Vitellogenesis in Acanthoscelides obtectus (Coleoptera: Bruchidae). II—The conditions of vitellogenesis in a strain from Colombia. Comparative study and adaptive significance

The reproductive activity of an Acanthoscelides obtectus strain originating in the high Colombian plateau (altiplanos) was compared to that of a European strain. Colombian females exhibited greater individual variations than their European counterparts. Some females did not synthesize vitellogenin during the 140-day period of observation, while others performed synthesis but not incorporation into oocytes. Under these conditions, 40–50% of the females could form a limited number of oocytes. The presence of Phaseolus vulgaris seeds stimulated vitellogenin synthesis and incorporation by most females. This initiation of ovarian activity enabled mating to occur, which in turn led to maximal stimulation of oogenesis. This host plant—mating interaction leads to the production and release of a large number of eggs. The observed variability of reproductive activity and its dependence on stimulatory factors probably reflect an adaptation to the ecological conditions prevailing in the high-altitude environment of these insects.     

Queen power in relation to age and mating status in the Argentine antIridomyrmex humilis (Mayr)

Summary Queen power inIridomyrmex humilis during six arbitrarily chosen physiological stages of queens (virgin winged queens at the time of emergence, the same 4–5 days old, mated winged queens 5–6 days old, mated queens at the time of dealation, young egg-laying queens, and old egg-laying queens) was tested with regard to workers. Tested workers and queens were nestmates. The results were as follows. 1) Power of the old queens remained rather constant throughout the reproductive season. 2) Young queens were always less attractive than older ones. No changes were observed from the time of emergence to dealation. 3) At the time of egg-laying, these young queens became markedly attractive for workers but never as much as old egg-laying queens. Therefore, insemination and dealation do not trigger the increase in queen power. In contrast, oogenesis ending by egg-laying produces a significant increase in queen power.     

Multiple mating and its effect on the reproductive success of female Epiphyas postvittana (Lepidoptera: Tortricidae)

Abstract.

• 1 Multiple mating and its effect on reproductive performance of female Epiphyas postvittana (Walker) moths were studied under controlled conditions.
• 2 The age at which the moths mated for the first time ranged from the first to the tenth day after emergence, but 71% of first matings were during the first 3 days.
• 3 The majority (63%) of females had one or two spermatophores in the bursa copulatrix. Some (24%) were found with three to five spermatophores, whereas no successful mating occurred among 13% of individuals. The number of matings was partly dependent on the number of mates available to the female. Between the range of sex ratios of one male to one female and four males to one female maximal mating success occurred at the ratio of three males to one female.
• 4 Virgin females were capable of egg-laying, but mating stimulated and accelerated oviposition. Mated individuals laid twice as many eggs as unmated ones.
• 5 The level of copulatory activity did not influence the longevity of females irrespective of the number of males available to them.
• 6 Sex ratios with greater than one male to a female improved the reproductive success by marginally increasing fecundity and fertility.
• 7 It is concluded that multiple mating would enhance population growth, and is of particular benefit to populations with a preponderance of females, as is known to occur naturally in this species.

     

Salt sensitivity in chickpea (Cicer arietinum L.): ions in reproductive tissues and yield components in contrasting genotypes

The reproductive phase in chickpea (Cicer arietinum L.) is affected by salinity, but little is known about the underlying cause. We investigated whether high concentrations of Na⁺ and Cl^– in the reproductive structures influence reproductive processes. Chickpea genotypes contrasting in tolerance were subjected to 0, 35 or 50 mm NaCl applied to soil in pots. Flower production and abortion, pod number, percentage of empty pods, seed number and size were evaluated. The concentrations of Na⁺, K⁺ and Cl^– were measured in various plant tissues and, using X‐ray microanalysis, in specific cells of developing reproductive structures. Genotypic variation in reproductive success measured as seed yield in saline conditions was associated with better maintenance of flower production and higher numbers of filled pods (and thus seed number), whereas seed size decreased in all genotypes. Despite the variation in reproductive success, the accumulation of Na⁺ and Cl^– in the early reproductive tissues of developing pods did not differ between a tolerant (Genesis836) and a sensitive (Rupali) genotype. Similarly, salinity tolerance was not associated with the accumulation of salt ions in leaves at the time of reproduction or in seeds at maturity.     

