Patulin production by Penicillium expansum isolates from apples during different steps of long-term storage

2016 ◽  
Vol 9 (3) ◽  
pp. 379-388 ◽  
Author(s):  
N. De Clercq ◽  
G. Vlaemynck ◽  
E. Van Pamel ◽  
D. Colman ◽  
M. Heyndrickx ◽  
...  

Penicillium expansum is the principal cause of blue mould rot and associated production of patulin, a weak mycotoxin, in apples worldwide. P. expansum growth and patulin production is observed during improper or long-term storage of apples. We have investigated the extent to which each successive step during long-term storage contributes to patulin production in various P. expansum isolates. Fungal isolates collected on apples from several Belgian orchards/industries were identified to species level. Random amplification of polymorphic DNA (RAPD) analysis and β-tubulin gene sequencing identified P. expansum and Penicillium solitum as the most prevalent Penicillium species associated with Belgian apples. All 27 P. expansum isolates and eight reference strains were characterised for their patulin production capacity on apple puree agar medium for five days under classical constant temperature and atmosphere conditions. Under these conditions, a large range of patulin production levels was observed. Based on this phenotypic diversity, five P. expansum isolates and one reference strain were selected for in vitro investigation of patulin production under representative conditions in each step of long-term apple storage. Patulin accumulation seemed highly strain dependent and no significant differences between the storage steps were observed. The results also indicated that a high spore inoculum may lead to a strong patulin accumulation even at cold temperatures (1 °C) combined with controlled atmosphere (CA) (3% O2, 1% CO2), suggesting that future control strategies may benefit from considering the duration of storage under CA conditions as well as duration of deck storage.

2020 ◽  
Vol 10 (2) ◽  
pp. 71
Author(s):  
Arkan Setiaji ◽  
Rr Rifka Annisa

ABSTRAKTanaman anggrek (Orchidaceae) telah menjadi komoditas penting di pasar perdagangan internasional karena keeksotisan dan daya tahan bunganya. Meskipun keragaman anggrek spesies menduduki peringkat kedua setelah Asteraceae dan hibridanya menduduki peringkat pertama, namun anggrek menghadapi ancaman kepunahan dan penurunan kualitas genetik. Program pemuliaan, seperti persilangan dan penyisipan gen unggul, serta perbanyakan in vitro perlu didukung dengan cara memastikan ketersediaan eksplan. Dalam rangka penyimpanan untuk kebutuhan jangka panjang, eksplan dapat disimpan menggunakan teknik kriopreservasi. Review ini bertujuan untuk memberikan gambaran umum terhadap kemajuan penelitian di bidang kriopreservasi, khususnya tanaman anggrek. Melalui program penyimpanan jangka panjang, gen-gen dan eksplan unggulan baik untuk pengembangan anggrek hibrida atau khususnya untuk tujuan konservasi anggrek langka bisa dipastikan ketersediaannya. Dalam artikel review ini telah dibahas berbagai riset tentang teknik kriopreservasi pada biji, protokorm, dan serbuk sari anggrek. Kemajuan pengembangan teknik telah dicapai, namun masih diperlukan banyak modifikasi agar suatu protokol kriopreservasi dapat diterapkan pada semua spesies dan hibrida anggrek.Kata kunci: kriopreservasi; anggrek; suhu dingin; eksplan ABSTRACTOrchid plants (Orchidaceae) have become important commodities in the international trades market because of their exoticism and flower endurance. Although the diversity of orchid species is ranked second after Asteraceae and number of hybrids are ranked first, but orchids face the threat of extinction and genetic degradation. Breeding programs, including such as crossing and insertion of superior genes, and in vitro propagation need to be supported by ensuring the availability of explants. In the context of maintaining storage for long-term needs, explants can be stored using cryopreservation techniques. This review aims to provide an overview of the progress of research in the field of cryopreservation, specifically orchid plants. Through a long-term storage program, superior genes and explants both for the development of hybrid orchids or in particular for the purpose of conservation of rare orchids can be ensured availability. In this review article various researches on cryopreservation techniques in seeds, protocorms, and pollen have been discussed in this article. Advances in technical development have been achieved, but many modifications are still needed so that a cryopreservation protocol can be applied to all orchid species and hybrids.Keywords: cryopreservation; orchids; cold temperatures; explants


