Allelopathic effect of aqueous leaf extracts of selected trees on germination and seedling growth of rice

Aim: The present investigation aimed to study the allelopathic effects of aqueous leaf extracts of Emblica officinalis, Inga dulcis, Alstonia scholaris, Syzygiumcuminis, Madhuca indica and Azadirachta indica trees on germination and seedling growth of rice.Methodology: The studies on germination and seedling growth was conducted in a BOD incubator. The number of seeds germinated daily was counted to study speed of germination, germination energy and number of days to 50% germination. DMSO was used to extract the chlorophyll and carotenoid pigments of leaves. The chlorophyll and carotenoid contents were estimated by measuring the optical density through UV-VIS spectrophotometer. Relative watercontent of leaves was determined by soaking of leaves in water followed by oven drying. Results: The effect of leaf extracts (5 and 10%) of Emblica officinalis, Inga dulcis, Alstonia scholaris, Syzygium cuminis, Madhuca indica and Azadirachta indica was studied on two rice cultivars viz. NK-5251 (Hybrid) and Gontra Bidhan-2 (high yielding variety). The experimental findings revealed that leaf extracts of different trees had significant effect on the germination and seedling growth of rice. The leaf extract of most of the trees, except Madhuca indica, reduced germination, chlorophyll content and RWC at higher concentration. The aqueous extracts of Madhuca indica significantly increased germination, seedling vigour, seedling dry weight,germination energy, speed of germination, chlorophyll content and RWC as compared to control. However, 5% extract of Madhuca indica recorded the highest germination percentage, seedling vigour, speed of germination, germination energy, seedling dry weight, chlorophyll content and RWC among all the treatments. Interpretation: The leaf extract of Emblica officinalis, Inga dulcis, Alstonia scholaris, Syzygium cuminis and Azadirachta indica plants at higher concentration reduced germination and early seedling growth of rice. The leaf extract of Madhuca indica plant, however, enhanced the performance. The positive allelopathic effect of Madhuca indica leaf extract may be attributed to the presence of phytohormones and biostimulants

Promoting effect of platelets on macrophage inhibition and phagocytosis of fungi / 中华实验眼科杂志

Objective@#To study the effects of platelets on macrophages phagocytosis and inhibition of fungi.@*Methods@#Macrophages were cultured, Fusarium Pythium spores were extracted and platelets were isolated from blood of mouse.Simple spore group, spore+ macrophage group and mixed platelet group were set, and were inoculated with fungal spore, equal proportion spore+ macrophage and platelet+ spore+ macrophage, respectively.The prepared plate was placed on a spinning disk laser scanning confocal microscope at 1 hour, 2, 3 and 4 hours after culture, five visual fields were randomly selected at the corresponding time points for photography.The phagocytic rate, phagocytic index and fungal spore germination rate were calculated.Fungal hyphae length of each group at 4, 6 and 8 hours after culture were calculated.The single macrophage group, spore+ macrophage group and mixed platelet group were set and the cytotoxicity was measured by real-time cell analyzer.The breeding and use of mice was in according with the ARVO statement.This study was approved by the Experimental Animal Ethics Committee of Henan Eye Institute (HNEECA-2017-04).@*Results@#The phagocytic rate and phagocytic index of macrophages in mixed platelet group at 1 hour, 2, 3 and 4 hours after culture were significantly higher than those in spore+ macrophage group at corresponding time point (all at P<0.05). There were significant differences in spore germination rate at 1 hour, 2, 3 and 4 hours after culture among different groups (H=60.05, 37.89, 55.15, 60.52; all at P<0.001). The spore germination rates of spore+ macrophage group at 1 hour, 2, 3 and 4 hours after culture were lower than those of simple spore group, while the spore germination rates of mixed platelet group at 1 hour and 3, 4 hours after culture were lower than that of spore+ macrophage group, the differences were statistically significant (all at P<0.01). There were significant differences in fungal hyphae length at 4, 6 and 8 hours after culture among the three groups (H=13.76, 43.57, 60.87; all at P≤0.001). The fungal hyphae lengths of spore+ macrophage group at 4, 6 and 8 hours after culture were lower than those of simple spore group, and the fungal hyphae lengths of mixed platelet group at 6 and 8 hours after culture were lower than those of spore+ macrophage group at the corresponding time point.The differences were statistically significant (all at P<0.05). There was no significant difference in cell index between 0 hour, 6, 12, 18 and 24 hours after culture (F=0.02, 1.08, 1.61, 1.58, 2.52; all at P>0.05). There were significant differences in cell index among different groups at 30, 36, 42 and 48 hours after culture (F=10.81, 8.08, 5.61, 5.72; all at P<0.05). The cell indexes in spore+ macrophage group at different time points were significantly lower than those in simple macrophage group (all at P<0.01).@*Conclusions@#Platelets can promote the phagocytosis and inhibition of macrophages on fungi, and platelets may have antagonistic effect on fungal cytotoxicity.

