Prosopis chilensis is a plant highly tolerant to heat shock

At temperatures between 25 and 35°C, 100% of Prosopis chilensis seeds germinated within 24 h. At higher temperatures, the germination rate was reduced; at 50°C, seeds did not germinate. After germination at 25°C, the optimal temperature for seedling growth was 35°C and the seedlings did not grow at a temperature of 50°C. However, when germination was at 35°C, the optimal temperature for seedling growth was 40°C and some seedlings grew at 50°C, suggesting that thermotolerance was induced during seed germination at 35°C. Further thermotolerance can be induced in seedlings germinated at 35°C, by exposing them to 40°C for 2h. Under these conditions, seedlings exhibited increased growth rate at 45 and 50°C. Fluorography of SDS-polyacrylamide gel electrophoresis of the proteins synthesized and accumulated during 2 h at temperatures of 35, 40, 45 and 50°C in the presence of [³⁵S]methionine revealed the expression of 11 proteins not detectable at 35°C. Most of the proteins present at 35°C also increased in expression. The temperature for maximal expression of these proteins was 45°C.     

Composition of citrus pulp

Eight groups of citrus varieties grown in Spain were included in this study. Citrus pulp composition was (dry matter basis) 60–65% peel, 30–35% segment pulp and 0–10% seeds. Citrus seeds had a high percentage of protein, ether extract and crude fibre. Segment pulp contained slightly less fibre than citrus pulp. The proximate composition of citrus pulp was similar to that of the peel fraction and did not differ from previous results. Significant differences in fibre and acid detergent lignin of the dried citrus pulp samples were found between varieties.The drying process was studied. Temperatures over 130°C and the addition of calcium hydroxide affected some fractions of the pulp, mainly by increasing ash and fibre contents.     

Effects of temperature on development,survival, longevity,and fecundity of Serangium japonicum (Coleoptera: Coccinellidae), a predator of Bemisia tabaci Gennadius (Homoptera: Aleyrodidae)

In this study, we evaluated the effect of temperature on the development and reproductive biology of Serangium japonicum (Coleoptera: Coccinellidae) at seven constant temperature regimes (17, 20, 23, 26, 29, 32 and 35°C) for its effect as a predator of Bemisia tabaci (Homoptera: Aleyrodidae). Results indicated that the duration of the egg, larval and pupal stages were significantly affected by temperature. The developmental time gradually declined with the increase of temperature from 17 to 29°C, however an extension in the developmental periods was observed in the temperature range of 32 to 35°C. The survival rates of different insect stages were stable at temperatures between 20 and 32°C; however at extreme temperatures of 35°C, a sharp decrease was evident. The highest fecundity of the female (387.2 eggs per female) was recorded at 20°C. Based on these results, life tables of S. japonicum were constructed for temperatures in the range 20–35°C. The maximum reproductive rate (R ₀=279.9) occurred at 26°C. The maximum values for innate capacity for increase (r _m=0.1131) and the finite rate of increase (λ=1.1197) occurred at 29°C. The mean generation time (T) decreased with increased temperature, the longest of which was 76.0 days (at 20°C) and the shortest was 36.6 days (at 32°C). These results offer valuable insight on the importation and establishment of S. japonicum into new environments with diverse temperature regimes.     

Life table and heat tolerance of Acyrthosiphon pisum (Hemiptera: Aphididae) in subtropical Taiwan

The effect of temperature on the life table of Acyrthosiphon pisum reared on Pisum sativum was evaluated under laboratory conditions using temperatures of 10, 15, 20, 25, 30, and 35°C. The development time of juvenile A. pisum decreased with increasing temperature (from 21.3 days at 10°C to 4.7 days at 35°C). Adult longevity also decreased with increasing temperature (from 53.2 days at 10°C to 2.3 days at 35°C). Interestingly, 70% and 25% of A. pisum nymphs reared at 30°C and 35°C, respectively, successfully developed into adults. These temperatures have previously been considered unsuitable for A. pisum development. However, adult aphids reared at 30°C and 35°C failed to reproduce. Linear regression analysis revealed that the lower development threshold of A. pisum was 153.1 degree‐days above 1.9°C. Maximal average reproductive capability was observed at 10°C for A. pisum adults, with each adult producing more than 120 nymphs. The intrinsic rate of increase (r_m) of A. pisum increased from 0.124/day at 10°C to 0.337/day at 25°C, whereas opposite trends were observed for the net reproductive rate (R₀) and the mean generation time (GT). At 20°C and 25°C, the intrinsic rate of increase of A. pisum was significantly higher than at 10°C and 15°C (P < 0.0001), indicating that 20°C and 25°C are within the optimal range for the growth of A. pisum, and that 30°C is beyond the upper threshold limit for reproduction, which involves a temperature range that is narrower than that of the survival range (upper limit is unknown, but above 35°C).     

