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1.
Plant Physiol ; 184(2): 564-565, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-33020323
2.
BMC Ecol ; 20(1): 49, 2020 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-32867734

RESUMO

BACKGROUND: Vertebrate-mediated seed dispersal is probably the main long distance dispersal mode. Through endozoochory, large mammals act as mobile links between habitats within and among forest patches. Along with other factors, their feeding regimes do affect their contribution as dispersal vectors. We conducted a cross-species comparative experiment involving two herbivores, red deer and roe deer; and two opportunistic omnivores, wild boar and brown bear, all occurring in the forest and steppe-forest ecotone habitats of the south-eastern Caspian region. We compared their role as endozoochorous seed dispersal agents by monitoring seedling emergence in their dungs under greenhouse and natural conditions. RESULTS: In total, 3078 seedlings, corresponding to 136 plant taxa sprouted from 445 paired dung sub-samples, under greenhouse and natural conditions. Only 336 seedlings, corresponding to 36 plant taxa, emerged under natural conditions, among which five taxa did not appear under greenhouse conditions. Graminoids and forbs composed 91% of the seedlings in the greenhouse whereas shrubs were more abundant under natural conditions, representing 55% of the emerged seedlings. Under greenhouse conditions, first red deer and then wild boar dispersed more species than the other two mammals, while under natural conditions brown bear was the most effective vector. We observed remarkably higher species richness and seedling abundance per dung sub-sample under buffered greenhouse conditions than we did under natural conditions. CONCLUSIONS: The four sympatric mammals studied provided different seed dispersal services, both in terms of seedling abundance and species richness and may therefore be regarded as complementary. Our results highlight a positive bias when only considering germination under buffered greenhouse conditions. This must be taken into account when planning management options to benefit plant biodiversity based on the dispersal services concluded from greenhouse experiments.


Assuntos
Cervos , Dispersão de Sementes , Animais , Germinação , Herbivoria , Plântula , Sementes
3.
Chemosphere ; 254: 126918, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32957302

RESUMO

The increasing application of various surfactants nowadays, may lead to the contamination of the natural environment and represent potential threat to terrestrial higher plants. In this article, the effect of 13 surfactants, with dodecyl alkyl chain and various aromatic (imidazolium, pyridinium, thiazolium) and aliphatic (guanidinium, ammonium, thiosemicarbazidium) polar heads, on germination, development and growth of wheat and cucumber was investigated. The study aimed to prove how changes in lipophilicity of surfactants and their various structural modifications (existence of the aliphatic or aromatic polar group, the introduction of oxygen and sulfur) influence toxicity towards investigated plants. The calculated lipophilic parameter (AlogP) is shown to be a useful parameter for predicting potential toxicity of the compound. The strategy of using surfactants with aliphatic polar heads instead of aromatic prove to be a promising strategy in reducing harmful effect, as well as the introduction of polar groups in the structure of cation. From all investigated compounds, surfactants with imidazolium polar head displayed the most harmful effect towards wheat and cucumber. The cucumber seeds were more sensitive to the addition of surfactants comparing to wheat. All obtained experimental results were additionally investigated using computational methods, simulating the transport of surfactants through a lipid bilayer. The influence of cation tendency to fit in lipid bilayer structure was correlated with toxicity. For the first time, it is concluded that cation ability to mimic the structure of bilayer have less harmful effect on plant development.


Assuntos
Cucumis sativus/efeitos dos fármacos , Imidazóis/toxicidade , Compostos de Piridínio/toxicidade , Tensoativos/toxicidade , Triticum/efeitos dos fármacos , Cátions , Membrana Celular/química , Membrana Celular/efeitos dos fármacos , Cucumis sativus/crescimento & desenvolvimento , Germinação/efeitos dos fármacos , Imidazóis/química , Bicamadas Lipídicas/química , Simulação de Dinâmica Molecular , Compostos de Piridínio/química , Compostos de Piridínio/farmacologia , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimento , Sementes/efeitos dos fármacos , Sementes/crescimento & desenvolvimento , Relação Estrutura-Atividade , Tensoativos/química , Triticum/crescimento & desenvolvimento
4.
Int J Periodontics Restorative Dent ; 40(5): e205-e209, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32926006

