Efficacy of the antagonist Aureobasidium pullulans PL5 against postharvest pathogens of peach,apple and plum and its modes of action

The efficacy of Aureobasidium pullulans PL5 against different postharvest pathogens of fruits (Monilinia laxa on plums and peaches, Botrytis cinerea and Penicillium expansum on apples) were evaluated under storage conditions when applied at 10⁸ cells ml⁻¹ and their interactions were studied in vitro and in vivo to discover the possible modes of action. Under 1.2 °C and 95% relative humidity (RH) for 28 days, the efficacy of PL5 against M. laxa on plums was 45%, reducing disease incidence from 78% to 43%. Under 1 °C and 95% RH for 21 days, the efficacy against M. laxa on peaches was 63%, reducing disease incidence from 79% to 29%. Under 4 °C and 95% RH for 45 days, the efficacy against B. cinerea and P. expansum on apples was 56% and 46%, respectively. In Lilly–Barnett minimal salt medium with the fungal cell walls of pathogens as sole carbon source, PL5 produced β-1,3-glucanase, exo-chitinase and endo-chitinase. Nutrient concentrations had significant effect on pathogen growth reduction by PL5. No attachment was observed in antagonist–pathogen interactions in vitro or in vivo. PL5 completely inhibited pathogen spore germination in PDB at 10⁸ cells ml⁻¹, whereas at 10⁶ cells ml⁻¹ the efficacy was significantly decreased. However, inactivated cells and culture filtrate of PL5 had no effect on pathogen spore germination and germ tube elongation. Our results showed that A. pullulans PL5 could be introduced in commercial formulations to control postharvest pathogens on fruits and its activity was based on secretion of lytic enzymes and competition for nutrients.     

Cold storage of <Emphasis Type="Italic">Trichogramma nerudai</Emphasis> using an acclimation period

The availability of suitable storage methods for parasitoids is a valuable tool in biological control programs. Studies were conducted to investigate the effects of cold storage with acclimation period on the quality of Trichogramma nerudai Pintureau and Gerding. Prepupae were stored 50, 75 and 100 days at 5 °C with a previous acclimation period of 10 or 20 days at 12 °C. It was possible to arrest the development of T. nerudai. All the treatments with acclimation period of ten days had emergence values under 10% that were not useful to establish a cold storage protocol. Twenty days of acclimation had a positive impact on cold storage tolerance at 50 and 75 days. The adult emergence, the emergence time, the sex ratio, the parasitism and the progeny quality have not been affected by the storage of T. nerudai using an acclimation period of 20 days and until 50 days under cold temperature.     

Synthetic seed technology for short term conservation of medicinal orchid Dendrobium densiflorum Lindl. Ex Wall and assessment of genetic fidelity of regenerants

Artificial seeds were obtained through encapsulation of protocorm-like bodies (PLBs) of Dendrobium densiflorum in calcium alginate beads. This paper demonstrates the alginate-encapsulation and conversion (complete plantlet regeneration) from PLBs, the effect of storage conditions (at different temperature; 4, 8, 16 °C, RT and duration; 15, 30, 45, 60, 75, 90 days) on viability of encapsulated plant materials as well as the assessment of genetic fidelity of the regenerants. Individual PLBs were encapsulated in calcium alginate beads for mass propagation, short-term storage and germplasm sharing. The superior gel matrix for encapsulation was obtained using 3 % sodium alginate and 100 mM calcium chloride (CaCl₂·2H₂O). The highest percentage of conversion (100 %) of encapsulated PLBs (capsules) was obtained on MS2 medium (MS medium + 2 mg/l BAP). Capsules were successfully stored till 60 days at 8 °C with conversion frequency of 95.5 %. Plantlets regenerated from encapsulated beads were acclimatized successfully with 95 % survival rate. A total of 40 primers were screened, out of which 10 primers successfully generated 39 scorable bands, ranging from 0.2 to 1.3 kb amplicons. The uniform RAPD banding profile among the plantlets derived from encapsulated PLBs following 60 days of storage confirmed genetic fidelity.     

