Stimulation of somatic embryo growth and development in Picea spp. by polyethylene glycol

The objective of the presented study was to compare the effect of osmotic stress, induced by various concentrations of polyethylene glycol (PEG) MW 4000, on the development, maturation, and conversion of somatic embryos of Picea abies (model species) and P. omorika (endemic species) into somatic seedlings. Embryogenic tissue (ET) of P. abies (line A and B) and P. omorika were incubated on a maturation medium with 20 μM abscisic acid (ABA), 1 μM indole-3-butyric acid (IBA) and PEG 4000 at 0, 5, and 7.5%. After 5 weeks, the number of somatic embryos produced, and the number of cotyledonary somatic embryos per 1 gram of ET, was assessed. Cotyledonary somatic embryos were selected and transferred to a Margara germination medium for two months. Their growth, as measured by hypocotyl and radicle length, was evaluated after one month, and the somatic embryos were transferred to fresh medium. After the second month of incubation, the conversion frequency of germinated embryos into the seedlings was assessed. In general, ETs of both of the tested spruce species cultured on a maturation medium amended with 5% PEG 4000 exhibited a tendency to produce a higher total number of embryos, as well as a higher number of cotyledonary embryos. The B line of P. abies produced a significantly greater number of cotyledonary embryos, relative to the control (no PEG). PEG only stimulated hypocotyl growth in embryos of both lines (A and B) of P. abies during the germination stage. Somatic embryos of Picea omorika were characterized by poor growth of both hypocotyls and radicles, irrespective of PEG treatment. The addition of PEG 4000 to the maturation medium did not improve the conversion frequency of germinated somatic embryos into somatic seedlings in either spruce species after a month of incubation on Margara medium. The effect of PEG 4000 on somatic embryogenesis efficiency was more evident in the ET of the two P. abies lines, relative to the P. omorika ET line, during both the maturation and the germination stage. Results indicated that the P. omorika ET line was almost completely insensitive to all of the PEG concentrations tested

Unsupervised SIFT features-to-Image Translation using CycleGAN

The generation of video content from a small set of data representing the features of objects has very promising application prospects. This is particularly important in the context of the work of the MPEG Video Coding for Machine group, where various efforts are being undertaken related to efficient image coding for machines and humans. The representation of feature points well understood by machines in a video form, which is easy to understand by humans, is an important current challenge. This paper presents results on the ability to generate images from a set of SIFT feature points without descriptors using the generative adversarial network CycleGAN. The impact of the SIFT keypoint representation method on the learning quality of the network is presented. The results and a subjective evaluation of the generated images are presented

Effect of Chlorocholine Chloride (CCC) on the Plants’ Height and Inulin Content in Jerusalem Artichoke (Helianthus tuberosus L.)

Jerusalem artichoke (Helianthus tuberosus L.) is herbaceous perennial plant rich in inulin and useful source of biomass. Due to its low agricultural requirements and high adaptability, it can provide very high biomass yields even on low quality sites. The plant is used in food industry, bio-fuel production, forage, pharmacy and nutrition. Its tubers accumulate approx. 10-20% of inulin in fresh weight. Currently, the use of the Helianthius tuberosus L. as a potential dietary strategy in patients affected by type 2 Diabetes is challenge. Moreover, deep understanding of the relationship between diet and composition of gut microbiota can bring the new insight in the treatment of inflammatory dependent diseases. The aim of this study was to examine an effect of plant growth retardant Chlorocholine Chloride (CCC) on the plants’ height of H. tuberosus and inulin content in the tubers. We examined in the field a procedure for its shoots reduction. Material for the experiment were bought in a Polish commercial company and 528 tubers were planted in field in the middle of April 2014. Then, half of them were sprayed with 0.75% retardant of CCC . Furthermore, every week for 12 following weeks, the plants’ heights were measured. After the vegetation was over, 6 tubers for each treatment were dug out and chemically analyzed for inulin content using High Pressure Size Exclusion Chromatography. After first week of CCC use, 16% decrease of the heights plants was observed. Height of plants sprayed with CCC were significantly different comparing to Control. Weekly growth was significantly  slower in plants sprayed with CCC on first three weeks after applying retardant. Differences in plants height sustain to the end of measurements. Used retardant and its concentration did not affect the inulin content of the tubers