RESUMO

During a scaling and root planing procedure, a large, actively germinating seed was removed from a deep periodontal pocket. The histologic examination confirmed that it was a germinating tomato seed (Solanum lycopersicum). Since all seeds inside their fruits are in a quiescent stage, this seed was quiescent when the patient ate the tomato. Therefore, the germination occurred inside the periodontal pocket. This case led to a very interesting biologic finding: A periodontal pocket is not only a favorable environment for the development of periodontal microbiota, it is also an ecologic niche that can promote the germination and development of a plant seed.


Assuntos
Germinação , Lycopersicon esculentum , Humanos , Bolsa Periodontal , Aplainamento Radicular , Sementes
5.
Bull Environ Contam Toxicol ; 105(4): 553-558, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32918155

RESUMO

The aim of this study was to evaluate, through nonlinear regression models, the initial development of soybean (Glycine max L. Merr. cv. BRS 257) in soil supplemented with different copper levels. The experiment was performed in a greenhouse under natural light and temperature conditions. The seeds were sowed in soil containing different copper levels (11.20, 32.28, 52.31, 64.51, 79.42, 117.70, 133.53, 144.32, or 164.00 mg kg- 1). Germination percentage was not affected by the increase of copper content in the soil, but there was a delay in the germination process. There was no influence of copper levels on the seedling emergence speed index until 98.42 mg kg- 1; however, higher copper amounts reduced this parameter. Low copper concentrations increased plant development, but higher concentrations compromised mainly root growth. Overall, these results suggest that copper supplementation in the soil exerted dose-dependent dual effects on soybean seedlings.


Assuntos
Cobre/efeitos adversos , Germinação/efeitos dos fármacos , Poluentes do Solo/efeitos adversos , Soja/efeitos dos fármacos , Relação Dose-Resposta a Droga , Dinâmica não Linear , Análise de Regressão , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimento , Solo/química , Soja/crescimento & desenvolvimento
6.
PLoS One ; 15(8): e0227528, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32841235

RESUMO

The morphology and physiology of diaspores play crucial roles in determining the fate of seeds in unpredictable habitats. In some genera of the Brassicaceae different types of diaspores can be found. Lepidium appelianum produces non-dormant seeds within indehiscent fruits while in L. campestre dormant seeds are released from dehiscent fruits. We investigated whether the allocation of relevant defence compounds into different tissues in different Lepidium species may be related to the diverse dispersal strategy (indehiscent and dehiscent) and seed physiology (non-dormant and dormant). Total glucosinolate concentration and composition were analysed in immature and mature seeds and pericarps of L. appelianum and L. campestre using high-performance liquid chromatography. Moreover, for comparison, transgenic RNAi L. campestre lines were used that produce indehiscent fruits due to silencing of LcINDEHISCENCE, the INDEHISCENCE ortholog of L. campestre. Total glucosinolate concentrations were lower in immature compared to mature seeds in all studied Lepidium species and transgenic lines. In contrast, indehiscent fruits of L. appelianum maintained their total glucosinolate concentration in mature pericarps compared to immature ones, while in dehiscent L. campestre and in indehiscent RNAi-LcIND L. campestre a significant decrease in total glucosinolate concentrations from immature to mature pericarps could be detected. Indole glucosinolates were detected in lower abundance than the other glucosinolate classes (aliphatic and aromatic). Relatively high concentrations of 4-methoxyindol-3-ylmethyl glucosinolate were found in mature seeds of L. appelianum compared to other tissues, while no indole glucosinolates were detected in mature diaspores of L. campestre. The diaspores of the latter species may rather depend on aliphatic and aromatic glucosinolates for long-term protection. The allocation patterns of glucosinolates correlate with the morpho-physiologically distinct fruits of L. appelianum and L. campestre and may be explained by the distinct dispersal strategies and the dormancy status of both species.


