scholarly journals Water permeability/impermeability in seeds of 15 species of Caragana (Fabaceae)

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6870 ◽  
Author(s):  
Dali Chen ◽  
Rui Zhang ◽  
Carol C. Baskin ◽  
Xiaowen Hu

Majority legumes in the temperate and arctic zones have water-impermeable seeds (physical dormancy, PY). However, various authors have reported that seeds of some Caragana species are water-permeable and thus non-dormant. We (1) tested seeds of 15 species of Caragana matured in the same site in 2014, 2016 and/or 2017 for presence of PY, (2) determined if dry storage decreased or increased the percentage of seeds with PY and (3) located the site on the seed coat of 11 species where water enters the seed. Sixty-three percent and 45% of the seeds of C. roborovskyi had PY in 2016 and 2017, respectively, but only 0–14% of the seeds of the other 14 species had PY. The palisade layer in the seed coat of water impermeable seeds had no cracks in it, whereas cracks were present in the palisade layer of water-permeable seeds. Year of collection and dry storage had significant effects on imbibition of two species (C. acanthophylla and C. roborovskyi). In two (C. acanthophylla and C. roborovskyi) of the 11 species tested, the hilum was the site of water entry into seeds (control seeds, not any dormant broken treatments), but for the other nine species tested water entered through all parts of the seed coat.


2015 ◽  
Vol 25 (3) ◽  
pp. 255-266 ◽  
Author(s):  
Giuseppe Puglia ◽  
Simona Grimaldi ◽  
Angelino Carta ◽  
Pietro Pavone ◽  
Peter Toorop

AbstractGlebionis coronaria (L.) Cass. ex Spach is a common Mediterranean weed producing distinctive central and peripheral dormant cypselae with a hard fruit coat, which was previously hypothesized to impose physical dormancy. Analysis of water uptake in cypselae and in naked seeds showed that it preferentially takes place at the basal end of the fruit; however, seeds within an intact pericarp do not fully imbibe when compared with naked seeds. Germination was not significantly different between the two heteromorphs, and afterripening or cold stratification did not increase germination, while warm stratification at 35/20°C, as revealed by logistic regression, resulted in a significant improvement. However, loss of viability was also rapid at these high temperatures. Central and peripheral cypselae generally showed very low germination. In both heteromorphs, faster and higher germination (60–70%) was reached only after extensive scarification of pericarp tissue, and full germination was observed only after complete removal of pericarp tissue. Although the pericarp significantly reduced water uptake, no palisade layer(s) of macrosclereids could be observed. Xylem-vessel elements were found running through the basal end of the pericarp and forming the main point of water entry. We reject the hypothesis that G. coronaria cypselae have physical dormancy. Instead, water uptake and germination are impeded by: (1) directed water uptake, mainly through a pericarp-spanning channel-like structure; and (2) mechanical constraint on embryo growth exerted by the hard pericarp. The channel-like structure forms the principal system for controlling seed germination.



2006 ◽  
Vol 54 (6) ◽  
pp. 565 ◽  
Author(s):  
S. R. Turner ◽  
D. J. Merritt ◽  
J. M. Baskin ◽  
C. C. Baskin ◽  
K. W. Dixon

Seeds of the endemic Western Australian species Diplopeltis huegelii Endl. were successfully germinated after the presence of combinational dormancy was identified, following the observation of selected seed characteristics. D. huegelii seeds were found to have large, fully developed, peripheral coiled embryos (with no endosperm) that are 7–8 mm long when uncoiled. Seed-coat dormancy was overcome by dipping seeds in hot water for ≥15 s, but seeds also required a period of after-ripening before they would germinate readily. After-ripening occurred while intact seeds were stored dry at ambient laboratory conditions for 13 months or when scarified (hot-water treated) seeds were stored at 13, 23 or 50% RH at 23°C for 6 weeks. Scarified 13-month-old seeds germinated readily at 7/18, 13/26 and 18/33°C in a 12-h photoperiod and in constant darkness, whereas scarified 1-month-old seeds germinated to ≤43%. Thus, seed dormancy in this species is caused by a water-impermeable seed coat (physical dormancy, PY) and a (non-deep) physiologically dormant embryo (PD), i.e. combinational dormancy (PY + PD). This is only the second report of combinational dormancy in seeds of Sapindaceae and the first report in this family of the PD component of (PY + PD) being broken during dry storage.



