scholarly journals Influence of scarification method on seed germination of the terrestrial orchid Anacamptis laxiflora (Lam.)

2021 ◽  
Vol 5 (1) ◽  
pp. 15-23
Author(s):  
Gwenaëlle Deconninck ◽  
Argyrios Gerakis

AbstractA critical step during in vitro sexual propagation of terrestrial orchids is the treatment of the microscopic seeds with a disinfecting solution that kills bacteria and fungi attached to the seeds. This treatment is necessary to prevent infection of the culture vessels. At the same time, the treatment serves to scarify the seeds, a process that disrupts seed dormancy and initiates germination. The literature is inconclusive with respect to the proper combination of disinfecting solution strength and treatment duration. Both factors should be adapted to each species to guarantee minimal infection rate without damaging the embryo. This research aims to compare three disinfection/scarification methods for seeds of Anacamptis laxiflora (Lam.): (i) soaking in 0.5% NaClO, (ii) soaking in 0.5% NaClO, then centrifugation, and (iii) presoaking the seeds in sucrose solution, then soaking in 0.5% NaClO. The seeds were soaked in the disinfecting solution for 5 to 85 min. Following scarification, the seeds were sown in modified Malmgren nutrient medium. Infected and germinated vessels were counted at 41 and 189 d after sowing. We found that the longer the chemical treatment, the lower the infection rate, and the higher the germination rate. There was no significant difference in germination rate between the NaClO and the NaClO-plus-centrifugation method; in fact, the slight savings in disinfection time effected by centrifugation were more than offset by the added complexity of the method. Moreover, we found that centrifugation significantly delays germination. The sucrose presoak-plus-NaClO method was superior to plain NaClO, as the sucrose stimulates the germination of microbial spores on the surface of the seeds, making them easier to kill. Perhaps seeds with thicker testa as well as whole immature capsules could benefit even more from the pretreatment in sucrose solution.

Author(s):  
Cristina Úsuga-Monroy ◽  
José Julian Echeverri ◽  
Albeiro López-Herrera

The bovine leukemia virus (BLV) is a retrovirus that primarily affects dairy cattle, reducing milk production between 2.5 and 5%. The Colombian Blanco Orejinegro (BON) is a well-adapted, rustic, creole breed resistant to in vitro infections of Foot-and-mouth disease virus and vesicular stomatitis virus, as well as to Brucella abortus. This study aimed to determine if the crossing of BON and Holstein breeds is resistant to infection by BLV. Blood samples of 124 individuals (59 Holstein, 40 BON, and 25 BON x HOL) of the same herd were taken. The DNA was extracted, and a nested PCR was performed related to a region of the env gene of BLV. A fragment of 444 bp was obtained for positives animals. The molecular in-herd prevalence was 33% for BLV. A significant difference for BLV infection was found among the groups (p<0.05). The infection rate for the Holstein group was 55.9%, for BON cattle 5%, and for BON x HOL cattle 24%. The latter showed a reduction in the infection rate of 32% to the Holstein breed, which can be attributed to the presence of resistance genes in the BON breed. It was found that the level of infection is lower in BON x HOL cattle in contrast with Holstein dairy cows.


2012 ◽  
Vol 60 (7) ◽  
pp. 592 ◽  
Author(s):  
Nicole Dowling ◽  
Manfred Jusaitis

Determining the seed quality and germination requirements for threatened orchid species in storage is vital for future conservation efforts. Seeds of many Australian terrestrial orchid species are held in conservation collections around the country, but few have been germinated in vitro, fuelling concerns over their long-term viability. This study tested three methods of assessing orchid seed quality; asymbiotic germination was compared with vital staining using triphenyltetrazolium chloride or fluorescein diacetate. Six culture media were examined for efficacy in promoting asymbiotic seed germination of four Australian terrestrial orchid species (Pterostylis nutans, Microtis arenaria, Thelymitra pauciflora and Prasophyllum pruinosum). Germination occurred on all media but germination rates were consistently highest on BM1 and development was most advanced on BM1, P723 and Malmgren media. Subsequent trials tested the efficacy of BM1 for asymbiotic germination of additional genera (Caladenia, Calochilus and Diuris), several congeneric species, and two species collected from several different provenances within each of their ranges. The results indicate that asymbiotic germination on BM1 medium is an effective technique for testing the performance of Australian terrestrial orchid seeds. The efficacy of vital stains to determine seed viability, however, remains uncertain, as significant disagreement between degree of staining and germinability was observed for some species.


