Toxicological Indices of Wistar Rats Fed Formulated Chaw of Telfairia occidentalis Planted on Crude Oil Contaminated and Remediated Soil

Toxicological indices of wistar rats fed formulated chaw of Telfairia occidentalis planted on crude oil contaminated and bioremediated soil was studied. Farmland, measuring 18 m2 was divided into three lots of 4 m2 and 2 m space was allowed between each lot (A, B and C). Two lots were polluted, subjected to 16 weeks of bioremediation and viable seeds of T. occidentalis were planted and grown for 28 days. The harvested vegetable leaves were analyzed. Leaves from natural attenuated soil showed high concentration of both aliphatic and polycyclic aromatic hydrocarbons with values of 9.34+0.03 mg/kg and 9.18+0.05 mg/kg for C36 and Fluoranthene respectively, while the bioaugmented soil had Lead as the highest heavy metal with a value of 0.10+0.02 g/100g. Four groups, of 9 rats each (totalling 36 rats) of adult males and females, wealing males and females were subsequently sub-grouped into 3 and allowed to acclimatize for a period of 1 week. These animals were fed formulated rat chaw of 50% dry weight of T. occidentalis, from the three lots (control, bioaugmented and natural attenuated soil) for a period of 28 days. Assay of animals’ toxicological index showed elevated concentrations of alkaline phosphatase, alanine and aspartate aminotransferases, urea and creatinine in their sera. A slight increase in serum amylase activity was recorded, while concentrations of their haemoglobin and Packed Cell Volume (PCV) reduced. The obtained results from these biomarkers were confirmed by the histopathological sections of the animal organs.

The Imbibition, Viability, and Germination of Caper Seeds (Capparisspinosa L.) in the First Year of Storage

The caper is a shrub that adapts to harsh environments when it is established, but it presents serious difficulties in its propagation, both by cuttings and by seeds. Its seeds have low germination percentages, and germination is a very slow process. Significant increases in germination have been obtained with scarification and with the addition of gibberellic acid (GA3) to the substrate, leading to the hypothesis that they have possible physical and physiological dormancy. However, the only way to examine the water-impermeability of the cover is through imbibition analysis. This study analyzes the imbibition, viability, and germination of two seed lots, obtained in different years and evaluated immediately after their collection (FS) and after being stored (7 °C) for one month (DS) and one year (SS). The seed moisture content stabilizes from the fourth day, exceeding in all cases 31% in all three seed states tested (FS, DS and SS). This allows the germination of all viable seeds, only with the addition of GA3 to the germination substrate, without the need for scarification, so that caper seeds exclusively appear to present a physiological latency. Germination decreased in storage, even with just one month. With the GA3 addition, high germination values were obtained (up to 95% in FS).

The Effectiveness of the Sexual Reproduction in Selected Clonal and Nonclonal Species of the Genus Ranunculus

Generative processes have been evaluated in six European buttercup species in order to verify the hypothesis that the reproduction efficiency of clonal species is lower than that of nonclonal ones. The study covered common species (Ficaria verna, Ranunculus auricomus, R. bulbosus, R. cassubicus, R. lanuginosus) and the endangered R. illyricus. The following properties have been assessed: pollen viability (staining method), pollen grain germination and the pollen-tube elongation in pistil tissues (fluorescence microscopy), seed formation efficiency, seed viability (tetrazolium test) and germination ability by introducing factors interrupting dormancy (low temperature and gibberellin application). Additionally, the pistil morphology was documented for R. bulbosus, R. illyricus and R. cassubicus using SEM techniques. It was demonstrated that the reproductive efficiency, expressed as the production of viable seeds able to germinate, was significantly higher in the species reproducing sexually (especially in R. lanuginosus) compared to the clonal ones. However, the complexity observed leads to separation of an additional group (cluster) of apomictic species: R. auricomus and R. cassubicus, distinguished by the lowest pollen viability and a low ability of the seeds to germinate. In the vegetatively reproducing R. illyricus, the seed formation efficiency was just 13.2% despite the having highest number of pistils in its flowers. The developed seeds of this species observed in our experiment were viable, but in general effective methods to stimulate their germination have not been proposed yet. Here, the first comparative study concerning the biology of sexual reproduction of R. illyricus is presented in the context of its decreasing distribution in natural habitats.