For identification of varieties, it is desirable to use genetically predetermined traits that are decisive for the varietal identification of the distinguishing characteristics of the varieties production and new genotypes for selection. The presence a complete evaluation of the selection samples a particular crop is the basis for the formation of informative databases characteristics the varieties of standards used in plant examination to determine the level of expression a characteristic particular genotype according to the code of their manifestation. For the 20 traits we used to identify, we identified 6 least volatile, highly trait-stable traits over the years of study to identify. These are: “coloring of the pubescence of the main stem”, “the size of the lateral leaf”, “the intensity of green leaf color”, “flower color”, “the intensity of brown bean color”, “basic color of the seed coat”. The other 14 traits are highly variable and unstable among varieties, but may be significant under certain conditions. According to the results of the research we have determined the conformity of the collection varieties by code graduation. In the study, we selected varieties with corresponding codes of attributes of the reference varieties the UPOV technique. On the basic of the color the pubescence of the main stem, 36% varieties are with grey stem pubescence. Among the standards: Apache, Alaric, Talon according to the grey color of the pubescence, we identified varieties Zolotysta, Ozzie, Diona. The 2947 564/84, Stepnaya-90, Knyazhna. The lateral leaf size is a sign that affects the increase in green mass of plants and subsequently on productivity. Graduation of the sign small size of leaf had varieties: Zuma, Ksenya; middle – Heinong 37, Yuh-30; large – 2947 564/84, Vinni, DSS 2504. The following is a sign of the intensity of leaf plate, which is divided by gradation into light, moderate and dark. Among our samples with a light degree of color, we can distinguish Diona, Sribna Ruta, and Zuma. For varieties with moderate gradation of color are selected: Perlyna, 93/99, Knyazhna. To the dark color of the leaf plate we attributed the varieties: Stepnaya-90, Ozzie. Among the varieties we studied of the basics of flower color 37% varieties are with a white flower, and 63% with a purple. According to the varieties of standards: Chandor, Cresir, Toreador to the white color of the flower we attributed varieties Knyazhna, Ozzie, Zolotysta. With the purple color of the flower we have selected varieties: 93/99, Zhemchuzhna, Heinong 37. On the basis of the intensity of brown color bean, which characterizes the generative organs of the plant, is divided into weak, moderate and strong, but the other identifiers there are gradations: sandy, gray, light brown, brown and dark brown, so we decided what would be better identify by color gradation. To the sandy color of the beans we attributed varieties Perlyna, Yuh-30; gray – Sribna Ruta; light brown – Kobza, Knyazhna; brown – Ksenya; dark brown – Zhemchuzhna, Vinni. Important features that identify the description of varieties include basic color of the seed coat, which affects the taste of the seeds. In particular, the seeds are divided by color into yellow – Kobza, Yuh-30; yellow-green – Vinni, Luch Nadezhdy; green – Heorhina; light brown – 2947 564/84, brown – DSS 2504; dark brown – 2974 YS-24 and black color – not detected. Following the results of the previous collection of soybean varieties from the morphological sings of vegetative, generative organs of plants, it was possible to identify varieties with stable manifestation of standard identifying sings of soybean. Collection varieties with one standard characteristics: Heinong 37, Luch Nadezhdy, DSS 2504, 2974 YS-24; two signs: Zolotysta, Diona, Stepnaya-90, Zuma, Ksenya, Heorhina, Sribna Ruta, Perlyna, 93/99, Zhemchuzhna; three signs: Ozzie, 2947 564/84, Yuh-30, Vinni, Knyazhna.