Assuntos
Glucosinolatos/metabolismo , Lepidium/fisiologia , Sementes/metabolismo , Brassicaceae/fisiologia , Cromatografia Líquida de Alta Pressão/métodos , Ecossistema , Frutas/metabolismo , Frutas/fisiologia , Germinação/fisiologia , Lepidium/crescimento & desenvolvimento , Dormência de Plantas , Sementes/fisiologia , Água
7.
BMC Ecol ; 20(1): 48, 2020 08 29.
Artigo em Inglês | MEDLINE | ID: mdl-32861248

RESUMO

BACKGROUND: Salvia is a large, diverse, and polymorphous genus of the family Lamiaceae, comprising about 900 ornamentals, medicinal species with almost cosmopolitan distribution in the world. The success of Salvia limbata seed germination depends on a numerous ecological factors and stresses. We aimed to analyze Salvia limbata seed germination under four ecological stresses of salinity, drought, temperature and pH, with application of artificial intelligence modeling techniques such as MLR (Multiple Linear Regression), and MLP (Multi-Layer Perceptron). The S.limbata seeds germination was tested in different combinations of abiotic conditions. Five different temperatures of 10, 15, 20, 25 and 30 °C, seven drought treatments of 0, -2, -4, -6, -8, -10 and -12 bars, eight treatments of salinity containing 0, 50, 100.150, 200, 250, 300 and 350 mM of NaCl, and six pH treatments of 4, 5, 6, 7, 8 and 9 were tested. Indeed 228 combinations were tested to determine the percentage of germination for model development. RESULTS: Comparing to the MLR, the MLP model represents the significant value of R2 in training (0.95), validation (0.92) and test data sets (0.93). According to the results of sensitivity analysis, the values of drought, salinity, pH and temperature are respectively known as the most significant variables influencing S. limbata seed germination. Areas with high moisture content and low salinity in the soil have a high potential to seed germination of S. limbata. Also, the temperature of 18.3 °C and pH of 7.7 are proposed for achieving the maximum number of germinated S. limbata seeds. CONCLUSIONS: Multilayer perceptron model helps managers to determine the success of S.limbata seed planting in agricultural or natural ecosystems. The designed graphical user interface is an environmental decision support system tool for agriculture or rangeland managers to predict the success of S.limbata seed germination (percentage) in different ecological constraints of lands.


Assuntos
Germinação , Salvia , Inteligência Artificial , Ecossistema , Sementes , Temperatura
8.
Am J Bot ; 107(8): 1106-1113, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32767569

RESUMO

PREMISE: The novel-weapons hypothesis predicts that some plants are successful invaders because they release allelopathic compounds that are highly suppressive to naïve competitors in invaded ranges but are relatively ineffective against competitors in the native range. For its part, the evolution of enhanced weaponry hypothesis predicts that invasive populations may evolve increased expression of the allelopathic compounds. However, these predictions have rarely been tested empirically. METHODS: Here, we made aqueous extracts of roots and shoots of invasive (North American) and native (European) Brassica nigra plants. Seeds of nine species from North America and nine species from Europe were exposed to these extracts. As control solutions, we used pure distilled water and distilled water with the osmotic potential adjusted with polyethylene glycol (PEG) to match that of root and shoot extracts of B. nigra. RESULTS: The extracts had a strong negative effect on germination rates and seedling root lengths of target species compared to the water-control. Compared to the osmolality-adjusted controls, the extracts had a negative effect on seedling root length. We found no differences between the effects of B. nigra plant extracts from the invasive vs. native populations on germination rates and seedling root growth of target plant species. Responses were largely independent of whether the target plant species were from the invaded or native range of B. nigra. CONCLUSIONS: The results show that B. nigra can interfere with other species through allelochemical interactions, but do not support predictions of the novel-weapons hypothesis and evolution of increased allelopathy.


