The effect of addition of olive oil and "Aceto balsamico di Modena" wine vinegar in conjunction with active atmosphere packaging on the microbial and sensory quality of "Lollo Verde" lettuce and rocket salad

Fresh rocket “Eruca Sativa” and lettuce “Lollo Verde” leaves were stored with the addition of olive oil and wine vinegar “Aceto balsamico di Modena” under modified atmosphere packaging (MAP) (5% O₂/10% CO₂/85% N₂ for MAP A and 2% O₂/5% CO₂/93% N₂ for MAP B). The microbial (mesophilic, psychrotrophic bacteria and Enterobacteriacae), physical (color and firmness) and sensory parameters of samples were studied in relation to storage time (up to 10 days at 5 ± 1 °C). The effect of wine vinegar and the application of both MAP treatments reduced the growth of all bacteria populations (p < 0.05). Samples with olive oil stored under MAP A gave the best score for overall impression (3 and 2.1 for MAP A and B respectively at the 9th day of storage) while the addition of vinegar limited sensory shelf-life to 3 days (p < 0.05). Firmness was negatively affected by wine vinegar while samples with olive oil stored under MAP A maintained firmness close to normal. Color attributes were maintained better under both MAP treatments (p < 0.05).     

Study of changes in physicochemical and microbiological characteristics of shrimps (Melicertus kerathurus) stored under modified atmosphere packaging

Fresh minimally processed shrimps were stored under modified atmosphere packaging (60% CO₂:40% N₂ for MAP A and 92.9% N₂:5.1% CO₂:2% O₂ for MAP B) for 5 days at 3 °C. Total mesophiles, H₂S forming bacteria, Pseudomonas spp., Brochothrix thermosphacta, firmness, color and sensory parameters were investigated throughout the whole time of the experiment. During storage period samples stored under MAP B managed to retain firmness values close to the initial values. All microbial populations growth was suppressed by the presence of MAP A. Samples stored under MAP B managed to maintain their firmness values close to the initial ones while MAP A samples were significantly less firm (p < 0.05).     

Study of the effect of atmosphere modification in conjunction with honey on the extent of shelf life of Greek bakery delicacy "touloumpaki"

The aim of the present work was to evaluate the effect of atmosphere modification on microbial (mesophiles, yeast and molds) qualities, color, pH, texture and water activity of the Greek bakery product “touloumpaki”. Samples were stored under MAP (60% CO₂) either alone or with the addition of honey syrup for 16 days at room temperature (22–24 °C). Texture was better maintained under MAP and the addition of honey prevented the increase of shear force needed (1.498 and 3.20 for samples with and without honey). Honey inhibited the growth of yeasts on samples stored under MAP (1.6 and 2.02 log CFU/g for samples under MAP with and without honey respectively) while multivariant analysis showed that MAP and honey acted synergistically in confining yeasts. Presence of honey restrained the mesophilic growth until the end of storage period (5.21 and 4.29 log CFU/g for MAP and control samples respectively) while MAP did not have any beneficial effect. Water activity (a_W < 0.754) was strongly associated with reduced mesophile growth. Lightness values showed a significant decrease during time with no significant changes among treatments in both internal layers and external surface of the product.     

Effect of several MAP compositions on the microbiological and sensory properties of Graviera cheese

The shelf life of Graviera cheese, a full fat cheese produced in Heraklion (Crete Greece), was investigated. Graviera cheese was stored at 4 °C for up to 90 days in polyamide packages under three different modified atmosphere compositions. Control cheeses were packaged in air whereas MAP mixtures were MAP₁: 40% CO₂/55% N₂/5% O₂, MAP₂: 60% CO₂/40% N₂ and MAP₃: 50% CO₂/50% N₂. Sampling of product was carried out every 10 days to investigate its sensory quality and microbiological characteristics. Ten trained panelists participated in the sensory panel to evaluate the cheeses for external appearance (color, texture), taste, and flavor in a scale from 1 to 10 (1 very poor, 10 very good). The microbiological analysis revealed that there were no colonies of Staphylococcus aureus and Listeria monocytogenes whereas both Escherichia coli and Total Viable Counts (TVC) increased strongly in control samples but were inhibited under all MAP compositions.     