Further observations on effects of cations on enzyme induction in marine bacteria

Summary Induction of resting cells ofPseudomonas natriegens, nov. spec. to the oxidation of L-arabinose and mannitol, and an additional marine isolate (L5) to oxidation of lactose and mannitol, was found dependent on the presence of Na⁺ with marine levels of Mg⁺⁺ and K⁺ included in the suspending media. However, omission of Na⁺ and Mg⁺⁺, and increase of the concentration of K⁺ in the suspending media, permitted rapid utilization of these substrates (but not of glucuronate) by resting cells and greatly accelerated the rates of induced enzyme formation. Inclusion of Mg⁺⁺ in the suspending media suppressed the rates of induction and oxidation stimulated by elevation of the K⁺ concentration. Incubation of resting cells of isolate L5 in an assay medium containing 0.26 M KCl preserved the ability of the organisms to produce a significant level of the enzymes for oxidation of mannitol, even after 8 hrs aging of the cells in the cold. Chloramphenicol inhibited the synthesis of induced oxidative enzymes in both these marine isolates suspended in high K⁺ medium, and the extent of inhibition was proportional to the time of addition of the antibiotic. Interruption of induction of isolate L5 cells to mannitol by washing within 30 min removed the stimulatory effect of the elevated level of K⁺, whereas longer periods of incubation before interruption yielded cells more fully induced. A greater amount of β-galactosidase was produced by resting cells of the marine isolate L5 incubated with the inducer in media with elevated K⁺ concentrations than by those cultured on lactose or induced in the resting state in the presence of Na⁺. Moreover, inclusion of an elevated K⁺ concentration in the suspending media stimulated the production of L-arabinose isomerase in resting cells ofP. natriegens. The requirement for Na⁺ for the growth of these bacteria, however, was not replaceable by elevation of the K⁺ concentration of culture media. Supported by grant no.G-15838 from the National Science Foundation and equipment loan contract NR-103-398 with the Office of Naval Research. Contribution no. 35 from the University of Georgia Marine Institute at Sapelo Island.     

Low Temperature Storage of <Emphasis Type="Italic">Telenomus remus</Emphasis> (Nixon) (Hymenoptera: Platygastridae) and its Factitious Host <Emphasis Type="Italic">Corcyra cephalonica</Emphasis> (Stainton) (Lepidoptera: Pyralidae)

We conducted three bioassays to evaluate the effect of low-temperature storage of eggs (host) and pupae and adults (parasitoid) on the biology and parasitism capacity of the egg parasitoid Telenomus remus (Nixon) (Hymenoptera: Platygastridae). Viable stored Corcyra cephalonica (Stainton) (Lepidoptera: Pyralidae) eggs were parasitized to the same degree or even higher than fresh eggs when stored until 14 days at 5°C or until 21 days at 10°C. In contrast, the percentage of parasitized sterilized eggs was equal to the control only when stored for 7 and 14 days. Survival of T. remus pupae declined with storage time at both studied temperatures (5 and 10°C). However, after 7 days of storage, survival of pupae was still 86.3 and 64.9% at 10 and 5°C, respectively. The number of adult male survivors remained similar until the fourth storage day at both 5 and 10°C. In contrast, female survival did not differ until day 8 at 10°C or day 6 at 5°C. Parasitism capacity of stored adults was not altered by storage compared with the control. Therefore, we conclude that the maximal storage time at 10°C is 21 days for viable C. cephalonica eggs and 7 days for T. remus pupae, while parasitoid adults should not be stored for more than 4 days at either 5 or 10°C.     

Biomass accumulation and carbon storage of four different aged Sonneratia apetala plantations in Southern China