2007 ◽  
Vol 19 (1) ◽  
pp. 185
Author(s):  
K. Tominaga ◽  
F. Iwaki ◽  
E. Yamaguchi ◽  
Y.-M. Dou ◽  
I. Kijihana ◽  
...  

Ultra-rapid cooling by direct plunging of gel-loading-tip (GL-tip) into liquid nitrogen (LN2) contributed to the high post-warm survival rates of in-vitro-produced (IVP) bovine embryos (Tominaga and Hamada 2001 J. Reprod. Dev. 47, 267–273). Since GL-tip vitrification and other ultra-rapid vitrification methods have potential risk of microbiological contamination in the LN2, the current study was undertaken to develop a closed system of GL-tip vitrification for IVP bovine blastocysts before and after biopsy. Day 7 blastocysts were produced in vitro (Tominaga et al. 2000 Theriogenology 53, 1669–1680), and biopsied for sex determination (Tominaga and Hamada 2004 Theriogenology 61, 1181–1191). The blastocysts were exposed first to 10% ethylene glycol (EG) +10% DMSO in TCM-199/20% FCS for 2 min at 37°C, and then placed in vitrification medium with 20% EG + 20% DMSO + 0.6 M sucrose in TCM 199/20% FCS for 30 s at 37°C. Three to 4 blastocysts in 0.6 µL of the vitrification medium were aspirated into a GL-tip (NK-tip; Nippon Medical &amp; Chemical Instruments Co., Ltd., Osaka, Japan). Immediately before being plunged into LN2, the tip of the GL-tip was sealed by dipping into 100% glycerol at 4°C, and the opposite open end of the GL-tip was sealed by inserting a holding stick under LN2 vapor. After warming in 0.25 M sucrose solution at 37°C, the glycerol-seal was removed from the tip by gentle shaking. The blastocysts diluted in a two-step manner were cultured up to 72 h for survival assay. Within the 72 h of culture, intact embryos that initiated hatching and biopsied embryos that re-expanded were considered as surviving. Two more biopsied blastocysts derived from ovum pickup, IVF, and IVC were vitrified–warmed in the closed system, and then transferred to 2 recipients. The results indicate no significant difference in the post-thaw survival rates of either intact or biopsied blastocysts in both closed and open systems (Table 1). One recipient became pregnant and delivered a female calf. Gestation period (287 days) and birth weight (22 kg) were within the normal range of the Tajima strain of Japanese Black cattle. We reached the conclusion that the closed system of GL-tip vitrification was simple and highly effective for IVP bovine blastocysts before and after biopsy. Table 1. In vitro survival of intact and biopsied bovine blastocysts after GL-tip vitrification in closed and open systems


PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11043
Author(s):  
Shumin Gao ◽  
Yahong Sun ◽  
Yan Zhou

Obtaining 2n pollen from the diploid Chinese old rose ‘Old Blush’ through artificial induction is one important means of hybridizing and breeding modern tetraploid roses. We used colchicine-induced 2n pollen to assess normal viability during hybridization and fructification. The results showed that the pollen mother cell had lagging chromosomes and parallel spindles at meiosis I stage, following which the 2n pollen was produced from dyads and triads with doubled chromosomes. We obtained 4.30% viable 2n pollen, which was significantly higher than the yield of the spontaneous 2n pollen (1.00%) using an optimal treatment combination of induction for 24 h with 0.50% colchicine. There was no significant difference between the external morphology of the induced 2n pollen and the spontaneous 2n pollen, whereas both types of 2n pollen possessed finer furrows, and fewer and smaller pores than the 1n pollen, and the external morphology of 2n pollen was more evolved. In terms of in vitro germination rate and pollen tube length, the induced 2n pollen did not differ significantly from the spontaneous 2n pollen. The survival rate of the floral buds was significantly decreased with increased colchicine concentration and treatment time.