Growth and photosynthetic response of <Emphasis Type="Italic">Fagus crenata</Emphasis> seedlings to ozone and/or elevated carbon dioxide

We investigated the effects of ozone (O₃) and/or elevated CO₂ concentration ([CO₂]) on growth and photosynthetic traits of Fagus crenata seedlings. Two-year-old seedlings were grown in four experimental treatments comprising two O₃ treatments (charcoal-filtered air and 100 nmol mol⁻¹ O₃; 6 h/day, 3 days/week) in combination with two CO₂ treatments (350 and 700 μmol mol⁻¹) for 18 weeks in environmental control growth chambers. The four treatments were designated as control, elevated O₃, elevated CO₂, and elevated CO₂ + O₃. Dry matter growth of the seedlings was greater in elevated CO₂ + O₃ than in elevated CO₂. In elevated CO₂ + O₃, a marked increase of second-flush leaves, considered a compensative response to O₃, was observed. The net photosynthetic rate of first-flush leaves in elevated CO₂ + O₃ increased earlier and was maintained for a longer period of time than that in elevated CO₂. Because emergence of second-flush leaves of F. crenata is greatly affected by the amount of assimilation products of first-flush leaves in current year, we consider that an early increase in the net photosynthetic rate of first-flush leaves contributed to the marked increase in second-flush leaf emergence under elevated CO₂ + O₃. These results imply that we must account for changes in compensative capacity with respect to not only morphological traits but also phenological traits and physiological functions such as photosynthesis when evaluating effects of O₃ on F. crenata under elevated [CO₂].     

Storage of Shredded Cabbage under a Dynamically Controlled Atmosphere of High O2 and High CO2

Shredded cabbage (Brassica oleracea L., Capitata group) was stored under a dynamically controlled atmosphere (DCA) and modified atmosphere (MA) at 5°C. Quality factors were measured every 2 days. Browning was suppressed as the CO₂ concentration was increased (0% to 15%), with no influence from O₂ concentration (2.5% to 10%). The development of an off-odor was markedly delayed with an increase in O₂ concentration, such an odor being detected after 6 days at 2.5% O₂,8 to 10 days at 5% to 7.5% O₂, and not at all above 10 days at 10% O₂, while the off-odor development was little affected by CO₂ concentration (5% to 15%). Total sugar, polyphenolics, total ascorbate, and total microbial count were little influenced by O₂ and CO₂. These results show that shredded cabbage can be kept in good condition with a combined high O₂ and high CO₂ atmosphere. These findings are largely different from those for MA storage.     

Physiological and antioxidant response by Beauveria bassiana Bals (Vuill.) to different oxygen concentrations

The effect of three levels of oxygen (normal atmosphere (21% O₂), low oxygen (16% O₂) and enriched oxygen (26% O₂)) on the production and germination of conidia by Beauveria bassiana was evaluated using rice as a substrate. The maximum yield of conidia was achieved under hypoxia (16% O₂) after 8 days of culture (1.51 × 10⁹ conidia per gram of initial dry substrate), representing an increase of 32% compared to the normal atmosphere. However, germination was reduced by at least 27% due to atmospheric modifications. Comparison of antioxidant enzyme activity (superoxide dismutases and catalases) with the oxidation profiles of biomolecules (proteins and lipids) showed that a decrease in catalase activity in the final days of culture coincided with an increase in the amount of oxidized lipids, showing that oxidative stress was a consequence of pulses of different concentrations of O₂. This is the first study describing oxidative stress induction by atmospheric modification, with practical implications for conidia production.     

Preservation of fresh edible cactus stems (<i>Opuntia ficus indica</i> Mill.) by modified atmosphere packaging

Cactus stems, the cladodes of Opuntia spp. cacti, are consumed in Mexico and other countries due to their fresh and herbaceous flavor, and because of their widely known nutraceutical benefits. In order to extend the postharvest life of this vegetable, the effect of a modified atmosphere packaging (MAP) was studied in cactus stems of the cultivar Atlixco stored at 4 ± 1 °C for 20 days under three types of atmospheres: (1) air (passive atmosphere), (2) 5 kPa O₂ + 4 kPa CO₂, and (3) N₂. During storage, the titratable acidity decreased and the color of cladodes became darker and less green; however, the 5 kPa O₂ + 4 kPa CO₂ atmosphere was able to preserve both quality characteristics. All modified atmospheres reduced weight loss (from 8 to <2%) and the symptoms of chilling injury, and this physiological disorder appeared earlier in controls than in MAP-stored cladodes. The levels of fermentation metabolites were low in all three evaluated atmospheres. Because of this, only cladodes stored under the N₂ atmosphere were selected for furthersensory analysis of the MAP effect on odor perception as evaluated by a trained panel. Results indicated that there was no detrimental effect (atypical odors) of MAP on this sensory characteristic. We conclude that cultivar Atlixco is suitable for preservation using MAP technology.     