Plants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1655
Author(s):  
Soňa Felšöciová ◽  
Przemysław Łukasz Kowalczewski ◽  
Tomáš Krajčovič ◽  
Štefan Dráb ◽  
Miroslava Kačániová

Contamination of malting barley grain and malt with micromycetes sampled at various periods post-harvest (3rd, 6th, and 9th month of storage) and types of storage (storage silo and floor warehouse) was investigated. Each of these barley grain samples was malted. This article reports on the changes in the fungal microbiome composition and their overall count in barley grain and malt. From the surface-disinfected barley grain samples collected immediately after harvest, there were eight genera isolated, with a predominance of Alternaria. A small increase of isolated microfungi was detected in barley stored in silo for 3 and 6 months (from 142 isolates to 149) and decreased below the number of isolates in barley before storage (133 isolates). Fungal count during storage gradually decreased up to 9 month in barley stored in floor warehouse (from 142 isolates to 84). The initial total count of microscopic fungi in malt before storage was the highest (112 isolates) with 7 genera detected, compared to malts prepared from barley stored for longer time (54 isolates, 7 genera, 9th month of storage). Alternaria was the most abundant and frequent genus. Quantitative representation of the filamentous microscopic fungi was lower compared to yeasts especially in barley and malt prepared from barley stored at third month of storage in both type of storage. Yeasts were identified from all grain samples and malt samples with mass spectrometry. Most attention was given to the widely distributed fungus Penicillium, 79% of strains produced at least one mycotoxin detected under in vitro assays using the TLC method (97% of them produced griseofulvin, 94% CPA, 79% patulin, 14% roquefortin C, and penitrem A was produced by two screening strains under laboratory conditions). It is therefore important to monitor the microflora throughout the production cycle of “barley to beer”.


1970 ◽  
Vol 10 ◽  
pp. 15-20
Author(s):  
Shambhu P. Dhital ◽  
Hira K. Manandhar ◽  
Hak T. Lim

Cryopreservation has been recognized as a practical and efficient tool for long-term storage of vegetatively propagated plants. This study was conducted to investigate the effects of sucrose concentration, hardening temperature and different cryopreservation methods on the survival rate of potato shoot tips after cryopreservation. Excised shoot tips of in vitro plantlets of potato cultivars, Atlantic and Superior were cryopreserved by vitrification, encapsulationvitrification and encapsulation-dehydration. Cryopreservation by vitrification method was used to determine the optimum concentration of sucrose and cold hardening temperature during sub-culturing period to the donor plantlets. Nine-percent sucrose gave 46.7% survival in Atlantic and 40% in Superior. The most optimum hardening temperature for 50% survival in Atlantic and 43.3% in Superior was 10°C. In the case of comparative study of three different cryopreservation methods, the highest survival (52%) as well as regeneration (46%) were observed when the shoot tips were cryopreserved by encapsulation-vitrification method, and the lowest survival (36%) and regeneration (28%) from the vitrification. Plant and tuber morphology of potato regenerated after cryopreservation were similar to those of the non-cryopreserved in vitro plantlets (control). Thus, this study demonstrated that encapsulation-vitrification method was the most effective one among other methods for higher survival as well as regeneration in in vitro shoot tips of potato.Key words: Cryopreservation; Dehydration; Encapsulation; Potato; Regeneration; VitrificationDOI: 10.3126/njst.v10i0.2804Nepal Journal of Science and Technology Volume 10, 2009 December Page: 15-20