2021 ◽  
pp. 1-25
Author(s):  
Roberto Lujan Rocha ◽  
Yaseen Khalil ◽  
Aniruddha Maity ◽  
Hugh J. Beckie ◽  
Michael B. Ashworth

Abstract Wild oat is a herbicide resistance-prone global weed species that causes significant economic losses in dryland and horticultural agriculture. As a result, there has been a significant research effort in controlling this species. A major impediment to this research is the seed coat-mediated dormancy of wild oat, requiring a labor-intensive incision or puncturing of the seed coat to initiate seed germination. This study defines the most efficient settings of a mechanical thresher to overcome wild oat seed dormancy and then validates these settings using multiple populations collected from the Western Australian grain belt. We also compare the effects of rapid mechanical scarification and known germination stimulus tactics such as scarification with sulfuric acid (H2SO4), partial endosperm removal, sandpaper scarification of the seed coat, and immersion in sodium nitroprusside (NO donor SNP) solution on wild oat seedling growth rate. Threshing treatment of 1,500 rpm for 5 s provides equivalent germination compared with manually puncturing individual wild oat seeds, with no difference in seedling relative growth rate. The mechanical scarification of seeds using the thresher resulted in greater germination (66%) than H2SO4 scarification (0%), partial endosperm removal (10%), sandpaper seed coat scarification (25%), and exposure to NO donor SNP (34%). This study demonstrates that the physical dormancy of wild oat can be rapidly overcome using a commercially available mechanical thresher.



2021 ◽  
pp. 004051752110388
Author(s):  
Ayşe Şevkan Macit ◽  
Bahar Tiber

Ultrasonic seaming has become an important issue in recent years due to its various features. In this study, waterproof polyester knitted fabrics with polyurethane coating were used and the bursting strength, bending property and water permeability property of ultrasonic seaming were examined by changing various parameters. Besides, the ultrasonic seaming method was compared to conventional seaming and adhesive tape application. It is observed that there were high water permeability values generally in ultrasonic seaming and also fabrics with no water penetration were seen in this method, although, in some ultrasonic seaming parameters, values are lower than adhesive tape sealed ones. On the other hand, the bursting strength values of the ultrasonically sewn fabrics are found to be comparable to conventional seam and sealing adhesive tape when the optimum seaming parameters are determined. Also, it can be said that for the bending property according to increasing bending length values in this method compared with the others, ultrasonic seaming may find more usage areas where fabric stiffness is more advantageous. It has been observed that it is important to determine the fabric and ultrasonic sewing parameters according to the required performance property.



2016 ◽  
Vol 8 (2) ◽  
pp. 77
Author(s):  
Stephen I. Mensah ◽  
Chimezie Ekeke

<p class="1Body">The seed dormancy of <em>Senna obtusifolia</em> was investigated through various methods, namely pretreatments in concentrated sulfuric acid, 2% potassium nitrate (KNO<sub>3</sub>), 99% ethanol, 99% methanol, and in hydrogen perioxide; examination of the seed coverings; and the determination of water uptake by the seeds in order to ascertain the most effective technique for breaking dormancy and also determine the dormancy type. The results showed that sulfuric acid treatment recorded the highest germination (100%); followed by 2% hydrogen peroxide treatment (24%) in 15minutes immersion. The methanol and ethanol pretreatments gave 18.33% and 16.5% germinations respectively. Pretreatment in 2% potassium nitrate gave the lowest germination (8.50%), while the intact seeds of <em>S. obtusifiolia</em> (control) gave 0% germination. The anatomy of the seed coat indicated the presence of hard, thickened and specialized cells of cuticle, macrosclereids, osteoscereids, and disintegrated parenchyma layers. The water uptake of intact seeds was low (13.5%) after 24 hr imbibitions. These findings revealed that the seed coat acts as barrier to germination by preventing water absorption, possibly gaseous diffusion in and out of the seed and conferring mechanical resistance to the protrusion of embryo. Pretreatments, such as immersion in H<sub>2</sub>SO<sub>4 </sub>will soften the seed coat and permit germination. Seed dormancy in <em>S. obtusifolia </em>can be considered of physical nature and classified as physical dormancy. The results obtained in this study may serve as useful information in the production and improvement of <em>S. obtusifolia </em>seedlings, as knowledge on seed dormancy and germination is a critical factor and requirements to the understanding of the propagation of this plant either in situ or ex-situ, in view of the economic potentials/attributes of this species.</p>



