scholarly journals SEED GERMINATION PLASTICITY OF TWO ENDANGERED SPECIES OF FERULA IN THE CONTEXT OF CLIMATE CHANGE

2020 ◽  
Vol 80 ◽  
pp. 13-33
Author(s):  
Parvin Salehi Shanjani ◽  
Amir Mousavi ◽  
Faeze Rasoulzadeh Farsad

Ferula assa-foetida and F. gummosa, Apiaceae, are important endemic and endangered medicinal plants. Survival of the species is threatened by climate change, overexploiting (as source of oleo-gum resin and for-age) and lack of organized cultivation. Cultivation of these valuable medicinal plants is restricted by insuffi-cient domestication knowledge. Germination characteristics of different populations of Ferula taxa were studied with the aim of describing and comparing their responses to continuous cold stratification condition. Germination cues for the species were complex, with dormancy mechanisms present to restrict germination until cold stratification are fulfilled. Results indicated that a period of 4 weeks of stratification is sufficient for germination of F. assa-foetida, but optimal germination of F. gummosa require stratification for periods of 8 weeks. Both species were able to germinate at very low temperatures (4°C). Within-taxon differences in dor-mancy breaking and seedling emergence may interpret as local adaptations. The continued regeneration and propagation of the species in the wild will depend on the temperature and moisture status of the soil during winter and the maintenance of conditions suitable for stratification for an appropriate length of time.

2020 ◽  
pp. 71-90
Author(s):  
Parvin Salehi Shanjani ◽  
Amir Mousavi ◽  
Faeze Rasoulzadeh Farsad

Ferula assa-foetida and F. gummosa, Apiaceae, are important endemic and endangered medicinal plants. Survival of the species is threatened by climate change, overexploiting (as source of oleo-gum resin and forage) and lack of organized cultivation. Cultivation of these valuable medicinal plants is restricted by insufficient domestication knowledge. Germination characteristics of different popula-tions of Ferula taxa were studied with the aim of describing and comparing their responses to continu-ous cold stratification condition. Germination cues for the species were complex, with dormancy mechanisms present to restrict germination until cold stratification are fulfilled. Results indicated that a period of 4 weeks of stratification is sufficient for germination of F. assa-foetida, but optimal germi-nation of F. gummosa require stratification for periods of 8 weeks. Both species were able to germi-nate at very low temperatures (4°C). Within-taxon differences in dormancy breaking and seedling emergence may interpret as local adaptations. The continued regeneration and propagation of the species in the wild will depend on the temperature and moisture status of the soil during winter and the maintenance of conditions suitable for stratification for an appropriate length of time.


2020 ◽  
Vol 48 (2) ◽  
pp. 1017-1026
Author(s):  
Şeref AKDAĞ ◽  
Burcu TUNCER

Eremurus spectabilis is a perennial herbaceous species that grows in the wild. Commonly consumed as a vegetable, it is also classified among medicinal plants and popular ornamental geophytes. Germination is not achieved under normal conditions because of seed dormancy. In this study, various combined treatments were experimented with to improve the germination and emergence performance of E. spectabilis seeds. The seeds were immersed in solutions of potassium nitrate (KNO3: 5 mM for 24 and 48 hours), calcium chloride (CaCl2: 5 mM for 24 and 48 hours) and subjected to tip cutting. Pre-treated seeds were then subjected to moist-cold stratification periods treatments for different durations (30, 50, 80 and 100 days). In the 5 mM KNO3 treatments, 48-hour KNO3 and 100 days of stratification treatments had better germination (11.1%) and emergence values (9.7%). In the 5 mM CaCl2 treatments, 24-hour CaCl2 yielded better germination (10.2%) and emergence (8.4%) values. Seed tip-cutting treatments were the most successful among all the treatments for the germination and emergence parameters.


