Effects of partial removal of seed reserves on some aspects of seedling ecology of seven dune species

1991 ◽  
Vol 69 (7) ◽  
pp. 1457-1462 ◽  
Author(s):  
Jianhua Zhang ◽  
M. A. Maun

Greenhouse studies were conducted to determine the effects of partial removal of endosperm or cotyledons from seeds of seven dune species on seed germination, seedling emergence, seedling size, and dry matter allocation. Different proportions (0, 30, and 60%) were surgically removed from seeds of Agropyron psammophilum, Calamovilfa longifolia, Elymus canadensis, Leymus arenarius, Panicum virgatum, Lupinus perennis, and Strophostyles helvola. Partial removal of seed reserves caused a significant reduction in seedling variables 1 or 2 weeks after planting in sand. For example, seedling height, leaf area, dry weight of leaves, stem, and roots were significantly lower than control. The data suggest that the principal determinant of seedling size at an early stage was the amount of energy reserves in the endosperm or cotyledons of seeds. In addition to reduction in food reserves, partial removal of seed reserves caused some physiological damage to seedlings. In grass species, seedlings from surgically treated seeds devoted more dry matter to the roots and less to the leaves and stem than control seedlings. In dicot species, however, plants from treated seeds devoted more dry matter to the leaves and less to the roots. Key words: seed injury, seed germination, seedling size, energy allocation, dune plants.

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 633c-633
Author(s):  
C.L.H. Finneseth ◽  
Desmond R. Layne ◽  
R.L. Geneve

Little scientific information is available describing morphological development of pawpaw during seed germination. To provide this information, a study was designed to outline important developmental stages and describe seedling characteristics within each stage. Stratified pawpaw seeds were sown in vermiculite and germinated at 25°C in a growth chamber. Ten seedlings were randomly chosen and destructively harvested at 5-day intervals starting at radicle protrusion. Length (mm), fresh and dry weight, and percentage of total dry weight were determined for seedling components. Pawpaw seeds have a small rudimentary embryo with all food reserves stored in a ruminate endosperm. Dry weight measurements showed a dramatic reallocation of reserves from the storage tissue to developing seedling parts. Initial embryo length was less than 3 mm, but within 70 days seedlings exceeded 350 mm. Twelve days after planting, simultaneous radicle and cotyledon growth occurred (3.4 and 3.0 mm, respectively), but neither hypocotyl nor epicotyl was visible. Radicle protrusion was observed at 15 days with radicle, cotyledon and hypocotyl lengths increasing to 4.4, 4.0, and 3.2 mm, respectively. Endosperm comprised 99.1% of total dry weight at this stage. The hypocotyl hook emerged after 30 days and endosperm comprised 76.1% of total dry weight. Cotyledons reached maximum length (29.0 mm) at day 40 and the epicotyl was discernible. At 55 days, the seed coat containing cotyledons and residual endosperm abscised and the average radicle, hypocotyl and epicotyl lengths were 182.0, 61.1, and 7.3 mm, respectively. It is suggested that the cotyledons primary function is absorption of food reserves from the endosperm for transfer to the developing seedling.


PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0242035
Author(s):  
Simone Pedrini ◽  
Jason C. Stevens ◽  
Kingsley W. Dixon

To achieve global ambitions in large scale ecological restoration, there is a need for approaches that improve the efficiency of seed-based interventions, particularly in overcoming the bottleneck in the transition from germination to seedling establishment. In this study, we tested a novel seed-based application of the plant stress modulator compound salicylic acid as a means to reduce seedling losses in the seed-to-seedling phase. Seed coating technology (encrusting) was developed as a precursor for optimising field sowing for three grass species commonly used in restoration programs, Austrostipa scabra, Microlaena stipoides, and Rytidosperma geniculatum. Salicylic acid (SA, 0.1mM) was delivered to seeds via imbibition and seed encrusting. The effects of SA on seed germination were examined under controlled water-limited conditions (drought resilience) in laboratory setting and on seed germination, seedling emergence, seedling growth and plant survival in field conditions. Salicylic acid did not impact germination under water stress in controlled laboratory conditions and did not affect seedling emergence in the field. However, seedling survival and growth were improved in plants grown from SA treated seeds (imbibed and encrusted) under field conditions. When SA delivery methods of imbibing and coating were compared, there was no significant difference in survival and growth, showing that seed coating has potential to deliver SA. Effect of intraspecific competition as a result of seedling density was also considered. Seedling survival over the dry summer season was more than double at low seedling density (40 plants/m2) compared to high seedling density (380 plants/m2). Overall, adjustment of seeding rate according to expected emergence combined with the use of salicylic acid via coating could improve seed use efficiency in seed-based restoration.


1990 ◽  
Vol 12 (1) ◽  
pp. 25 ◽  
Author(s):  
A Bogusiak ◽  
B Rice ◽  
M Westoby ◽  
MH Friedel

The ecology of hummock-grass vegetation involves recurring fires. The hypothesis was tested that soil seed banks of hummock grass species are stimulated to germinate by the heat of fire or by ash addition. Hummocks of Plectrachne schinzii Henr., Triodia basedowii E. Pritz., and Triodia pungens R. Br. were burned, removed, or removed with the ash returned, and subsequent regeneration was recorded, in Ulum National Park. Regeneration of hummock grass was by seedlings only. Seedling emergence averaged 5/m2, with no differences between treatments or hummock grass species. This indicates the heat of fires and ash addition may not be important in stimulating seed germination of these hummock grass populations. Gemination was distributed over more than one rainfall event following the treatments.