Medium Selection and Effect of Higher Oxygen Concentration Pulses on <Emphasis Type="Italic">Metarhizium anisopliae</Emphasis> var<Emphasis Type="Italic">. lepidiotum</Emphasis> Conidial Production and Quality

Rice and oat flours were analyzed as media for the production of conidia by M. anisopliae var. lepidiotum. The presence of peptone increased conidia yield regardless of the substrate used; however, the highest yield was achieved on oat flour media. The effect of oxygen on conidia production using oat-peptone medium was also studied at two levels: Normal atmosphere (21% O₂) and Oxygen-rich pulses (26% O₂). Maximum conidia production (4.25 × 10⁷ conidia cm⁻²) was achieved using 26% O₂ pulses after 156 h of culture, which was higher than 100% relative to conidial levels under normal atmosphere. Conidia yield per gram of biomass was 2.6 times higher with 26% O₂ (1.12 × 10⁷ conidia mg⁻¹). Conidia quality parameters, such as germination and hydrophobicity, did not show significant differences (P < 0.05) between those treatments. Bioassays parameters, using Tenebrio molitor adults, were analyzed for conidia obtained in both atmospheres and data were fitted to an exponential model. The specific mortality rates were 2.22 and 1.26 days⁻¹, whereas lethal times for 50% mortality were 3.90 and 4.31 days, for 26% O₂ pulses and 21% O₂ atmosphere, respectively. These results are relevant for production processes since an oxygen increase allowed superior levels of conidia by M. anisopliae without altering quality parameters and virulence toward Tenebrio molitor adults.     

Elevated CO<Subscript>2</Subscript> ameliorated oxidative stress induced by elevated O<Subscript>3</Subscript> in <Emphasis Type="Italic">Quercus mongolica</Emphasis>

Using open top chambers, the effects of elevated O₃ (80 nmol mol⁻¹) and elevated CO₂ (700 μmol mol⁻¹), alone and in combination, were studied on young trees of Quercus mongolica. The results showed that elevated O₃ increased malondialdehyde content and decreased photosynthetic rate after 45 days of exposure, and prolonged exposure (105 days) induced significant increase in electrolyte leakage and reduction of chlorophyll content. All these changes were alleviated by elevated CO₂, indicating that oxidative stress on cell membrane and photosynthesis was ameliorated. After 45 days of exposure, elevated O₃ stimulated activities of superoxide dismutase (SOD, EC 1.15.1.1) and ascorbate peroxidase (APX, EC 1.11.1.11), but the stimulation was dampened under elevated CO₂ exposure. Furthermore, ascorbate (AsA) and total phenolics contents were not higher in the combined gas treatment than those in elevated O₃ treatment. It indicates that the protective effect of elevated CO₂ against O₃ stress was achieved hardly by enhancing ROS scavenging ability after 45 days of exposure. After 105 days of exposure, elevated O₃ significantly decreased activities of SOD, catalase (CAT, EC 1.11.1.6) and APX and AsA content. Elevated CO₂ suppressed the O₃-induced decrease, which could ameliorate the oxidative stress in some extent. In addition, elevated CO₂ increased total phenolics content in the leaves both under ambient O₃ and elevated O₃ exposure, which might contribute to the protection against O₃-induced oxidative stress as well.     

Effect of three MAP compositions on the physical and microbiological properties of a low fat Greek cheese known as "Anthotyros"

Anthotyros is a type of low fat cheese produced from a mixture of sheep and goat milk. Anthotyros cheese in Crete is produced from the whey of hard cheese such as kefalotyri and graviera. Anthotyros is a cheese which comes from the myzithra cheese (whey) dehydration. The dehydrated anthotyros’ physicochemical properties are moisture content of 35%, fat content in dry matter of 55% and low concentration of salt. The purpose of this study was to identify which of the three gas compositions applied; MAP₁:40% CO₂, 55% N₂, 5% O₂, MAP₂: 60% CO₂, 40% N₂ and MAP₃: 50% CO₂, 50% N₂ can lead to greater shelf life prolongation of anthotyros. The control samples were packaged in air. All cheese samples were kept under refrigeration (4 ± 0.5 °C) for 55 days. The statistical analysis of organoleptic characteristics was carried out by using the Principal Component Analysis (PCA) by means of JMP5.0.1.     