Proliferation of Oogonia and folliculogenesis in the viviparous teleost Ilyodon whitei (Goodeidae)

Oogonial proliferation in fishes is an essential reproductive strategy to generate new ovarian follicles and is the basis for unlimited oogenesis. The reproductive cycle in viviparous teleosts, besides oogenesis, involves development of embryos inside the ovary, that is, intraovarian gestation. Oogonia are located in the germinal epithelium of the ovary. The germinal epithelium is the surface of ovarian lamellae and, therefore, borders the ovarian lumen. However, activity and seasonality of the germinal epithelium have not been described in any viviparous teleost species regarding oogonial proliferation and folliculogenesis. The goal of this study is to identify the histological features of oogonial proliferation and folliculogenesis during the reproductive cycle of the viviparous goodeid Ilyodon whitei. Ovaries during nongestation and early and late gestation were analyzed. Oogonial proliferation and folliculogenesis in I. whitei, where intraovarian gestation follows the maturation and fertilization of oocytes, do not correspond to the late oogenesis, as was observed in oviparous species, but correspond to late gestation. This observation offers an example of ovarian physiology correlated with viviparous reproduction and provides elements for understanding the regulation of the initiation of processes that ultimately result in the origin of the next generation. These processes include oogonia proliferation and development of the next batch of germ cells into the complex process of intraovarian gestation. J. Morphol. 275:1004–1015, 2014. © 2014 Wiley Periodicals, Inc.     

Reproductive biology of Aechmea bracteata (Sw.) Griseb. (Bromelioideae: Bromeliaceae)

• Individuals of Aechmea bracteata show inflorescences with red scape bracts and odourless, yellow, tubular diurnal flowers, with closely arranged sexual organs, producing a large amount of fruits.
• In order to investigate the reproductive system of this species, a suite of characters was assessed: phenology, floral morphology and biology, nectar production dynamics, and fruit and seed production and germination, as a result of controlled pollination crosses. The study was conducted during two flowering seasons in wild populations in Yucatán, Mexico.
• Results suggest an annual flowering pattern with one flowering peak; flowers were diurnal, showing partial dichogamy (protandry)‐herkogamy, anthers and stigma become mature before floral aperture, which could lead to self‐pollination, nectar is produced during anthesis, varying in volume and total sugar concentration during the day; fruits and seeds were produced in all experimental crosses (cross‐pollination, obligated cross‐pollination, assisted and unassisted selfing, geitonogamy and apomixis), as well as high percentage seed germination.
• Several species of Aechmea are reportedly self‐compatible and autogamous, as suggested by results of selfing and non‐assisted selfing crosses, but these results are negated by the presence of apomixis, indicating that the species is apomictic. This is the first report of this breeding system for subgenus Aechmea and the sixth for Bromeliaceae. Polyembryony is here suggested for the first time in this genus and family based on the fact that more seeds were recorded that expected based on ovule numbers. Finally, when performing experimental crosses, estimating reproductive success based on number of seeds is a better approach than number of fruits, due to the effect of pseudogamy.

