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

Biology ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 85
Author(s):  
Dawid Kocot ◽  
Ewa Sitek ◽  
Barbara Nowak ◽  
Anna Kołton ◽  
Alina Stachurska-Swakoń ◽  
...  

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.

Plants ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 43
Author(s):  
Adeel Khan ◽  
Munir Ahmad ◽  
Mukhtar Ahmed ◽  
M. Iftikhar Hussain

Temperature across the globe is increasing continuously at the rate of 0.15–0.17 °C per decade since the industrial revolution. It is influencing agricultural crop productivity. Therefore, thermotolerance strategies are needed to have sustainability in crop yield under higher temperature. However, improving thermotolerance in the crop is a challenging task for crop scientists. Therefore, this review work was conducted with the aim of providing information on the wheat response in three research areas, i.e., physiology, breeding, and advances in genetics, which could assist the researchers in improving thermotolerance. The optimum temperature for wheat growth at the heading, anthesis, and grain filling duration is 16 ± 2.3 °C, 23 ± 1.75 °C, and 26 ± 1.53 °C, respectively. The high temperature adversely influences the crop phenology, growth, and development. The pre-anthesis high temperature retards the pollen viability, seed formation, and embryo development. The post-anthesis high temperature declines the starch granules accumulation, stem reserve carbohydrates, and translocation of photosynthates into grains. A high temperature above 40 °C inhibits the photosynthesis by damaging the photosystem-II, electron transport chain, and photosystem-I. Our review work highlighted that genotypes which can maintain a higher accumulation of proline, glycine betaine, expression of heat shock proteins, stay green and antioxidant enzymes activity viz., catalase, peroxidase, super oxide dismutase, and glutathione reductase can tolerate high temperature efficiently through sustaining cellular physiology. Similarly, the pre-anthesis acclimation with heat treatment, inorganic fertilizer such as nitrogen, potassium nitrate and potassium chloride, mulches with rice husk, early sowing, presoaking of a 6.6 mM solution of thiourea, foliar application of 50 ppm dithiothreitol, 10 mg per kg of silicon at heading and zinc ameliorate the crop against the high temperature. Finally, it has been suggested that modern genomics and omics techniques should be used to develop thermotolerance in wheat.


2014 ◽  
Vol 65 (17) ◽  
pp. 5093-5107 ◽  
Author(s):  
Peng Zhao ◽  
Xue-mei Zhou ◽  
Jie Zou ◽  
Wei Wang ◽  
Lu Wang ◽  
...  

2010 ◽  
Vol 56 (No. 12) ◽  
pp. 580-583 ◽  
Author(s):  
Z. Martinková ◽  
A. Honěk

After flowering has ceased, dandelion (Taraxacum agg.) capitula close to enable maturation of seeds. In late summer the period of seed maturation lasts for 9 days. The capitula mowed later than 4 days after the start of this period and desiccated at 25°C produce viable seeds. If cut and prostrated on insolated ground inflorescences can experience temperatures exceeding 50°C which may impair seed viability. We determined the effect of desiccation temperature (5, 15, 25, 35, 45 or 55°C) on viability of ripening seeds using inflorescences harvested on September 5, 2008 at Prague-Ruzyne (50°05'N, 14°18'09 E), five days after flowering ceased (about 4 days before seed dispersal). As control, ripe seeds were collected at dispersal on the same day and desiccated at identical temperatures. Desiccated seeds were germinated at constant 17°C. Ripening seeds of maturing capitula only remained germinable if desiccation temperatures were ≤ 35°C (optimum 25°C) and were killed at 45 and 55°C. The viability of ripe seed was not affected by any of the desiccation temperatures. Time of germination of 50% seeds that germinated was significantly shorter in ripe than ripening seeds. Exposure of mowed dandelion inflorescences on insolated ground (solarization) may thus decrease production of viable seeds because of high temperatures experienced during desiccation.  


2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Kiflu Gebramicael Tesfamicael ◽  
Endale Gebre ◽  
Timothy J. March ◽  
Beata Sznajder ◽  
Diane E. Mather ◽  
...  

Abstract Enset (Ensete ventricosum (Welw.) Cheesman) is a drought tolerant, vegetatively propagated crop that was domesticated in Ethiopia. It is a staple food for more than 20 million people in Ethiopia. Despite its current importance and immense potential, enset is among the most genetically understudied and underexploited food crops. We collected 230 enset wild and cultivated accessions across the main enset producing regions in Ethiopia and applied amplified fragment length polymorphism (AFLP) and genotype by sequencing (GBS) analyses to these accessions. Wild and cultivated accessions were clearly separated from each other, with 89 genes found to harbour SNPs that separated wild from cultivated accessions. Among these, 17 genes are thought to be involved in flower initiation and seed development. Among cultivated accessions, differentiation was mostly associated with geographical location and with proximity to wild populations. Our results indicate that vegetative propagation of elite clones has favoured capacity for vegetative growth at the expense of capacity for sexual reproduction. This is consistent with previous reports that cultivated enset tends to produce non-viable seeds and flowers less frequently than wild enset.


Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1877
Author(s):  
Davide Zanelli ◽  
Fabio Candotto Carniel ◽  
Marina Garrido ◽  
Lorenzo Fortuna ◽  
Massimo Nepi ◽  
...  