Effects of elevated CO2 and O3 on leaf damage and insect abundance in a soybean agroecosystem

By altering myriad aspects of leaf chemistry, increasing concentrations of CO₂ and O₃ in the atmosphere derived from human activities may fundamentally alter the relationships between insect herbivores and plants. Because exposure to elevated CO₂ can alter the nutritional value of leaves, some herbivores may increase consumption rates to compensate. The effects of O₃ on leaf nutritional quality are less clear; however, increased senescence may also reduce leaf quality for insect herbivores. Additionally, changes in secondary chemistry and the microclimate of leaves may render plants more susceptible to herbivory in elevated CO₂ and O₃. Damage to soybean (Glycine max L.) leaves and the size and composition of the insect community in the plant canopy were examined in large intact plots exposed to elevated CO₂ (~550 μmol mol⁻¹) and elevated O₃ (1.2*ambient) in a fully factorial design with a Soybean Free Air Concentration Enrichment system (SoyFACE). Leaf area removed by folivorous insects was estimated by digital photography and insect surveys were conducted during two consecutive growing seasons, 2003 and 2004. Elevated CO₂ alone and in combination with O₃ increased the number of insects and the amount of leaf area removed by insect herbivores across feeding guilds. Exposure to elevated CO₂ significantly increased the number of western corn rootworm (Diabrotica virgifera) adults (foliage chewer) and soybean aphids (Aphis glycines; phloem feeder). No consistent effect of elevated O₃ on herbivory or insect population size was detected. Increased loss of leaf area to herbivores was associated with increased carbon-to-nitrogen ratio and leaf surface temperature. Soybean aphids are invasive pests in North America and new to this ecosystem. Higher concentrations of CO₂ in the atmosphere may increase herbivory in the soybean agroecosystem, particularly by recently introduced insect herbivores. Handling editor: Gary Felton.     

Photosynthetic net O<Subscript>2</Subscript> evolution enhancement as a sign of acclimation to phosphorus deficiency in bean (<Emphasis Type="Italic">Phaseolus vulgaris</Emphasis> L.) leaves

Primary leaves of bean (Phaseolus vulgaris L.) seedlings cultivated for 14 days in a growth chamber on complete (control) and phosphate deficient (−P) Knop liquid medium were used for measurements. The −P leaves were smaller and showed an increased specific leaf area (SLA). Their inorganic phosphate (P_i) concentration was considerably lowered. They did not show any significant changes in chlorophyll (Chl) (a + b) concentration and in their net CO₂ assimilation rate when it was estimated under the conditions close to those of the seedlings growth. Light response curves of photosynthetic net O₂ evolution (P _NO₂) of the leaves for the irradiation range up to 500 μmol(photon) m⁻² s⁻¹ were determined, using the leaf-disc Clark oxygen electrode. The measurements were taken under high CO₂ concentration of about 1 % and O₂ concentrations of 21 % or lowered to about 3 % at the beginning of measurement. The results obtained at 21 % O₂ and the irradiations close to or higher than those used during the seedlings growth revealed the phosphorus stress suppressive effect on the leaf net O₂ evolution, however, no such effect was observed at lower irradiations. Other estimated parameters of P _NO₂ such as: apparent quantum requirement (QR_A) and light compensation point (LCP) for the control and −P leaves were similar. However, with a high irradiation and lowered O₂ concentration the rate of P _NO₂ for the −P leaves was markedly higher than that for the control, in relation to both the leaf area and leaf fresh mass. This difference also disappeared at low irradiations, but the estimated reduced QR_A values indicate, under those conditions, the increased yield of photosynthetic light reaction, especially in the −P leaves. The presented results confirm the suggestion that during the initial phase of insufficient phosphate feeding the acclimations in the light phase of photosynthesis, both structural and functional appear. They correspond, probably, to the increased energy costs of carbon assimilation under phosphorus stress, e.g. connected with raised difficulties in phosphate uptake and turnover and enhanced photorespiration. Under the experimental conditions especially advantageous for the dark phase of photosynthesis (saturating CO₂ and PAR, low O₂ concentration), those acclimations may be manifested as an enhancement of photosynthetic net O₂ evolution.     