Effect of temperature on the rate of oxidation of pyrrhotite-rich sulfide ore flotation concentrate and the structure of the acidophilic chemolithotrophic microbial community

Oxidation of flotation concentrate of a pyrrhotite-rich sulfide ore by acidophilic chemolithoautotrophic microbial communities at 35, 40, and 45°C was investigated. According to the physicochemical parameters of the liquid phase of the pulp, as well as the results of analysis of the solid residue after biooxidation and cyanidation, the community developed at 40°C exhibited the highest rate of oxidation. The degree of gold recovery at 35, 40, and 45°C was 89.34, 94.59, and 83.25%, respectively. At 40°C, the highest number of microbial cells (6.01 × 10⁹ cells/mL) was observed. While temperature had very little effect on the species composition of microbial communities (except for the absence of Leptospirillum ferriphilum at 35°C), the shares of individual species in the communities varied with temperature. Relatively high numbers of Sulfobacillus thermosulfidooxidans, the organism oxidizing iron and elemental sulfur at higher rates than other acidophilic chemolithotrophic species, were observed at 40°C.     

Comparison of thermotolerance of sun-exposed peel and shaded peel of ‘Fuji’ apple

The thermotolerance of the sun-exposed peel and the shaded peel of ‘Fuji’ apple (Malus domestica Borkh.) fruit was evaluated by measuring pigments, chlorophyll a fluorescence transients and O₂ evolution or uptake after exposure to 25, 35, 40, 42, 44, 46 or 48 °C for 30 min in the dark. A major effect of heat stress at 46–48 °C on the chlorophyll a fluorescence transients was the appearance of a very clear K step at 200–300 μs for both peel types. The K step was slightly more pronounced in the sun-exposed peel than in the shaded peel, suggesting that the resistance of oxygen-evolving complex to heat stress is slightly lower in the sun-exposed peel than in the shaded peel. Minimal fluorescence (F_O), relative to the value at 25 °C, increased to a greater extent in the shaded peel than in the sun-exposed peel after exposure to 46–48 °C, but the temperature dependencies of F_O changes were similar for both peel types. Maximum quantum yield of PSII (F_V/F_M) decreased to a similar extent in the sun-exposed peel and the shaded peel as temperature rose from 25 to 44 °C, but the sun-exposed peel reached slightly lower values at 46–48 °C. Correspondingly, gross O₂ evolution rate, relative to that at 25 °C, was also slightly lower in the sun-exposed peel than in the shaded peel at 46–48 °C. In response to heat stress, the ratio of Q_A-reducing reaction centers (RCs) to total RCs and the ratio of Q_B-reducing RCs to Q_A-reducing RCs decreased, but both of them decreased to lower values in the sun-exposed peel than in the shaded peel at 46–48 °C, indicating that the capacity of electron transfer between P₆₈₀⁺ and Q_B via Q_A was damaged to a greater extent in the sun-exposed peel than in the shaded peel. At each given temperature, dark respiration was similar between the two peel types. Overall, it appears that the exposure to higher surface temperature under high light does not make the sun-exposed peel more tolerant of heat stress than the shaded peel of apple fruit.     

INFLUENCE OF TEMPERATURE ON CERTAIN BIOLOGICAL ATTRIBUTES OF A LADYBEETLE COCCINELLA SEPTEMPUNCTATA LINNAEUS

Influence of temperature on certain biological attributes of an aphidophagous ladybeetle, Coccinella septempunctata Linnaeus, feeding on mustard aphid, Lipaphis erysimi (Kaltenbach), at five different temperatures, viz. 20, 25, 27, 30 and 35°C was investigated. Its developmental period was shortest (11.7 ± 0.09 days) at 35°C and longest (20.6 > 0.35 days) at 20°C. Developmental rate increased with increase in temperature. Hatching percent, larval survival, adult emergence and growth index were maximum at 30°C and minimum at 20°C. Oviposition period and fecundity were highest at 30°C and lowest at 20°C. A positive linear relationship exists between temperature and developmental rate and negative correlation between the duration of immature life stages and temperature. The proportion of developmental period allocated to each immature stage was found to be similar at each temperature regime. Thus, 30°C was found as the most suitable for C. septempunctata amongst the five temperatures tested.     

Suppression of an exocellular proteinase synthesis inBacillus megaterium by increased temperature

During cultivation ofBacillus megaterium at 42 °C the amount of the exocellular protease produced by growing cells sharply decreases as compared with temperatures of 28 and 35 °C. Within the above range the growth rate and incorporation of amino acids increase with increasing temperature. The culture adapted to 42 °C does not produce more proteinase at this temperature than the non-adapted culture. The high temperature does not induce accumulation of the enzyme in the cells. Total protein excretion was slightly lower at 42 °C than at 28 and 35 °C.     

