scholarly journals Physical seed dormancy in Abrus precatorious (Ratti): a scientific validation of indigenous technique

2021 ◽  
Vol 2 ◽  
Author(s):  
Rajender Kumar Sharma

Abstract Seeds of Abrus precatorius L. (Fabaceae) were used as weight measure by Indigenous people. Where, the seeds were referred as Ratti; a traditional Indian unit of mass measurement. Seed weight fluctuates depending upon age, moisture, storage-period/conditions. Therefore, use of seeds as a weighing unit become dubious and need to be validated. For this purpose, seeds of A. precatorious were subjected to different moisture conditions and periodically monitored. Surprisingly, there was no change in seed weight was observed, indicating the impermeability of seed coat. The later was confirmed by scarification of seed coat which resulted in 53% increase in seed weight against 0% in control. Further, presence of a potent toxin (abrin) in the seed coat protects it from pests and microbes, and contributes to the maintenance of impermeability for longer period of time. The data validates the use of A. precatorious seeds as a weighing unit (ratti) by the indigenous people and discussed.

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>


2012 ◽  
Vol 34 (4) ◽  
pp. 541-548 ◽  
Author(s):  
Ísis Barreto Dantas ◽  
João Almir de Oliveira ◽  
Heloisa Oliveira dos Santos ◽  
Édila Vilela Resende Von Pinho ◽  
Sttela Dellyzete Veiga Franco da Rosa

Seed quality may be affected by several factors, including permeability, color, and lignin content in the seed coat. This study aimed at evaluating influence of lignin content in the tegument of seed samples of six different soybean cultivars, in which half of each sample was inoculated with the fungus Aspergillus flavus, on the physical and physiological quality, and on the seed health, during 180 days storage period, under cold chamber with controlled conditions of temperature and RH. For that, at each interval of 60 days, samples were removed, and the physiological quality of these seeds was assessed by means of moisture and lignin contents; and by tests of seed health, germination, and electrical conductivity. The moisture content of seeds remained constant during all storage period. In the seed health test, it was found that inoculation was efficient, once the minimum incidence of the fungus in the inoculated seeds was 85%. In the germination test, there was a trend of reduction on percentage germination with the increase in storage period. However, there was an increase on electrical conductivity of seeds assessed. It was concluded that there is no interference of the lignin content in the seed coat on the resistance to infection by the fungus Aspergillus flavus, even after seed storage for a period of 180 days.


Weed Science ◽  
1977 ◽  
Vol 25 (3) ◽  
pp. 233-237 ◽  
Author(s):  
R.J. Newton ◽  
G.H. Egley

Dormant (fresh) and nondormant (afterripened) prickly sida (Sida spinosaL.) seeds were extracted and bioassayed for both inhibitory and promotory growth regulators. Both dormant and nondormant prickly sida seeds contained water-soluble inhibitors, but these inhibitor levels in nondormant seeds did not change after 8 hr of incubation. A basic inhibitor was present in dormant seeds, but not in nondormant seeds. Exogenous growth regulators stimulated germination of dormant seeds only when a portion of the seed coat was removed. Promoter levels in nonincubated, dormant and nondormant seeds were similar, but there were increases in promoter levels in nondormant seeds after 8 hr of incubation. However, it was not determined whether the promoter increases were a cause or a result of germination.


2004 ◽  
Vol 55 (11) ◽  
pp. 1189 ◽  
Author(s):  
M. Mera ◽  
R. Jerez ◽  
H. Miranda ◽  
J. L. Rouanet

Abstract. The relatively high seed coat proportion of the narrow-leafed lupin reduces its economic value. This character has been shown to be affected by seed weight, and this limits the use of seed coat proportion as a selection criterion. We examined the variation for seed coat specific weight, a potential alternative selection criterion, and tested its relationship with seed coat proportion and seed weight. Seeds were sampled from mainstem pods of 14 winter-sown genotypes of Lupinus angustifolius L. grown at 4 southern Chile sites over 2 years. Seed coat specific weight had an overall mean of 30.1 mg/cm2. Highly significant genotypic effects were found (range 28.9–32.1 mg/cm2). The ranges for sites and years were 29.1–31.1 and 28.9–31.2 mg/cm2, respectively. Genotypes interacted significantly with years, but not with sites. Broad-sense heritability was 0.59, a value that predicts a good response to selection for this character. Seed coat specific weight was weakly correlated (rph = 0.11*) with seed coat proportion, and was not associated with mean seed weight. Seed coat proportion was negatively correlated with mean seed weight (rph = –0.75***) and had high broad-sense heritability (0.95). The correlation between seed coat specific weight and a theoretical seed coat thickness, calculated under the assumptions of equal mass density of seed coat, cotyledons, and embryo, and a spherical-shaped seed, was r = 0.14*. Phenotypic and genotypic correlations between seed coat specific weight and number of seeds per pod were 0.41 and 0.84, respectively. Our results indicate that selection for low seed coat proportion will lead to larger seeded genotypes, but will not reduce seed coat specific weight. Selection for low seed coat proportion after crosses would presumably be effective in reducing seedcoat specific weight if all segregating materials were uniformly large seeded, but that scenario is unrealistic. The evidence presented here suggests that selection for low seed coat specific weight (or measures correlated with it) in segregating populations will be necessary in order to increase the proportion of higher value kernels in seeds and to improve the economic yield of lupins.