     

The Effects of Primates and Squirrels on Seed Survival of a Canopy Tree,Afzelia quanzensis,in Arabuko‐Sokoke Forest,Kenya1

I examined the fate of seeds from ten focal trees of Afzelia quanzensis (Leguminosae), a canopy tree in the Arabuko‐Sokoke, Kenya. The study was conducted for one fruiting season, between August 1990 and July 1991. Yellow baboons (Papio cynocephalus), Syke's monkeys (Cercopithecus albogularis), sun squirrels (Heliosciurus rufobrachium), and bush squirrels (Paraxerus palliatus) were all observed to interact with A. quanzensis seeds at various stages of pod development. Baboons and squirrels consumed high percentages of seeds when they were still immature, but the seeds were still unavailable to Syke's monkeys at this stage. Baboons bit open the hard green pods and squirrels gnawed through the pods to extract the immature seeds (hereafter referred to as seed predation), but monkeys were unable to open the pods. Upon maturity, the pods opened slightly, revealing red arils that were sought by baboons, monkeys, and squirrels. Monkeys removed the highest percentage of mature seeds from these pods. These mammal dispersers ate the arils from the mature seeds and discarded the viable part that germinates (hereafter referred to as seed dispersal). My data indicate that baboons and squirrels are seed predators while monkeys are seed dispersers of A. quanzensis.     

Seed dormancy and control of germination in Sisymbrella dentata (L.) O.E. Schulz (Brassicaceae)

• Seed germination responsiveness to environmental cues is crucial for plant species living in changeable habitats and can vary among populations within the same species as a result of adaptation or modulation to local climates. Here, we investigate the germination response to environmental cues of Sisymbrella dentata (L.) O.E. Schulz, an annual endemic to Sicily living in Mediterranean Temporary Ponds (MTP), a vulnerable ecosystem.
• Germination of the only two known populations, Gurrida and Pantano, was assessed over a broad range of conditions to understand the role of temperatures, nitrate, hormones (abscisic acid – ABA and gibberellins – GA) and after‐ripening in dormancy release in this species.
• Seed germination responsiveness varied between the two populations, with seeds from Gurrida germinating under a narrower range of conditions. Overall, this process in S. dentata consisted of testa and endosperm rupture as two sequential events, influenced by ABA and GA biosynthesis. Nitrate addition caused an earlier testa rupture, after‐ripening broadened the thermal conditions that allow germination, and alternating temperatures significantly promoted germination of non‐after‐ripened seeds.
• Primary dormancy in S. dentata seeds likely allows this plant to form a persistent seed bank that is responsive to specific environmental cues characteristic of MTP habitats.

     

Taking a chance on moths: oviposition by Delia flavifrons (Diptera: Anthomyiidae) on the flowers of bladder campion, Silene vulgaris (Caryophyllaceae)

Abstract.

• 1 Delia flavifrons Zetterstedt (Diptera: Anthomyiidae) visits flowers of Silene vulgaris (Moench) Garcke (Caryophyllaceae), where the adults feed, mate, lay their eggs, and the larvae feed on developing seeds. The objective of the study was to examine how an ovipositing female fly assures a food resource for her progeny.
• 2 Ovipositing females preferred young, non-pollinated flowers over older pollinated ones. The flies did not pollinate the flowers and survival of the larvae depended on the flowers being pollinated by moths.
• 3 Flowers containing fly eggs were pollinated more often than expected from chance, probably as a result of both flies and moths visiting particular flowers.
• 4 Eggs were laid singly, and multiple oviposition occurred randomly. Although most eggs hatched, only about half produced larvae that made their way into the fruits. As a result, the probability of competition arising from multiple oviposition may be reduced to such an extent that selection does not favour females that avoid flowers with conspecific eggs.
• 5 Moth larvae of the noctuid genus Hadena also feed on the seed pods of S. vulgaris and will kill any fly larvae they encounter. However, there was no deviation from random oviposition by the flies in relation to eggs laid by the moths, but the competitively weaker fly usually started to lay eggs towards the end of the moth's egg-laying period.
• 6 The relationship between Delia flavifrons and Silene vulgaris superficially parallels that for known pollinator/predator systems, but floral adaptations to hypothetically pollinating flies seems not to have taken place.