Assuntos
Alelopatia , Mostardeira , Europa (Continente) , Germinação , Espécies Introduzidas , América do Norte
9.
PLoS One ; 15(8): e0237536, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32790719

RESUMO

Melatonin is effective in enhancing various abiotic stress resistances of plants. However, its underlying mechanisms in drought-resistance in winter wheat (Triticum aestivum L.) is not clear. The goal of this work was to investigate the effect of melatonin on seed germination and to evaluate leaf antioxidant physiology for two wheat varieties. Experiments included 20% PEG, melatonin plus 20% PEG and a control using two contrasting wheat varieties (JM22- drought sensitive and HG35- drought resistant). Melatonin levels were 0, 1, 10, 100 and 300 µmol L-1. Results revealed that 300 µmol L-1 of melatonin alleviated the negative effect of water stress on germination and increased radicle length, radicle number, and plumule length of the germinated seeds. Principal component analysis showed a significant change in amino acid content during germination and this change was dependent on melatonin concentration and the variety. Lysine (Lys) content in wheat seeds under the PEG plus 300 µmol L-1 melatonin treatment increased compared with that of the seeds under PEG alone. There was a significant and positive correlation between Lys content and morphological index of germination. During seedling growth, soluble protein was involved in osmotic adjustment and superoxide dismutase (SOD) activity was increased to mitigate the damage in the cytomembrane of JM 22 leaf under 300 µmol L-1 melatonin plus PEG treatment. The effect of melatonin was dependent on SOD activity increasing significantly for HG35-a drought resistant variety. The results of this work lays a foundation for further studies to determine if melatonin can be economically used to mitigate the impact of dry planting conditions on wheat productivity in North China Plain.


Assuntos
Antioxidantes/farmacologia , Germinação/efeitos dos fármacos , Melatonina/farmacologia , Polietilenoglicóis/toxicidade , Sementes/efeitos dos fármacos , Estresse Fisiológico , Triticum/efeitos dos fármacos , Secas , Osmose , Sementes/crescimento & desenvolvimento , Sementes/metabolismo , Triticum/crescimento & desenvolvimento , Triticum/metabolismo
10.
Ecotoxicol Environ Saf ; 204: 111104, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32791360

RESUMO

Since development of antioxidant defence system is high energy demanding event, innate defence system and stress tolerance of plant is strictly governed by plant age. This study is aimed towards evaluating variation of tolerance in germinating seeds and seedlings of Oryza sativa L. cv. Swarna against nano-scale zero valent iron (nZVI). A comparative study of several physiological and biochemical parameters have been carried out among 2 distinct plant groups, Group I treated with variable concentrations of nZVI (50, 100, 150 and 200 mg L-1) during germination and Group II treated with similar nZVI doses on 7th day after germination. Upon treatment with higher nZVI concentrations, Group I seedlings showed susceptibility towards oxidative stress while Group II seedlings showed tolerance against these higher doses of nZVI. Significant growth enhancement was observed upon treatment with 50-150 mg L-1 nZVI, since up-regulation of plant's endogenous antioxidant system protected relatively aged Group II seedlings from oxidative damages. Hierarchical clustering based on overall physiological, biochemical and stress parameters confirmed that in Group I seedlings 100-200 mg L-1 nZVI treatments were toxic where as in Group II seedlings 50-150 mg L-1 nZVI treatments showed growth promoting effects. This differential response is due to developmental stage related resistance in plants.


Assuntos
Germinação/efeitos dos fármacos , Nanopartículas Metálicas/toxicidade , Oryza/crescimento & desenvolvimento , Antioxidantes/metabolismo , Ferro/metabolismo , Oryza/efeitos dos fármacos , Oxirredução , Estresse Oxidativo/efeitos dos fármacos , Plântula/efeitos dos fármacos , Sementes/metabolismo
11.
PLoS One ; 15(8): e0237844, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32834013

