scholarly journals Seed germination in sedges: a short review

2010 ◽  
Vol 19 (1) ◽  
pp. 15-22 ◽  
Author(s):  
Waldemar Żukowski ◽  
Agnieszka Bogdanowicz ◽  
Marlena Lembicz

Seed germination in sedges: a short reviewFive patterns of seed germination in the sedges of the genusCarexare presented, based on the literature data and the results of the authors' own research. They include the pattern ofC. acutiformis, C. arenaria, C. remota, C. flavaandC. communis. These patterns were constructed on the basis of seed specific requirements for development, such as stratification, temperature, dormancy and time of germination. Majority of sedges follow the pattern ofC. acutiformisorC. remota. In both cases, stratification and either high or low temperature are essential for seed germination. Seeds that start to germinate early (C. remotapattern) are characterized by the absence of the distinct peaks of germination, as opposed to theC. acutiformispattern with the germination peak in March. Our long-term investigations, conducted on the group of individuals in controlled conditions, revealed significant differences in seed size and the ability of seeds to germinate depending on the age of mother plants. We postulate that mother plant age is a new factor that should be considered in the construction of seed germination patterns.

1993 ◽  
Vol 73 (4) ◽  
pp. 1123-1125 ◽  
Author(s):  
J. M. Turner ◽  
K. K. Tanino ◽  
C. Stushnoff

When acclimated strawberry plants (Fragaria × ananassa Duch. ’Redcoat’) from the field were placed in a programmable freezer, mother strawberry crowns were as hardy or hardier than daughter crowns when frozen to −11 °C. However, under field conditions, daughter plants expressed consistently greater hardiness than mother plants. Mulching had no effect on daughter plant survival, whereas enhanced mother plant survival was observed. Field-growth habit of mother crowns may be the important factor for consistent winter survival under prairie conditions. A simple scoring system was developed to predict survival of strawberry plants. Key words. Fragaria × ananassa Duch., strawberry, crowns, low temperature hardiness


The distribution limits of three species, in the British Isles are discussed. For Verbena officinalis and Tilia cordata low temperatures are shown to influence distribution, by limiting the capacity either to flower or to fertilize ovules, respectively. In the case of Umbilicus rupestris , a long-term transplant population beyond the natural geographical limit of the species has evolved new low-temperature responses of seed germination and winter survival. The effect is a marked change of phenology, compared with populations of the species within its natural range, which enhances the capacity of the population to survive in a colder environment.


2020 ◽  
Author(s):  
Thabiso Michael Mokotjomela ◽  
Loyd Vukeya ◽  
Ntsoaki Malebo ◽  
Saheed Oke

Abstract Avian frugivores provide directed seed dispersal services that contribute in shaping the native plant communities and facilitate population persistence. By transporting and scarifying the seeds during ingestion, avian frugivores reduce the competition with siblings, and may improve the germination which is critical for dispersal effectiveness. However, generally, there is limited knowledge on how deposited seeds interact/compete in the new microsite. Therefore, we investigated 1) whether bird-dispersed seeds benefit from improved germination after their passage through the bird’s gut; and 2) the potential impact of seed density on competition at the microsites by determining whether seed density and species diversity influence germination in the Free State Province, South Africa. Overall, the results partly supported the hypothesis. Germination trials with defecated seeds of five plant species compared with the manually depulped seeds showed that despite prolific seed germination observed in Ziziphus mucronata, only Searsia lancea seeds had significantly high seed germination after passage through the bird gut. Overall, there was a significant correlation between seed size and the germination of bird-ingested seeds except in Olea subsp. africana possibly due to possession of extremely hard protective seed cover. Seeds competition experiments pointed to Z. mucronata and O. subsp. africana having significant germination performance that was positively correlated to seed density and seed size while E. rigida did not germinate at all. Seed species diversity in the germination trays did not have significant impact since only two former plant species consistently displayed significantly higher germination across the competition levels. We conclude that not all bird-defecated seeds have their germination improved, and that further long-term tests for germination physiological responses of the seeds’ samples used in this study are required since poor germination observed in other tree/shrub species cannot be attributed to competition solely.


2017 ◽  
Vol 65 (7) ◽  
pp. 593 ◽  
Author(s):  
Oscar Cruz ◽  
Juan García-Duro ◽  
Mercedes Casal ◽  
Otilia Reyes

Acacia melanoxylon R.Br. (Leguminosae) is one of the most widely distributed tree species in the world. It has significant commercial use but can be a danger to natural ecosystems as an invader species. For these reasons it is necessary to have a deep knowledge about its germinative response to fire and the role the mother plant age plays in that response. In this work we assessed the effects of the interaction of the mother plant age with the main fire agents (smoke, charcoal, ash and heat) on the germinative response of A. melanoxylon. To reach this aim, germination tests were conducted with seeds from young, intermediate and mature mother plants, with 20 treatments each applied. Results show that fire can act as a great stimulator of the germination of A. melanoxylon but it can also strongly inhibit it. The mother plant age does not modify the final germination values, but it influences the time in which the first germinations occur after fire. This trait can be more important than the final germination percentage when looking at the success of post-fire regeneration. These results have important implications for A. melanoxylon management, for both species control and ecological restoration purposes.