Elevated CO2 and O3 effects on fine-root survivorship in ponderosa pine mesocosms

Atmospheric carbon dioxide (CO₂) and ozone (O₃) concentrations are rising, which may have opposing effects on tree C balance and allocation to fine roots. More information is needed on interactive CO₂ and O₃ effects on roots, particularly fine-root life span, a critical demographic parameter and determinant of soil C and N pools and cycling rates. We conducted a study in which ponderosa pine (Pinus ponderosa) seedlings were exposed to two levels of CO₂ and O₃ in sun-lit controlled-environment mesocosms for 3 years. Minirhizotrons were used to monitor individual fine roots in three soil horizons every 28 days. Proportional hazards regression was used to analyze effects of CO₂, O₃, diameter, depth, and season of root initiation on fine-root survivorship. More fine roots were produced in the elevated CO₂ treatment than in ambient CO₂. Elevated CO₂, increasing root diameter, and increasing root depth all significantly increased fine-root survivorship and median life span. Life span was slightly, but not significantly, lower in elevated O₃, and increased O₃ did not reduce the effect of elevated CO₂. Median life spans varied from 140 to 448 days depending on the season of root initiation. These results indicate the potential for elevated CO₂ to increase the number of fine roots and their residence time in the soil, which is also affected by root diameter, root depth, and phenology.     

Conversion of photosynthetic products in the light in CO2-free O2 and N2 in leaves of Zea mays L. and Phaseolus vulgaris L.

Summary After 10 min illumination of segments of bean (Phaseolus vulgaris L.) or maize (Zea mays L.) leaves in air with ¹⁴CO₂, the atmosphere was changed to CO₂-free O₂ or N₂ and conversion of photosynthetic products in the light was investigated. The experiments have shown that after the ¹⁴CO₂ assimilation period the bean leaves contain the pool of weakly fixed ¹⁴C (WF-¹⁴C) which is converted into stable products during the subsequent period of illumination in CO₂-free N₂. In O₂ atmosphere the WF-¹⁴C pool is initially the main source of CO₂ evolved. The marked decrease in radioactivity of sucrose and starch during illumination of bean leaves in O₂ atmosphere indicates that these compounds were also the source of CO₂ evolved in the light. The total amount of previously fixed ¹⁴C remained almost on the same level during illumination of maize leaves in N₂ as well as in O₂. However, oxygen changed the distribution of ¹⁴C in photosynthetic products, which is suggested to be the consequence of the photorespiration process in maize.Abbreviation WF-¹⁴C weakly fixed ¹⁴C     

Somatic embryo and root regeneration from quince leaves cultured in ventilated vessels or under different oxygen and carbon dioxide levels

Summary The influence of the gaseous composition of the atmosphere inside culturing vessels on somatic embryogenesis and on adventitious root formation was investigated in the quince clone (Cydonia ablonga Mill.) BA29. Leaves taken from in vitro-grown shoots were cultured in glass Petri dishes and exposed to ventilation with atmospheric air (flow rate 25 ml min⁻¹) for 0, 5, 10, 20, and 40 d. Twenty days of ventilation reduced the frequency of embryogenic leaves and a further decrease was observed after 40d of treatment. Conversely, adventitious root formation in the ventilated dishes was never different from the untreated cultures. In a second test, leaves were incubated in atmospheres containing different levels of oxygen (0, 5.0, 10.0, and 21.0%) or carbon dioxide (0, 0.04, 0.15, 1.5, and 3.0%). Anoxia conditions almost completely inhibited somatic embryo and adventitious root formation, but without compromising callus formation and explant viability. In contrast, embryo and root regeneration occurred even in totally CO₂-free atmosphere. Oxygen seemed to influence somatic embryogenesis according to a quadratic response; a similar relationship was also observed for root regeneration. Instead, no clear trend could be inferred between embryo or root regeneration and CO₂ levels. Furthermore, in dishes flushed with gas mixtures containing oxygen or carbon dioxide somatic embryo formation was almost always lower than in confined dishes. A different result was observed for root regeneration, since the number of roots was never lower than in the control and increased appreciably with 3.0% CO₂. These results demonstrate that atmosphere composition of the culture head-space can influence somatic embryogenesis in quince. The finding that both vessel ventilation and atmosphere replacement with different gas mixtures reduced somatic embryo formation suggests that gaseous compounds, different from O₂ an CO₂, present in the gaseous environment may promote embryogenesis in this species.     

