scholarly journals Methods for overcoming dormancy in Stryphnodendron pulcherrimum seeds

2016 ◽  
Vol 36 (87) ◽  
pp. 195
Author(s):  
Adriano Gonçalves Pereira ◽  
Eniel David Cruz ◽  
Hellen Síglia Demétrio Barros

Seed dormancy is a phenomenon observed in several tropical species. This condition causes low and non-uniform germination. The present study was designed to identify an efficient method of breaking seed dormancy in Stryphnodendron pulcherrimum. Seeds of four mother plants were subjected to the following treatments: immersion in sulfuric acid for 2, 4, 6, 8, 10 and 12 min and scarification on 150-grit sandpaper. Seeds were sown on substrate containing sand and sawdust (1:1). It was evaluate the days to onset seedlings emergence, seedlings emergence (SE), emergence speed index (ESI), germination (G), hard seeds (HS), dead seeds (DS), dormant seeds (DMS), abnormal seedlings (AS) and dry mass of aerial part (DMAP) and roots (DMR). The experimental design was completely randomized with four replications of 25 seeds for each treatment. Data were subjected to analysis of variance and means compared by Tukey's test (p < 0.05). Significant differences among treatments were observed for ESI, SE, G, HS, DMAP and DMR. Highest HS was observed in control treatment (85%). Highest G was observed in seeds scarified with sulfuric acid for 10 min (82%) and 12 min (74%). These treatments also showed highest ESI, DMAP and DMR, indicating that these scarification treatments were the most efficient in overcoming dormancy.

2018 ◽  
Vol 41 (4) ◽  
Author(s):  
Rômulo André Beltrame ◽  
José Carlos Lopes ◽  
Julião Soares de Souza Lima ◽  
Vagner Mauri Quinto

ABSTRACT The objective of this study was to analyze the spatial distribution of the attributes that determine the physiological quality of Joannesia princeps seeds. Seeds were collected, individually from, 40 mother plants in the Horto Florestal Municipal Laerth Paiva Gama, in Alegre-ES, which constituted the georeferenced sampling mesh. For germination, the seeds tegument was cracked and was held the imbibition in gibberellic acid GA3 500 mg L-1 for 24 h in environmental chamber with temperature adjusted to 30 ºC. The seeds were sown in plastic bags of ± 600 cm3 containing soil+sand+manure in the proportion of 1:1:1. On the 65th day after sowing, the following variables were analised: emergence (E), emergence speed index (IVE), root length (CR), diameter of base (DC), shoot length of the aerial part (CPA), fresh mass of the root system (MFSR), fresh mass of the aerial part (MFPA), dry mass of the root system (MSSR) and dry mass of the aerial part (MSPA). Data were subjected to descriptive statistics, geostatistics and kriging. With the exception of CPA and MFSR, it was found spatial dependence for the other studied variables: E, IVE, CR, DC, MFPA, MSSR e MSPA; varying of 14,0 a 47,5 m, so that the lowest range for the CR and longer range and degree of spatial dependence for the IVE. The analysis of the spatial distribution of the physiological quality of seeds of J. princeps can be used as a tool to define the sampling region of seeds with high and low vigor.


Nativa ◽  
2020 ◽  
Vol 8 (5) ◽  
pp. 643-649
Author(s):  
Antonio Henrique Cordeiro Ramalho ◽  
Fernanda Dalfior Maffioletti ◽  
Paulo André Trazzi ◽  
Eduardo Cordeiro Ramalho ◽  
Nilton Cesar Fiedler