Construction of Bem46 knockout strain and the role of the Bem46 gene in Aspergillus fumigatus / 中国人兽共患病学报

The aims of this study are to construct the Bem46 knockout strain of Aspergillus fumigatus,investigate the effect of the Bem46 in the growth and germination,and observe the sensitivity of the oxidative stress,the osmotic stress,the temperature and the response to caspofungin and nikkomycin.The Bem46 gene was identified by sequence alignment in A.fumigatus genome database.The Bem46 knockout strain was construction by the protoplast.The growth was observed and compared between Ku80 and △Bem46 on different culture medium,such as GMM,GMM containing hydrogen peroxide,formamide,sodium chloride and sorbitol.The growth diameter was measured under the different temperatures.The germination rate was observed and compared by microscope.Results showed that the Bem46 gene,Afu7g04660,contained 1 116 bp bases pair and encoding 311 amino acids.Six transformants were obtained by gene cloning and protoplast method and only one was confirmed by PCR and Southernblot.The △Bem46 grew significantly faster than the control strain on the medium containing sorbitol.And there were no visible difference between △Bem46 and Ku80 on the other medium.The germination rate of the △Bem46 was more retarded than the Ku80 in GMM liquid medium.In conclusion,the Bem46 gene plays a role in osmotic stress in A.fumigatus and involved in osmotic pressure induced by sorbitol.And there is no visible effect in oxidative stress.The Bem46 gene has a positive effect on spore germination.

Study on Standardization of Germination Test of Astragalus membranacus Seed / 中国药房

OBJECTIVE:To select the optimum conditions for germination test of Astragalus membranaceus seed and provide reference for the formulation of testing rules of A. membranaceus seed. METHODS:First,the dormancy of A. membranaceus seeds were broken by soaking seed with 98% H2SO4 for 30 min and 35 ℃ warm water for 9 h,then treated with different temperatures of germination,different germinating beds and light conditions. Different treatment methods were evaluated by germination rate, germination potential and germination index. RESULTS:With the increase of temperature,germination rate,germination potential and germination index decreased. At 30 ℃,germination rate,germination index,and germination potential were significantly low-er than those of seed with other treatments,in which the germination rate was the highest at 15℃;but there wasn’t significant dif-ference in germination rate of 15 ℃ and 20 ℃. There were no significant differences in germination rate of different germination beds,but sand bed could restrain bacterial growth well. Under both light and dark conditions,seed could normally germinate. The appropriate condition of A. membranacus seed germination was at 15 ℃,sand bed and dark. The germination rate,germination po-tential and germination index were(98.5±0.65)%,(85.5±0.87)%and 175.8±2.31,respectively. Meanwhile,the germination pe-riod was only 4 days. CONCLUSIONS:Suggested quality control method of A. membranaceus seed is that at 15 ℃,sand bed and dark. The second day of germination as initial counting time and forth day as the last counting time are used to calculate germina-tion index. This method is easy and controllable. It also has short germination period and high germination rate.

