scholarly journals Embryological features, pollen and seed viability of Arnica montana (Asteraceae) – a threatened endemic species in Europe

2016 ◽  
Vol 75 (1) ◽  
pp. 39-44 ◽  
Author(s):  
Elina Yankova-Tsvetkova ◽  
Petka Yurukova-Grancharova ◽  
Georgi Baldjiev ◽  
Antonina Vitkova
Keyword(s):  
Sexual Reproduction ◽  
Endemic Species ◽  
Vegetative Reproduction ◽  
Seed Viability ◽  
Embryological Study ◽  
Mature Pollen ◽  
Reproductive Capacity ◽  
Mode Of Reproduction ◽  
Arnica Montana ◽  
High Viability

Abstract The embryological features, mode of reproduction and reproductive capacity (pollen and seed viability) on two naturalized populations of Arnica montana in Bulgaria were studied. The embryological study shows that A. montana is a facultative apomictic species in which sexual reproduction predominates. In this species, it was established that there is a comparatively high viability of the mature pollen and embryos, which enables the successful realization of its reproductive capacity. The results of the study on A. montana reveal that both sexual and asexual vegetative reproduction with rhizomes undoubtedly play more important roles than the apomixis (namely diplospory) for support and preservation of the populations.

scholarly journals Phytochemical Investigation and Reproductive Capacity of the Bulgarian Endemic Plant Species Marrubium friwaldskyanum Boiss. (Lamiaceae)

Plants ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 114
Author(s):  
Valtcho D. Zheljazkov ◽  
Ivanka B. Semerdjieva ◽  
Jan F. Stevens ◽  
Wenbin Wu ◽  
Charles L. Cantrell ◽  
...  
Keyword(s):  
Endemic Species ◽  
Male Gametophyte ◽  
Seed Viability ◽  
The Other ◽  
Reproductive Capacity ◽  
Separate Experiment ◽  
Caryophyllene Oxide ◽  
Endemic Plant ◽  
Germacrene D ◽  
Total Oil

Marrubium friwaldskyanum Boiss (Lamiaceae) is a Bulgarian endemic species. Overall, the essential oil (EO) composition of M. friwaldskyanum was different from that of the other Marrubium species reported in the literature. The main EO constituents of M. friwaldskyanum were (E)-caryophyllene, germacrene D, and caryophyllene oxide. The effect of the harvest stage was significant only on α-copaene, (E)-caryophyllene, caryophyllene oxide, and τ-muurolol. The concentration of α-copaene (1.26–1.83% range of the total oil), (E)-caryophyllene (31–41%), caryophyllene oxide (6.4–11.8%), and τ-muurolol (1.3–2.8%) were the highest at 2–3 pair of leaves or before flowering and lower at flowering. The harvest stage did not significantly affect the concentrations of the other six identified EO compounds β-bourbonene (1.1%), α-humulene (2.8%), germacrene D (23.3%), bicyclogermacrene (2.85%), δ-cadinene (1.1%), and spathulenol (2.8%). In a separate experiment, grinding of the biomass prior to EO extraction had a significant effect only on the concentrations of D-limonene (0.24–3.3%) and bicyclogermacrene (3.6–9.1%). Grinding in water or without water, maceration, and addition of Tween®20 had rather small effects on the EO profile. The identified EO constituents and their mean concentrations in this experiment were (E)-caryophyllene (25.4%), germacrene D (17.6%), caryophyllene oxide (9.1%), spathulenol (6.5%), τ-muurolol (5.0%), carvacrol (3.9%), α-copaene (2.5%), β-bourbonene (2.5%), δ-cadinene (2.4%), α-humulene (1.8%), and Z-β-farnesene (1.3%). Embryological studies observed anther and the development of the male gametophyte and ovule and development of the female gametophyte of M. friwaldskyanum. Furthermore, pollen and seed viability assays were conducted, and mass spectrometry-based metabolomics analysis of an extract from shoots revealed the presence of 45 natural products, identified as flavonoids, phenolic acids, and (tri)terpenoids. Overall, the phytochemistry and some of the microscopic analyses distinguished this endemic species from other species in Marrubium.