The objectives of this study were to examine plant biomass accumulation and carbon (C) storage in four different aged Sonneratia apetala plantations in the Leizhou Bay in South China. The allometric equations using diameter at breast height (DBH) and height (H) were developed to quantify plant biomass. The total forest biomass (TFB) of S. apetala plantation at 4, 5, 8, and 10 years old was 47.9, 71.7, 95.9, and 108.1 Mg ha^?1, respectively. The forest biomass C storage in aboveground (AGB) and roots at 4, 5, 8, and 10-year plantation was 19.9, 32.6, 42.0, 49.0 Mg ha^?1, respectively. Soil organic C (SOC) on the top 20 cm of sediments increased by 0.3, 6.8, 27.4, and 35.0 Mg ha^?1after 4, 5, 8, and 10 years of reforestation, respectively. The average annual rate of total carbon storage (TCS) accumulation at 4, 5, 8, and 10-year S. apetala plantation was 5.0, 7.9, 8.7, and 8.4 Mg ha^?1 yr^?1, respectively. The TCS values in this study were underestimated because we only estimated SOC storage on the top 20-cm sediments in these plantations. This study suggests these young S. apetala plantations have the characteristics of fast growth, high biomass accumulation, and high C storage capacity, especially in sediments. They sequestrated C at a high but varying rate over time. The large-scale reforestation of S. apetala plantations in the open coastal mudflats in southern China has great potential to sequestrate more C as well as restore the degraded coastal land. The potential ecological issues associated with the increasing monoculture plantations were discussed. More long-term monitoring and research are needed to further evaluate biomass and C accumulation of S. apetala plantations over time as well as how the increasing distribution of this monoculture plantation will influence the few native mangrove remnants.     

Effect of long-term cold storage of the predatory mite Neoseiulus californicus at high relative humidity on post-storage biological traits

The present study investigated whether long-term cold storage at high relative humidity (RH) affected the quality of the predatory mite Neoseiulus californicus (McGregor) (Acari: Phytoseiidae) in terms of its survival and reproduction. For this purpose, we examined biological traits at the end of storage and during the post-storage period. Mated females three?days after adult emergence were stored individually in 1.5-ml vials for 15, 30, 45, 60, or 75?days at 5.0?±?0.3°C and RH of 99?±?0.1% under continuous darkness. At the end of the storage period, 94–100% of females had survived when the storage period was ≤30?days, but percent survival decreased with longer storage. After storage, female survival and oviposition rates were equivalent to un-stored females at 24?±?1°C, RH of 93?±?2%, and a photoperiod of LD 16:8?h. The quality of progeny (hatchability, survival to adulthood, and sex ratio) of stored females was not affected by storage periods as long as 60?days. These results indicate that storage using the tested method can preserve N. californicus for at least 30?days without any degradation.     

Studies on microbial glucose isomerase: 4. Characteristics of immobilized whole-cell glucose isomerase from Streptomyces spp.

Whole-cell glucose isomerase from a Streptomyces spp. was immobilized by entrapment in gelatin matrices crosslinked with glutaraldehyde. The resultant immobilized enzyme preparation had up to 40% recovery yield of the activity and showed relatively long stabilities during storage and the isomerizing reaction. The storage half-life of the preparation was 19 months at 5°C and the half-life of the enzyme during operation was 260 days in the presence of 1 mM Co²⁺ and 80 days in the absence of the metal ion. Optimum pH and temperature were 7.5 and 70–75°C, respectively. The K_m values for glucose and fructose were 0.29 and 0.46 m, respectively, with a maximum theoretical conversion yield of 56%. The simulation results based on the reversible one-substrate enzyme kinetic model agreed well with the experimental data obtained from a batch reactor. The continuous operation of packed bed reactors demonstrated that some effects of the external film diffusion resistance were apparent at low flow rates of the substrate feed solution, whereas the internal pore diffusion resistance was negligible up to the pellet size used in this work.     

High Energy Charge as a Requirement for Axis Elongation in Response to Gibberellic Acid and Kinetin during Stratification of Acer saccharum Seeds

The growth potential of embryonic axes of Acer saccharum Marsh. increased during moist storage at 5 C but not at 20 C. During the period of increasing growth potential, the oxygen consumption of the axes remained constant. It was possible to distinguish three phases of the stratification-germination process at 5 C with respect to response of the axis to gibberellic acid and kinetin. From 0 to 10 days the growth regulators had no effect on elongation; from 10 to 60 days axis elongation was stimulated; and between day 60 and day 75, when germination had begun, the growth substances were inhibitory. The adenylate energy charge remained low (0.15) in axes of dry dormant seeds but increased to 0.78 following imbibition of water and 10 days of moist storage at 5 C. This phenomenon was not specifically related to low temperature stratification, since a rapid increase in the energy charge of the axes also occurred following imbibition and moist storage at 20 C. The excised axes would elongate in response to the growth substances only when a high energy charge (approximately 0.8) was maintained.     