Effect of light quality on Tabebuia rosea (Bignoniaceae) seed germination / Efecto de la calidad de la luz en la germinación de Tabebuia rosea (Bignoniaceae) / Efeito da qualidade da luz na germinação de Tabebuia rosea (Bignoniaceae)

Tabebuia rosea germination capacity and rate have been examined under light and dark conditions. However, seeds responses to light quality, in particular to short and mid-wavelengths, are not well known. We hypothesized that short wavelengths would have a positive effect on T. rosea germination. The effects of short, mid and long-wavelengths on germination capacity, rate (germination rate index, germination rate R50, a devised index of germination rate R50- and peak value), mean daily germination and germination value were evaluated. Light quality had little effect on germination capacity; it was reduced only in darkness. Seeds under short and mid-wavelengths germinated faster (germination rate) than under any other light treatments. We concluded that although T. rosea seeds respond to all light quality treatments, the short and mid-wavelengths are the cue for increasing germination speed. For synchronizing germination, short and mid-wavelengths transmitted by red cellophane paper can be used as a pre-germinative treatment for restoration and silvicultural purposes.

La capacidad y tasa de germinación de las semillas de Tabebuia rosea han sido evaluadas bajo condiciones de luz y oscuridad. Sin embargo, aún se desconocen las respuestas a la calidad de la luz, particularmente a las longitudes de onda corta y media del espectro. Nuestra hipótesis fue que las longitudes de onda corta podrían tener un efecto positivo en la germinación de T. rosea. Se evaluaron los efectos de las longitudes de onda corta, media y larga sobre la capacidad germinativa, la tasa de germinación (índice de la tasa de germinación, tasa de germinación R50 y R50- y valor pico), germinación media diaria y valor de germinación. La calidad de la luz tuvo poco efecto en la capacidad de germinación, la cual se redujo únicamente en condiciones de oscuridad. Aunque las semillas de T. rosea respondieron de manera similar en todas las condiciones de luz evaluadas, se presentó un incremento en la velocidad de germinación cuando las semillas se sometieron a longitudes de onda corta y media, las cuales incidieron de manera positiva en la sincronización del proceso de germinación. Estos hallazgos son aplicables para la restauración y en estrategias de producción de plántulas para proyectos de silvicultura.

Examinou-se a taxa e a capacidade de germinação de Tabebuia rosea em condições de luz y escuridao; no entanto, a resposta das sementes para da qualidade da luz, em particular aos comprimentos de onda curto e médio nao são bem conhecidos. Nossa hipótese é que os comprimentos de onda curtos tém um efeito positivo sobre a germinação de T. rosea. Os efeitos de curto, médio e longo comprimentos de onda sobre a capacidade de germinação, taxa (índice de velocidade de germinação, velocidade de germinação R50 e R50- e valor de pico), média de germinação diaria e valores de germinação foram avaliados. A qualidade da luz teve pouco efeito sobre a capacidade de germinação; a germinação decresceu apenas na escuridao. A taxa de germinação de sementes sob curto e médio comprimentos de onda foi mais rápido do que em quaisquer outras condições de luz; comprimento de onda curto nao teve nenhum efeito significativo sobre os parámetros de germinação. Concluímos que, embora as sementes T. rosea respondem a todos os tratamientos de qualidade de luz, os comprimentos de onda curto e médio aceleram a velocidade de germinação. Para sincronizar a germinação, ondas de curto e médio comprimento transmitidas através de papel celofane vermelho podem ser usadas como um tratamento pré-germinativo para a restaurado e para fins silvícolas.

Evaluation of Strains of Metarhizium anisopliae and Beauveria bassiana against Spodoptera litura on the Basis of Their Virulence, Germination Rate, Conidia Production, Radial Growth and Enzyme Activity

