scholarly journals Endozoochory by native and exotic herbivores in dry areas: consequences for germination and survival ofProsopisseeds

2008 ◽  
Vol 18 (2) ◽  
pp. 91-100 ◽  
Author(s):  
Claudia M. Campos ◽  
Begoña Peco ◽  
Valeria E. Campos ◽  
Juan E. Malo ◽  
Stella M. Giannoni ◽  
...  

AbstractMammalian herbivores can play a role in the endozoochorous dispersal ofProsopisseeds in the arid zones of Argentina, and the introduction of exotic mammals can change relevant parameters of the plant's reproductive ecology. Our specific goals were to quantify the seeds ofProsopis flexuosa,P. chilensisandP. torquatacontained in the faeces of native [mara (Dolichotis patagonum), guanaco (Lama guanicoe)] and exotic [donkey (Equus asinus) and hare (Lepus europaeus)] mammals, and to determine the mortality, germination percentage and germination speed of seeds borne in faeces, compared with those collected from trees. In 2006, seeds were collected directly from trees or removed from mammal faeces. Seeds were counted and classified as apparently healthy or damaged.P. torquataandP. flexuosaseeds were found in the dung of guanaco, hare and mara, whereas onlyP. flexuosaseeds appeared in donkey faeces.P. chilensisseeds were only found in guanaco faeces. There was a notable relative abundance of seeds contained in small herbivore faeces in comparison to the large herbivores. The passage through the digestive tract of animals modified seed germination capacity and speed, with great variability between animal species. Guanacos had greater effects than donkeys on mortality, germination percentage and germination speed. Differences between the effects of both smaller-sized herbivores on seeds were much smaller.

2021 ◽  
Vol 43 ◽  
Author(s):  
Nancy Araceli Godínez-Garrido ◽  
Juan Gabriel Ramírez-Pimentel ◽  
Jorge Covarrubias-Prieto ◽  
Francisco Cervantes-Ortiz ◽  
Artemio Pérez-López ◽  
...  

Abstract: Chitosan is a biopolymer obtained from deacetylation of chitin; it has multiple applications in agriculture as an antifungal, soil conditioner, inducer of defense mechanisms, fruits postharvest coating, leaves and seeds, among others. The objective in this research was to evaluate the effect of chitosan coatings mixed with fungicide (dithiocarbamate) on the germination and germination speed of bean and maize seeds in storage and to determine the retention capacity of the fungicide in the coated seeds under different times of imbibition. Two coating treatments at concentrations of 0.1 and 0.5% chitosan in water, two coatings treatments at 0.1 and 0.5% chitosan supplemented with 0.5% fungicide and a coating without chitosan using only 0.5% fungicide in water were used in bean and maize seed; and as control seeds imbibed in distilled water were used; after treatments, germination percentage and germination speed were determined, also fungicide release were determined at 0, 1, 2 and 6 h of imbibition, and the effect of storage time on germination and germination speed was determined at 30, 60, 90, 120, 150 and 180 days of storage at 4 °C and 45% relative humidity. The fungicide release effect was determined by inhibiting Fusarium oxysporum conidia germination. There were no negative effects of coatings on seed germination after storage. The treatment that provided both greater retention of the fungicidal agent and released it gradually, was 0.5% chitosan mixed with fungicide concentration. Chitosan coating seeds mixed with fungicide do not cause negative changes in seed germination or germination rate.


2011 ◽  
Vol 13 (4) ◽  
pp. 507-511 ◽  
Author(s):  
J.M. Vasconcelos ◽  
M.A. Rodrigues ◽  
S.C. Vasconcelos Filho ◽  
J.F. Sales ◽  
F.G. Silva ◽  
...  

"Quina" (Strychnos pseudoquina A. St. Hil) is a medicinal plant species from the Brazilian Cerrado. As its seeds show dormancy, they were subjected to the treatments pre-cooling at 5ºC during 7 days, pre-heating at 40ºC during 7 days, pre-soaking in sulfuric acid PA during 5 and 15 min, pre-soaking in boiling water during 5 and 15 min, pre-soaking in 100 and 200 ppm gibberellic acid during 48 h, pre-soaking in distilled water during 24 and 48 h, and mechanical scarification to break dormancy. Counts were daily conducted from the 2nd day after the experiment implementation until the germination stabilization at the 65th day. The germination speed index (GSI) and the germination percentage were evaluated. Germination rates above 96% were reached in seeds pre-soaked in water during 48 h and substrate moistened with water or KNO3.