2007 ◽  
Vol 55 (1) ◽  
pp. 83 ◽  
Author(s):  
Tasmien N. Horsley ◽  
Steven D. Johnson ◽  
Terrence K. Stanger

The best sucrose solution for maximum in vitro germination of Eucalyptus pollen was investigated in order to evaluate pollen germination rate as an indicator of pollen viability. In vitro germination of both freshly collected and 1-year-old pollen (stored at 4°C) of Eucalyptus grandis, E. smithii, E. nitens, E. dunnii and E. macarthurii was carried out in 0, 10, 20, 30, 40 and 50% (w/v) sucrose solutions, either with (0.15 mg L–1) or without boric acid. Similar trends were obtained for both fresh and 1-year-old pollen, with all species responding most favourably to 30% (w/v) sucrose and 0.15 mg L–1 boric acid. When an optimal in vitro germination medium had been established, the viabilities (%germination) of E. smithii, E. nitens and E. grandis pollen, stored at room (25°C), fridge (4°C), freezer (–10°C) and liquid nitrogen (–196°C) temperatures, were compared. For all tested species, germination declined as storage temperature increased, and by 8 months, the highest survival was obtained with cryostored pollen.


2007 ◽  
Vol 37 (2) ◽  
pp. 371-382 ◽  
Author(s):  
HyeKyoung Cho ◽  
Toshizumi Miyamoto ◽  
Kunihide Takahashi ◽  
SungGak Hong ◽  
JongJin Kim

Abies koreana Wilson is an endemic tree species that is facing critical population declines in Korea. To identify factors affecting the natural regeneration of A. koreana, we examined the role of seed pathogens in the overwintering survival of seeds in natural seedbeds on Mount Halla, Korea. In September 2003, seeds of A. koreana were placed on seedbeds in the following three types of sites: Sasa dominated, shaded by rocks, or forest floor; seeds were then recovered from beneath the snow cover in April 2004 and were analyzed for the occurrence of harmful microfungi. Racodium therryanum Thuem. was the fungus most often isolated from retrieved seeds and was also the most detrimental of the eight fungal species tested in a pathogenicity trial. In vitro, R. therryanum caused a total loss of germination ability in A. koreana seeds at 0 °C after 100 days. The infection rate of R. therryanum was negatively correlated with the seed germination rate. The infection rate of R. therryanum was highest on the forest floor and increased with the duration of snow cover. The occurrence of R. therryanum was temporally restricted to the period of snow cover and spatially to the thick A0 soil layer on the forest floor. This study suggests that R. therryanum may be a significant factor inhibiting the natural regeneration of A. koreana at the seed stage.


2013 ◽  
Vol 19 (1) ◽  
pp. 7-11
Author(s):  
Aleksandra Djordjevic ◽  
Jelena Lazarevic ◽  
Violeta Mitic ◽  
Radosav Palic ◽  
Gordana Stojanovic

The in vitro antimicrobial activity of Hypericum annulatum and Hypericum elegans essential oils was evaluated against a panel of standardized bacteria and fungi using broth microdilution assay. Both essential oils showed antimicrobial activity against all the tested microorganisms. Hypericum annulatum essential oil showed better antibacterial than antifungal activity, being more effective against Pseudomonas aeruginosa and Escherichia coli while H. elegans essential oil showed no significant difference between antibacterial and antifungal activity. Antimicrobial testing of ?-pinene, ?-pinene and ?-myrcene compounds was also performed. All the compounds were active against all the tested microorganisms, however, based on the MIC, MBC and MFC values, none of these compounds could be thought of as the main bearer of the oils? antimicrobial activity. This is the first report regarding the antimicrobial activity of the essential oils of the two Hypericum species.


2010 ◽  
Vol 22 (1) ◽  
pp. 220
Author(s):  
P. Zhang ◽  
Z. W. Wang ◽  
B. Tang ◽  
J. B. Zhang ◽  
Z. Y. Li