Desiccation, dormancy, and storage of Pterocarya fraxinifolia (Juglandaceae) seeds: application in Hyrcanian and Colchian forest conservation

Pterocarya fraxinifolia (Poir.) Spach (Juglandaceae) is a model relict tree species native to South Caucasus and is a typical element of threatened riparian forests. Intensive land transformations, which are common in Transcaucasia, have resulted in loss of natural habitat and population decline of the species. One of the methods of ex situ conservation is seed banking. Cryopreservation in liquid nitrogen (−196 °C) is of particular interest, as it allows safe preservation of valuable plant genetic resources. However, the feasibility of seed cryopreservation is related to the desiccation tolerance and intrinsic composition of the seeds. In this study, we examined the physiological traits of Pterocarya fraxinifolia seeds, for which desiccation tolerance is unknown or controversial, and their feasibility for cryopreservation. Additionally, we tested stratification methods for dormancy assessment. Results showed that seeds survived desiccation to a moisture content of 2.8% with a germination rate of 64%. Stratification at a temperature of 3 °C for 8 weeks proved to be both fast and effective. Seed moisture content ranging from 2.8% to 18.1% was determined to be safe for cryopreservation. There was no difference in seedling emergence in seeds stored for 1 year regardless of the storage temperature (−3, −18, or −196 °C). Based on our results, Pterocarya fraxinifolia seeds can be classified as orthodox. This study demonstrates for the first time the feasibility of cryopreserving Pterocarya fraxinifolia seeds

Oxidation processes related to seed storage and seedling growth of Malus sylvestris, Prunus avium and Prunus padus.

Seeds stored in controlled conditions in gene banks, faster or slower lose their viability. The effects of seed moisture content levels (ca. 5, 8, 11%) combined with storage temperatures (-3°, -18°, -196°C) were investigated in terms of the description of seeds defined as orthodox under oxidative stress after seed storage, during germination, and initial seedling growth. Hydrogen peroxide (H2O2), thiobarbituric acid reactive substances (TBARS) and ascorbate (Asc) were analyzed in relation to seed germinability and seedlings emergence in three species: Malus sylvestris L., Prunus avium L. and Prunus padus L. The effect of seed storage conditions on H2O2 levels appeared in germinated seeds after the third year of storage in each species. The H2O2 levels were negatively correlated with the germination and seedling emergence of P. avium seeds after three years of storage under all examined combinations. The emergence of P. padus seedlings was not linked to any of the stress markers tested. The P. padus seed biochemical traits were least altered by storage conditions, and the seeds produced tolerant seedlings of relatively high levels of H2O2 and TBARS. To cope with different H2O2 levels, TBARS levels, and Asc levels in seeds of three species varying storage conditions different molecular responses, i.e. repairing mechanisms, were applied during stratification to compensate for the storage conditions and, as a result, seeds remained viable and seedlings were successfully established

Thermotherapy and Storage Temperature Manipulations Limit the Production of Reactive Oxygen Species in Stored Pedunculate Oak Acorns

For many species, seed storage protocols are still being improved to provide viable seeds of the highest quality. Seed storage is extremely problematic for short-lived seeds categorized as recalcitrant, including pedunculate oak (Quercus robur L.), for which the optimal seed storage protocol involves a temperature of –3 °C and 40% acorn moisture content recommendations. The sensitivity of pedunculated oak seeds to temperature manipulations under preparation for long-term storage has been poorly investigated, particularly in terms of the production of reactive oxygen species (ROS), which are assumed to be determinants of seed longevity. Thermotherapy, the pathogen elimination procedure, did not increase the level of three types of ROS: hydrogen peroxide (H2O2), superoxide anion radical and hydroxyl radical (•OH). The temporal heat stress of thermotherapy resulted in slightly reduced levels of H2O2, indicating activation of the antioxidant systems in acorn preparation for storage. The effect of constant storage temperatures (−3, −5, −7 °C) and their combinations (−3 → −5 °C or −3 → −5 →−7 °C) on ROS levels and seed viability was investigated in three provenances. The highest ROS levels were detected in acorns stored at −7 °C, whereas three-step cold acclimation was beneficial for reducing ROS levels. Interestingly, the levels of H2O2 were not affected by temperature in thermotherapized acorns. In contrast, decreasing storage temperature caused a linear increase in •OH levels in all provenances. The effect of heat stress and cold stress on ROS levels in relation to long-term seed storage of pedunculate oak is discussed here in relation to the seed viability evidenced via germination rates, seedling emergence and electrolyte leakage. Thermotherapy and cold acclimation of acorns can improve their viability after storage by decreasing ROS levels