A produtividade florestal depende das potencialidades genéticas das matrizes, do ambiente proposto pelos substratos, frequência de irrigação, disponibilidade de luz, nutrição e das condições fitossanitárias. Assim, objetivou-se com o presente estudo analisar os efeitos da aplicação de potássio e de irrigação na qualidade de mudas de Eucalyptus urophylla. Para tal adotou-se o delineamento experimental em parcelas subdivididas definindo as 2 lâminas de irrigação (10 mm e 15 mm) como parcelas e os 5 níveis de potássio (0; 1,2; 2,4; 4,8; e 9,6 g L-1) como subparcelas, em 5 repetições compostas por 9 plantas. A comparação entre os métodos foi feita através teste de Tukey com 5% de probabilidade. Aos 120 dias, foram avaliadas: altura da parte aérea, diâmetro do colo, massa seca da parte aérea e da raiz. O tratamento testemunha apresentou as melhores médias em todos os parâmetros, sendo considerado o mais eficiente. A lâmina de irrigação de 15 mm foi considerada a mais eficiente. Portanto, conclui-se que qualquer que seja o incremento de potássio na produção de mudas, o mesmo deve se relacionar harmonicamente com a quantidade pré-existente no substrato base e com as exigências da cultura, de maneira que haja equilíbrio entre todas as partes. Palavras-chave: manejo hídrico; rustificação; substrato; casa de sombra.   IRRIGATION AND POTASSIUM LEVELS IN THE QUALITY OF EUCALYPTUS   ABSTRACT:  Forest productivity depends on the genetic potential of the matrices, the environment proposed by the substrates, frequency of irrigation, availability of light, nutrition and phytosanitary conditions. Thus, the aim of this study was to analyze the effects of potassium and irrigation on the quality of Eucalyptus urophylla seedlings. For this purpose, the experimental design was adopted in subdivided plots, defining the 2 layers of irrigation (10 mm and 15 mm) as plots and the 5 levels of potassium (0; 1.2; 2.4; 4.8; and 9.6 g L-1) as subplots, in 5 repetitions composed of 8 plants. The comparison between the methods was made using the Tukey test with a 5% probability. At 120 days, the following were evaluated: height of the aerial part, diameter of the neck, dry mass of the aerial part and the root. The control treatment showed the best averages in all parameters, being considered the most efficient. The 15 mm irrigation blade was considered the most efficient. Therefore, it is concluded that whatever the potassium increase in the production of seedlings, it must be harmoniously related to the pre-existing quantity in the base substrate and to the requirements of the culture, so that there is balance between all parts. Keywords: water management; rustification; substrate; shadow house.


Author(s):  
Monoj Sutradhar ◽  
Subhasis Samanta ◽  
Brijesh Kumar Singh ◽  
Md. Nasim Ali ◽  
Nirmal Mandal

Dormancy in rice serves as a mechanism of survival by protecting the seed from germinating in the mother plants; however, it becomes a problem in germination during sowing in soil or under in vitro conditions. This study was conducted to determine the effect of heat treatment and sodium hypochlorite (NaOCl) treatment of seeds on dormancy alleviation. The seeds included both freshly harvested seeds and one-year-old stored seeds, which were tested for germination after different types of seed treatments. Both the treatments increased the germination percentage in seeds, however, it was lesser in the case of old seeds. The best results were obtained from 2% NaOCl treatment for 24 hrs in new seeds, i.e. 92.84±0.103 % germination percentage (GP). However, the higher GP in old seeds were obtained from 48 hrs of heat-treated seeds i.e. 82.9±0.509 % GP. The results of the experiment revealed that rice seeds start to lose viability within a year due to seed dormancy, but this can be reversed with proper measures. These methods of breaking seed dormancy can be considered effective to break seed dormancy and improve seed germination in rice.


2018 ◽  
Vol 32 (5) ◽  
pp. 564-569 ◽  
Author(s):  
Renci Xiong ◽  
Ying Wang ◽  
Hanwen Wu ◽  
Yan Ma ◽  
Weili Jiang ◽  
...  

