Components of seed mass and their relationships to seedling size in Calamovilfa longifolia

1993 ◽  
Vol 71 (4) ◽  
pp. 551-557 ◽  
Author(s):  
Jianhua Zhang ◽  
M. A. Maun

Greenhouse studies were conducted to determine the relative contribution of endosperm and embryo masses to seed mass and seedling size in Calamovilfa longifolia. Seed mass in a sample varied from 0.71 to 3.17 mg per seed, and according to fitted functions, from approximately 0.26 to 2.48 mg per endosperm and from 0.15 to 0.50 mg per embryo. Both the embryo and endosperm masses were significantly correlated with mass, length, width, and area (length × width) of seeds. Seedling (2-weeks old) height, leaf area, and dry weights of leaves, stems, and roots were also highly positively correlated with seed mass. Because endosperm mass contributed much more to the variation in seed mass and showed stronger correlation with seed mass than embryo mass, seedling size may depend mainly on the amount of seed reserves in the endosperm rather than the embryo. Key words: seed mass, seedling size, embryo mass, endosperm mass, Calamovilfa longifolia.

1994 ◽  
Vol 72 (3) ◽  
pp. 402-406 ◽  
Author(s):  
Jianhua Zhang

Cakile edentula produces dimorphic seeds from the upper and lower fruit segments. The upper seeds are well adapted to long-distance dispersal and have greater mean seed mass and surface area than those from the lower seeds. Great mean mass of the upper seeds is probably adaptive because it ensured early independent growth of seedlings and thus enhanced their chances of surviving environmental stresses. Large seed reserves also resulted in high chlorophyll content of the cotyledons. Large seed surface area resulted in large cotyledon area and cotyledon area to biomass ratio of the subsequent seedlings, but the adaptive advantage is not clear. Since increased seed surface area necessitates great protective tissues (fruit coat) that may improve the buoyant ability of seeds, large seed surface area of the upper seeds may be a result of selection for dispersal. Key words: seed mass, seed dimorphism, establishment, sand dune, selection, Cakile edentula.


Botany ◽  
2015 ◽  
Vol 93 (8) ◽  
pp. 529-533 ◽  
Author(s):  
Karen Bauk ◽  
Reyes Pérez-Sánchez ◽  
Sebastián R. Zeballos ◽  
M. Laura Las Peñas ◽  
Joel Flores ◽  
...  

Several studies reported a negative relationship between altitude and seed mass. In cactus species, seed mass has been also related to seedling morphology (size and shape). Here we studied Gymnocalycium monvillei (Lem.) Pfeiff. ex Britton & Rose, a cactus species with a wide altitudinal distribution, with the main aim of analyzing how altitude affects seed mass and seedling size (height and width) and shape (globose or columnar). We collected seeds from five sites along the entire altitudinal distribution of the species in the Córdoba Mountains (sites were located between 878 and 2230 m a.s.l.), encompassing a marked climatic gradient (6 °C of mean annual temperature difference between the extreme sites). Seed mass and seedling traits were measured in the laboratory. Seedling height increased with altitude, whereas seed mass was not related to this parameter. Seedlings became more globose (reduced surface/volume ratio) with decreasing altitude. Variation in seedling shape along the altitudinal gradient may be related to the contrasting climatic conditions to which seedlings are exposed, and could account for the wide altitudinal distribution of G. monvillei. Our results highlight the importance of seedling traits in the species’ response to climatic change.


1997 ◽  
Vol 75 (2) ◽  
pp. 332-335 ◽  
Author(s):  
Michael A. Setterington ◽  
Daniel M. Keppie

Relationships between external cone characteristics (length, width, wet and dry mass), cone quality (total seed mass as a proportion of cone mass, total number of seeds per cone, total seed mass per cone), and number of cones in caches were evaluated for caches of jack pine (Pinus banksiana) cones belonging to red squirrels (Tamiasciurus hudsonicus) in two plantations in southern New Brunswick. Cone length and mass were good predictors of the total number of seeds per cone and total seed mass per cone. Length accounted for a small proportion of the variance of total seed mass as a proportion of cone mass. There was no relationship between the number of seeds or total seed mass per cone and the number of cones per cache.


2019 ◽  
Vol 11 (10) ◽  
pp. 154
Author(s):  
Vinicius de Souza Oliveira ◽  
Cássio Francisco Moreira de Carvalho ◽  
Juliany Morosini França ◽  
Flávia Barreto Pinto ◽  
Karina Tiemi Hassuda dos Santos ◽  
...  

The objective of the present study was to test and establish mathematical models to estimate the leaf area of Garcinia brasiliensis Mart. through linear dimensions of the length, width and product of both measurements. In this way, 500 leaves of trees with age between 4 and 6 years were collected from all the cardinal points of the plant in the municipality of São Mateus, North of the State of Espírito Santo, Brazil. The length (L) along the main midrib, the maximum width (W), the product of the length with the width (LW) and the observed leaf area (OLA) were obtained for all leaves. From these measurements were adjusted linear equations of first degree, quadratic and power, in which OLA was used as dependent variable as function of L, W and LW as independent variable. For the validation, the values of L, W and LW of 100 random leaves were substituted in the equations generated in the modeling, thus obtaining the estimated leaf area (ELA). The values of the means of ELA and OLA were tested by Student’s t test 5% of probability. The mean absolute error (MAE), root mean square error (RMSE) and Willmott’s index d for all proposed models were also determined. The choice of the best model was based on the non significant values in the comparison of the means of ELA and OLA, values of MAE and RMSE closer to zero and value of the index d and coefficient of determination (R2) close to unity. The equation that best estimates leaf area of Garcinia brasiliensis Mart. in a way non-destructive is the power model represented by por ELA = 0.7470(LW)0.9842 and R2 = 0.9949.