scholarly journals Seed germination requirements of Hypericum scruglii, an endangered medicinal plant species of Sardinia (Italy)

Botany ◽  
2020 ◽  
Vol 98 (10) ◽  
pp. 615-621 ◽  
Author(s):  
Marco Porceddu ◽  
Martina Sanna ◽  
Sara Serra ◽  
Maria Manconi ◽  
Gianluigi Bacchetta
Keyword(s):  
Medicinal Plant ◽  
Seed Bank ◽  
Seed Viability ◽  
Base Temperature ◽  
Endemic Plant ◽  
Endangered Medicinal Plant ◽  
High Viability ◽  
Wide Range ◽  
Baseline Information ◽  
Germination Requirements

Hypericum scruglii Bacch., Brullo & Salmeri is an endangered endemic plant of Sardinia, and the phloroglucinol compounds identified in this species have been reported to inhibit the activity of the Human Immunodeficiency Virus. Seed banks are a genetic repository that effectively preserve taxa of conservation interest, and they hold knowledge about the biology and germination ecophysiology of the taxa they preserve. The main goals of this study were to investigate the germination requirements for H. scruglii, to evaluate the seed viability after eight years of long-term conservation and to suggest an efficient protocol for germination. Seeds stored at –25 °C in the seed bank were tested at temperatures from 5 to 30 °C and 25/10 °C. Base temperature (Tb) and thermal time (θ50) for germination were estimated. Seeds of H. scruglii germinated over a wide range of temperatures, responding positively to high temperatures and 25/10 °C. Tb was estimated at 4.92 °C, and θ50 was estimated at 198.27 degree days. The high viability detected in seeds of H. scruglii allows us to suggest the use of seeds stored in a seed bank when fresh material for plant propagation is scarce. Our results provide new and useful baseline information for implementing conservation and multiplication strategies for this endangered medicinal plant.

Vegetative Reproduction Potential of Common Purslane (Portulaca oleracea)

2011 ◽  
Vol 25 (4) ◽  
pp. 694-697 ◽  
Author(s):  
Christopher A. Proctor ◽  
Roch E. Gaussoin ◽  
Zachary J. Reicher
Keyword(s):  
Leaf Growth ◽  
Vegetative Reproduction ◽  
Reproductive Capacity ◽  
Plant Tissues ◽  
Stem Cuttings ◽  
Stem Node ◽  
Greenhouse Study ◽  
Mechanical Methods ◽  
Stem Internode ◽  
Common Purslane

Common purslane is a widely distributed summer annual weed. It can reproduce vegetatively from stem cuttings by forming adventitious roots from the cut end of the stem. Apart from large stem cuttings, it is unclear whether purslane cuttings of various plant tissues differ in their ability to reproduce asexually. The objective of the study was to determine the survival and asexual reproductive capacity of purslane cuttings. A greenhouse study evaluated three cuttings from two stem locations and a leaf from one stem location for their survival and new leaf growth after 21 d. Cuttings included a stem node with either leaves attached or removed and a stem internode, all from proximal and distal stem locations relative to the root crown, and a leaf from a proximal stem node. Stem node cuttings had ≥ 70% survival, whereas internodes had 0% survival. Nodes with leaves attached further increased survival by > 20%. The location of the cutting on the main stem did not affect survival. Only noded cuttings produced new leaves, and cuttings with leaves attached produced the most new leaves. For purslane to vegetatively reproduce, nodes on stem cuttings are required, and the presence of leaves on the cutting improves the survival and new leaf growth of cuttings. Therefore, mechanical methods of weed control that chop and spread purslane leaves and stems might not be effective and could ultimately increase weed populations.