Proceedings: Preservation of bacteria by freezing at moderately low temperatures

In order to get some basic information for the development of a long-term preservation method by freezing at moderately low temperatures, the viability of 259 strains belonging to 32 genera and 135 species was measured. Cells were suspended in 10% glycerol and stored at ?53 °C for 16 months. About 93%, 88%, and 74% of aerobic bacteria gave viable cell counts higher than 10⁵/ml, 10⁶/ml, and 10⁷/ml, respectively. About 10% of gram-positives and 3% of gram-negatives gave viable cell counts lower than 10⁵/ml. There seemed to be some species—and genus—specificity with respect to viability after frozen storage and liquid paraffin-seal storage. Strains of coryneform bacteria, genera of the family Enterobacteriaceae, and the genus Pseudomonas were generally resistant. Pseudomonas putrefaciens proved to be specifically sensitive. Lactic acid bacteria were subject to sublethal injury, requiring special recovery media. Psychrophilic bacteria were very susceptible to frozen storage. All the tested strains of acetic acid bacteria survived frozen storage well both in 10% glycerol and in 10% honey at ?28 °C for 4.5 years. Honey proved to be a better adjuvant for frozen storage than glycerol. It was suggested from the results that for many kinds of bacteria, long-term preservation by freezing at moderately low temperatures might be possible when appropriate procedures are applied.     

Potential biocontrol activity of a strain of Pichia guilliermondii against grey mold of apples and its possible modes of action

The efficacy of Pichia guilliermondii strain M8 against Botrytis cinerea on apples was evaluated under storage conditions, and its possible modes of action were investigated both in vitro and in vivo experiments. After storage at 1 °C for 120 days, M8 reduced grey mold incidence from 45.3% (control) to 20.0%. In apple juice medium (AJM) and in wound-inoculated apples, M8 at 10⁹ and 10⁸ cells ml⁻¹ inhibited the spore germination of B. cinerea and the grey mold development. When co-culturing B. cinerea in vitro or in vivo in the presence of the yeast, neither inactivated cells nor culture filtrate of the yeast had any effect on spore germination or germ tube elongation. In AJM, the spore germination was significantly recovered by the addition of 1% glucose, sucrose and fructose, or 0.5% and 1% of (NH₄)₂SO₄, phenylalanine and asparagine. When the pathogen and the yeast were co-incubated in apple wounds with addition of the same nutrients, the inhibition of rots was significantly reduced by the supplemental nutrients. Light microscopy revealed that the yeast strongly adhered to the hyphae and spores of B. cinerea. M8 produced hydrolytic enzymes, including β-1,3-glucanase and chitinases in minimal salt media with different carbon sources. Pretreatment with M8 at 10⁸ cells ml⁻¹ followed by washing, significantly reduced grey mold lesions, suggesting an induction of defense responses. Direct attachment, competition for nitrogen and carbon sources, secretion of hydrolytic enzymes and induction of host resistance play a role in the biocontrol mechanism of P. guilliermondii M8 against B. cinerea.     

Survival of Brucella abortus Strain RB51 Lyophilized and as Liquid Vaccine under Different Storage Conditions

Brucella abortus strain RB51 (SRB51) is a new cattle vaccine that is approved for use in the U.S. for prevention of brucellosis. At the present time, other countries are implementing or considering the use of SRB51 vaccine in their brucellosis control programs. In the current study, the effect of three stabilizing media, two fill volumes (1 and 3 ml), and three storage temperatures (−25, 4 and 25°C) on the viability of lyophilized SRB51 over a 52 week period was determined. The effects of three concentrations of bacteria (5×10⁸, 1×10⁹, or 5×10⁹ cfu/ml) and two storage temperatures (4 or 25°C) on viability of liquid SRB51 vaccine were also determined. For lyophilized strain RB51 vaccine, fill volume did not influence viability (P> 0·05) during lyophilization. Although fill volume did not influence viability during storage in World Health Organization (WHO) media or media containing both WHO and Lactose Salt (LS) media, 1 ml fill volumes of SRB51 in LS media had greater (P< 0·05) viability when compared to 3 ml fill volumes. Lyophilized SRB51 vaccine stored at 25°C had a more rapid decline in viability (P< 0·05) when compared to vaccine stored at −25 or 4°C. With the exception of the 3-ml fill volumes of LS media, all three stabilizing media were similar in maintaining viability of SRB51 at −25°C storage temperatures. However, when compared to WHO or WHO/LS media, stabilization in LS media was associated with a more rapid decline in viability during storage at 4 or 25°C (P< 0·05). Initial SRB51 concentration in liquid vaccine did not influence (P> 0·05) viability during storage at 4 or 25°C. When compared to liquid SRB51 vaccine stored at 25°C, storage at 4°C was associated with a slower decline in viability (P< 0·05) during 12 weeks of storage. Biochemical and morphological characteristics of SRB51 were stable under the storage conditions utilized in the present study. This study suggests that viability of SRB51 can be readily maintained during storage as a lyophilized or liquid brucellosis vaccine.     