Ten strains of the entomopathogenic fungi Metarhizium anisopliae and Beauveria bassiana were evaluated to find the most effective strain for optimization studies. The first criterion tested for strain selection was the mortality (> 50%) of Spodoptera litura larvae after inoculation of the fungus for 4 days. Results on several bioassays revealed that B. bassiana BNBCRC showed the most virulence on mortality S. litura larvae (80% mortality). B. bassiana BNBCRC also showed the highest germination rate (72.22%). However, its conidia yield (7.2 x 10(8) conidia/mL) was lower than those of B. bassiana B 14841 (8.3 x 10(8) conidia/mL) and M. anisopliae M6 (8.2 x 10(8) conidia/mL). The highest accumulative radial growth was obtained from the strain B14841 (37.10 mm/day) while the strain BNBCRC showed moderate radial growth (24.40 mm/day). M. anisopliae M6 possessed the highest protease activity (145.00 mU/mL) while M. anisopliae M8 possessed the highest chitinase activity (20.00 mU/mL) during 96~144 hr cultivation. Amongst these criteria, selection based on virulence and germination rate lead to the selection of B. bassiana BNBCRC. B. bassiana B14841 would be selected if based on growth rate while M. anisopliae M6 and M8 possessed the highest enzyme activities.

Germinação de sementes de dalbergia nigra (Vell.) Allemao ex Benth. (Fabaceae-Papilionoideae) no armazenamento / Germination of Dalbergia nigra (Vell.) Allemao ex Benth. (Fabaceae-Papilionoideae) during storage

Dalbergia nigra (Vell.) Allemao ex Benth. (jacarandá-da-bahia), espécie de alto valor econômico pela qualidade da madeira e potencial ornamental em razão da copa bem formada e à delicadeza da folhagem, está na lista de espécies ameaçadas de extinção. Em função disso, conduziu-se este trabalho, visando à avaliação da qualidade de suas sementes, submetidas a períodos crescentes de armazenamento. Os frutos foram coletados em outubro de 2003, e as sementes armazenadas em geladeira a 6º C ± 2, em sacos de plástico transparente fechados. Mensalmente, durante 690 dias, foram retiradas 200 sementes, sendo que 100 foram utilizadas nos ensaios de germinação (quatro repetições de 25 sementes) e 100 para a determinação do teor de água. Os ensaios germinativos foram conduzidos em estufa tipo B.O.D., a 25º C e com fotoperíodo de 12 horas. As variáveis analisadas foram a porcentagem de germinação, índice de velocidade de germinação e massa seca das plântulas originadas. Os resultados indicaram que, até 360 dias de armazenamento, as sementes apresentaram porcentagem de germinação próxima de 50 por cento, com redução de cerca da metade do índice de velocidade de germinação, porém, com maior comprometimento do acúmulo da massa seca das plântulas. A porcentagem de germinação inicial e final foram de 87 por cento e 36 por cento, respectivamente. As sementes de D. nigra têm comportamento ortodoxo e podem ser armazenadas por um período de até dois anos em sacos de plástico a baixa temperatura, com redução em cerca de 50 por cento de sua capacidade.

Dalbergia nigra (Vell.) Allemao ex Benth. (Brazilian rosewood) is a highly economically valuable species because of its wood quality and ornamental potential, mainly due to its well formed canopy and the delicacy of its foliage. Unfortunately, these features contributed to list it as an endangered Brazilian species (IBAMA Regulation number 06/92). This work had as its objective to study the quality of Dalbergia nigra seeds submitted to increasing storage periods. Fruits from trees located at the Botanical Institute of Sao Paulo were collected in October 2003. After harvested, the fruits were sun dried and the seeds manually separated. The seeds were stored in closed transparent plastic bags under refrigeration (6º C ± 2). Monthly, during 690 days, 200 seeds were removed from the refrigerator. One hundred (100) seeds were used in germination tests, which consisted of four repetitions with 25 seeds each; and the other 100 were used in the determination of water content. The germination tests were conducted in a B.O.D. chamber at 25º C under a 12 hour photoperiod. The analyzed variables were; the germination percentage, germination velocity index, and dry mass of the seedlings. The results indicated that after 360 days of storage, the seeds showed germination percentage close to 50 percent and reduction of the germination velocity index to half, whereas the dry mass accumulation was the most compromised. The initial and final germination percentages were 87 percent and 36 percent, respectively. We concluded that Dalbergia nigra seeds present orthodox behavior and can be stored for a period of approximately two years in plastic bags at low temperature, compromising 50 percent of their germination capacity.