RESUMO

The feasibility of the production of germinated rice extracts using indigenous rice from Southern Thailand, including Khemtong (KHT) and Khai Mod Rin (KMR) from a single location at the Pak Phanang River Basin in Nakhon Si Thammarat, was investigated. The nutritional composition and bioactivity of the germinated rice extracts from both cultivars were evaluated. Optimum germination time for both rices was 96 h, leading to the highest GABA, thiamine, free amino acid, total sugar, and α-amylase activity (p<0.05). Germinated KHT had a higher α-amylase activity than germinated KMR at all germination times. Mashing at 60°C/pH 5.5 rendered the extract with the highest GABA content (p<0.05) and desirable contents of other nutrients. In comparison with germinated Sungyod (local colored rice) and Jasmine (commercial Thai rice) extracts, KHT and KMR showed a higher scavenging activity against DPPH•, OH•, and H2O2 (p<0.05) with a comparable ABTS•+ inhibition. For metal chelation, reducing power and ACE inhibitory activity, the germinated Sungyod extract was greater than KHT/KMR. The results demonstrated the potential use of germinated local Thai rice for the production of functional beverages.


Assuntos
Germinação , Fenômenos Fisiológicos da Nutrição , Oryza/química , Oryza/crescimento & desenvolvimento , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Aminoácidos/análise , Inibidores da Enzima Conversora de Angiotensina/farmacologia , Antioxidantes/farmacologia , Compostos de Bifenilo/química , Estudos de Viabilidade , Flavonoides/análise , Depuradores de Radicais Livres/química , Minerais/análise , Fenóis/análise , Ácido Fítico/análise , Picratos/química , Açúcares/análise , Tiamina/análise , Fatores de Tempo , alfa-Amilases/metabolismo , Ácido gama-Aminobutírico/análise
12.
An Acad Bras Cienc ; 92(suppl 1): e20181313, 2020 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-32756841

RESUMO

Quinoa, classified as a pseudocereal, presents greater nutritional value compared to traditional cereals. Considering the potential for cultivation presented by the species and the benefits of studying plant morphology and morphobiometry, this paper describes seed and seedling morphobiometric characteristics of quinoa (Chenopodium quinoa Willd.) cultivar BRS Piabiru during germination and emergence. To evaluate seed morphobiometry the 1000-seeds weight, moisture content, seed morphological characterization and the tetrazolium test were performed. The morphological characterization of germination and seedling emergence were performed by periodic observations during the development, allowing the description using pictures and drawings. Quinoa seeds cv. BRS Piabiru present an average diameter of 2.05 mm and 1.07 width. 1000-seeds weight of 2.68 g and moisture content of 11%. Externally, quinoa seeds present the pericarp as testa, the hilum and the raphe and, internally, the embryonic axis (cotyledons, radicle and hypocotyl-radicle), perisperm and endosperm. The germination is characterized as epigeal, phanerocotylar type, with radicle protrusion at 3 hours after sowing and complete formed seedlings at 24 hours after sowing. Emergence occurs at 9 days after sowing and plants are completely formed at 12 days after sowing.


Assuntos
Chenopodium quinoa , Germinação , Valor Nutritivo , Plântula , Sementes
13.
An Acad Bras Cienc ; 92(suppl 1): e20190400, 2020 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-32756845

RESUMO

The in vitro rescue of immature embryos can be employed both for preservation of mango germplasm and rescue of hybrids produced from crosses to obtain traits of interest. The objective of this work was to establish a protocol for in vitro rescue of immature embryos aiming to preserve mango germplasm. Immature embryos of two mango varieties, 'Carlota' and 'Ubá', were inoculated in MS/2 medium supplemented with 100 mg L-1 of cysteine, 0.5 mg L-1 of gibberellic acid (AG3) and 30 g L-1 of sucrose. The experimental design was completely randomized with 30 repetitions, each composed of two embryos/flask. After in vitro growth for 84 days, some of the plantlets were transferred for acclimatization. The parameters evaluated were plant height, number of leaves and leaf, stem and root dry weight. The germination began on the sixth day after seeding, and the immature embryos presented a high oxidation rate, with 60% oxidized after 72 hours. The plantlets from immature embryos showed better development than those from aborted embryos. The results showed the viability of rescuing mango embryos in the immature phase and of their in vitro conservation for a period of 12 months.


