scholarly journals Polyphenols leaching and seed dormancy in carob (Ceratonia siliqua L.) in relation to hot water treatment

2021 ◽  
Vol 43 (11) ◽  
Author(s):  
Valeria Cavallaro ◽  
Carmelo Maucieri ◽  
Cristina Patanè ◽  
Giancarlo Fascella ◽  
Alessandra Pellegrino ◽  
...  

AbstractCarob (Ceratonia siliqua L.) is a relevant element of the Mediterranean spontaneous vegetation. Moreover, it is useful in reforestation, and it is currently re-valued for sustainable agriculture in dryland areas. However, the difficulties tied to carob propagation (mainly seed dormancy) hamper its large-scale cultivation. In this paper, the effects of four seed treatments (no treatment [control], soaking at 70 °C and 90 °C in water, or in 96% sulphuric acid) on five carob genotypes germination were studied. As compared to the very low germination of untreated seeds (0–13% germination), sulphuric acid (93–100% germination) and 90 °C water soaking (from 72 to > 90% germination in four out the five genotypes) were effective in promoting germination. Soaking at 90 °C resulted in the leaching of a higher amount of total polyphenols from the genotypes seed coat as compared to soaking at 70 °C. A significant correlation (0.75**) was ascertained between polyphenol leaching of the different genotypes and germination. These results suggest that dormancy in this species is not primarily associated with seed coat hardness, as it is generally thought, but also with the release of polyphenols. Polyphenols determination of the dormant and the few non-dormant seeds of the different genotypes also seem to confirm this hypothesis since these last showed an almost halved total polyphenols content (on average 17.0) as compared to dormant ones (34.8 mg g−1 of seed FW). Further studies may determine the polyphenols involved, but also assess new, easier to carry out, seed treatments. The important role of the galactomannans on seed germination of carob is also discussed. Finally, similar studies may enhance the knowledge of dormancy processes in other Fabaceae species whose germination is positively affected by hot water treatments.

1997 ◽  
Vol 45 (4) ◽  
pp. 329-331 ◽  
Author(s):  
Félix Pérez-García ◽  
Adrian Escudero

Effect of mechanical scarification, dry heat, hot water, and sulphuric acid on the germination behavior ofCistus populifoliusL. (rockrose) was studied. Untreated seeds after 60 days of incubation germinated less than 7%. After thermal treatments, 90% germination was achieved, and sulphuric acid pretreatment gave 61% germination. Soaking in distilled water did not increase germination, but scarification of the seed coat gave 57%. Hardness and impermeability of the seed coat appear to cause deep dormancy inC. populifoliusseeds.


HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 787E-788
Author(s):  
Geoffrey C. Denny* ◽  
Michael A. Arnold

An experiment was initiated to evaluate the effects of previously recommended seed treatments for baldcypress [Taxodium distichum (L.) Rich.] or pondcypress [Taxodium distichum (L.) Rich. var. imbricarium (Nutt.) Croom] on Montezuma cypress [Taxodium distichum (L.) Rich. var. mexicanum Gordon], and to determine which, if any, provided optimum germination. Factorial combinations of seed treatments and stratification (2 °C for 0, 45, or 90 d) were applied to seeds of Montezuma cypress. Treatments included: 1) 90% ethanol 5 min soak, 2) ethyl ether 5 min soak, 3) 100 mg·L-1 citric acid 48 h soak, 4) mechanical scarification, 5) five hot water baths (42 °C) allowing the water to cool to room temperature between baths, and 6) a non-treated control. Three more seed treatments consisted of water soaks at room temperature (25 °C) for 0, 45, or 90 d. Seeds were germinated on moist filter paper in a growth chamber with a 12-h day/night photoperiod at a constant 25 °C. Data was collected daily for 14 d and then weekly for the following 4 wks. Radicle elongation of 1 cm was considered germination. Without stratification, 100 mg·L-1 citric acid and the hot water bath treatments were significantly different from other treatments by 7 d, though not from each other, with a mean cumulative germination of 15.6% and 12.2%, respectively. By 14 d, the 100 mg·L-1 citric acid treatment differed only from the ethyl ether wash attaining 28.9% and 14.4% germination, respectively. There were no other statistically significant differences observed among any other treatments without stratification. Germination percentages were low,<30%, without stratification. Effects of additional stratification will also be discussed.


HortScience ◽  
2016 ◽  
Vol 51 (9) ◽  
pp. 1184-1187
Author(s):  
Scott B. Lukas ◽  
Joseph DeFrank ◽  
Orville C. Baldos

In Hawaii, Waltheria indica (uhaloa) has been identified for expanded usage as a roadside groundcover in lowland dry ecosystems. Seed dormancy through lack of germination of viable seeds was identified in uhaloa. The presence of physical dormancy in uhaloa seeds was determined and dormancy relief methods were evaluated including hand scarification, dry heat temperature exposure, hot water exposure, and mechanical abrasion in an electric drum scarifier. As a compliment to dormancy relief, long-term storage parameters were evaluated for scarified and nonscarified seeds. The elucidation of physical dormancy was determined through hand scarification, resulting in 96% germination compared with 8% of nonscarified seeds, but is not practical on a large-scale basis. The greatest practical dormancy relief was achieved with a mechanical electric drum scarifier lined with 80-grit sandpaper for a duration of 15 or 30 seconds producing 95% and 99% germination, respectively. Seeds immersed in boiling water for 3 and 5 seconds resulted in 58.6% and 57.7% germination, respectively. Dormancy relief through dry heat exposure was inferior to other relief methods, producing 39% germination at 75 °C for 60 minutes. Nonscarified seeds exhibited minimal loss of viability during 10 months of storage at 5 °C at 12% and 50% relative humidity (RH), but a significant decline in viability of scarified seeds was detected.


Agrologia ◽  
2018 ◽  
Vol 2 (1) ◽  
Author(s):  
Marthen Marthen ◽  
Elizabet Kaya ◽  
Herman Rehatta

In developing productive forests, seeds play a crucial role. The seeds of forests tree have physical condition of hard seed coat, especially Leguminoceae family. Silvicultural techniques that can overcome seed coat dormancy are dyeing and submersion of seeds. The knowledge and experience in breaking seed dormancy of Sengon (Paracerianthes falcataria L.) is rare, therefore it is necessary to study how to overcome seed dormancy. The objective of this study was to determine the effect of dyeing and submersion treatments to overcome seed dormancy of Sengon seed to improve its viability. This research used Completely Randomized Design (CRD) with two factors: namely Seed (Factor A), dipped in hot water at 60 º C for (A0 = Control, A1 = 2 minutes, A2 = 4 minutes, A3 = 6 minutes), Factor B, seeds soaked in cold water: (B0 = control, B1 = 6 hours of soaking, B2 = 12 hours, B3 = 18 hours, B4 = 24 hours). The parameters observed were germination percentage, germination rate and vigor index. The results showed that among all parameters observed the interaction of factors A1B2, A2B2 and A3B2 were the best treatment for germination percentage which was equal to 100 percent, the best germination rate of 3.897 days and the best vigor index of 27.02


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