2002 ◽  
Vol 78 (1) ◽  
pp. 137-145 ◽  
Author(s):  
Victor J Lieffers ◽  
Bradley D Pinno ◽  
Kenneth J Stadt

This study examines light competition between aspen and spruce during the sequence of aspen development. Leaf area index and light transmission were measured or estimated for aspen stands from 2 to 125 years old. Light transmission was lowest at 15-25 years, and in some stands, transmission was less than 5% of above-canopy light. Hypothetical aspen stands with various stem configurations and heights were developed, and positions were identified that would meet or fail Alberta free-to-grow (FTG) standards. Light transmission was estimated at each position with the MIXLIGHT forest light simulator. Positions in canopy gaps or at the northern sides of canopy gaps had higher light. In general, however, there was little difference in available light between positions that met or failed FTG criteria. Stand density and size of aspen trees appears to be a better index to predict light transmission and spruce success in juvenile aspen stands than current FTG criteria. Key words: competition, free to grow, hardwood, spruce, light


1983 ◽  
Vol 63 (1) ◽  
pp. 137-141 ◽  
Author(s):  
G. K. WALKER

Evaporation rates beneath maize canopies were measured using an intact soil core technique. Early in the growing season evaporation rates were periodically high (4.0 mm∙day−1) following rain, but declined rapidly. At full crop cover, when energy supply normally limits evaporation, significant differences in evaporation were detected between canopies with leaf area indices of 3.0 and 4.0. Key words: Evaporation measurement, energy supply, Zea mays L., leaf area, soil evaporimeter, lysimeter


2008 ◽  
Vol 68 (3) ◽  
pp. 553-559 ◽  
Author(s):  
AVF. Jardim ◽  
MA. Batalha

Although there have been advances in methods for extracting information about dispersal processes, it is still very difficult to measure them. Predicting dispersal groups using single readily-measured traits would facilitate the emergence of instructive comparisons among ecological strategies of plants and offer a path towards improved synthesis across field experiments. The leaf-height-seed scheme consists of three functional traits: specific leaf area, plant canopy height, and seed mass. We tested, applying logistic regression analysis, whether these traits are potential predictors of dispersal guilds in a disjoint cerrado woodland site in southeastern Brazil. According to our results, none of the plant traits studied could predict dispersal guild; this means that abiotically and biotically dispersed species showed similar values of specific leaf area, height, and seed mass. The species of both guilds exhibited sclerophylly, probably a result of the typical soil nutrient deficiency of cerrado, which also may have placed constraints upon plant canopy height regardless of the dispersal mode. In the cerrado, some abiotically dispersed trees might present higher than expected seed mass as support to the investment in high root-to-shoot ratio at the seedling stage. Seeds of bird-dispersed species are limited in size and mass because of the small size of most frugivorous birds. Since soil nutrient quality might contribute to the similarity between the dispersal guilds regarding the three traits of the scheme, other plant traits (e.g., root depth distribution and nutrient uptake strategy) that detail the former should be considered in future predictive studies.


2018 ◽  
Vol 111 (3) ◽  
pp. 597 ◽  
Author(s):  
Kazem GHASSEMI-GOLEZANI ◽  
Salar FARHANGI-ABRIZ ◽  
Ali BANDEHAGH

<p>This research was conducted to investigate the morpho-physiological effects of salicylic acid and jasmonic acid on soybean performance and productivity under salinity. Leaf chlorophyll content index, carotenoids and anthocyanins content, photosystem II efficiency, relative water content, leaf area, leaf mass, specific leaf area, water use efficiency, seed filling duration, assimilate mobilization efficiency and seed mass decreased, but leaf temperature, specific leaf mass and electrolytic leakage of leaves increased with enhancing salinity. Salicylic acid improved leaf chlorophyll content index, anthocyanins content, leaf area, specific leaf area, water use efficiency, seed filing duration, assimilate mobilization efficiency and seed mass under both saline and non-saline conditions. The superior effects of salicylic acid on some traits such as maximum quantum yield of PSII, relative water content and leaf electrolytic leakage only occurred under different salinity levels. Jasmonic acid improved leaf mass, specific leaf mass, carotenoids content, relative water content, seed filling rate and reduced chlorophyll content index, leaf temperature, leaf area, specific leaf area, seed filling duration, assimilates mobilization efficiency and relative electrolytic leakage of soybean, with no significant effects on photosystem II efficiency and seed mass. Application of salicylic acid was, therefore, the superior treatment for enhancing physiological performance and seed mass of soybean plants under different salinity levels.</p>


2017 ◽  
Vol 31 (9) ◽  
pp. 1770-1779 ◽  
Author(s):  
Bianca A. Santini ◽  
John G. Hodgson ◽  
Ken Thompson ◽  
Peter J. Wilson ◽  
Stuart R. Band ◽  
...  

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