Self-pollination of the orchid Cycnoches haagii from Brazilian Cerrado results in albino phenotype seedlings

Cycnoches haagii Barb. Rodr. is an epiphytic orchid very targeted by collectors, but no reference was found in the literature about its reproductive biology. Thus, the purpose of this study was to obtain initial information regarding pollination types and its influence on seed viability of this native orchid of the Brazilian Cerrado, in order to enable future propagation and preservation programs. Pollination among flowers of the same plant (geitonogamy) or different plants (xenogamy) were carried out. Seeds extracted from the capsules were sown in B&G medium, with full and half strength. Seeds from geitonogamic resulted in 25% of albino protocorms and consequently in albino seedlings. This phenomenon did not occur in seedlings derived from xenogamic pollination. Pigment analysis showed that even the albino seedlings presented chlorophylls and carotenoids, however, in significantly minor concentrations, 16% and 37% respectively, in relation to green seedlings. Geitonogamic and xenogamic pollinations resulted in C. haagii viable seeds with high germination percentage (90%) under in vitro conditions. The germination of seeds from xenogamic pollination resulted in chlorophyll or normal seedlings only, and can be recommended at conservation programs. On the other hand, although geitonogamic pollination should be avoided at conservation programs of this orchid species as it leads to albino seedlings, it showed a very interesting system to obtain seedlings with this phenotype, an interesting plant material to future investigation.

Serotiny in Melocactus matanzanus (Cactaceae) and role of cephalium in dispersal of seeds after the individual's death

Serotiny is a strategy in which the retention of mature seeds in parent structures allows plants to cope with environmental variability like heat, drought or fire. Although this phenomenon might be common in Cactaceae, and particularly in Melocactus, it has generally been scarcely addressed. The main goal of our work is to investigate if there are seeds hidden in the cephalium of Melocactus matanzanus and if there are, determine whether or not these seeds maintain their viability. We also discuss some advantages the cephalium may offer as diaspore after the death of individuals. Cephalia collected from dead individuals were divided into four slices and their seeds counted; we also assessed the viability and photoblastic response of the seeds by using growth chambers at 25/30°C, and by a cut test on the seeds that did not germinate. Our results showed retention of viable seeds of different ages in all slices of the cephalium. Seeds were photoblastic positive with germination between 11–22% and viability above 50% in the portion of the lots that did not germinate.

Dependence of spring wheat seed productivity on mineral fertilizer doses and seeding rates

The article presents the results of field studies conducted in 2018-2020 on the leached chernozem of the Volga foreststeppe. The objects of the research are the varieties of spring wheat Tulaykovskaya 10 (control), Yoldyz and Tulaykovskaya 108. At seeding rates of 5.0 and 5.5 million viable seeds per 1 ha the effect of mineral fertilizers was studied. The fertilizers were represented by a complete NPK mineral fertilizer of 16 kg a.i. and by top-dressing with mineral nitrogen fertilizer in the tillering phase at the doses of 30, 60 and 90 kg a.i./ha against this background. An increase in the seeding rate of seeds from 5.0 to 5.5 million seeds per 1 ha led to a significant increase in the yield of spring wheat in all years of study (by 0.11-0.26 t/ha), the weight of 1000 seeds – by 1.44 g (LSD05 = 1.14), the nature of grain - by 8 g/l (LSD05 = 5). The effect of top-dressing with nitrogen fertilizers has been proved – the increase in yield ranged from 0.15 to 0.28 t/ha over three years on the average, the maximum from a dose of 60 kg a.i. A statistically significant increase in the weight of 1000 seeds was provided by nitrogen fertilization in doses of 60 and 90 kg a.i./ha – by 2.79 and 1.87 g, respectively (LSD05 = 1.47), grain nature increased at doses of 30, 60 and 90 kg a.i./ha by 34, 23 and 16 g/l, respectively (LSD05 = 2). The average yield of spring wheat varieties with the selected combination of factors (5.5 million seeds/ha, N60) was in the range of 2.64-2.70 t/ha with a mass of 1000 grains 44.03-44.56 g, the nature of grain 765-783 g/l. The studied varieties differed in responsiveness to nitrogen fertilization (N60 against the NPK background): Tulaykovskaya 10 (+0.43 t/ha), Tulaykovskaya 108 (+0.39 t/ha), Yoldyz (+0.24 t/ha). Increases in yield from an increase in the seeding rate were 0.20 (Yoldyz), 0.25 (Tulaykovskaya 108) and 0.26 t/ha (Tulaykovskaya 10). In general, according to the experiment relative to the control variety Tulaykovskaya 10, the variety Yoldyz stood out with a stable increase in yield over the years of research (+0.08 t/ha), statistically significant in years with insufficient moisture. The Yoldyz variety was distinguished by an increased profitability of cultivation – up to 59.4 % at a seeding rate of 5.5 million viable seeds/ha against the background of applying mineral fertilizers N16P16K16 for pre-sowing soil cultivation.