Cryopreservation of oocytes and embryos is very useful to conservation of animal genetic resources. Recently, parthenogenesis has received considerable attention as a tool for the production of stem cells. Oocytes and embryos undergo considerable morphological changes and functional damage during cryopreservation, and the survival rate is highly depending on species and developmental stage of oocytes and embryos. The aim of this study was to investigate the survival rate and embryonic quality of bovine parthenogenetic blastocysts post-vitrification cryopreservation. Cumulus-oocyte complexes (COC) from slaughterhouse ovaries were aspirated from 2-mm to 8-mm visible follicles with a 5-mL syringe. The COC were matured in vitro for 22 h in bicarbonate-buffered TCM199 media supplemented with 1 mg mL-1 of FSH, 10 mg mL-1 of LH, 1 mg mL-1 of 17-βiestradiol, and 10% FBS. After in vitro maturation, cumulus cells were removed from COC, oocytes with first polar body were activated by 5 μM ionomycin for 5 min and 2 mM 6-DMAP for 4 h. Subsequently, oocytes were co-cultured with bovine fetal fibroblast cells in SOF media supplemented with amino acids (1% NEAA and 2% EAA), 4 mg mL-1 of BSA, and 10% FBS at conditions of 38.5°C and 5% CO2 for 7 to 9 days. The good expanded blastocysts were selected and refrigerated in different vectors [glass micropipettes (GMP) and straws] and same vitrification solution (VS, 20% EG + 20% DMSO). Blastocysts were exposed to VS, loaded on vectors, and plunged into liquid nitrogen within 25 s. After two days refrigeration, vitrified blastocysts were thawed in air for 10 s and placed into 0.25 M sucrose solution for 1 min and 0.15 M sucrose solution for 5 min. Then, the blastocysts were cultured in the SOF medium same as above. Our results showed that when VS was 20% EG + 20% DMSO, the hatching rate (65%) of blastocysts loaded into GMP was significantly higher (P < 0.05) than that (19%) of blastocysts loaded into straws post-vitrification. Meanwhile, vitrified and nonvitrified blastocysts were fixed and stained for differential cell counting as described by Thouas GA et al. 2001 Reprod. Biomed. Online 3, 25-29). By the differential staining, the total cells of nonvitrified parthenogenetic bovine blastocysts were 102.7, which was higher (P > 0.05) than that (86.7) of vitrified blastocysts. Also, no significant difference (P > 0.05) was seen on ratios between vitrified blastocysts (ICM/TE = 0.22) and nonvitrified blastocysts (ICM/TE = 0.25). Our results indicated that a glass micropipette vector was much better than a straw in vitrification cryopreservation of bovine parthenogenetic blastocysts and caused less damage to blastocyst cells. This study lays the foundation for further research to increase the survival rate of vitrification cryopreservation of bovine embryos. This work was supported by the grant from national support plan, China, No. 2007BAD55B03; corresponding author: Ziyi Li.


MedPharmRes ◽  
2018 ◽  
Vol 2 (2) ◽  
pp. 5-20
Author(s):  
Vu Ho ◽  
Toan Pham ◽  
Tuong Ho ◽  
Lan Vuong

IVF carries a considerable physical, emotional and financial burden. Therefore, it would be useful to be able to predict the likelihood of success for each couple. The aim of this retrospective cohort study was to develop a prediction model to estimate the probability of a live birth at 12 months after one completed IVF cycle (all fresh and frozen embryo transfers from the same oocyte retrieval). We analyzed data collected from 2600 women undergoing in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) at a single center in Vietnam between April 2014 and December 2015. All patients received gonadotropin-releasing hormone (GnRH) antagonist stimulation, followed by fresh and/or frozen embryo transfer (FET) on Day 3. Using Cox regression analysis, five predictive factors were identified: female age, total dose of recombinant follicle stimulating hormone used, type of trigger, fresh or FET during the first transfer, and number of subsequent FET after the first transfer. The area under the receiver operating characteristics curve for the final model was 0.63 (95% confidence interval [CI] 0.60‒0.65) and 0.60 (95% CI 0.57‒0.63) for the validation cohort. There was no significant difference between the predicted and observed probabilities of live birth (Hosmer-Lemeshow test, p > 0.05). The model developed had similar discrimination to existing models and could be implemented in clinical practice.


Author(s):  
Rathika Rai ◽  
M. A. Easwaran ◽  
K. T. Dhivya

Aim: To evaluate the surface detail reproduction of dental stone this is immersed in different disinfectant solution and studied under stereomicroscope. Methodology: Total number of 30 specimens of dental stone (Type III) were made with measurements of 1.5cm diameter and 1cm height .This samples are divided in to 3 groups group A,B,C. were A is immersed in Distilled water which was taken as control group ;B is immersed in 2% Glutaraldehyde and C is immersed in 5%sodium hypochlorite. Each specimen were immersed in the disinfectant solution for 15 minutes and dried under room temperature for 24 hrs. After 24 hrs each specimens are studied under stereomicroscope for surface details. Result: The results showed no significant difference in the surface irregularities and porosities for a group 1 and group 2 except group 3 which showed significant increase in the porosities, surface irregularities and erosions after disinfection with 5% NaHOCl by immersion method. Conclusion: The surface detail reproduction capacity of die stone was adversely affected when 5% Sodium hypochlorite was used as disinfectant solution when compare d to control group and 2% Glutaraldehyde


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