AbstractField bindweed, a member of the Convolvulaceae family, is a problematic perennial weed in cotton fields and orchards in northwest China. The species exhibits strong seed dormancy, causing delayed germination. A clear understanding of the mechanisms involved in alleviating seed dormancy is important for effective plant propagation and successful management of field bindweed. Experiments were conducted to investigate seed germination and radicle growth of field bindweed by breaking seed dormancy using mechanical scarification, sulfuric acid, hot-water scarification, cold stratification, and chemical treatment. Chemical treatments (gibberellic acid or potassium nitrate) had no effect on breaking seed dormancy, whereas mechanical scarification (sandpaper and blade) resulted in 92% to 98% seed germination, indicating that seed dormancy of field bindweed was mainly due to the presence of a hard seed coat. Seeds pretreated with 80% sulfuric acid for 15 to 60 min or 98% sulfuric acid for 15 to 30 min had germination rates above 80%, and soaking seeds in 70 C water for 4 to 16 min or in boiling water for 5 to 20s were effective in breaking seed dormancy but had no effect on the radicle growth of field bindweed. Cold stratification at 5 C for 2 to 8wk partially accelerated seed dormancy release, resulting in 53% to 67% seed germination. Results indicated that field bindweed could potentially form a persistent soil seed bank with physically dormant seed; therefore, strategies for eliminating seed production should be adopted.


2016 ◽  
Vol 37 (2) ◽  
pp. 693
Author(s):  
Camila Aquino Tomaz ◽  
Cibele Chalita Martins ◽  
Givanildo Zildo da Silva ◽  
Roberval Daiton Vieira

The period of 21 days suggested by the Brazilian Rules for Seed Testing for the germination test of B. humidicola seeds seems too long for seed producing companies and laboratories since they depend on the results for decisions concerning the storage or the commercialization of the seed lots. So, the objective of this work was to evaluate the possibility of getting germination results of B. humidicola seeds in a shorter period. The procedures consisted in submitting the seeds to a dormancy breaking treatment and to alternating temperatures during the germination test. Seed samples of nineteen S1 and S2 seed lots were submitted to the following treatments: moistening the germination substratum with 1) deionized water (check treatment), 2) a KNO3 (0.2%) solution, and 3) scarifying the seeds with sulfuric acid for 10 minutes. The germination test was conducted under the conditions of 1) alternating temperatures of 20 and 35 °C and 2) alternating temperatures of 15 and 35 °C both with 8 hours of light. Normal seedlings were evaluated in daily countings. The results showed that the germination test of B. humidicola seeds may be carried out under alternating temperatures of 15 and 35 °C without breaking seed dormancy with a final evaluation of the germination 10 days after the sowing of the seeds.


2021 ◽  
Vol 6 ◽  
pp. 1-9
Author(s):  
Roberto Takane ◽  
Cyro Fragoso Silva ◽  
Jessica Soares Pereira ◽  
Christian Morimasa Takemura ◽  
Talita Angélica ◽  
...  

The present work aimed to evaluate the influence of use, as well as to determine adequate doses in organic fertilization of the bokashi type in the cultivation of two basil (Ocimum basilicum L.) cultivars. Seeds from the collection of the Floriculture Laboratory of the Phytotechnics Department of the Federal University of Ceará were used. The treatments used were arranged in a randomized block design (RBD), arranged in a 2x5 factorial scheme, consisting of two cultivars of basil (Genovese and Anão) and five doses of Bokashi, namely: 0, 3, 6, 9 and 18 g.L-1. Plants that received no dose (0 g.L-1) served as a control treatment. Each treatment contained 5 repetitions, with the plot consisting of 7 pots, one plant per pot, the useful unit a pot with a basil seedling. From the transplant, applications of bokashi were started in doses of 0, 3, 6, 9, and 18 g.L-1 in both cultivars. Both applications were performed every 20 days after the first application of Bokashi. Fivety five days after transplantation in the final pot, the following variables were analyzed: plant height, stem diameter, fresh and dry mass of the aerial part and the root. The 9 g.L-1 dose of Bokashi showed the best results for the variables analyzed for both cultivars, in addition to being efficient when compared to the control, in which the vegetative growth was incipient.