Purple prairie clover seed viability and germinability after passing through the digestive tracts of yearling steers

2019 ◽  
Vol 99 (5) ◽  
pp. 734-739
Author(s):  
Chen Gu ◽  
Alan D. Iwaasa ◽  
Mengli Zhao
Keyword(s):  
Low Cost ◽  
Seed Viability ◽  
Germination Percentage ◽  
Cattle Dung ◽  
Western Canada ◽  
Important Method ◽  
Hard Seed ◽  
Native North American ◽  
High Viability ◽  
Clover Seed

Endozoochory by cattle has been considered an important method for population self-regeneration; however, the effects of cattle digestive tracts on the viability and germinability of purple prairie clover (Dalea purpurea Vent.), a native North American species, remain understudied. The experiment was conducted at the Agriculture and Agri-Food Canada Swift Current Research and Development Centre in the semiarid prairie of western Canada. Purple prairie clover seeds extracted from cattle dung pats were tested for germination and compared with uningested and scarified seeds from the same paddock. The germination percentage (within 200 d) of the ingested seeds was 16.5% ± 0.8%, two times higher after passing through digestive tracts than uningested seeds (8.3% ± 1.2%), while 76.6% ± 1.5% of ingested seeds remained dormant. As many as 92.4% ± 0.9% of purple prairie clover seeds survived digestion due to their high hard seed rate (90.5% ± 1.0%), which was lower than the uningested seeds by 6.9%. Therefore, cattle dispersing purple prairie clover seeds with high viability and germinability is a low-cost method to increase and rejuvenate purple prairie clover for late-season grazing pastures.

Niche differentiation between two rhizomatous plant species: Typha latifolia and Typha angustifolia

1982 ◽  
Vol 60 (1) ◽  
pp. 46-57 ◽  
Author(s):  
James B. Grace ◽  
Robert G. Wetzel
Keyword(s):  
Sexual Reproduction ◽  
Shallow Water ◽  
Surface Area ◽  
Leaf Surface ◽  
Vegetative Reproduction ◽  
Typha Latifolia ◽  
Morphological Characteristics ◽  
Niche Differentiation ◽  
Typha Angustifolia ◽  
Leaf Surface Area

Morphological characteristics and biomass allocation were examined for two species of Typha in a small pond. Typha latifolia differed from T. angustifolia in having shorter leaf height, wider leaves, greater leaf surface area, greater allocation to leaves, greater number of smaller rhizomes, greater allocation to vegetative reproduction, smaller allocation to sexual reproduction, and fewer number of flowering plants. For both species, those plants growing in deeper water had taller leaves, a greater allocation to leaves, and a decreased allocation to sexual and vegetative reproduction. Previous studies of these populations have demonstrated that these two species are segregated according to water depth with T. latifolia being competitively superior in shallow water (less than 15 cm) but T. angustifolia having the potential to grow in deeper water than T. latifolia. Results from this study indicate that T. latifolia is competitively superior in shallow water because of its greater leaf surface area but that T. angustifolia's tall, narrow leaves and large rhizome storage permit it to grow in deeper water than T. latifolia. The greater amount of sexual reproduction in T. angustifolia is correlated with its more restricted distribution and fugitive nature.

Effect of prolonged vegetative reproduction of olive tree cultivars (Olea europaea L.) in mitochondrial homoplasmy and heteroplasmy

Genome ◽  
2003 ◽  
Vol 46 (3) ◽  
pp. 377-381 ◽  
Author(s):  
Angel García-Díaz ◽  
Ricardo Oya ◽  
Antonio Sánchez ◽  
Francisco Luque
Keyword(s):  
Mitochondrial Genome ◽  
Sexual Reproduction ◽  
Olea Europaea ◽  
Vegetative Reproduction ◽  
Intergenic Spacer Region ◽  
Olea Europaea L ◽  
Chloroplast Genomes ◽  
Mitochondrial Region ◽  
Olive Trees ◽  
Olea Europaéa