FLORESTA ◽  
2014 ◽  
Vol 44 (4) ◽  
pp. 669 ◽  
Author(s):  
Helena Cristina Rickli ◽  
Antonio Carlos Nogueira ◽  
Henrique Soares Koehler ◽  
Katia Christina Zuffellato-Ribas

Guaricica (Vochysia bifalcata) é uma espécie arbórea nativa do Brasil, presente na vegetação secundária da Floresta Ombrófila Densa dos estados do Paraná, Santa Catarina, São Paulo, Rio de Janeiro e Minas Gerais, sendo de grande importância na regeneração de áreas degradadas e para fins madeireiros. Este estudo teve por objetivo avaliar os efeitos de diferentes temperaturas (20, 25 e 30 °C) e substratos (rolo de papel, papel mata-borrão e vermiculita) na germinação de sementes de Vochysia bifalcata, as quais foram mantidas em germinadores sob luz constante. Foram realizadas avaliações diárias até o 20° dia após a semeadura, analisando-se as seguintes variáveis porcentagem de germinação, índice de velocidade de germinação, tempo médio de germinação e índice de sincronização. A temperatura de 25 °C, nos substratos papel mata-borrão e vermiculita apresentaram a maior germinação (70 e 73%, respectivamente) e maior índice de velocidade de germinação, porém com menor sincronismo. Assim, para o teste de germinação de guaricica, é recomendado o uso dos substratos papel mata-borrão ou vermiculita na temperatura de 25 °C.Palavras-chave:  Vochysiaceae; guaricica; índice de sincronização; índice de velocidade de germinação. AbstractGermination of Vochysia bifalcata under different substrates and temperatures. Guaricica (Vochysia bifalcata) is a native Brazilian tree species, present in the secondary vegetation of the Ombrophilous Dense Forest in the States of Paraná, Santa Catarina, São Paulo, Rio de Janeiro, and Minas Gerais. It is of great importance in degraded areas regeneration and for timber production. This research aimed to evaluate the effects of different temperatures (20, 25 and 30 ºC) and substrates (paper roll, blotting paper and vermiculite) during the germination of Vochysia bifalcata seeds. We conducted germination tests inside germination chambers under constant illumination. Until the 20th day after the installation, daily evaluations analyzed the following variables: germination percentage, germination speed index, average germination time, and synchronization index. The temperature of 25 °C in blotting paper and vermiculite substrate presented the highest germination (70 and 73%, respectively) and highest germination speed index, but with less synchronism. Therefore, it recommends use of blotting paper and vermiculite as substrates in a temperature of 25 ºC for the Vochysia bifalcata germination test.Keywords: Vochysiaceae; guaricica; index synchronization; germination speed index


Author(s):  
Marcelo Laranjeira Pimentel ◽  
Henara Valéria Miranda Castro ◽  
Mike Kirixi Munduruku ◽  
Larissa Conceição Cunha Ponte ◽  
Deyvielen Maria Ramos Alves ◽  
...  

The use of fungi in seed treatment can improve the plant's physiological characteristics. The aim of this study was to evaluate the influence of the use of Trichoderma harzianum on the physiological quality of bean seeds. The experiment was set up and conducted in the forest seed laboratory of the Federal University of Western Para, in a randomized design, using 4 procedures on the basis of a colony forming unit (CFU): T1 (0 CFU), T2 (4 x 109 CFU), T3 (8 x 109 CFU) and T4 (12 x 109 CFU), with 5 repetitions. Germination percentage (G%), germination speed index (GSI), hypocotyl length (HL) and radicle length (RL) were evaluated as variables. The data were analyzed by variance analysis and the averages were compared using the Tukey test (p≤0.05), in addition to the regression analysis, using the Minitab© version 18 statistical software. There were differences between the germination percentage tests, in which T2 obtained 100% of germinated seeds, for GSI it was observed that T2 and T3 were equal and superior to the other treatments, while for RL T1 and T2 obtained the best results, however, for HL there were no statistical differences between treatments. T2 was more efficient in the physiological quality of seeds to germination percentage and germination speed index


Nativa ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 317
Author(s):  
Cássio Do Prado Borges ◽  
Cheila Deisy Ferreira ◽  
Daniela Pereira Dias