Products containing graphene-related materials (GRMs) are becoming quite common, raising concerns for environmental safety. GRMs have varying effects on plants, but their impact on the sexual reproduction process is largely unknown. In this study, the effects of few-layer graphene (FLG) and a similarly layered phyllosilicate, muscovite mica (MICA), were tested in vivo on the reproductive structures, i.e., pollen and stigma, of Cucurbita pepo L. ssp. pepo ‘greyzini’ (summer squash, zucchini). Pollen was exposed to FLG or MICA, after careful physical-chemical characterization, at concentrations of 0.5 and 2 mg of nanomaterial (NM) per g of pollen for up to six hours. Following this, pollen viability was tested. Stigmas were exposed to FLG or MICA for three hours and then analyzed by environmental scanning electron microscopy to verify possible alterations to their surface. Stigmas were then hand-pollinated to verify the effects of the two NMs on pollen adhesion and in vivo pollen germination. FLG and MICA altered neither pollen viability nor the stigmatic surface. However, both NMs equivalently decreased pollen adhesion and in vivo germination compared with untreated stigmas. These effects deserve further attention as they could impact on production of fruits and seeds. Importantly, it was shown that FLG is as safe as a naturally occurring nanomaterial.


1972 ◽  
Vol 12 (58) ◽  
pp. 517 ◽  
Author(s):  
RL Harty ◽  
LG Paleg ◽  
D Aspinall

The reduction of 2,3,5-triphenyl tetrazolium chloride (TTC) to a coloured formazan derivative by dehydrogenase enzyme systems in viable seeds has been examined. TTC reduction occurs in dry but not wetmilled tissue and the coloured product could be extracted by any of several organic solvents. This formazan product was estimated spectrophotometrically at 480 nm. The influence of fineness of grinding the tissue, TTC concentration, period of treatment, sample size, vacuum infiltration of the milled tissue with TTC and of extracting solvent were examined and a standard procedure is suggested. Using this procedure, a close correlation between seed viability and TTC reduction was demonstrated. The advantages of this method over the widely used topographical method for estimating seed viability with TTC are discussed.


2020 ◽  
Author(s):  
Miguel A Copete ◽  
José M Herranz ◽  
Raquel Herranz ◽  
Elena Copete ◽  
Pablo Ferrandis

Abstract Aims In species with morphophysiological seed dormancy (MPD), little is known about the effects of desiccation of imbibed seeds on embryo growth and germination. We studied seed responses to dehydration in nine species with different levels of MPD. Methods For each species, a control test was conducted by keeping seeds permanently hydrated and exposed to the optimal stratification-incubation sequence to promote embryo growth. Simultaneously, tests were run in which seed stratification was interrupted for 1 month by desiccation at room temperature. Important Findings In Clematis vitalba and Ribes alpinum, with nondeep simple MPD, desiccation affected neither embryo growth nor seed viability, but the desiccation led to a decrease of germinative ability in R. alpinum by 16%. The seeds of Narcissus pseudonarcissus subsp. munozii-garmendiae, with deep simple epicotyl MPD, tolerated desiccation in different embryo growth stages, but their germinative ability decreased slightly. The response of species with complex levels of MPD to desiccation was more variable: Delphinium fissum subsp. sordidum, with intermediate complex MPD, and Anthriscus sylvestris and Meum athamanticum, both with deep complex MPD, tolerated desiccation. In contrast, Ribes uva-crispa with nondeep complex MPD, Lonicera pyrenaica with intermediate complex MPD, and Chaerophyllum aureum with deep complex MPD, had diminished germination ability by desiccation. Although seeds of the species with simple levels of MPD tolerated desiccation, those of some species with complex levels were also highly tolerant. Thus, desiccation did not induce secondary dormancy in late embryo growth stages. The desiccation tolerance of imbibed seeds of most of the nine species may show their adaptability to climate change in the Mediterranean region.


Plants ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 705 ◽  
Author(s):  
Angel J. Matilla

The production of viable seeds is a key event in the life cycle of higher plants. Historically, abscisic acid (ABA) and gibberellin (GAs) were considered the main hormones that regulate seed formation. However, auxin has recently emerged as an essential player that modulates, in conjunction with ABA, different cellular processes involved in seed development as well as the induction, regulation and maintenance of primary dormancy (PD). This review examines and discusses the key role of auxin as a signaling molecule that coordinates seed life. The cellular machinery involved in the synthesis and transport of auxin, as well as their cellular and tissue compartmentalization, is crucial for the development of the endosperm and seed-coat. Thus, auxin is an essential compound involved in integuments development, and its transport from endosperm is regulated by AGAMOUS-LIKE62 (AGL62) whose transcript is specifically expressed in the endosperm. In addition, recent biochemical and genetic evidence supports the involvement of auxins in PD. In this process, the participation of the transcriptional regulator ABA INSENSITIVE3 (ABI3) is critical, revealing a cross-talk between auxin and ABA signaling. Future experimental aimed at advancing knowledge of the role of auxins in seed development and PD are also discussed.


2002 ◽  
Vol 12 (1) ◽  
pp. 17-29 ◽  
Author(s):  
T. Repo ◽  
D.H. Paine ◽  
A.G. Taylor

A method, electrical impedance spectroscopy (EIS), is introduced to study seed viability non-destructively. Snap bean (Phaseolus vulgaris L.) seeds were studied by EIS to determine the most sensitive EIS parameter(s) and the optimal range of moisture content (MC) for separation of viable and non-viable seeds. Hydrated seeds exhibited two impedance arcs in the complex plane at the frequency range from 60 Hz to 8 MHz, and impedance spectra of viable and non-viable seeds differed. The hydrated seeds were best-modelled by an equivalent electrical circuit with two distributed circuit elements in series with a resistor (Voigt model). Moisture content and seed viability had strong effects on the EIS parameters. The most sensitive EIS parameters for detecting the differences between viable and non-viable seeds were the capacitance log(C2), the resistance R2, the resistance ratio R2/R1 and the apex ratio, which all represent specific features of the impedance spectrum. The highest differentiation in the EIS parameters between the viable and non-viable seeds occurred in partially imbibed seeds between MC of 40 and 45% (fresh weight basis).


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