Seed size as a determinant of germination rate in Crepis tectorum (Asteraceae): evidence from a seed burial experiment

1996 ◽  
Vol 74 (4) ◽  
pp. 568-572 ◽  
Author(s):  
Stefan Andersson
Keyword(s):  
Seed Size ◽  
Germination Rate ◽  
Local Population ◽  
Seed Viability ◽  
Seed Burial ◽  
Small Seed ◽  
Crepis Tectorum ◽  
Winter Annual ◽  
Selection For ◽  
The Relationship

The present study of the winter annual Crepis tectorum examines the relationship between seed (achene) size and the extent to which seeds resist germination during the year of their production. I carried out two seed burial experiments, one at an outcrop site occupied by a small-seeded population, and another in an experimental garden with soil from the same field site, with seeds representing the local population and a segregating generation of a cross between two other populations. Using logistic regression with data corrected for seed viability, I found an association between small seed size and failure to germinate in the first autumn. The small seed size characterizing many outcrop populations may have evolved as a response to selection for delaying germination in a habitat subject to unpredictable droughts during the growth season. Keywords: Crepis tectorum, germination, seed bank, seed size.

scholarly journals Variation of seed sizes and its effect on germination and seedling growth of mahogany (Swietenia macrophylla)

2019 ◽  
Vol 20 (9) ◽  
Author(s):  
AGUS ASTHO PRAMONO ◽  
DIDA SYAMSUWIDA ◽  
Kurniawati Purwaka Putri
Keyword(s):  
Seed Size ◽  
Seedling Growth ◽  
Germination Rate ◽  
Fruit Size ◽  
Seed Viability ◽  
Initial Growth ◽  
Seed Selection ◽  
Swietenia Macrophylla ◽  
Seed Collection ◽  
Growth Of Seedlings

Abstract. Pramono AA, Syamsuwida D, Putri KP. 2019. Variation of seed sizes and its effect on germination and seedling growth of mahogany (Swietenia macrophylla). Biodiversitas 20: 2576-2582. To get high-quality seeds, the size of seed is often suggested to be criteria of selection in seed collection. However, the size is not always effective to be used as a basis for seed selection. The study is aimed to determine the variation of mahogany (Swietenia macrophylla) seed sizes and its effect on the germination and seedlings growth. The fruits were collected from stands of mahogany in Jonggol and Parung Panjang, Bogor District, Indonesia. The seeds were grouped into 5 classes based on seed size. The observation was conducted on seed viability of each size class as well as the growth of seedlings until 3 months old. The results showed that the seed size of mahogany was affected by position of the seeds inside the fruit, the mother trees, and fruit size. The seeds size of < 6 cm long had significantly lower germination rate and capacity than those seeds of more than 6 cm long. The size of seeds affected the initial growth of seedlings, but did not influence the subsequent growth of seedling after 3 months old. The selection of seeds was done by removing the seeds of less than 6 cm long.  

scholarly journals Cercis canadensis L. Seed Size Influences Germination Rate, Seedling Dry Matter, and Seedling Leaf Area

HortScience ◽  
2002 ◽  
Vol 37 (1) ◽  
pp. 206-207 ◽  
Author(s):  
Gary A. Couvillon
Keyword(s):  
Leaf Area ◽  
Seed Size ◽  
Woody Plant ◽  
Germination Rate ◽  
Annual Crops ◽  
Cercis Canadensis ◽  
Small Seed ◽  
Percent Germination ◽  
Germination Value ◽  
Seedling Leaf

Several studies with annual crops have shown that large seeds improve percent germination, seedling growth, and uniformity, yield, seedling vigor, and stress tolerance. Little information is available on the influence of seed size on the resulting seedlings of woody plant species. Cercis canadensis L. seeds were divided into large and small seed size fractions and the seeds scarified, stratified, and planted. A larger percentage of large seeds germinated than did small seeds. Seedlings from large seeds had a greater peak and germination value than small seeds, indicating greater vigor and a more rapid germination rate thus more uniform seedlings. Seedlings from large seeds, as indicated by fresh and dry weights, were larger and contained a greater leaf area than those produced by small seed.

scholarly journals Peanut Tolerance to Paraquat as Influenced by Seed Size1

1994 ◽  
Vol 21 (1) ◽  
pp. 12-16 ◽  
Author(s):  
Glenn Wehtje ◽  
Barry Brecke ◽  
J. P. Bostick
Keyword(s):  
Seed Size ◽  
Growth Reduction ◽  
Herbicide Application ◽  
Peanut Seed ◽  
Net Return ◽  
Small Seed ◽  
Effect On Yield ◽  
Kg Medium ◽  
The Relationship ◽  
Common Plant