2014 ◽  
Vol 41 (No. 2) ◽  
pp. 55-63 ◽  
Author(s):  
Dj. Ružić ◽  
T. Vujović ◽  
R. Cerović

In vitro-grown shoot tips of Gisela 5 (Prunus cerasus × Prunus canescens) cherry rootstock were tested for regrowth after cryopreservation using vitrification technique. Explants were precultured in the dark at 23°C, in a liquid MS medium with a progressively increasing sucrose concentration (0.3 M for 15 h, then 0.7 M for 5 h), and subsequently loaded in a solution containing 2 M glycerol and 0.4 M sucrose for 20 minutes. Shoot tips were dehydrated at 0°C using either the original PVS2 or modified PVS2 solution (PVS A3 – 22.5% sucrose, 37.5% glycerol, 15% ethylene glycol and 15% DMSO) for 30, 40 and 50 minutes. The survival and regrowth of the cryopreserved shoot tips dehydrated with the original PVS2 solution ranged between 36–54% and 8–17%, respectively. However, the dehydration with the PVS A3 solution resulted in considerably higher survival rates (81–92%), as well as higher regrowth rates (39–56%) after cryopreservation. These results prove the feasibility of the PVS A3-based vitrification technique for a long-term storage of this genotype.  


Parasitology ◽  
2020 ◽  
Vol 147 (9) ◽  
pp. 1048-1054
Author(s):  
Teivi Laurimäe ◽  
Philipp A. Kronenberg ◽  
Cristian A. Alvarez Rojas ◽  
Theodor W. Ramp ◽  
Johannes Eckert ◽  
...  

AbstractThe metacestode of Echinococcus multilocularis is the etiological agent of alveolar echinococcosis. The metacestode stage used for research is maintained in rodents by serial passages. In order to determine whether cryopreservation of E. multilocularis metacestodes would be suitable for long-term maintenance and replace serial passages, isolates of different geographic origin were cryopreserved in 1984–1986. The aim of the current study was to test the viability of cryopreserved isolates following long-term cryopreservation (up to 35 years) and to determine the phylogenetic clades these isolates belonged to. Cryopreserved isolates were tested for viability in vitro and in vivo in gerbils. In vitro results of 5 isolates indicated protoscolex survival in 13 of 17 experiments (76%) and metacestode survival in 5 of 12 (42%) in vivo experiments. In vivo results showed ‘abortive lesions’ in 13 of the 36 animals, 15 were negative and 8 harboured proliferating metacestode tissue containing protoscoleces. Genetic analysis confirmed the isolates belonged to European, Asian and North-American clades. In conclusion, the results of the current study indicate that metacestodes of E. multilocularis are able to survive long-term cryopreservation. Therefore, cryopreservation is a suitable method for long-term storage of E. multilocularis metacestode isolates and reduces the number of experimental animals.