Assuntos
Mangifera , Germinação , Folhas de Planta
14.
Sci Total Environ ; 745: 141055, 2020 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-32736110

RESUMO

Plant seedlings are susceptible to copper (Cu) toxicity. As copper levels in soil continue to rise with the use of Cu-based agrochemicals, alleviation of Cu stress is of paramount importance. Traditional approaches to allay Cu stress are well documented but are typically found to be either costly or inefficient. Given their small size, ionic character, and high biocompatibility, specific polymeric nanoparticles (NPs) may have the potential for mitigating metal toxicity to crops. In this pioneering study, we investigated the effects of newly synthesized polysuccinimide NPs (PSI-NPs) on corn (Zea mays L.) seed germination and seedling growth under different levels of Cu stress. The results showed that PSI-NPs influenced seed germination in a dose-dependent manner with an optimal rate of 200 mg L-1. In addition, the positive effects of PSI-NPs on seed germination indexes were found to be positively correlated with enhanced seed imbibition (r = 0.82). The addition of PSI-NPs significantly mitigated Cu stress as indicated by improved growth of shoots and roots, and higher antioxidant enzyme activity observed with co-exposure to PSI-NPs as compared to Cu stress treatment only. Cu concentrations in seedling root and shoot significantly increased with increasing Cu treatment rate. Higher uptake of Cu by plant was observed in the Cu-PSI-NPs co-treatment than single Cu treatment. The alleviation effect of PSI-NPs could be explained by the enhanced antioxidant enzyme activities and storage of Cu as Cu-PSI complexes in plants with reduced phytotoxicity. These findings will open the opportunity of using PSI-NPs as a regulator to enhance seed germination and improve seedling growth under stress of heavy metals like Cu.


Assuntos
Germinação , Nanopartículas/toxicidade , Cobre/toxicidade , Raízes de Plantas , Plântula , Sementes
15.
Ying Yong Sheng Tai Xue Bao ; 31(7): 2211-2218, 2020 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-32715683

RESUMO

Borrelia latifolia is an annual herb suitable to be used as cover crop for weed control in orchards in southern China. To understand the competition between B. latifolia and common weeds in orchards, we investigated the allelopathic interactions between B. latifolia and two Asteraceae species, Ageratum conyzoides and Bidens alba. The results showed that the aqueous extracts of B. latifolia at 10-50 mg·mL-1 significantly inhibited seed germination and seedling growth of A. conyzoides and B. alba, with the radicle length of A. conyzoides and B. alba being reduced by 57.4%-90.2% and 57.3%-62.3%, respectively. The aqueous extracts of A. conyzoides and B. alba also had strong allelopathic effects on seed germination of B. latifolia. Under the treatment of 50 mg·mL-1 aqueous extracts, the two Asteraceae species almost entirely inhibited the germination of B. latifolia. After treated with 10 mg·mL-1 aqueous extract of B. latifolia for 30 d, net photosynthesis, plant height and biomass of A. conyzoide were reduced by 15.2%, 20.6% and 41.5%, respectively, compared with the control, while the biomass of B. alba also showed a decreasing trend. Instead, the growth of B. latifolia was not affected. Under mixed culture, biomass of B. latifolia was comparable to that under monoculture, whereas those of A. conyzoides and B. alba were reduced by 86.0% and 27.1%, respectively. Compared with A. conyzoides and B. alba, the allelopathic advantage of B. latifolia is that it can inhibit growth of the two Asteraceae species as well as inhibit seed germination.


Assuntos
Asteraceae , Alelopatia , China , Germinação , Extratos Vegetais , Plantas Daninhas
16.
Ying Yong Sheng Tai Xue Bao ; 31(7): 2219-2226, 2020 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-32715684