Este trabalho objetivou avaliar a germinação e vigor de sementes de Plathymenia reticulata Benth. submetidas a diferentes tratamentos para superação de dormência. Os tratamentos testados foram: controle - sementes intactas (T0), escarificação mecânica com lixa d’água nº 60 (T1), desponte na região lateral do tegumento (T2), imersão em água fervente por 10 min (T3), em hipoclorito de sódio por 15 min (T4) e em solução com detergente por 15 min (T5). Foram determinados: peso de mil sementes, grau de umidade, porcentagem de germinação, índice de velocidade de germinação (IVG), tempo médio de germinação (TMG), curva de embebição, teste da condutividade elétrica e comprimento da radícula. A porcentagem de germinação das sementes submetidas ao T1 e T2 foi estatisticamente igual (respectivamente, 90 e 88%) e superiores aos outros tratamentos testados (12%). As sementes expostas aos T1 e T2 apesentaram porcentagem de absorção de água superiores e em menor tempo, assim como maiores IVG e menores TMG, comparadas aos demais tratamentos. O comprimento das radículas não variou entre os tratamentos testados. A condutividade elétrica da solução com as sementes do T0 foi superior aos outros tratamentos testados. Sementes de P. reticulata expostas ao T1 e T2 apresentam maior germinação e vigor.Palavras-chave: germinação, índice de velocidade de germinação, teste de condutividade elétrica, vigor, vinhático. DORMANCY BREAKING OF Plathymenia reticulata Benth. SEEDS ABSTRACT:This study aimed to evaluate the germination and vigor of Plathymenia reticulata Benth. seeds submitted to different dormancy breaking treatments. Testing treatments were: control - intact seeds (T0); mechanical scarification with sandpaper n. 60 (T1), coating cutting in the lateral side of tegument (T2), immersion in boiling water during 10 min (T3), in sodium hypochlorite solution during 15 min (T4), and in detergent solution during 15 min (T5). Moisture content, 1000-seed weight, germination percentage, germination speed index (GSI), mean germination time (MGT), imbibition curve, electrical conductivity test, and radicle length were determined. Germination percentage to T1 and T2 were statistically equal (90 and 88 %, respectively) and higher than others treatments tested (12%). Seeds exposed to T1 and T2 also presented higher and faster water absorption percentage, when compared to the others treatments, as well as higher GSI, and lower MGT. The rootlets length did not vary among treatments tested. Electrical conductivity of intact seeds was higher than others treatments. P. reticulata seeds expose to T1 e T2 had highest germination percentage and vigor.Keywords: germination, germination speed index, electrical conductivity test, vigor, vinhático.


2017 ◽  
Vol 107 (0) ◽  
Author(s):  
Aldo Arriagada ◽  
Luisa Baessolo ◽  
Cristián Saucedo ◽  
Julio E. Crespo ◽  
Julio Cerda ◽  
...  

RESUMEN En Chile los armadillos Zaedyus pichiy (Desmarest, 1804) y Chaetophractus villosus (Desmarest, 1804) tienen poblaciones periféricas restringidas a planicies de altura y estepa patagónica en la vertiente occidental de la Cordillera de los Andes, donde además han sido escasamente estudiadas. En este trabajo entregamos información sobre los hábitos alimenticios de ambas especies de armadillos, obtenida mediante el análisis de heces colectadas en dos áreas de la región de Aysén, Patagonia chilena. En 38 heces de Z. pichiy identificamos dos taxones de plantas, seis de invertebrados y cuatro de vertebrados, mientras que en 72 heces C. villosus identificamos tres, nueve y cuatro taxones de las mismas categorías. En ambas especies de armadillos los invertebrados fueron la categoría más diversa y con mayor frecuencia de ocurrencia, siendo Coleoptera, Orthoptera y Hemiptera los grupos mejor representados en términos de abundancia. Entre los vertebrados se observó mayor frecuencia de restos del camélido Lama guanicoe (Müller, 1776) y el lagomorfo Lepus europaeus (Pallas, 1778). El análisis de rarefacción muestra que la riqueza de taxones fue mayor en C. villosus que en Z. pichiy, y el índice de Pianka indica que no existió un solapamiento trófico significativo entre especies de armadillos. Nuestras observaciones indican que poblaciones periféricas de ambas especies de armadillos muestran dietas omnívoras oportunistas, con un mayor consumo de invertebrados y plantas; además, sugieren que C. villosus se desarrolla en un rango ambiental más amplio, con una dieta más diversa y mayor presencia de esta especie en ambas áreas de estudio.


2005 ◽  
Vol 62 (4) ◽  
pp. 319-324 ◽  
Author(s):  
Mário Lúcio de Carvalho Bittencourt ◽  
Denise Cunha Fernandes dos Santos Dias ◽  
Luiz Antônio dos Santos Dias ◽  
Eduardo Fontes Araújo

The osmotic conditioning or priming is considered a promising technique to speed up germination and to improve seed performance. Four seed lots of asparagus, Mary Washington cultivar, were primed at 25°C for seven or 14 days using PEG 6000 at -1.0 or -1.2 MPa, or sea water at -3.3 MPa; or for three days in distilled water. The physiological quality of the seeds was evaluated by standard germination, first count germination, speed of seedling emergence, and germination percentage and seedling fresh and dry weights after controlled deterioration test. Primed seeds presented higher germination speed, independently of their initial physiological quality. Beneficial effects of priming on germination and vigour were more expressive in the seed lot of low physiological quality. Priming in PEG 6000 at -1.0 MPa for 14 days was the most beneficial treatment to improve asparagus seeds performance.