The inheritance of mitochondrial and chloroplast genomes does not follow Mendelian laws, but proceeds by vegetative segregation. Most organisms show organelle homoplasmy, which is probably produced and maintained during sexual reproduction. We have tested the effect of prolonged vegetative multiplication in the maintenance of mitochondrial homoplasmy and the generation of heteroplasmy in cultivated olive trees, Olea europaea L. Seven trees, each representing a different variety of olive, were analysed by the study of an intergenic spacer region of the mitochondrial genome. A very high level of heteroplasmy was detected in all cases. We found multiple genome variants of the sequence analysed. The frequency of genomes with no changes in the spacer region was 11.5%. This means that 88.5% of genomes contain at least one change. The same spacer mitochondrial region was sequenced in several clones from four olive trees of a second generation of sexually reproduced trees. In these trees, many clones were identical and had no changes, which represents a clear reduction of the heteroplasmy (p < 0.001). Therefore, this work supports the relevance of the role of sexual reproduction in the maintenance of mitochondrial homoplasmy and also shows that mutations accumulate in a non-coding sequence of the mitochondrial genome when vegetative propagation is maintained for a long period of time.Key words: mitochondrial genome, homoplasmy, heteroplasmy, olive trees, vegetative reproduction, sexual reproduction.

Reproduction of salal (Gaultheriashallon) under forest canopy

1990 ◽  
Vol 20 (1) ◽  
pp. 91-100 ◽  
Author(s):  
F. L. Bunnell
Keyword(s):  
Sexual Reproduction ◽  
Forest Canopy ◽  
Vegetative Reproduction ◽  
Resource Limitation ◽  
Shoot Density ◽  
Physiological Integration ◽  
Forest Canopies ◽  
Plant Persistence ◽  
Crown Closure ◽  
Optimality Models

Sexual and vegetative reproduction of salal (Gaultheriashallon Pursh) was measured under forest canopies of different closure. Sexual reproduction occurred only at ≤33% closure; vegetative reproduction occurred under sparse and dense closure. Crown closure influenced sexual reproduction primarily through interception of radiation and associated reductions in salal vigour. Irradiance had a greater influence on the mode of reproduction than did shoot density, and allocation of total reproductive effort (sexual plus vegetative) was contrary to optimality models, but consistent with resource limitation. No shoot <5 years old flowered; shared costs of flowering indicated physiological integration among salal shoots. Vegetative reproduction was negatively associated with age (r2 = 0.95), and 85% of the space occupied after 9 years of growth was occupied during the first 3 years. Under canopy the spatial pattern of salal shoots was better adapted to maintain plant persistence than to colonize new areas. Implications of salal's rates and modes of reproduction to forest and wildlife management are noted.

scholarly journals Seed embryonic death in invasive populations of Ulmus pumila L. and Ulmus suberosa Moench in the steppe Dnieper region

2019 ◽  
Vol 24 ◽  
pp. 308-312
Author(s):  
O. A. Kravets ◽  
Ya. V. Pirko ◽  
L. O. Kalafat ◽  
A. M. Rabokon ◽  
Yu. O. Bilonozhko ◽  
...  
Keyword(s):  
Physiological State ◽  
Seed Viability ◽  
Reproductive State ◽  
Ulmus Pumila ◽  
Seed Productivity ◽  
Aim Analysis ◽  
Seed Reproduction ◽  
High Viability ◽  
Different Levels ◽  
Embryonic Death

Aim. Analysis of seed embryonic death and seed viability as a indexes of the genetic and reproductive state of Ulmus pumila L. and U. suberosa Moench to determine the mechanisms of invasiveness of their populations in the Dnieper steppe. Methods. Morphological, anatomical, cytological, statistical. Results. Investigated U. pumila populations differed on indexis of the embryonic death, seed viability and seed productivity. Populations growing in more favorable environmental conditions are distinguished by a better reproductive, physiological, and genetic conditions. Two from three U. pumila populations are characterized by low rates of embryonic death, high viability indices and seed productivity. This can indicate their heterogeneous origin and a significant level of heterozygosity. Vice versa, U. suberosa population has a high rates of embryonic death of seeds and low seed viability which may be due to population's limited and/or its poor physiological state and a decrease in heterozygosity. Conclusions. There are different levels of heterozygosity in the U. pumila population at the steppe Dnieper. Probably seed reproduction and distribution of this species is not significantly limited by genetic, physiological or environmental factors. Populations of U. suberosa in this region are characterized by worse genetic status. Seed reproduction of invasive populations of this species can be significantly limited. Keywords: seed embryonic death, empty samara, seed viability, heterozygosity, invasive populations, Ulmus pumila L., Ulmus suberosa Moench.