Light- and CO2-saturated photosynthesis: enhancement by oxygen

Oxygen may enhance CO₂-saturated photosynthesis in intact leaves, which display the Warburg effect when illuminated at the current atmospheric level of CO₂ and O₂, of about 350 μl l⁻¹ and 21%, respectively. The magnitude of the stimulation depends on irradiance. The K _M(O₂) of the stimulation is 128 μM (10.6% O₂). Maximum enhancement in wheat leaves is 6.1 and 5.3 μmol m⁻² s⁻¹ under 27.9 and 18.7 mW cm⁻², respectively, corresponding to a 25–30% increase in the ribulose 1,5-bisphosphate (RuBP) turnover rate if compared with O₂-free ambient gas phase. The stimulation appears in 5–10 s after a sharp increase in O₂. In response to a decrease in O₂, the new stabilized rate is reached in 5–7 min. The stimulation does not involve any increase in the activity of Rubisco. The effect correlates with increased concentration of RuBP. Oxygen enhances CO₂-saturated photosynthesis by acting as a terminal electron acceptor in the photosynthetic electron transport. The magnitude of the effect may be adopted as an index of the pseudocyclic photophosphorylation in vivo.     

Saturated Aldehydes C6–C10 Emitted from Ashleaf Maple (<Emphasis Type="Italic">Acer negundo</Emphasis> L.) Leaves at Different Levels of Light Intensity,O<Subscript>2</Subscript>, and CO<Subscript>2</Subscript>

Aldehydes, a group of volatile organic compounds (VOCs) often detected in the atmosphere, play a key role in atmospheric chemistry and plant resistance to stresses. We used gas chromatography/mass spectrometry to examine the volatiles of saturated aldehydes C6–C10 that were emitted from cuttings of ashleaf maple (Acer negundo L.) under varying levels of light intensity (80, 400, and 800 μmol m⁻² s⁻¹), O₂ (2% and 50%), and CO₂ (600, 1,000, and 1,200 ppm). An apparent, positive correlation was found between light intensity and emissions, and their release also was significantly enhanced by higher O₂ concentrations. In contrast, emissions clearly were negatively correlated with CO₂ levels. We speculate that the reactive oxygen species (ROS) generated during photosynthesis contribute to these elevated emissions. However, the mechanism for this ROS trigger is unknown.     

Post-harvest treatments for the control of Phytophthora syringae storage rot of apples

Oospores of Phytophthora syringae germinating at 10 and 15°C under artificial light formed one or more sporangia, which yielded zoospores. Furalaxyl and metalaxyl demonstrated eradicant action against infections occurring on zoospore-inoculated apples. Control was obtained at 10°C when treatment was delayed 5–11 days after inoculation. Storage in 5% CO₂+ 3% O₂ and 0% CO₂+ 2% O₂ reduced rotting compared with storage in air.     

Atmospheric conditions required for the growth ofGaleola septentrionalis seedlings

The seedling of an achlorophyllous orchid,Galeola septentrionalis, requires for its early growth anomalous atmospheric conditions appropriate to each process of development. The most favorable atmosphere for the enlargement of protocorm consists of 10% O₂, 6% CO₂ and 84% N₂ at a pressure of 1.4 kg/cm². Tolerable ranges of atmospheric pressure, concentrations of O₂ and CO₂ were 1.1–2.0 kg/cm², 5–12% and 2–10%, respectively. Such a range for culture temperatures was 20–26 C. Subsequent development of the seedlings was little influenced by atmospheric pressure (1.0–1.8 kg/cm²) and concentration of CO₂ (0–8%), but influenced by O₂ concentration. Optimum and tolerable concentrations of O₂ were 10–15% and 5–19.7%, respectively. These atmospheres are discussed hypothetically as the conditions required to pass an inevitable process specific to the epigenetic ontogeny of scobiform (sawdusty) seeds.