RESUMO

Allelopathic effects of Miscanthus floridulus at different growth stages on Brassica peki-nensis, Lactuca sativa, and Oryza sativa were examined using six parameters of seed germination and seedling growth, including germination rate, germination speed index, germination index, root length, stem length, and biomass. The results showed that the allelopathic effects of M. floridulus leaf extract were stronger than that of stem extract, with the germination index and biomass of reci-pient plants treated by leaf extract being significantly lower than those treated by stem extract. The allelopathic effect of M. floridulus in the withering stage was stronger than that in the vigorous growth stage. There was a significant dose-effect relationship between the concentrations of leaf extract and the allelopathic effects on three different receptor plants. The higher the extract concentration was, the stronger the allelopathic inhibition was. Leaf extract of M. floridulus could completely inhibit all the germination indices of B. pekinensis and L. sativa at the concentrations of 0.075 and 0.10 g·mL-1, respectively. The inhibition rates of 0.10 g·mL-1 leaf extract on germination rate, germination speed index, and germination index of O. sativa were 13.8%, 27.2% and 19.3%, respectively. Leaf extract of M. floridulus could completely inhibit all the growth indices of B. pekinensis and L. sativa at the concentrations of 0.05 and 0.10 g·mL-1, respectively. However, the inhibition rates of 0.10 g·mL-1 leaf extract on root length, stem length, and biomass of O. sativa were 64.6%, 92.9% and 21.8%, respectively. In summary, according to the comprehensive allelopathy response index (SE) of seed germination and seedling growth, the susceptibility of the three tested species to the extracts of M. floridulus was B. pekinensis (Cruciferae) > L. sativa (Compositae) > O. sativa (Gramineae).


Assuntos
Alelopatia , Plântula , Germinação , Extratos Vegetais , Poaceae , Sementes
17.
Ying Yong Sheng Tai Xue Bao ; 31(7): 2243-2250, 2020 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-32715687

RESUMO

We examined the allelopathic effect of extracts from different parts of foxtail millet straw with different concentrations (undiluted water extracts, 10-fold, 50-fold, and 100-fold dilution) on three different kinds of malignant weeds (Amaranthus retroflexus, Chenopodium album, and Setaria viridis) by water extract. In this experiment, we measured biological indicators for seed germination period and potted seedling physiological parameters. The results showed that water extract of foxtail millet leaves and stems had significant allelopathic effects on the three species of weeds, with the effects of different concentrations being different. Undiluted water extract inhibited the growth, while dilution (10-fold, 50-fold, 100-fold dilution) promoted the growth. Under the treatment of undiluted water extract of leaf and stem, the germination rate of three weeds decreased 63.9%, 37.3% and 41.7%, respectively, while root length was only 27.8%, 37.8% and 18.4% of the control. The bud length was only 34.5%, 27.7% and 17.6% of the control. The net photosynthetic rate accounted for 66.6%, 89.9% and 88.2% of the control. The transpiration rate accounted for 69.0%, 87.5% and 56.1% of the control, while the synthesis allelopathic index of the three weeds were -0.699, -0.716 and -0.795 by undiluted water extract, respectively. Results implied strong allelopathic inhibition. The allelopathy promoting effect of dilution increased first and then decreased with the increases of dilution folds. Among which, 50-fold dilution had the strongest promoting effect with the germination rate, root length and bud length of the three weeds being significantly different from those of the control, with the synthesis allelopathic index being 0.261, 0.217, and 0.165, respectively. A large number of associated weeds grow in foxtail millet field which is related to the leaching of allelopathic substances in straw.


Assuntos
Alelopatia , Setaria (Planta) , Germinação , Plantas Daninhas , Água
18.
Ying Yong Sheng Tai Xue Bao ; 31(7): 2251-2256, 2020 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-32715688

RESUMO

Velvetleaf (Abutilon theophrasti) is a common weed in dryland, which can reduce crop yield. Allelopathy is one of the possible reasons resulting in crop yield reduction. In this study, we analyzed the allelopathic effect of velvetleaf volatile oil components on germination and seedling growth of three dryland crops, wheat (Triticum aestivum), maize (Zea mays), and soybean (Glycine max). A total of 26 compounds in velvetleaf volatile oil were identified by GC-MS, accounting for 98.1% of the total chromatographic peak areas. The terpenes with lower molecular weight in the volatile oil were α-pinene, eucalyptol, α-terpinolene, ß-terpinene, trans-α-ionone, and trans-ß-ionone. The saturated aqueous solution of velvetleaf volatile oil could inhibit seed germination of three crops by filter paper and soil. Velvetleaf volatile oil could inhibit the seedling growth of three crops through air, filter paper, and soil. Wheat was the most susceptible to volatile oil, followed by maize and soybean. The inhibitory effect of volatile oil on the growth of wheat was the strongest in air medium, followed by filter paper and soil medium. The lower molecular weight of terpene components from volatile oil might be the important allelochemicals.