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.


2010 ◽  
Vol 2 (2) ◽  
pp. 41-45 ◽  
Author(s):  
Vinay Madhukar RAOLE ◽  
Aruna Girish JOSHI ◽  
Sandhya Kiran GARGE ◽  
Rinku Jitendrakumar DESAI

The district of Kachchh contains many culturally important plants. However, their conservation status is little known due to direct and indirect human activities. This study was undertaken with the aim of contributing to the conservation of the native species of these semi-arid regions through germination trials under laboratory conditions. Mature fruits of ten selected species were collected randomly from the known habitats to obtain viable seeds. These seeds were pre-treated with growth regulators singly or in combination after acid scarification or without scarification. Seeds were found to be dormant due to presence of thick seed coat or due to low level of endogenous hormonal level. Most of these seeds required different storage period to mature. Only seeds of Capparis cartilaginea germinated without treatment while the other species required treatments. Addition of growth regulators has enhanced seed germination in few taxa singly and in some plant cases in combination.


2019 ◽  
Vol 33 (03) ◽  
pp. 509-517
Author(s):  
Moria E. Kurtenbach ◽  
Eric N. Johnson ◽  
Robert H. Gulden ◽  
Christian J. Willenborg

AbstractFlax yield can be severely reduced by weeds. The combination of limited herbicide options and the spread of herbicide-resistant weeds across the prairies has resulted in a need for more weed control options for flax producers. The objective of this research was to evaluate the tolerance of flax to topramezone, pyroxasulfone, flumioxazin, and fluthiacet-methyl applied alone as well as in a mix with currently registered herbicides. These herbicides were applied alone and in mixtures at the 1X and 2X rates and compared with three industry standards and one nontreated control. This experiment was conducted at Carman, MB, and Saskatoon, SK, as a randomized complete block with four replications. Data were collected for crop population, crop height, yield, and thousand-seed weight. Ratings for crop damage (phytotoxicity) were also taken at three separate time intervals: 7 to 14, 21 to 28, and 56+ d after treatment. Crop tolerance to these herbicides varied between site-years. This was largely attributed to differences in spring moisture conditions and the differences in soil characteristics between sites. Herbicide injury was transient. Hence, no herbicide or combination of herbicides significantly impacted crop yield consistently. Flumioxazin was the least promising herbicide evaluated, as it caused severe crop damage (&gt;90%) when conditions were conducive. Overall, flax had excellent tolerance to fluthiacet-methyl, pyroxasulfone, and topramezone. Flax had excellent crop safety to the combination of pyroxasulfone + sulfentrazone. However, mixing fluthiacet-methyl and topramezone with MCPA and bromoxynil, respectively, increased crop damage and would not be recommended.


1993 ◽  
Vol 23 (7) ◽  
pp. 1306-1313 ◽  
Author(s):  
G.E. Caron ◽  
B.S.P. Wang ◽  
H.O. Schooley

The effects of cone storage period and pregermination treatment on seed maturity and dormancy were compared for cones of white spruce (Piceaglauca (Moench) Voss) collected from individual trees in 1984 and 1988. Seeds were extracted from cones and germinated after 2 or 6 weeks of cone storage in 1984 and after 2, 4, 6, 10, or 14 weeks in 1988. Based on cumulative degree-days, seeds were more mature at collection time in 1988 than in 1984. Seeds from 1984 cones stored for 6 weeks matured during storage, and both germination percentage (GP) and rate of germination (GR) were significantly improved. In contrast, storage up to 14 weeks in 1988 did not increase GP and GR, as seed had attained maturity prior to cone collection. Seed dormancy was present in both 1984 and 1988. Significant improvements in GP and GR were achieved in 1984 with a pregermination treatment even before seed maturity was attained. Prechilling of seed after 6 weeks of cone storage increased GP from 60 to 95% in 1984 and 64 to 89% in 1988.


1974 ◽  
Vol 54 (2) ◽  
pp. 301-305 ◽  
Author(s):  
L. A. McLEAN ◽  
F. W. SOSULSKI ◽  
C. G. YOUNGS

When averaged over a wide range in soil nitrogen and moisture conditions, cultivar differences in yield and protein content of non-inoculated field peas (Pisum sativum L.) were relatively small. The inherent differences in seed weight were responsible for most of the variations in yield among the three cultivars. Nitrogen fertilization in the growth room experiment markedly increased plant weight, seed yield and protein content, and water-use efficiency was substantially improved. When maintained within the upper half of the available range, soil moisture supply had only a limited influence on plant growth. Periodic wilting did cause a severe reduction in plant weight and seed yield, but there was little change in protein content. For these fertilizer and moisture treatments, responses in seed yield were primarily due to changes in number of pods per plant; the seeds per pod and seed weight were relatively stable. It appeared that field peas were efficient converters of soil nitrogen to seed protein and, in the absence of nitrogen-fixing bacteria, nitrogen fertilization was the principal factor influencing the protein content of field peas. The correlation coefficient between yield and protein content was very low.


1996 ◽  
Vol 97 (2) ◽  
pp. 291-302 ◽  
Author(s):  
G. I. Mclntyre ◽  
A. J. Cessna ◽  
A. I. Hsiao
Keyword(s):  

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