Abstract Studies were conducted over a 2-year period at Headland, Ala. and Jay, Fla. to evaluate the relationship between peanut seed size and tolerance of the resultant crop to normal and excessive rates of the herbicide paraquat (1,1′-dimethyl-4,4′-bipyridinium ion). Three seed sizes, termed small (3340 seeds/kg), medium (2615 seeds/kg), and large (1820 seeds/kg), were planted to achieve a common plant population. While seedling size at emergence reflected seed size, no interaction between seed size and herbicide treatment was detected for crop growth measured as the increase in canopy diameter over a 5-week period following herbicide application. None of the seed sizes resulted in seedlings that were either uniquely sensitive or abnormally tolerant of paraquat. Two sequential applications of paraquat at 0.14 kg ai/ha each was consistently the most damaging treatment as measured in growth reduction, however yield was reduced in only one of four trials. Seed size had an effect on yield in only two of the four trials, and within these two trials the average yield improvement from large seed relative to medium and small seed was only 10 and 12%, respectively. Net return generally was independent of seed size. However, medium-sized seed resulted in maximum net return in two out of the four experiments.

Tourism awareness as a tourism development strategy: status of the issue

2020 ◽  
Vol 13 (9) ◽  
Author(s):  
M.I. Rosas-Jaco ◽  
S.X. Almeraya-Quintero ◽  
L.G. Guajardo-Hernández
Keyword(s):  
Development Strategy ◽  
Design Methodology ◽  
Local Development ◽  
Local Population ◽  
Host Community ◽  
Government Policies ◽  
Training Manual ◽  
Environmental Development ◽  
Main Engine ◽  
The Relationship

Objective: Tourism has become the main engine of economic, social and environmental development in several countries, so promoting tourism awareness among tourists and the local population should be a priority. The present study aims to suggest a status of the research carried out on the topic of tourism awareness. Design / methodology / approach: The type of analysis is through a retrospective and exploratory bibliometric study. The analysis materials were scientific articles and a training manual published between 2000 and 2020, registered by Scopus, Emerald insight and Dialnet, using “tourism awareness” as the keyword. Results: When considering the three senses in which tourism awareness ought to operate, it is concluded that studies are more focused on the relationship and contact of the host community with the tourist. It is observed that four out of six articles in this sense consider that education, training, and government policies around tourism awareness should be developed in a better way in the destinations, in order to be an element that contributes to the development of communities and reduces poverty in developing countries. Study limitations / implications: It is considered a limitation not to include thesis dissertations. Findings / conclusions: It is necessary to make visible the importance of tourism awareness as a local development strategy for communities, in addition to including tourism awareness on the part of tourists.

Reflections on Local Population Studies and Social Science History

2018 ◽  
pp. 43-51
Author(s):  
Osamu Saito
Keyword(s):  
Social Science ◽  
Population Studies ◽  
Local Population ◽  
Local Source ◽  
Personal Reflection ◽  
Social Scientists ◽  
Science History ◽  
Social Science History ◽  
The Relationship ◽  
Source Materials

This personal reflection of more than 40 years' work on the supply of labour in a household context discusses the relationship between social science history (the application to historical phenomena of the tools developed by social scientists) and local population studies. The paper concludes that historians working on local source materials can give something new back to social scientists and social science historians, urging them to remake their tools.

scholarly journals Effects of Cultivar and Ethanol Disinfection on Aseptic Germination of Loquat (Eriobotrya japonica) Seeds

HortScience ◽  
2017 ◽  
Vol 52 (7) ◽  
pp. 941-945
Author(s):  
Kunkun Li ◽  
Weiqi Dong ◽  
Yun Zhao ◽  
Hongxia Xu ◽  
Junwei Chen ◽  
...  
Keyword(s):  
Detrimental Effect ◽  
Germination Rate ◽  
Fruit Tree ◽  
Final Concentration ◽  
Eriobotrya Japonica ◽  
Seedling Height ◽  
Disinfection Procedure ◽  
Aba Content ◽  
Subtropical Fruit ◽  
The Relationship

Loquat (Eriobotrya japonica Lindl.) is an economically important subtropical fruit tree, originating and commercially produced mainly in China and Japan. The aseptic seed germination of 13 loquat cultivars, including 9 white-fleshed cultivars and 4 red-fleshed ones, was studied, and the relationship between the germination rate and the content of endogenous ABA in seeds was explored. The germination rate and the seedling height at 80 days after sowing of white-fleshed cultivars were generally higher than that of red-fleshed ones. The ABA content in seeds was generally lower in white-fleshed cultivars, and the ABA content negatively correlated with the germination rate at 80 days after sowing. A moderate detrimental effect of 75% ethanol disinfection on aseptic germination of loquat seeds was observed, especially, for the cultivar Dahongpao, and the germination rate and seedling height were reduced by around half and one-third, respectively. The addition of plant preservative mixture (PPM) to the germination medium at a final concentration of 25 mg·L−1 effectively controlled contamination when the 75% ethanol disinfection procedure was omitted.

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