Factors affecting the efficacy of methyl bromide fumigation to control Liriomyza trifolii in imported chrysanthemum cuttings

Laboratory investigations were made into the effect of cultivar type, prior cold storage, fumigation temperature and methyl bromide concentration, on the efficacy of a fumigation treatment to control Liriomyza trifolii in chrysanthemum cuttings. The tests related to the standard quarantine treatment used in the UK to control Spodoptera littoralis on imported chrysanthemum cuttings: cold storage for 2 days at 1 – 2°C followed by methyl bromide fumigation at 15°C with a concentration time product (CTP) of 54 g h/m³. L. trifolii larvae, within detached leaves, and 1 – 2 and 2 – 3 day old pupae, were treated. Methyl bromide concentrations of 6·75 or 13·5 g/m³ were used to achieve a range of CTPs and thus obtain accurate dose-response lines and estimates of the LD99 and LD99·9 for each insect stage. Fumigation temperatures were 8, 11 or 15°C. Efficacy of the standard treatments differed between the three cultivars tested, but the LD99 for larvae remained below 54 g h/m³. Decreasing fumigation temperature to 11°C or less increased LD99 values for larvae and pupae and substantially increased variability. There is therefore little scope for using fumigation temperatures of less than 15°C for quarantine purposes. Omitting the cold storage treatment prior to fumigation did not significantly affect efficacy of fumigation. Reducing the methyl bromide concentration from 13·5 to 6·75 g/m³ did not significantly affect the LD99 for larvae but significantly reduced LD99s for pupae.     

Use of thermal stability studies to compare Bacteroides fragilis lyophilized in skim milk and polyvinylpyrrolidone solutions

Bacteroides fragilis cells suspended in two different suspending media, polyvinylpyrrolidone (PVP) and skim milk (SM) solutions, were lyophilized and evaluated for stabilities through accelerated thermal degradation studies. The lyophilized preparations were exposed to 70, 60, 50, 48, 35, 25, and 4 °C. Modified Arrhenius statistical models were used to compare quantitative estimates (colony forming units) of viability at 4 °C to the observed counts with each medium at that temperature. Results with the PVP suspension were not acceptable. However, the estimated time for the SM preparation to degrade to the observed viability count was within 8 days when data from all seven temperature exposures were used for the calculations.     

Giardia sp.: physical factors of excystation in vitro, and excystation vs eosin exclusion as determinants of viability.

The effects of several factors on Giardia sp. excystation in vitro were investigated. Temperature, pH, time, and incubation medium were shown to affect the levels of excystation achieved. In general, those conditions most closely approximating the organism's in vivo environment induced the highest levels of excystation. The viability of Giardia sp. cyst suspensions was compared by eosin exclusion and excystation. Eosin exclusion consistently indicated higher cyst viability than could be demonstrated by in vitro excystation. Using excystation as the criterion of viability, the effect of storage at ?13, 8, 21, and 37 C and of exposure to boiling water on Giardia sp. cyst survival was studied. Storage at 8 C permitted longest cyst survival, 77 days, at which time the cyst suspension was exhausted. Cysts stored at 21 C retained their viability for 5 to 24 days, while those at 37 C never survived longer than 4 days. Freezing and thawing cysts resulted in an almost complete loss of viability although a low level of viability (< 1%) persisted for at least 14 days. Cysts exposed to boiling water were immediately incapable of excystation.     