Samara size versus dispersal and seedling establishment in Ailanthus altissima (Miller) Swingle.

We have specifically carried out a greenhouse experiment to assess relationship between samara weight and seed success. Relationship assessed as dispersal potential, germination level, germination rate and early seedling mass for the invasive species Ailanthus altissima. For this purpose, we considered two close stands as seeds source. We found no correlation between samara size and neither germination level, germination rate, nor seedling mass, but a positive correlation with samara projected area. These results suggest that samara weight is not directly related to germination, dispersal and invasion potential neither. Nevertheless, stands differed in the invasion potential of their samaras; one stand presented samaras with higher projected area per weight unit whereas the other one presented samaras that produced heavier seedlings. Whatever the origin, (genetic or environmental) of this differences it should be advantageous for a colonizing invader species such as A. altissima since it could imply a wider range of habitats susceptible to invasion.

Seed Germination of Gastrodia elata Using Symbiotic Fungi, Mycena osmundicola

The germination rate and longevity of seeds of Gastrodia elata Blume have been observed for 48 weeks using Mycena osmundicola strain H-21, one of fungi stimulating seed germination. Storage condition of post-harvest seeds was observed in the different temperature ranges of -30degrees C, -5degrees C, 5degrees C and 30degrees C for 48 weeks. After storage period of 48 weeks, the germination rate of G. elata was 65.7% at 5degrees C and 71.6% at -5degrees C, respectively. Although the germination rate of G. elata was 77.3% for 11 weeks at 25degrees C, the germination rate had been decreased gradually to 49.3% at 13 weeks, 0.3% at 23 weeks and then 0% at 25 weeks. The germination rate was reached to the level of 10% for 2 weeks at -30degrees C and then decreased to 0%.

Rule of breaking Ferula fukanensis seed dormancy under low-temperature and content changes of endogenous hormone / 中草药

Objective To study the rule of breaking Ferula fukanensis seed dormancy under low-temperature and content changes of endo-hormone.Methods The seeds were treated with stratification under 4 ℃ and germinated under 20 ℃.The content of endo-hormone,such as Z,GA_3,IAA,and ABA,was mensurated by HPLC.Results The seed germination rate achieved as high as 14% in 20 d and more than 60% in 40 d.Among breaking the seed dormancy,the content of endo-hormone was decreased gradually,while the rate of GA_3 and ABA was increased quickly in 10—20 d under 4 ℃ stratification.ConclusionThe stratification under 4 ℃ could break the seed dormancy.The rate of GA_3 and ABA is a pivotal factor of the seed dormancy.The endo-hormones IAA and Z have the significant effect on seed germination.

Effects of various seed sources and different storage conditions on seed germination rate of Valeriana officinalis / 中草药

Objective To investigate the effects of seed sources and storage conditions on the seed germination rate of Valeriana officinalis. Methods The seeds of V. officinalis under different storage conditions were used as materials for germination test, and the germination rate was calculated and compared according to the results. Results The seed germination rate of valerians is varied with different sources. The seed germination rate of V. officinalis is higher than that of V. officinalis var. latifolia, and the seed germination rate of cultivated valeriana is much higher than that of the wild plant. The storage periods, storage temperature, and germination conditions also affect the germination rate. Conclusion To maintain the seed germination rate, the seed of V. officinalis should be stored in conditions with ventilation and at suitable low temperature. Lower temperature helps to prolong the seed life with relatively high germination rate. Valeriana seed should also be propagated at available temperature conditions in proper seasons.

Effects of light, gibberellin and ethephon on germination of seed of Hypericum perforatum / 中草药

Object To provide the theoretical basis for the artificial planting of Hypericum perforatum L., the effects of light, gibberellin and ethephon on the germination of H. perforatum seeds were studied. Methods The method of direct germination was used. Results The seeds germinated to 79% in the light, while didn't germinate in the dark. Gibberellin and ethephon not only promoted the germination in the light, but also induced the germination in the dark. But ethephon inhibited the growth of seedling radicals severely. Conclusion The seed of H. perforatum is light-dependent seed, its light-dependence is related to gibberellin and ethephon.