Changes in Proline Levels during Seed Development of Orthodox and Recalcitrant Seeds of Genus Acer in a Climate Change Scenario

In the present study, we examined the utility of proline usage as a biochemical indicator of metabolic changes caused by climate change (mean temperature and precipitation) during seed development of two Acer species differing in desiccation tolerance: Norway maple (Acer platanoides L.—desiccation tolerant—orthodox) and sycamore (Acer pseudoplatanus L.—desiccation sensitive—recalcitrant). In plants, proline is an element of the antioxidant system, which has a role in response to water loss and high temperatures. Our study considered whether proline could be treated as an indicator of tree seed viability, crucial for genetic resources conservation. Proline content was measured biweekly in developing seeds (between 11 and 23 weeks after flowering) collected in consecutive years (2017, 2018, and 2019). We showed that proline concentrations in recalcitrant seeds were positively correlated with mean two-week temperature. In contrast, in orthodox seeds no such relationship was found. Proline content proved to be sensitive to thermal-moisture conditions changes, which makes it a promising biochemical marker of seed desiccation tolerance in different climatic conditions

Changes in Reserve Materials Deposited in Cotyledons of Pedunculate Oak (<i>Quercus robur</i> L.) Seeds during 18 Months of Storage

Pedunculate oak (Quercus robur L.) produces desiccation-sensitive seeds, the long-term storage of which is limited. We investigated the effectiveness of using a slightly lowered storage temperature (−5 °C) in combination with slight dehydration of acorns (38% MC) for improving seed viability during 18 months of storage. To this end, we performed a factorial experiment using storage temperatures of −5 °C and −3 °C combined with 38% and 40% seed MC and subsampled the acorns at 4-month intervals over 18 months. The modified regime of −5 °C combined with 38% MC resulted in increased germination and emergence rates but only when seeds were stored for 12 months. It also restricted seed biomass loss. Starch depletion was recorded on consecutive sampling dates, showing little dependence on storage conditions. At −5 °C at both MC, it was accompanied by an accumulation of soluble carbohydrates. Fat reserves also decreased under all storage conditions, but the slowest decrease was at −5 °C and 38% MC. We conclude that storing acorns in a slightly dehydrated state (38% MC) at −5 °C produced a transient improvement in seed viability and that the observed increase in soluble carbohydrates may indicate initiation of prosurvival mechanisms, such as osmo- and cryoprotection

Changes in Reserve Materials Deposited in Cotyledons of Pedunculate Oak (Quercus robur L.) Seeds during 18 Months of Storage

Pedunculate oak (Quercus robur L.) produces desiccation-sensitive seeds, the long-term storage of which is limited. We investigated the effectiveness of using a slightly lowered storage temperature (&minus;5 &deg;C) in combination with slight dehydration of acorns (38% MC) for improving seed viability during 18 months of storage. To this end, we performed a factorial experiment using storage temperatures of &minus;5 &deg;C and &minus;3 &deg;C combined with 38% and 40% seed MC and subsampled the acorns at 4-month intervals over 18 months. The modified regime of &minus;5 &deg;C combined with 38% MC resulted in increased germination and emergence rates but only when seeds were stored for 12 months. It also restricted seed biomass loss. Starch depletion was recorded on consecutive sampling dates, showing little dependence on storage conditions. At &minus;5 &deg;C at both MC, it was accompanied by an accumulation of soluble carbohydrates. Fat reserves also decreased under all storage conditions, but the slowest decrease was at &minus;5 &deg;C and 38% MC. We conclude that storing acorns in a slightly dehydrated state (38% MC) at &minus;5 &deg;C produced a transient improvement in seed viability and that the observed increase in soluble carbohydrates may indicate initiation of prosurvival mechanisms, such as osmo- and cryoprotection