Thermal Inactivation of Nonproteolytic Clostridium botulinum Type E Spores in Model Fish Media and in Vacuum-Packaged Hot-Smoked Fish Products

Thermal inactivation of nonproteolytic Clostridium botulinum type E spores was investigated in rainbow trout and whitefish media at 75 to 93°C. Lysozyme was applied in the recovery of spores, yielding biphasic thermal destruction curves. Approximately 0.1% of the spores were permeable to lysozyme, showing an increased measured heat resistance. Decimal reduction times for the heat-resistant spore fraction in rainbow trout medium were 255, 98, and 4.2 min at 75, 85, and 93°C, respectively, and those in whitefish medium were 55 and 7.1 min at 81 and 90°C, respectively. The z values were 10.4°C in trout medium and 10.1°C in whitefish medium. Commercial hot-smoking processes employed in five Finnish fish-smoking companies provided reduction in the numbers of spores of nonproteolytic C. botulinum of less than 10³. An inoculated-pack study revealed that a time-temperature combination of 42 min at 85°C (fish surface temperature) with >70% relative humidity (RH) prevented growth from 10⁶ spores in vacuum-packaged hot-smoked rainbow trout fillets and whole whitefish stored for 5 weeks at 8°C. In Finland it is recommended that hot-smoked fish be stored at or below 3°C, further extending product safety. However, heating whitefish for 44 min at 85°C with 10% RH resulted in growth and toxicity in 5 weeks at 8°C. Moist heat thus enhanced spore thermal inactivation and is essential to an effective process. The sensory qualities of safely processed and more lightly processed whitefish were similar, while differences between the sensory qualities of safely processed and lightly processes rainbow trout were observed.     

The combined effect of high hydrostatic pressure,heat and bacteriocins on inactivation of foodborne pathogens in milk and orange juice

The objective of this study was to combine pressure (345 MPa) with heat (50 C), and bacteriocins (5000 AU/ml sample) for a short time (5 min) for the inactivation of relatively pressure-resistant strains of four foodborne pathogens: Staphylococcus aureus, Listeria monocytogenes, Escherichia coli O157:H7 and Salmonella in pasteurized milk and orange juice. Without bacteriocin addition, 5.5 log-cycle reduction was obtained for S. aureus 485 in milk whereas more than 8 log-cycle reduction was achieved for all the other strains studied. After storage of samples for 24 h at 4 C, S. aureus 765 also gave positive results on selective media, where no growth was observed for all the other micro-organisms assayed. Incubation of the same pressurized samples at 37 C for 48 h showed growth of L. monocytogenes strains in addition to S. aureus strains, where still no growth was observed for E. coli O157:H7 and Salmonella strains in their respective selective media. For orange juice samples, more than 8 log-cycle reduction was achieved for all the bacterial species studied. No growth was seen for these species on their respective selective media agar plates after storage at 4 C for 24 h and at 37 C for 48 h. When a bacteriocin-based biopreservative (BP₁) was combined with pressurization, more than 8 log-cycle reduction in cell population of the resistant strains of S. aureus and L. monocytogenes were achieved in milk after pressurization. Milk samples were stored at 25 C up to 30 days to test the effect of treatment and samples showed no growth whereas all the controls were positive.     

Effect of egg storage duration and brooding temperatures on chick growth,intestine morphology and nutrient transporters