     

Ovarian indexes as indicators of reproductive investment and egg-laying activity in social insects: a comparison among methods

High reproductive skew among colony members is a fundamental feature of insect’s societies, where one or few individuals monopolize reproductive output. However, many social insect species retain a high reproductive plasticity, with all colony members able of developing ovaries and laying eggs. Understanding the partition of reproduction inside these plastic societies is a key step in the comprehension of social evolution. The reproductive status of social insects is usually evaluated by looking at the degree of ovarian development, and a great variety of different methods has been used even in the same species. It is not known, however, to which extent the different methods give comparable results and represent good indexes of individual egg-laying activity. We used the model paper wasp species Polistes dominula to tackle these issues, by compiling the main methods of ovarian development assessment on the same set of individuals and quantifying their egg-laying activity. Our results showed that all examined methods give similar and highly correlated results, but none of them allows reliable estimates of the egg-laying activity. Ovarian indexes (whatever method is used) are good indicators of individual reproductive potential, but can only roughly reflect actual reproductive activity. We thus propose to be very cautious in extrapolating egg-laying activity levels from ovarian index estimations.     

Reproductive biology of the prawn Melicertus kerathurus (Decapoda: Penaeidae) in Thermaikos Gulf (N. Aegean Sea)

The reproductive biology including insemination frequency, ovarian maturation, gonadosomatic index (GSI), size at first maturity, and fecundity of Melicertus kerathurus were investigated using monthly samples from Thermaikos Gulf. Insemination was recorded by the presence of a spermatophore in the thelycum, and ovarian development was based on macroscopic ovarian staging (ST1–ST5). Inseminated females were found throughout the year with high percentages recorded from April to July. Although all ovarian stages were represented in mated females, insemination increased with size and ovarian maturation. High percentages of vitellogenic or mature ovarian stages were observed from May to July, while immature and developing ovaries were predominant mainly in winter. Spawned ovaries occurred from May to October. Carapace length at first maturity based on the presence of a spermatophore (CL_50sp) was estimated at 39.20 mm, while that based on the presence of vitellogenic and mature ovaries (CL_50ov) at 40.70 mm. The seasonal peak in the proportion of mature females (ST4) varied with size. Inseminated females at ST4 and GSI peaked in June–July. GSI varied in relation to insemination status and ovarian stage. In large females (>50 mm CL), the decline in mature ovaries and GSI increment with size indicates a relative reduction in the reproductive output. The number of oocytes ranged from 62,742 to 602,947 (mean ± SD: 268,000 ± 113,000). As the prawns are targeted during the spawning season, mainly by the artisanal fishery, and female size at first maturity is selected by artisanal net size, managerial measures toward artisanal fishery should be implemented.     

Seed dormancy of Cardiospermum halicacabum (Sapindaceae) from three precipitation zones in Sri Lanka

• This study investigated seed germination of Cardiospermum halicacabum, a medicinally important invasive species.
• We compared mass, moisture content (MC), dormancy and dormancy‐breaking treatments and imbibition and germination of scarified and non‐scarified seeds of C. halicacabum from a low‐elevation dry zone (DZ), low‐elevation wet zone (WZ1) and mid‐elevation wet zone (WZ2) in Sri Lanka to test the hypothesis that the percentage of seeds with water‐impermeable seed coats (physical dormancy, PY) decreases with increased precipitation.
• Seed mass was higher in WZ2 than in DZ and WZ1, while seed MC did not vary among the zones. All scarified DZ, WZ1 and WZ2 and non‐scarified DZ and WZ1 seeds imbibed water, but only a few non‐scarified WZ2 seeds did so. When DZ and WZ1 seeds were desiccated, MC and percentage imbibition decreased, showing that these seeds have the ability to develop PY. GA₃ promoted germination of embryos excised from fresh DZ and WZ1 seeds and of scarified WZ2 seeds.
• At maturity, seeds from DZ and WZ1 had only physiological dormancy (PD), while those from WZ2 had combinational dormancy (PY+PD). Thus, our hypothesis was not supported. Since a high percentage of excised embryos developed into normal seedlings; this is a low‐cost method to produce C. halicacabum plants for medicinal and ornamental purposes.

