scholarly journals Seed germination and dormancy traits of forbs and shrubs important for restoration of North American dryland ecosystems

Plant Biology ◽  
2018 ◽  
Vol 21 (3) ◽  
pp. 458-469 ◽  
Author(s):  
O. A. Kildisheva ◽  
T. E. Erickson ◽  
M. D. Madsen ◽  
K. W. Dixon ◽  
D. J. Merritt
Keyword(s):  
Seed Germination ◽  
North American ◽  
Dryland Ecosystems

scholarly journals First observation of true vivipary in Grindelia squarrosa (Asteraceae)

Biologia ◽  
2021 ◽  
Author(s):  
Artur Pliszko ◽  
Artur Górecki
Keyword(s):  
Seed Germination ◽  
North American ◽  
Flowering Plants ◽  
Southern Poland ◽  
Germinated Seeds ◽  
Considerable Size

AbstractIn flowering plants, true vivipary is defined as the precocious seed germination and the growth of the embryo to a considerable size before dispersal. True vivipary occurs mostly in mangroves and is very rare in Asteraceae. In this study, we present the first observation of true vivipary in Grindelia squarrosa, a North American member of Asteraceae, from a new locality in Poland. We examined 50 fruiting capitula which were collected in October 2020 in Brzegi, southern Poland. True vivipary occurred in 90% of capitula; however, the number of germinated seeds was low (3.42 on average) and very variable (CV = 106%). Seed germination was found only in fruits developed from disc flowers. We presumed that precocious seed germination in G. squarrosa was induced by prolonged rainfall. The importance of true vivipary in naturalization and invasion of G. squarrosa as well as the involvement of viviparous seedlings in autochory should be further explored.

The effects of temperature and scarification on seed germination of three Dalea species

2015 ◽  
Vol 95 (6) ◽  
pp. 1117-1120 ◽  
Author(s):  
M. P. Schellenberg ◽  
B. Biligetu
Keyword(s):  
Seed Germination ◽  
North American ◽  
Native Plants ◽  
Block Design ◽  
Optimum Temperature ◽  
Randomized Complete Block Design ◽  
Seed Scarification ◽  
Growth Chambers ◽  
Effects Of Temperature ◽  
Germination Experiment

Schellenberg, M. P. and Biligetu, B. 2015. The effects of temperature and scarification on seed germination of three Dalea species. Can. J. Plant Sci. 95: 1117–1120. Ecological varieties of North American native plants are used for reclamation or rangeland seeding in Canada. The objectives of the study were to determine the optimum temperature for seed germination and to evaluate the effect of seed scarification on germination of ecological varieties of purple prairie clover [Dalea purpureum (Vent) Rydb.], white prairie clover [Dalea candida (Michx.) Willd.], and a wild collection of hairy prairie clover [Dalea villosa (Nutt.) Spreng var. villosa]. Germination was studied in growth chambers with constant temperatures of 5, 10, 20, and 30°C for 28 d using a randomized complete block design (RCBD). An additional germination experiment was conducted at 20°C after seed scarification. Based on days to initiate first germination and final germination, the optimum temperature for germination was 20°C for the three species. Final germination was the highest for purple prairie clover (51%), intermediate for white prairie clover (27%), and lowest for hairy prairie clover (5%). Seed scarification increased final germination by around 20% for all three species.

Adaptation of the Connected Speech Test: Rerecording and Passage Equivalency

2020 ◽  
Vol 29 (2) ◽  
pp. 259-264 ◽  
Author(s):  
Hasan K. Saleh ◽  
Paula Folkeard ◽  
Ewan Macpherson ◽  
Susan Scollie
Keyword(s):  
Speech Perception ◽  
North American ◽  
First Language ◽  
Intraclass Correlation ◽  
Normal Hearing ◽  
Connected Speech ◽  
Internal Reliability ◽  
Speech Test ◽  
The Mean ◽  
Unit Standard

Purpose The original Connected Speech Test (CST; Cox et al., 1987) is a well-regarded and often utilized speech perception test. The aim of this study was to develop a new version of the CST using a neutral North American accent and to assess the use of this updated CST on participants with normal hearing. Method A female English speaker was recruited to read the original CST passages, which were recorded as the new CST stimuli. A study was designed to assess the newly recorded CST passages' equivalence and conduct normalization. The study included 19 Western University students (11 females and eight males) with normal hearing and with English as a first language. Results Raw scores for the 48 tested passages were converted to rationalized arcsine units, and average passage scores more than 1 rationalized arcsine unit standard deviation from the mean were excluded. The internal reliability of the 32 remaining passages was assessed, and the two-way random effects intraclass correlation was .944. Conclusion The aim of our study was to create new CST stimuli with a more general North American accent in order to minimize accent effects on the speech perception scores. The study resulted in 32 passages of equivalent difficulty for listeners with normal hearing.

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