Assuntos
Óleos Voláteis , Zea mays , Alelopatia , Germinação , Plântula , Soja , Triticum
19.
Ying Yong Sheng Tai Xue Bao ; 31(7): 2264-2270, 2020 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-32715690

RESUMO

We examined the effects of root extracts of Haloxylon ammodendron and Beta vulgaris in Chenopodiaceae extracted by water and ethanol on seed germination and haustorium formation of Cistanche deserticola by filter paper culture dish method. The results showed that only adding root extract had no effect on seed germination and haustorium formation of C. deserticola. The germination rate of C. deserticola seeds treated by adding 10 mg·kg-1 gibberellin to the root extracted by ethanol was not significantly different from that of the control (GA3), whereas those treated by adding gibberellin to the ethanol extract of two kinds of host root was increased by more than 10 times. The germination rate of C. deserticola seeds in the treatment with adding 1 mg·kg-1 fluridone (FL) to root extract was not significantly different from that in the control with only fluridone, while those in the treatment with B. vulgaris root water extraction was the highest (39.4%). Compared to the treatment of adding gibberellin to the root extract, the germination rate of C. deserticola seeds was only increased. When FL was added to the host root extract, the haustorium was formed on the germination tube, with the formation rate of the ethanol extraction group being the highest (16.2%). Seed germination rate of C. deserticola increased to 52.3% when GA3 and FL were added to the ethanol extract of H. ammodendron, but the formation rate of haustorium was not different from that of FL treatment. Only 6.7% of the seed formation haustorium in the control was significantly lower than that in FL treatment. There were differences in the position and shape of the haustorium of C. deserticola seeds under different treatments. The haustorium produced by adding the extract of the host root mostly appeared at the top of the bud tube, and many papillae raised into claws. The haustorium of FL treatment without adding the extract of the host root mostly appeared at the bottom or the top of the bud tube splitting. The results indicated that ethanol extraction and water extraction could extract the substances that could promote the formation of C. deserticola seeds haustorium from the host root, but did not affect seed germination. GA3 and FL could significantly improve the germination rate of C. deserticola seeds, but the formation of the haustorium was affected by some substances in the host root extract.


Assuntos
Cistanche , Germinação , Giberelinas , Extratos Vegetais , Sementes
20.
Ying Yong Sheng Tai Xue Bao ; 31(7): 2271-2278, 2020 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-32715691

RESUMO

Invasive plants can inhibit the survival and reproduction of native species through alle-lopathy. It is not clear whether the native plants, especially the mosses in the ground layer, inf-luence the invasive plants. In this study, we examined the effects of two native moss species, Brachythecium plumosum and Plagiomnium venustum, on two malignant invasive plants, Echinochloa crusgalli and Daucus carota. The effects of mosses on seed germination and seedling growth of both invasive species were determined based on the clump structure and allelopathy of the mosses. The germination rate, germination potential and germination index of the two invasive species were significantly inhibited when seeds fallen on or into the moss clump, with an order of inhibition effect: above moss clump>below moss clump>no moss. Radicle length and radicle/plumule of D. Carota were significantly affected when seeds fallen into the moss clump. Moss water extracts significantly reduced germination rate, germination potential, and germination index of the two invasive plants, with these effects being concentration-dependent. To some extent, moss water extracts increased the plumule length, radicle length and radicle/plumule of D. Carota seedlings, but without effect on E. crusgalli. Both mosses showed inhibitory effects on seed germination and seedling growth of two invasive plants, with higher sensitivity of E. crusgalli than D. Carota. Along with the increases in concentration of water extract, stronger inhibitory effects were found. Therefore, mosses could partially inhibit seed germination and seedling growth of invasive plants.


Assuntos
Bryopsida , Plântula , Alelopatia , Germinação , Sementes
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