum shape and pod width, and P. filicoidea varies geographically in its pod morphology. The red, balllike capitula are pollinated by bats; other visitors include birds, insects and non-flying mammals. In P. biglobosa a proportion of the capitula is functionally male. The pods of the African species contain mealy pulp. Dispersal involves mammals, especially primates, and birds. Information on uses, chemical composition of the seeds and insect pests is summarized.     

Establishment of an imported natural enemy,Neomusotima conspurcatalis (Lepidoptera: Crambidae) against an invasive weed,Old World climbing fern,Lygodium microphyllum,in Florida

Neomusotima conspurcatalis established populations against L. microphyllum at three locations in Florida during 2008. A total of 31,091 insects were released. Ten months later populations estimated at 1.6 to 8.2 million larvae per site had defoliated over 14,000 m² of L. microphyllum. Findings look promising for biocontrol of L. microphyllum in Florida.     

The reproductive biology of Chrysoblephus laticeps and C. cristiceps (Teleostei: Sparidae)

A detailed histological study showed that in two protogynous sparids, Chrysoblephus laticeps (Cuvier) and C. cristiceps (Cuvier), gametogenesis follows a pattern typical of temperate sparids and marine teleosts in general. Fertilization is external and both species produce numerous small eggs which are pelagic. They have a restricted summer breeding season and gonadal recrudescence is well correlated with temperature and photoperiod. Behavioural observations showed that C. laticeps are pair-spawners, releasing their gametes well above the substratum after an elaborate courtship routine. The testes of these fishes are small in relation to those of other sparids and are thought to reflect basic differences in the mating systems of sex-changing and gonochoristic species.     

The biology of the cutworm Tryphaena pronuba L. (Lepidoptera: Noctuidae)

Summary Adults of the cutworm Tryphaena pronuba L. fly between June and October and lay about 1,400 eggs. There are seven larval instars, followed by a pre-pupal (diapause) stage in January and pupation in May. The effects of different temperatures on the rate of egg, larval and pupal development are described and discussed.

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Zusammenfassung Die Imagines des Hausmütterchens, Tryphaena pronuba L., fliegen zwischen Juni und Oktober und legen etwa 1400 Eier ab. Auf sieben Larvenstadien folgt ein Präpuppenstadium, das von Anfang Januar bis Mitte Mai diapausiert. Systematische Versuche über den Einfluß der Temperatur auf die Entwicklungsrate von Eiern, Larven und Puppen zeigen, daß die optimale Entwicklungstemperatur für die Eier (90–100% Schlupf) bei etwa 25° liegt. Da sich jedoch die Jungraupen bei dieser Temperatur ebensowenig wie bei 10° normal weiterentweckeln können, ist als optimale Temperatur für Embryonal-und Larvenentwicklung 15–20° zu betrachten. Bei Wechseltemperaturen (zwischen verschiedenen 10°-Intervallen) stimmten Schlupfprozente und Entwicklungszeiten ziemlich genau mit den Werten überein, welche sich bei konstanten Temperaturen in Höhe der Mittelwerte ergeben hatten; nur bei 10° war der Schlupf gegenüber 5-und 15°-Wechsel stärker gehemmt und die Entwicklungszeit verdoppelt. Tiefere, Temperaturen (0,8–5°) erniedrigten-auch im Freiland-schon bei kurzer Einwirkungszeit die Schlupfprozente, obwohl sich die überlebenden bei 25° normal weiterentwickelten. Die Larvalentwicklung dauerte bei 10, 15, 20 und 25° neun, acht, drei bzw. zwei Monate bei einer Entwicklungsrate von 10, 40, 50 bzw. 7%. Das Präpuppenstadium dauerte bei 25° weniger als eine Woche, bei 10° über einen Monat.