2021 ◽  
pp. 1-19
Author(s):  
Vojtech Kouba ◽  
Juan Camilo Gerlein ◽  
Andrea Benakova ◽  
Marco Antonio Lopez Marin ◽  
Eva Rysava ◽  
...  

2021 ◽  
Vol 13 (9) ◽  
pp. 5223
Author(s):  
Miriam Benedetti ◽  
Daniele Dadi ◽  
Lorena Giordano ◽  
Vito Introna ◽  
Pasquale Eduardo Lapenna ◽  
...  

The recovery of waste heat is a fundamental means of achieving the ambitious medium- and long-term targets set by European and international directives. Despite the large availability of waste heat, especially at low temperatures (<250 °C), the implementation rate of heat recovery interventions is still low, mainly due to non-technical barriers. To overcome this limitation, this work aims to develop two distinct databases containing waste heat recovery case studies and technologies as a novel tool to enhance knowledge transfer in the industrial sector. Through an in-depth analysis of the scientific literature, the two databases’ structures were developed, defining fields and information to collect, and then a preliminary population was performed. Both databases were validated by interacting with companies which operate in the heat recovery technology market and which are possible users of the tools. Those proposed are the first example in the literature of databases completely focused on low-temperature waste heat recovery in the industrial sector and able to provide detailed information on heat exchange and the technologies used. The tools proposed are two key elements in supporting companies in all the phases of a heat recovery intervention: from identifying waste heat to choosing the best technology to be adopted.


1977 ◽  
Vol 53 (1) ◽  
pp. 75-80
Author(s):  
H. Taguchi ◽  
Z. Abdul-Cader ◽  
J. Perry ◽  
E. H. Reynolds ◽  
I. Chanarin

1. The isolated choroid plexus of the rabbit takes up 5-methyltetrahydrofolate from the incubation medium. 2. Other folate analogues (pteroylglutamic acid, methotrexate, 5-formyltetrahydrofolate = folinic acid) inhibited the uptake of 5-methyltetrahydrofolate. 3. The uptake of 5-methyltetrahydrofolate was inhibited by low temperature, anaerobic conditions and dinitrophenol. 4. The anticonvulsant drugs, diphenylhydantoin and phenobarbital, had no effect on 5-methyltetrahydrofolate uptake. 5. The inhibitory effect of pteroylglutamic acid on the uptake of 5-methyltetrahydrofolate by the choroid plexus may explain the effect of long-term folic acid therapy in aggravating vitamin B12 neuropathy in pernicious anaemia.


2021 ◽  
Author(s):  
Filippo Guzzon ◽  
Maraeva Gianella ◽  
Jose Alejandro Velazquez Juarez ◽  
Cesar Sanchez Cano ◽  
Denise E Costich

Abstract Background and Aims The long-term conservation of seeds of plant genetic resources is of key importance for food security and preservation of agrobiodiversity. Nevertheless, there is scarce information available about seed longevity of many crops under germplasm bank conditions. Methods Through germination experiments as well as the analysis of historical monitoring data, we studied the decline in viability manifested by 1000 maize (Zea mays subsp. mays) seed accessions conserved for an average of 48 years at the CIMMYT germplasm bank, the largest maize seedbank in the world, under two cold storage conditions: an active (–3 °C; intended for seed distribution) and a base conservation chamber (–15 °C; for long-term conservation). Key Results Seed lots stored in the active chamber had a significantly lower and more variable seed germination, averaging 81.4 %, as compared with the seed lots conserved in the base chamber, averaging 92.1 %. The average seed viability detected in this study was higher in comparison with that found in other seed longevity studies on maize conserved under similar conditions. A significant difference was detected in seed germination and longevity estimates (e.g. p85 and p50) among accessions. Correlating seed longevity with seed traits and passport data, grain type showed the strongest correlation, with flint varieties being longer lived than floury and dent types. Conclusions The more rapid loss of seed viability detected in the active chamber suggests that the seed conservation approach, based on the storage of the same seed accessions in two chambers with different temperatures, might be counterproductive for overall long-term conservation and that base conditions should be applied in both. The significant differences detected in seed longevity among accessions underscores that different viability monitoring and regeneration intervals should be applied to groups of accessions showing different longevity profiles.


2021 ◽  
Author(s):  
K. Doiron ◽  
P. Sauer ◽  
A. Schimmelmann ◽  
M. Mastalerz ◽  
A. Drobniak ◽  
...  
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