1978 ◽  
Vol 5 (5) ◽  
pp. 609 ◽  
Author(s):  
BD Patterson ◽  
R Paull ◽  
RM Smillie

Chilling resistance and other adaptations to low temperature were investigated in the wild tomato, Lycopersicon hirsutum, and the domestic tomato L. esculentum. Chilling resistance was assessed by the ability of seedlings to survive and grow after being exposed to 0°C for several days. For geogra- phical populations of L. hirsutum, chilling resistance was greatest in those derived from the higher altitudes. Other characteristics that correlated with the altitude of origin of the different populations were the rate at which the seeds germinated at low temperatures and chlorophyll development at low temperatures. L. esculentum cv. Rutgers did not tolerate chilling well and, in this respect, resembled low-altitude populations of L. hirsutum. L. hirsutum is a suitable species for physiological studies of chilling resistance, and its altitudinal variants are potential sources of genes 'tailored' to different temperature environments. Methods based on the above-mentioned responses to chilling may enable selection of chilling-resistant seedlings from hybrids of L. esculentum and L. hirsutum.


2016 ◽  
Vol 6 (1) ◽  
pp. 905-913
Author(s):  
Bahram Majd Nassiry ◽  
Neda Mohammadi

    One of the effects of reducing water content on soil is reduction of growth and development of seedlings and variation of field development. Seed priming technique has been known as a challenge to improve germination and seedling emergence under different environmental stresses. The objectives of this research were to evaluate the effects of osmo-priming on germination characteristics and changes of proline, protein and catalase activity of Ocimum basilicum seeds. Results showed that drought stress reduced the germination characteristics and drought stress in -8 bar was the critical stress.  Priming treatments were include KNO3, PEG and NaCl by 0, -4 and -8 bar concentrations. The seeds were primed with those materials for 8 and 16 hours. The highest germination characteristics were obtained from nitrate potassium in -8 bar for 16 hours priming. Therefore the best seed treatment under drought stress during germination was obtained from the osmo-primed with -8 bar nitrate potassium for 16 hours. The drought stress increased proline and catalase activity but reduced total protein. Priming treatment increases proline, total protein and catalase activity under drought and control conditions. It is concluded that priming results in improvement in germination components of Ocimum basilicum in drought stress conditions and increases the resistance to drought stress with improvement of proline, protein and catalase activity in germination phase.


2002 ◽  
Vol 12 (4) ◽  
pp. 261-271 ◽  
Author(s):  
A. Escudero ◽  
F. Pérez-García ◽  
A. L. Luzuriaga

AbstractMost Pinus species are obligate seeders. Thus, knowledge of germination characteristics can help in the understanding, prediction and manipulation of the regeneration and dynamics of pine forests. Seven pine species with contrasting habitat preferences and different genetic pairwise distances are present in the Iberian Peninsula and the Canary Islands: P. halepensis, P. nigra, P. pinaster, P. pinea, P. sylvestris, P. uncinata and P. canariensis. These seven pine species comprise an exceptional experimental set to test some questions related to germination traits, such as: (1) What are the effects of light and temperature on germination, taking into account interpopulation variability? (2) Is there any association of germination traits with habitat (montane versus lowland) preferences? and (3) What is the relationship between germination traits and the genetic distance between pine species? P. nigra, P. sylvestris and P. uncinata seeds showed faster germination rates. Seeds of P. nigra and P. sylvestris reached high total germination percentages in every temperature and light treatment, suggesting an opportunistic germination strategy. Unlike montane pines, lowland pines did show significant effects of temperature on germination response: final germination was higher between 15°C and 20°C than at warmer and alternating temperatures. Relatively low temperatures associated with the winter rainy season would favour germination of most of these species. Nested models showed that population variability was the main source of variation in germination response. Thus, there is no phylogenetic control of the germination response and, surprisingly, germination traits were not related to habitat preferences. As a consequence, we believe that studies of the germination characteristics of a pine species should consider different populations.