Trade of commercial potting substrates: A largely overlooked means of the long-distance dispersal of plants

Although long-distance dispersal (LDD) events are considered to be rare and highly stochastic, they are disproportionately important and drive several large-scale ecological processes. The realisation of the disproportionate importance of LDD has led to an upsurge in studies of this phenomenon; yet, we still have a very limited understanding of its frequency, extent and consequences. Humanity intentionally spreads a high number of species, but a less obvious issue is that it is associated with the accidental dispersal of other plant species. Although the global trade of potted plants and horticultural substrates is capable of dispersing large quantities of propagules, this issue has hardly been studied from an ecological point of view. We used the seedling emergence method to assess the viable seed content of different types of commercial potting substrates to answer the following questions: (i) In what richness and density do substrates contain viable seeds? (ii) Does the composition of substrates influence their viable seed content? and (iii) Are there common characteristics of the species dispersed this way? We detected altogether 438 seedlings of 66 taxa and found that 1 litre of potting substrate contains an average of 13.27 seeds of 6.24 species, so an average 20-litre bag of substrate contains 265 viable seeds. There was a high variability in the seed content of the substrates, as substrates containing cattle manure contained a substantially higher number of species and seeds than substrates without manure. Based on this, this pathway of LDD is an interplay between endozoochory by grazing livestock and accidental human-vectored dispersal, implying that the diet preference of grazing animals largely determines the ability of a plant species to be dispersed this way. According to our results, potting substrates can disperse large quantities of seeds of a wide range of plant species, moreover, these dispersal events occur on very long distances in almost all cases. We conclude that this kind of human-vectored LDD may have complex effects on plant populations and communities; however, as this dispersal pathway is largely understudied and has hardly been considered as a type of LDD, its consequences are still largely unknown and further studies of the issue are of great importance.

Flowering capacity and botanical seed production of sweet potato genotypes

ABSTRACT The identification of genotypes with greater capacity for flowering and seed production is crucial for greater efficiency in the genetic improvement of the sweet potato crop. Thus, the objective of this work was to evaluate the flowering capacity and the production of botanical seeds in sweet potato genotypes. The work was carried out in the municipality of Lavras, located in the southern region of Minas Gerais, Brazil. Twenty-two sweet potato genotypes belonging to the germplasm bank of the Federal University of Lavras (UFLA) were evaluated. The characteristics evaluated were the flowering period (days), the number of viable seeds, the total weight of viable seeds, the weight of 1000 seeds and the percentage of germination. The obtained data were analyzed by means of descriptive statistics, study of correlations and analysis of main components. The sweet potato genotypes evaluated showed a high capacity for flowering and production of botanical seeds. Flowering usually starts 125 days after planting and extends on average for 72 days. Considering future recombination to promote flowering capacity, seed production and greater germination, genotypes BD-05, BD-26 and BD-44 should be prioritized.

Measurement of inbreeding depression in Rhododendron kaempferi: seed production, germination, juvenile survival, and growth

To understand the reproductive ecology of a plant species with both selfing and outcrossing reproductive systems, it is important to know how selfed individuals contribute to the maintenance of a population. Further, examination of the magnitude of inbreeding depression after pollination is essential for accurate measurement of reproductive success. In this study, we investigated the characteristics of viable seeds and seedlings of Rhododendron kaempferi in a region where the bumblebee pollinator Bombus ardens are abundant. In a hand-pollination experiment, the fruit set from self-pollination was 32%, significantly lower than that from outcross-pollination (81%). The number of seeds per fruit from self-pollination was one sixth the number from outcross-pollination. However, the number of seeds per fruit was negatively correlated with the weight per seed. In addition, the germination rate was low when the seed weight was light. Although selfed seeds could germinate, 89% of the seedlings died within a year. The inbreeding depression coefficient 1 year after sowing was very high (0.89). These results indicate that R. kaempferi shows extremely strong selection for outcrossing but maintains a slight selfing potential in a natural population in central Japan.

Effects of repeated drought stress on the physiological characteristics and lipid metabolism of Bombax ceiba L. during subsequent drought and heat stresses

Background Trees of Bombax ceiba L. could produce a large number of viable seeds in the dry-hot valleys. However, the seedling regeneration of the species is difficult in these areas as mild drought often occur repeatedly which might be followed by heat stress. However, how the repeated drought affects the subsequent drought and heat tolerance of B. ceiba is not clear. In this study, chlorophyll fluorescence, soluble sugar content and lipid metabolism were measured for the drought-treated seedlings and heat-treated seedlings with or without drought hardening. Results Neither the first nor third dehydration treatments affected the photosynthetic activity and soluble sugar content of B. ceiba seedlings. However, they differentially affected the fluidity of the local membranes and the levels of diacylglycerol and phosphatidic acid. Heat shock severely decreased the photosynthetic efficiency but drought priming reduced the effects of heat shock. Moreover, heat shock with or without drought priming had differential effects on the metabolism of soluble sugars and some lipids. In addition, the unsaturation level of membrane glycerolipids increased following heat shock for non-drought-hardened seedlings which, however, maintained for drought-hardened seedlings. Conclusions The results suggest that two cycles of dehydration/recovery can affect the metabolism of some lipids during the third drought stress and may enhance the heat tolerance of B. ceiba by adjusting lipid composition and membrane fluidity.