2008 ◽  
Vol 44 (2) ◽  
pp. 185-195 ◽  
Author(s):  
Y. R. WANG ◽  
J. HANSON

SUMMARYDormancy in seeds of Sesbania sesban is caused by a water-impermeable seed coat (hard seeds or hardseededness). A two-phase pretreatment technique was developed for breaking seed dormancy and was validated using different accessions and seed lots. Seeds were first soaked in water at 80 °C for 8 min and prepared for the germination test. Ungerminated hard seeds at the first count (after four days incubation) during the germination test were then subjected to a second treatment by mechanically scarifying the seed coat. The effects of water temperature and variation in initial hardseededness and viability among and within accessions were also investigated. The optimum water temperature, allowing maximum seed germination without increasing the percentage of abnormal seedling/dead seeds was 80 °C. The mean percentage of hard seeds across 30 seed lots of six accessions was reduced to 26% after phase 1 and to 0% after phase 2. In addition, full germination occurred within only 10 days for treated seeds while germination in untreated seeds had reached only 48% after 14 days. Significant differences existed among the seed lots within the accessions (p > 0.05) for the percentage of initial hard seed and for the effects of treatments on breaking seed dormancy. The two-phase technique developed was validated using over 1000 seed lots of S. sesban, and it was found to be a rapid and cost-effective method for breaking hard seed dormancy with potential for wider use for hard-seeded legumes.


2019 ◽  
Vol 7 (2) ◽  
pp. 196
Author(s):  
Aline Figueiredo Cardoso ◽  
Marcela Cristiane Ferreira Rêgo ◽  
Telma Fátima Vieira Batista ◽  
Rafael Gomes Viana ◽  
Alba Lucia Ferreira de Almeida Lins ◽  
...  

Lettuce is a consumed crop in the world, and increased yield is a desirable trait, and can be realized with the use of biopromotors, already described in many cultures. The objective of this work was to test the ability of two rhizobacterial isolates P. fluorescens (BRM-3211) and B. pyrrocinia (BRM-3213) to promote anatomical and growth changes in lettuce plants in the seedling stage. The increments promoted by B. pyrrocinia were smaller when using P. fluorescens. The BRM-32111 isolate, promoted increases in leaf area of 133%, 31% and 307% of fresh shoot and root mass, also increased 51% and 143% of aerial and root dry mass. The plants inoculated with BRM-32111 increased in 100% and 68% of the aerial part and radicular compared to the control treatment, and induced alterations in the anatomical characteristics in the root in 74% in the radicular diameter, 20% of the thickness of the cortex, 67% of the exoderme and 171% of the endoderm. In the leaf anatomy, BRM 32111 increased by 18% in the parenchyma expansion, 56% in the number of parenchyma cell layers, 122% adaxial endoderm, 23% epidermis, 174% beam expansion, 37% when compared to control. In this way the use of BRM-32111 influences the growth and morphology of lettuce seedlings.


Planta Medica ◽  
2008 ◽  
Vol 74 (03) ◽  
Author(s):  
AE-D Helaly ◽  
H Al-Amier ◽  
AA Al-Aziz ◽  
LE Craker

Agronomy ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1765
Author(s):  
Wei Zhang ◽  
Lian-Wei Qu ◽  
Jun Zhao ◽  
Li Xue ◽  
Han-Ping Dai ◽  
...  

The innate physiological dormancy of Tulipa thianschanica seeds ensures its survival and regeneration in the natural environment. However, the low percentage of germination restricts the establishment of its population and commercial breeding. To develop effective ways to break dormancy and improve germination, some important factors of seed germination of T. thianschanica were tested, including temperature, gibberellin (GA3) and/or kinetin (KT), cold stratification and sowing depth. The percentage of germination was as high as 80.7% at a constant temperature of 4 °C, followed by 55.6% at a fluctuating temperature of 4/16 °C, and almost no seeds germinated at 16 °C, 20 °C and 16/20 °C. Treatment with exogenous GA3 significantly improved the germination of seeds, but KT had a slight effect on the germination of T. thianschanica seeds. The combined treatment of GA3 and KT was more effective at enhancing seed germination than any individual treatment, and the optimal hormone concentration for the germination of T. thianschanica seeds was 100 mg/L GA3 + 10 mg/L KT. In addition, it took at least 20 days of cold stratification to break the seed dormancy of T. thianschanica. The emergence of T. thianschanica seedlings was the highest with 82.4% at a sowing depth of 1.5 cm, and it decreased significantly at a depth of >3.0 cm. This study provides information on methods to break dormancy and promote the germination of T. thianschanica seeds.


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