2009 ◽  
Vol 19 (2) ◽  
pp. 115-123 ◽  
Author(s):  
Filip Vandelook ◽  
Nele Bolle ◽  
Jozef A. Van Assche

AbstractA low-temperature requirement for dormancy break has been observed frequently in temperate-climate Apiaceae species, resulting in spring emergence of seedlings. A series of experiments was performed to identify dormancy-breaking requirements of Aegopodium podagraria, a nitrophilous perennial growing mainly in mildly shaded places. In natural conditions, the embryos in seeds of A. podagraria grow in early winter. Seedlings were first observed in early spring and seedling emergence peaked in March and April. Experiments using temperature-controlled incubators revealed that embryos in seeds of A. podagraria grow only at low temperatures (5°C), irrespective of a pretreatment at higher temperatures. Seeds did not germinate immediately after embryo growth was completed, instead an additional cold stratification period was required to break dormancy completely. Once dormancy was broken, seeds germinated at a range of temperatures. Addition of gibberellic acid (GA3) had a positive effect on embryo growth in seeds incubated at 10°C and at 23°C, but it did not promote germination. Since seeds of A. podagraria have a low-temperature requirement for embryo growth and require an additional chilling period after completion of embryo growth, they exhibit characteristics of deep complex morphophysiological dormancy.


2019 ◽  
Vol 30 (2) ◽  
pp. 236-259
Author(s):  
WILLEM G. COETZER ◽  
COLLEEN T. DOWNS ◽  
MIKE R. PERRIN ◽  
SANDI WILLOWS-MUNRO

SummaryThe Cape Parrot Poicephalus robustus is a habitat specialist, restricted to forest patches in the Eastern Cape (EC), KwaZulu-Natal (KZN) and Limpopo provinces of South Africa. Recent census estimates suggest that there are less than 1,600 parrots left in the wild, although historical data suggest that the species was once more numerous. Fragmentation of the forest biome is strongly linked to climate change and exploitation of the forest by the timber industry. We examine the subpopulation structure and connectivity between fragmented populations across the distribution of the species. Differences in historical and contemporary genetic structure of Cape Parrots is examined by including both modern samples, collected from 1951 to 2014, and historical samples, collected from 1870 to 1946. A total of 114 individuals (historical = 29; contemporary = 85) were genotyped using 16 microsatellite loci. We tested for evidence of partitioning of genotypes at both a temporal and spatial scales by comparing shifts in allelic frequencies of historical (1870–1946) and contemporary (1951–2014) samples across the distribution of the species. Tests for population bottlenecks were also conducted to determine if anthropogenic causes are the main driver of population decline in this species. Analyses identified three geographically correlated genetic clusters. A southern group restricted to forest patches in the EC, a central group including birds from KZN and a genetically distinct northern Limpopo cluster. Results suggest that Cape Parrots have experienced at least two population bottlenecks. An ancient decline during the mid-Holocene (∼ 1,800-3,000 years before present) linked to climate change, and a more recent bottleneck, associated with logging of forests during the early 1900s. This study highlights the effects of climate change and human activities on an endangered species associated with the naturally fragmented forests of eastern South Africa. These results will aid conservation authorities with the planning and implementation of future conservation initiatives. In particular, this study emphasises the Eastern Cape mistbelt forests as an important source population for the species and calls for stronger conservation of forest patches in South Africa to promote connectivity of forest taxa.


Planta Medica ◽  
2019 ◽  
Vol 86 (01) ◽  
pp. 10-18 ◽  
Author(s):  
Wendy L. Applequist ◽  
Josef A. Brinckmann ◽  
Anthony B. Cunningham ◽  
Robbie E. Hart ◽  
Michael Heinrich ◽  
...  

AbstractThe recent publication of a World Scientistsʼ Warning to Humanity highlighted the fact that climate change, absent strenuous mitigation or adaptation efforts, will have profound negative effects for humanity and other species, affecting numerous aspects of life. In this paper, we call attention to one of these aspects, the effects of climate change on medicinal plants. These plants provide many benefits for human health, particularly in communities where Western medicine is unavailable. As for other species, their populations may be threatened by changing temperature and precipitation regimes, disruption of commensal relationships, and increases in pests and pathogens, combined with anthropogenic habitat fragmentation that impedes migration. Additionally, medicinal species are often harvested unsustainably, and this combination of pressures may push many populations to extinction. A second issue is that some species may respond to increased environmental stresses not only with declines in biomass production but with changes in chemical content, potentially affecting quality or even safety of medicinal products. We therefore recommend actions including conservation and local cultivation of valued plants, sustainability training for harvesters and certification of commercial material, preservation of traditional knowledge, and programs to monitor raw material quality in addition to, of course, efforts to mitigate climate change.


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