The effects of egg storage duration (ESD) and brooding temperature (BT) on BW, intestine development and nutrient transporters of broiler chicks were investigated. A total of 396 chicks obtained from eggs stored at 18°C for 3 days (ESD3-18°C) or at 14°C for 14 days (ESD14-14°C) before incubation were exposed to three BTs. Temperatures were initially set at 32°C, 34°C and 30°C for control (BT-Cont), high (BT-High) and low (BT-Low) BTs, respectively. Brooding temperatures were decreased by 2°C each at days 2, 7, 14 and 21. Body weight was measured at the day of hatch, 2, 7, 14, 21, 28 and 42. Cloacal temperatures of broilers were recorded from 1 to 14 days. Intestinal morphology and gene expression levels of H⁺-dependent peptide transporter (PepT1) and Na-dependent glucose (SGLT1) were evaluated on the day of hatch and 14. Cloacal temperatures of chicks were affected by BTs from days 1 to 8, being the lowest for BT-Low chicks. BT-High resulted in the heaviest BWs at 7 days, especially for ESD14-14°C chicks. This result was consistent with longer villus and larger villus area of ESD14-14°C chicks at BT-High conditions. From 14 days to slaughter age, BT had no effect on broiler weight. ESD3-18°C chicks were heavier than ESD14-14°C chicks up to 28 days. The PepT1 and SGLT1 expression levels were significantly higher in ESD3-18°C chicks than ESD14-14°C on the day of hatch. There was significant egg storage by BT interaction for PepT1 and SGLT1 transporters at day 14. ESD14-14°C chicks had significantly higher expression of PepT1 and SGLT1 at BT-Low than those at BT-Cont. ESD14-14°C chicks upregulated PepT1 gene expression 1.15 and 1.57-fold at BT-High and BT-Low, respectively, compared with BT-Cont, whereas PepT1 expression was downregulated 0.67 and 0.62-fold in ESD3-18°C chicks at BT-High and BT-Low. These results indicated that pre-incubation egg storage conditions and BTs affected intestine morphology and PepT1 and SGLT1 nutrient transporters expression in broiler chicks.     

Effects of Exogenous Phytohormones on Spore Germination and Morphogenesis of <Emphasis Type="Italic">Polystichum aculeatum</Emphasis> (L.) Roth Gametophyte in vitro Culture

The effects of exogenous phytohormones–gibberellic acid (GA3) and benzyl-aminopurine (BAP)–on the spore germination and morphogenesis of Polystichum aculeatum (L.) Roth gametophyte in vitro culture were studied. In the control, four stages of gametophyte morphogenesis were determined and their periods were established. Spore germination and protonema formation of P. aculeatum occurred according to the Vittaria-type and prothalium development according to the Aspidium-type. The spore germination percentage depended on the storage time duration. It was found that 80–95% of freshly collected spores germinated. Spore viability was within the range of 68–95% after 4–6-month storage under lab conditions and did not exceed 20% after 1.5 year of the storage period. High concentrations of exogenous GA3 (10^–5 and 10^–6 M) and BAP (10–5 M) significantly inhibited spore germination, whereas low concentrations (GA3 10^–7–10^–8 M) had an insignificant stimulating effect or did not affect germination at all (BAP 10^–6, 10^–7, 10^–8 M). All concentrations of exogenous BAP were demonstrated to inhibit the development of P. aculeatum gametophyte at the protonema stage, which might be due to the removal of apical dominance. The inhibiting effect directly depended on BAP concentrations. The formation of abnormal thalli of the P. aculeatum gametophyte in the response to exogenous GA3 treatments occurred as a result of impairment of cell growth by elongation. A direct interrelationship between GA3 concentrations and level of morphological abnormalities and grade of thalli underdevelopment was demonstrated.     

Cold storage ofPhytoseiulus persimilis (Phytoseiidae)

Phytoseiulus persimilis is commerelally mass-reared for use as a biological control agent for spider mites, primarilyTetranychus urticae, and cold storage is a potentially valuable aspect of mass-production. Cold storage ofP. persimilis in empty containers was found to be unsatisfactory, but provision of moisture during cold storage greatly increased survival. Provision of food further increased survival even though the mites were stored at temperatures below their threshold for development of 11°C. When food was provided, survival at 7.5°C was 97% after 4 weeks and 80% after 6 weeks. Subsequent longevity and fecundity of mites that survived 8 weeks at 7.5°C was comparable to mites taken directly from mass-rearing cultures. Survival of mites packaged in bran or vermiculite and held at 6°C for 10 days ranged from 75% to 85% and was not decreased by agitating the containers to simulate shipping. However, survival of mites held in bran or vermiculite at 5°C or 8°C for 4 weeks was poor, ranging from 0–19%, due to growth of mould in the media.Phytoseiulus persimilis can be successfully stored for 4 to 6 weeks in containers provisioned only with food and moisture; granular media used for distribution of the mites should be added just prior to shipping.