1982 ◽  
Vol 62 (3) ◽  
pp. 733-739 ◽  
Author(s):  
L. R. MAPPLEBECK ◽  
V. SOUZA MACHADO ◽  
B. GRODZINSKI

Seed germination and seedling characteristics of atrazine-susceptible and resistant wild turnip rape biotypes (Brassica campestris L.) were examined. Seeds of the susceptible biotype germinated earlier, and the germinated seeds grew faster and emerged earlier than seeds of the resistant biotype. Seedlings of the susceptible biotype emerged from greater planting depths than the resistant seedlings. Emerged susceptible seedlings were larger, with longer hypocotyls and greater cotyledon area, and produced more dry matter than the resistant biotype seedlings. Differences in water content of germinated seeds of the two biotypes were noted, with the susceptible biotypes consistently showing a higher water content. There was no significant difference in the respiration rate of the two biotypes at the early stage of seedling growth.


2009 ◽  
Vol 38 (spe) ◽  
pp. 160-169
Author(s):  
Kenneth Paul Vogel ◽  
Cesar Heraclides Behling Miranda

In the early 1970's research was initiated by the cooperative USDA-ARS and University of Nebraska grass breeding program to develop perennial grasses adapted to the mid-continental USA with improved forage quality. The initial breeding and animal evaluation work focused on switchgrass (Panicum virgatum) but has since expanded to several other warm-and cool-season perennial grasses. The in vitro dry matter digestibility (IVDMD) test was selected as the measure of forage quality that was used in the breeding work because of its previous successful application on improving bermudagrass (Cynodon dactylon). In all of the grass species that we have studied to date, there is genetic variability for IVDMD and forage yield. IVDMD is a heritable trait with narrow sense heritability's ranging from 0.2 to 0.4 which are similar to heritability's for forage yield. If significant improvements or difference in IVDMD (> 1%) can be detected in small plot trials (r=6), differences in cattle gains among experimental strains or cultivars can be demonstrated in grazing trials. Averaged over both cool- and warm-season grasses, a 1% increase in in vitro dry matter digestibility (IVDMD) generally leads to a 3.2% increase in average daily gains of beef cattle. Because increased IVDMD generally does not result in a decrease in forage yield, this results in a net increase in animal production per hectare of land.


2015 ◽  
Vol 37 (1) ◽  
pp. 63-69 ◽  
Author(s):  
Welison Andrade Pereira ◽  
Sara Maria Andrade Pereira ◽  
Denise Cunha Fernandes dos Santos Dias

Physiological quality and vigor of the seeds comprise properties that determine a high level of activity and performance during germination and seedling emergence, having a direct relation with the establishment of the stand of a crop. In this context, the assessment of seedling development, including the analysis of the seed reserves mobilization are a reliable method to investigate the physiological potential of seed lots. In this preliminary study, the aim was to investigate the dynamics of seed reserves mobilization of a sample of soybean commercial cultivars. By means of the seedling length bioassay and weight of dry matter of seeds, cotyledons, hypocotyls and radicles, information on the reserves mobilization during the germination process was obtained. Data were subjected to analysis of variance and Scott and Knott test, and afterwards, phenotypic correlations between traits were obtained. The results have shown that the dry matter of seeds, reserves reduction of seeds and dry matter of seedlings are positively correlated, and thus, seeds containing more reserves may be more effective during the early development of seedlings. In contrast, reserve reduction of seeds and conversion efficiency of the seeds reserves in the dry matter of seedlings are negatively correlated.


1983 ◽  
Vol 61 (4) ◽  
pp. 1216-1221 ◽  
Author(s):  
O. W. Archibold ◽  
L. Hume

Seed traps were installed in 10 summer fallow sites across Saskatchewan to monitor annual additions to buried seed populations. Soil cores (7.5 cm deep) were also collected at these sites and tested for viable seeds through seedling emergence under greenhouse conditions. Seedlings of 33 forb species, 5 grass species, and 3 tree species emerged from the traps, whereas seedlings of 28 forb species, 4 grass species, and 1 tree species emerged from the cores. Although the nature of seed input for agricultural sites in different parts of Saskatchewan was highly variable, the annual seed rain onto fallow represented an important supplement to the buried seed reserves and would be an influence on subsequent weed communities in cultivated fields.


Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1411
Author(s):  
Rashida Perveen ◽  
Xiukang Wang ◽  
Yasir Jamil ◽  
Qasim Ali ◽  
Shafaqat Ali ◽  
...  

The present investigation was undertaken to assess the effects of different doses (100, 300, and 500 mJ) of low power He–Ne laser (632.8 nm) irradiation on seed germination and thermodynamics attributes and activities of potential germinating enzymes in relation with changes in seed metabolites. He–Ne laser seed irradiation increased the amylase (Amy), protease (Pro) and glucosidase (Gluco) activities, with a significant improvement in seed thermodynamics and seed germination attributes. A fast increase was found in free fatty acids (FFA), free amino acids (FAA), chlorophyll (Chl), carotenoids (Car), total soluble sugars (TSS) and reducing sugars (RS) in laser treated seeds in parallel with fast decline in seed oil contents and total soluble proteins (TSP). Significant positive correlations were recorded in laser-induced enhanced seed energy levels, germination, activities of germination enzymes with levels of FAA, FFA, Chl, TSS and RS, but a negative correlation with the levels of TSP and oil. In conclusion, the seed treatment with 100 and 300 mJ He–Ne laser was more effective to improve the seed germination potential associated with an improvement in seed energy levels due to increased activities of germination enzymes due to the speedy breakdown of seed reserves to simple metabolites as building blocks.


Sign in / Sign up

Export Citation Format

Share Document