2018 ◽  
Vol 35 (1) ◽  
pp. 211-216
Author(s):  
A. Chapagain ◽  
A. Khanal

Cucumber is the fourth most important vegetable crop worldwide favored for its edible fruit. Cucumber cannot be grown in the winter months due to its intolerance to cold and frost. An experiment was conducted in IAAS, Lamjung to test the effectiveness of various nursery raising conditions for achieving earlier harvest in spring. Three treatments viz. cold frame, hotbed, and open were selected and replicated 30 times each. Data on germination speed, germination percentage, true leaf initiation, plant height, tendril initiation, days to first flowering, days to harvesting, length and diameter of fruit and fruit yield were recorded. Hotbed achieved earlier germination (8 days) followed by cold frames (8.57 days) and open (12.73 days) respectively with cold frame having the highest germination percentage (98%) followed by a hotbed (96%) and open (90%). True leaf initiation was earlier in a cold frame (21.5 days), followed by hot bed (22.83 days) and open (30.97 days). Transplanting of cold frame and hotbed seedlings could be performed 10 days prior to open. Final height attained was significantly maximum for cold-frame plants (97.93 cm) and minimum for a hotbed (76.19 cm) with open being indifferent (86.17 cm) to cold frame and hotbed. Days to tendril initiation, days to flowering and days to first harvest were 57.52, 66.87 and 82.93 days respectively for cold-frame which was significantly minimum compared to hotbed (64.04, 70.38 and 86.95 days) and open (65.73, 71.23, 85.58 days), both being indifferent. Significantly maximum yield was obtained from cold-frame (1465.73 g) with open yielding significantly minimum (1004.06 g) and hotbed being indifferent (1122.45 g) to cold frame and open. Cold-frames are found to be comparatively effective to hotbed and open condition with 3.12 days earlier and 35% higher yield.


Botany ◽  
2014 ◽  
Vol 92 (1) ◽  
pp. 69-75 ◽  
Author(s):  
Ali A. El-Keblawy ◽  
Arvind Bhatt ◽  
Sanjay Gairola

Salsola rubescens Franch. is a wind-pollinated halophytic shrub that produces fruits with red and yellow winged perianths. Germinability of seeds from both fruit types was determined under various light, temperature, and salinity treatments. Red seeds, with and without winged perianths, were heavier than yellow seeds. Germination percentage and germination rate index (speed) were significantly affected by the perianth colour, presence of wings, and temperature and light of incubation and most of their interactions. Germination percentage was greater for yellow-winged seeds than for red-winged seeds. Wing removal significantly enhanced the germination percentage and germination speed in the two types. The presence of wings enhanced germination at lower temperatures, but wing absence enhanced germination at higher temperatures. Wing removal enhanced germination to a greater degree in yellow than in red seeds. There was no light requirement during germination of red-winged seeds, but yellow-winged seeds germinated significantly more in light than in darkness. Red-winged and dewinged seeds were more tolerant to salinity than yellow seeds. Removal of wings significantly increased salinity tolerance for seeds of both wing colours. It is concluded that the showy perianth colours have an ecological role in wind-pollinated plants in regulating dormancy and germination behaviour in the heterogeneous unpredictable hyperarid deserts.


2019 ◽  
Vol 11 (7) ◽  
pp. 239 ◽  
Author(s):  
Rafaela Lanças Gomes ◽  
José Raimundo de Souza Passos ◽  
Juliana Iassia Gimenez ◽  
Marília Caixeta Sousa ◽  
Mariana de Fatima De-Pieri-Oliveira ◽  
...  

Atemoya currently has its seeds studied in several aspects, from the technological and physiological point of view. However, for the performance of the germination test, there is no standardization in relation to the number of seeds and replicates. Thus, this work aims to determine the optimal sample size for germination tests with atemoya seeds. A germination test was carried out with 5 treatments, considering 10, 20, 30 40 and 50 seeds per sampling unit with 50 replicates of each. Data were analyzed using logistic regression, non-linear Gompertz regression models, bootstrap simulation and graphs in the form of contour lines in order to be able to infer the best binomial of the number of seeds per sampling unit and the number of replicates. The expected germination percentage, maximum germination speed and times for the beginning of the germination process, maximum germination speed and interruption of the germination process were determined. The treatment of 20 seeds per sampling unit statistically differs from that of 40 seeds by the Tukey-Kramer test with 5% significance. It could be concluded that for germination tests with atemoya seeds to have statistical validity, the smallest sample size is 10 seeds per unit, regardless of number of replicates.


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