     

Oviposition substrate affects adult mortality, independent of reproduction, in the seed beetle Callosobruchus maculatus

Abstract.

• 1 Seed beetles (Coleoptera: Bruchidae) are commonly used to study the influence of reproduction on life-span and senescence. To study the physiological trade-off between reproduction and mortality, many experiments rely on manipulating access to oviposition substrates to manipulate the reproductive rate of females.
• 2 The presence of host seeds, independent of reproduction, results in increased mortality of female Cullosobruchus muculutus. This influence on mortality varies between two host seed species, suggesting a role of either allelochemicals or energetic costs associated with behaviour on hosts.
• 3 The influence of host seeds on survivorship, independent of reproduction, confounds the interpretation of cost-of-reproduction studies with seed beetles. This complication must thus be considered in the design and interpretation of life-history studies of seed beetles and other insects.

     

Is there reproductive diapause in the winterform of pear psylla Cacopsyla bidens?

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LIPID RESERVES OF SEEDS OF IMPATIENS CAPENSIS AND I. PALLIDA (BALSAMINACEAE): DEVELOPMENTAL ASPECTS

It has been known since 1948 that seeds of Impatiens species (family Balsaminaceae) contain a polyconjugated 18:4 fatty acid, α-parinaric acid. Content of this acid is high in seeds of the two species of Impatiens native to eastern North America, I. capensis Meerb. and I. pallida Nutt. The cotyledons of these seeds also have an unusual blue pigmentation that disappears when lipids are extracted. Deposition of oil reserves and appearance of cotyledon color was observed during fruit development. Pods of I. capensis and I. pallida were measured daily after anthesis. Length increased linearly to a maximum of about 27 mm (I. capensis) and 30 mm (I. pallida) by day 10 after which increase in girth and fresh weight of pods, and fresh weight of seeds, increased exponentially. At maturity (15 days) seeds of I. pallida were twice the weight of seeds of I. capensis. Lipid reserves, extracted with chloroform-methanol, were detectable by day 6 and increased rapidly to 28% fresh weight (2 mg/seed) in seeds of I. capensis and to 24% (4 mg/seed) in I. pallida. The characteristic ultra-violet (uv) spectrum of α-parinaric acid was already present by day 6, and content of this acid increased to 42% of total lipids in I. capensis and to 30% in I. pallida at maturity. Fatty acids as determined by gas chromatography of oil of mature seeds were 16:0 (13%, I. capensis; 11%, I. pallida); 16:1 (trace); 18:0 (2%); 18:1 (20%, 25%); 18:2 (17%, 14%); 18:3 + 18:4 (48%, 47%). Electron micrographs of mature seeds of I. capensis showed abundant oleosomes and protein bodies. The blue color of the cotyledons was faint at day 11 and then intensified with age. It was somewhat paler in I. pallida than in I. capensis, suggesting that it may be associated with the presence of α-parinaric acid.     

Chronology of reproductive investment determines predation risk aversion in a felid‐ungulate system

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Seed size selection by olive baboons