2020 ◽  
pp. 35-37
Author(s):  
В.Д. Богданова ◽  
М.В. Воробьев

Площади под свеклой в Российской Федерации колеблются в пределах 65-68 тыс. га, что составляет 7% от общей площади, занятой овощными культурами. Вопросы, связанные с продолжительностью хранения и периодического воспроизведения на всхожесть семян остаются актуальными. В работе исследованы изменения таких важнейших посевных качеств, как энергия прорастания и всхожесть семян столовой свеклы на примере сорта Двусемянная ТСХА после различных сроков хранения. Благодаря селекционной работе можно значительно увеличить сроки хозяйственной годности семян и продолжительность их биологической жизнеспособности. Цель исследований: оценка влияния сроков хранения семян столовой свеклы сорта Двусемянная ТСХА на их посевные качества (всхожесть и энергия прорастания). Для этого определяли всхожесть и энергию прорастания семян столовой свеклы различных семей сорта Двусемянная ТСХА в условиях длительного хранения, изучили полевую всхожесть семян в условиях длительного хранения, установили оптимальные сроки хранения. Полевая всхожесть отдельных семей существенно отличалась. В некоторых случаях, особенно после продолжительного хранения, разница достигала 70%. Наглядно показано, что энергия прорастания и всхожесть семян слабо изменяются в течение четырех лет при отсутствии различных обработок. Выявлено влияние погодных условий в год выращивания семян и генотипических различий семей, что рекомендуется учитывать в селекции и при производстве элитных семян. Результаты исследования свидетельствуют о высокой биологической долговечности семян свеклы (более 16 лет), даже при хранении в комнатных условиях. Это важно при репродукции, так как в результате потепления климата изменяется направленность отбора в сторону более позднеспелых форм, менее перерастающих и устойчивых к растрескиванию и деформации корнеплодов. Высокое качество семенного материала культурных растений зависит от условий формирования семян. The area under red beet in the Russian Federation ranges from 65-68 thousand ha, which is 7% of the total area occupied by vegetables. Questions related to the duration of storage and periodic reproduction for seed germination are relevant. The work investigated the changes in such important sowing qualities as the germination energy and germination of red beet seeds using the example of the Dvusemyannaya TSKHA variety, after different storage periods. Thanks to the conduct of breeding work, it is possible to significantly increase the terms of economic shelf life of seeds and the duration of their biological viability. The aim of the study was to assess the effect of the shelf life of seeds of red beet variety Dvusemyannaya TSKHA on their sowing qualities (germination and germination energy). To do this, we determined the germination and germination energy of seeds of red beet from different families of the variety Dvusemyannaya TSKHA under conditions of long-term storage, studied the field germination of seeds under conditions of long-term storage, and established the optimal storage periods. Field germination of individual families differed significantly. In some cases, especially as a result of long-term storage, the difference reached 70%. It is clearly shown that the energy of germination and germination of seeds change little over four years in the absence of various treatments. The influence of weather conditions in the year of seed cultivation and genotypic differences of families was revealed. It is recommended to take these factors into account in breeding and in the production of elite seeds. The research results presented by the author indicate a high biological longevity of beet seeds, even when stored in room conditions, which is more than 16 years. This is important for reproduction, since because of climate warming, the direction of selection changes towards later-maturing forms that are less outgrowing and resistant to cracking and deformation of root crops. The high quality of the seed material of cultivated plants depends on the conditions of seed formation.


2013 ◽  
Vol 64 (1) ◽  
pp. 39 ◽  
Author(s):  
P. Tian ◽  
T.-N. Le ◽  
K. F. Smith ◽  
J. W. Forster ◽  
K. M. Guthridge ◽  
...  

The temperate pasture grass Lolium perenne L. is commonly found in association with the fungal endophyte Neotyphodium lolii. Viability of both seed and endophyte was evaluated by inoculation of individual genotypes from the host cultivar Bronsyn with six distinct endophyte strains. The resulting populations were subjected to either long-term storage under various temperature conditions, or accelerated ageing (AA) treatments. High temperature storage was detrimental to endophyte viability. The AA variables (relative humidity [RH] and time) and subsequent temperature and duration of storage significantly (P < 0.05) affected both seed germination and endophyte viability. Significant interaction effects between the AA treatment and storage conditions were also observed. Endophyte viability following AA treatment was inversely correlated with both increasing RH and duration of treatment. Differential responses between different endophytes within the Bronsyn host were also apparent. The standard endophyte (SE) strain and the novel endophytes AR1 and AR37 exhibited higher viability than NEA2, NEA3, and NEA6 during seed storage, suggesting the importance of identification and selection for compatible symbiotic associations in agronomic varieties. The observed similarity between assessments of endophyte viability after AA treatments and following long-term storage confirmed the capacity of moderate conditions (e.g. 80% RH for 7 days or 100% RH for 4 days) to predict variation in viability between different endophyte strains.


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