2006 ◽  
Vol 16 (1) ◽  
pp. 83-88 ◽  
Author(s):  
Juvet Razanameharizaka ◽  
Michel Grouzis ◽  
Didier Ravelomanana ◽  
Pascal Danthu

The Adansonia (baobab) genus comprises seven species in Africa, six of which are endemic to Madagascar. Depending on the species, baobabs develop in widely varying ecosystems, including arid zones and savannahs, as well as dry and wet forests. Seeds from all species exhibited orthodox behaviour, tolerating dehydration to a moisture content of around 5%. There was no physical dormancy in the two species belonging to the Brevitubae section, A. grandidieri and A. suarezensis. Their seeds germinated without any prior scarification. The five other species, belonging to Adansonia and Longitubae section, have seeds with water-impermeable coats. In the case of A. digitata and A. za, the proportion of water-impermeable seeds was around two-thirds, whereas with A. rubrostipa, A. madagascariensis and A. perrieri, the proportion was >90%. Treatments allowing for the removal of physical dormancy needed to be markedly more severe with A. madagascariensis than with the other species. None the less, it seems impossible to link these characteristics and the interspecific differences to a strategy for adaptation by these species to their environment.



2018 ◽  
Vol 28 (3) ◽  
pp. 186-191 ◽  
Author(s):  
Robert L. Geneve ◽  
Carol C. Baskin ◽  
Jerry M. Baskin ◽  
K.M.G. Gehan Jayasuriya ◽  
Nalin S. Gama-Arachchige

AbstractPhysical dormancy (PY) occurs in at least 18 angiosperm plant families and is caused by water-impermeable palisade cells in seed (or fruit) coats. Breaking of PY involves disruption or dislodgement of water-gap structures causing the seeds/fruits to become water permeable (non-dormant). The water-gap region is a morphologically distinct area of the seed or fruit coat that forms a water-gap complex. The location, anatomy, morphology and origin of water-gaps can differ between and even within families and genera. Water-gap structures sense environmental conditions that allow seeds with PY to become permeable just prior to the commencement of conditions favourable for germination and plant establishment. There are three basic water-gap morpho-anatomies characterized by the way the water-gap opens: Type-I, Type-II and Type-III. In Type-I water-gaps, specific kinds of cells pull apart to form a surface opening, while in Type-II a portion of the surface structure is pulled away from adjacent cells, opening the water-gap. Type-III is the least common type and has a circular, plug-like structure that is dislodged, whereby water entry occurs. In addition, water-gap complexes are either simple or compound, depending on whether only a single primary water-gap structure is involved in dormancy release or an additional secondary water-gap structure opens, permitting water entry.



Author(s):  
Caroline Palacio de Araujo ◽  
Rodrigo Sobreira Alexandre ◽  
Thuanny Lins Monteiro Rosa ◽  
Edilson Romais Schmildt ◽  
José Carlos Lopes ◽  
...  

Lecythis pisonis produces edible seeds rich in nutritional and functional elements such as selenium and are a great alternative to Brazilian nuts. The seeds have low germination, which may be related to physical dormancy imposed by tegument, meaning that polyembryonic seedlings can be a strategy to increase final stand. The objective of this work was to study methods to overcome seed dormancy and auxin induction in polyembryonic seedlings of pisonis. The experiment to break dormancy consisted of seven treatments: T1: intact seeds; T2: seeds scarified on hilum’s opposite side; T3: seeds scarified hilum’s adjacent region; T4: seeds scarified in lateral region; T5: seeds scarified in both opposite and adjacent region to the hilum; T6: T2 + immersion in water at 40 °C/20 minutes; T7: T2 + immersion in water at 60 °C/5 minutes. The experiment to induce rooting was arranged in a 2 x 6 factorial randomized complete block design (environments: A. greenhouse and B. greenhouse covered with black polyolefin (80% shading) x concentrations of indole-3-butyric acid (IBA): 0; 1000; 2000; 3000; 4000 and 5000 mg L-1), with four replicates of eight polyembryonic seedlings. Seed coat scarification in hilum’s adjacent (T3) and lateral regions (T4) was the most efficient methods for breaking physical dormancy. IBA at 5000 mg L-1 promoted the greatest rhizogenesis of L. pisonis layers.



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