Seed size is an important plant fitness trait that can influence several steps between fruiting and the establishment of a plant’s offspring. Seed size varies considerably within many plant species, yet the relevance of the trait for intra-specific fruit choice by primates has received little attention. Primates may select certain seed sizes within a species for a number of reasons, e.g. to decrease indigestible seed load or increase pulp intake per fruit. Olive baboons (Papio anubis, Cercopithecidae) are known to select seed size in unripe and mature pods of Parkia biglobosa (Mimosaceae) differentially, so that pods with small seeds, and an intermediate seed number, contribute most to dispersal by baboons. We tested whether olive baboons likewise select for smaller ripe seeds within each of nine additional fruit species whose fruit pulp baboons commonly consume, and for larger seeds in one species in which baboons feed on the seeds. Species differed in fruit type and seed number per fruit. For five of these species, baboons dispersed seeds that were significantly smaller than seeds extracted manually from randomly collected fresh fruits. In contrast, for three species, baboons swallowed seeds that were significantly longer and/or wider than seeds from fresh fruits. In two species, sizes of ingested seeds and seeds from fresh fruits did not differ significantly. Baboons frequently spat out seeds of Drypetes floribunda (Euphorbiaceae) but not those of other plant species having seeds of equal size. Oral processing of D. floribunda seeds depended on seed size: seeds that were spat out were significantly larger and swallowed seeds smaller, than seeds from randomly collected fresh fruits. We argue that seed size selection in baboons is influenced, among other traits, by the amount of pulp rewarded per fruit relative to seed load, which is likely to vary with fruit and seed shape.     

Total extract of Beta vulgaris var. cicla seeds versus its purified phenolic components: antioxidant activities and antiproliferative effects against colon cancer cells

Introduction – Beta vulgaris var. cicla (BV) leaves contain chemopreventive compounds that have been investigated for new drug discovery. These compounds belong to the family of the apigenin‐glycosides. Since the leaves are seasonal products containing high percentages of water, they are easily degradable during storage in fresh conditions. To be stored they require a drying process, consuming time and a large amount of energy. The extraction of apigenin‐glycosides may also be conveniently performed from BV seeds, which represent a stable and year‐long available biomass. Objectives – The present report was undertaken to find a strategy of purification of bioactive flavonoids from BV seeds and test their ability to inhibit proliferation both on human colon cancer (RKO) cells and normal human fibroblasts (HF). Materials and methods – The ethyl‐acetate extract of BV seeds was fractionated on a Sephadex LH 20 column. A fraction of this extract, labeled as P4, exploited a marked antiproliferative activity on RKO cells. The components of P4 were purified on an RP₁₈ column chromatography and identified by HPLC‐ESI‐MS as 2,4,5‐trihydroxybenzaldehyde, 2,5‐dihydroxybenzaldehyde, vanillic acid, xylosylvitexin, glucopyranosyl‐glucopyrasyl‐rhamnetin and glucopyranosyl‐xylosyl‐rhamnetin. All of them were tested for cytostatic and cytotoxic activity on RKO and HF cells. Results – Xylosylvitexin exhibited the strongest antiproliferative activity on RKO cells, together with an enhancement of the apoptosis, an increase of cells in the G₁ phase and a reduction of cells in the S phase; on the contrary, the proliferation of HF was significantly stimulated. Conclusion – Xylosylvitexin is the main and more efficient chemopreventive compound in BV seeds, but the natural cocktail of molecules, represented by P4 fraction, showed a better compromise between the antiproliferative activity on RKO cells and the enhancement of HF proliferation. Copyright © 2011 John Wiley & Sons, Ltd.     

Triacontanol-Induced Changes in the Growth, Photosynthetic Pigments, Cell Metabolites, Flowering and Yield of Green Gram

Seedlings of green gram [Vigna radiata (L.) Wilezek] cultivar KM-2 were sprayed with different concentrations of triacontanol (TRIA) (0, 0.5, 1.0, and 2.0 mg dm^-3) at 15 and 25 days after sowing. Foliar spray of 0.5 mg dm^-3 TRIA significantly promoted the plant height, fresh mass, and contents of chlorophylls, saccharides, starch, soluble proteins, amino acid and phenols. Leaf nitrate content was reduced by 0.5 and 1.0 mg dm^-3 TRIA with a corresponding increase in nitrate reductase activity. TRIA of 0.5 mg dm^-3 stimulated the onset of flowering, pod production and retention, but less number of pods and seeds per plant were observed at 2.0 mg dm^-3 treatment.