     

The reproductive biology of the Mediterranean endemic Cyclamen balearicum Willk. (Primulaceae)

Knowledge of the reproductive biology of endemic plants improves our understanding of how mating system may be related to patterns of species abundance and provides a basis for the development of rational conservation programmes. In this paper we present natural population data on the floral biology and reproductive ecology of the endemic Mediterranean species Cyclamen balearicum Willk. This is a long-lived, diploid perennial herb which occurs in southern France in five fragmented and isolated regions and on the Balearic Islands of Mallorca, Menorca, Ibiza, Cabrera and Draponera. Our observations indicate a particularly scarce pollinator activity (rare syrphid visits) and dispersal by ants over small distances. A controlled pollination experiment in a natural population showed that in southern France C. balearicum is fully self-compatible and that selfing is autonomous and probably delayed (i.e. following opportunities for outcrossing). The proximity of stigmas and anthers will favour autonomous selfing. The high pollen/ovule ratio indicates nevertheless that C. balearicum has a mixed mating system. Patterns of variation in stigma-anther separation and pollen production per flower suggest that not only has the current mating system of the species evolved from an outcrossing ancestor but that due to the fragmentation and isolation of populations greater levels of selfing have evolved in southern France (and to an intermediate degree on Ibiza and Menorca). On the island of Mallorca where larger continuous belts of C. balearicum habitat still exist the species has floral traits indicating a more outcrossed mating system. To our knowledge this is the first paper to document such trends in floral traits in the endemic component of the Mediterranean flora.     

On the reproductive biology of the sand smelt Atherina boyeri Risso (Pisces: Atherinidae) and its evolutionary potential

The small, typically estuarine fish Atherina boyeri Risso forms local populations which can differ greatly in their population biology and morphology; this species is viewed as being on the brink of speciation. This analysis of the reproductive strategy shows that A. boyeri can rapidly adapt its life history and morphology to environments ranging from freshwater to polyhaline coastal lagoons and oceanic waters. The optimum strategy is shown to be tied to temperate seasonality: the cold winters act to lengthen the life cycle, and result in cyclic switching of energy between reproduction, somatic growth and fat storage. The adaptability of the fish to a range of environmental characters is viewed as being due to natural selection acting to produce a genotype capable of a flexible phenotypic response. This flexibility is essential for survival in the highly variable inshore/brackish habitat. It is argued that such preadaptive plasticity, coupled with the potential for populations to become isolated, produces ideal conditions for speciation. The importance of the coastal, estuarine and lagoonal environment as a springboard for teleost evolution is discussed.     

Relations between submarginal and marginal sori in ferns IV. The sori of Osmunda and selected Schizaeaceae and their morphological relations

Developmental types of sori in Osmunda and Schizaeaceae are comparatively studied and discussed in a systematic context. (1) The ``simultaneous marginal sorus' is characterized by a minute knob-like receptacle representing the thickened tip of a short costa, simultaneous initiation of massive sporangia, and absence of indusia. (2) The ``acropetal marginal sorus' is characterized as an accessory outgrowth at the end of a costa or at the margin of a sorophore, comprising a minute or elongated bifacial receptacle, acropetal initiation of massive marginal sporangia, and minute or long-extended or hood-shaped upper indusia. The state of superficial singly-arranged massive sporangia such as in Todea may give rise to the Osmunda type of the simultaneous marginal sorus and to the Schizaeaceae types of the acropetal marginal sorus. Phase differentiation in leaf development combined with complete laminar reduction leads to the Osmunda type, while phase differentiation in leaf lamina development and additional processes may give rise to the Mohria, Anemia, and Lygodium types. These morphological results support recent phylogenetic studies by other authors in disclaiming close relationships between Osmundaceae and Gleicheniaceae, and between Marattiaceae and Ophioglossaceae (``Eusporangiatae'). They also potentially support relationships between Osmunda- ceae and Schizaeaceae or between Ophioglossaceae and Schizaeaceae. The high complexity of the sori in Marattiaceae and Ophioglossaceae is surprising if the two families are viewed as basal groups.