Fire and substrate interact to control the northern range limit of black spruce (Picea mariana) in Alaska

2007 ◽  
Vol 37 (12) ◽  
pp. 2480-2493 ◽  
Author(s):  
Andrea H. Lloyd ◽  
Christopher L. Fastie ◽  
Hilary Eisen
Keyword(s):  
Sexual Reproduction ◽  
Picea Mariana ◽  
Fire History ◽  
Black Spruce ◽  
Seed Viability ◽  
Range Limit ◽  
Acidic Soils ◽  
Eastern Canada ◽  
Substrate Effects ◽  
Northern Range Limit

Black spruce ( Picea mariana (Mill.) BSP) is a common treeline species in eastern Canada but rare at treeline in Alaska. We investigated fire and substrate effects on black spruce populations at six sites along a 74 km transect in the Brooks Range, Alaska. Our southern sites, on a surface deglaciated >50 000 years ago, had significantly more acidic soils, more black spruce, and higher seed viability than our northern sites, which were deglaciated approximately 13 000 years ago. Despite similar fire history at five of our six sites, postfire recruitment dynamics varied with surface age. Sexual reproduction was vigorous in both postfire and nonfire years in populations on the older surface. On the younger surface, vigorous sexual reproduction was restricted to postfire decades and clonal reproduction by branch layering predominated in nonfire years. At the northernmost site, which was unburned, black spruce reproduced almost exclusively by layering. The species’ northern range limit thus reflects an interaction between fire and substrate: on recently deglaciated surfaces, sexual reproduction is restricted to postfire years. This substrate-induced dependence on fire may restrict the range of black spruce to sites that burn sufficiently often to allow occasional sexual reproduction.

scholarly journals Germination Temperature and the Effect of Storage Time on the Seed Viability of Zephyra elegans (Tecophilaeaceae)

HortScience ◽  
2018 ◽  
Vol 53 (6) ◽  
pp. 887-890
Author(s):  
Carlos De la Cuadra ◽  
Alexis K. Vidal ◽  
Patricia Peñaloza ◽  
Leví Mansur ◽  
Carlos Huenchuleo
Keyword(s):  
Room Temperature ◽  
Natural Habitat ◽  
Seed Viability ◽  
Dry Storage ◽  
High Viability ◽  
High Germination ◽  
Temperature Requirements ◽  
Variable Precipitation ◽  
Storage Times ◽  
Desert Climate

Zephyra elegans is a geophyte endemic to Chile that has horticultural value as a cut flower. Its natural habitat is a coastal desert climate with abundant cloud cover, little and variable precipitation, and mean monthly temperatures between 10 and 20 °C. It is hypothesized that the temperature requirements for germination of Z. elegans seeds are similar to those of Zephyra compacta, which shares the same habitat. As it is a species from a desert climate, it can be expected that its seeds remain viable during long periods of storage. The seeds used in this study were harvested in different years from plants grown from cultivated corms of Z. elegans. The germination test temperatures were 10, 15, 20, and 25 °C, and the dry storage times at room temperature (20 ± 5 °C) were 4, 16, 28, and 40 months. The temperature requirements for germination of Z. elegans seeds are similar to those of Z. compacta, which has been studied earlier, i.e., the temperature range for achieving high germination percentages is 10 to 20 °C, whereas 25 °C can be considered supraoptimal. After-ripening of the seeds occurred during dry storage, as shown by increased germination when tested at a supraoptimal temperature. The seeds had high viability after 40 months of dry storage at room temperature.

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