Multiple generation effects of high temperature on the development and fecundity of Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) biotype B

Insects are ectotherms and their ability to resist temperature stress is limited. The immediate effects of sub‐lethal heat stress on insects are well documented, but longer‐term effects of such stresses are rarely reported. In this study, survival, development and reproduction of the whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) biotype B, were compared over five consecutive generations at 27, 31 and 35 °C and for one generation at 37 °C. Both temperature and generation significantly affected the fitness of the whitefly. These impacts were more dramatic with increasing generations and temperatures. Among the experimental temperatures, the most favorable for development and reproduction were 27 °C and 31 °C. At 27 °C, survival, development and fecundity were all stable over these five generations. At 31 °C, immature survival rate was the highest in the fifth generation, but female fecundities decreased in the fourth and fifth generations. At 35 °C, egg hatching rate, immature survival rate and female fecundity decreased significantly in the fourth and fifth generations. At 37 °C, survival of B. tabaci was not adversely affected, but female fecundity at 37 °C was less than 10% of that at 27 °C or 31 °C. These results demonstrate that the lethal high temperature for B. tabaci is over 37 °C, and the whitefly population continued expanding in the five generations at 35 °C. The ability of B. tabaci biotype B to survive high temperature stress will play an important role in its population extension under global warming.     

Reproduction,survival, and life table parameters of the predatory mite <Emphasis Type="Italic">Cheyletus malaccensis</Emphasis> (Acari: Cheyletidae) at various constant temperatures

Reproduction, survival, and life table parameters of the predatory mite Cheyletus malaccensis Oudemans were evaluated at six constant temperatures: 17.5, 20, 25, 30, 32.5 and 35°C, feeding on Tyrophagus putrescentiae (Schrank). Preoviposition period of fertilized and virgin females varied with temperature from ca. 9 days at 17.5°C to ca. 1.5 day at 32.5°C and then increased to ca. 3 days at 35°C. Virgin female oviposition period was significantly shorter than for fertilized females at the temperatures examined with the exception of 17.5°C. The mean total number of eggs per fertilized (169.7 ± 6.6) and virgin female (60.7 ± 4.3) was highest at the temperature of 30°C. The data indicated a significant positive and nearly doubling effect of fertilization on female fecundity at the temperatures examined with the exception of 17.5°C. Age-specific fecundity was described by a temperature dependent model from which the maximum daily fecundity rate was estimated for fertilized and virgin females at 10.3 (at 30°C) and 6.8 (at 32.5°C) eggs/female, respectively. Virgin female longevity was significantly shorter than for fertilized females at 20, 30 and 32.5°C, and decreased from ca. 57 days at 17.5°C to ca. 17 days at 35°C. The Weibull function that was used to describe the age specific survival of fertilized and virgin females produced excellent fits to the survival data. Estimates of intrinsic rate of increase, net reproductive rate, mean generation time, doubling time and finite rate of increase, were obtained. The r_m value increased with temperature from 0.03 (day⁻¹) at 17.5°C to 0.21 (day⁻¹) at 32.5°C, after which it decreased to 0.15 (day⁻¹) at 35°C. These data indicate that C. malaccensis can reproduce at temperatures between 17.5 and 35°C and can be used for biological control of astigmatid mites within the temperature range where the pest occurs.     

Effect of Temperature Regimes on Germination of Dimorphic Seeds of Atriplex prostrata

Dimorphic seeds of Atriplex prostrata were removed from cold dry storage monthly over a one year period to test for fluctuations in seed dormancy and germination rate. For each seed type, four replicates of 25 seeds were exposed to four alternating night/day temperature regimes mimicking seasonal fluctuations in Ohio: 5/15 °C; 5/25 °C; 15/25 °C and 20/35 °C with a corresponding 12-h photoperiod (20 μmol m⁻² s⁻¹; 400 – 700 nm). We found a significant three-way interaction of seed size, temperature and month for both percent germination and the rate of germination. Large seeds showed the greatest germination at the 20/35 °C and 5/25 °C temperature regimes and small seeds at the 5/25 °C regime. Large seeds had greater germination at all temperatures as compared to small seeds. Large seeds had the fastest germination rates at 20/35 °C followed by 5/25 °C whereas small seeds had the fastest rates at 5/25 °C followed by 20/35 °C. This revised version was published online in July 2006 with corrections to the Cover Date.     

Foliage colour influence on seed germination of Bienertia cycloptera in Arabian deserts

Bienertia cycloptera (Chenopodiaceae) produces two types of leaf foliage colour (reddish and yellowish). In order to determine the role of leaf colour variation in regulating the germination characteristics and salinity tolerance during germination, a study was conducted on seeds collected from plants of both colours. Seeds with and without pulp were germinated under two illumination conditions (12‐h light photoperiod and continuous dark), three alternating temperature regimes (15/25°C, 20/30°C and 25/35°C), and several salinity levels at 20/30°C. Germination percentage was significantly higher for seeds without pulp as compared to the seeds with pulp. The response of B. cycloptera seeds to salinity depended on the leaf colour. Thus, the seeds collected from reddish coloured plants were able to tolerate higher salinity compared to those of yellowish coloured plant. The germination recovery results indicate that the seeds from both coloured plants could remain viable in saline condition and they will be able to germinate once the salinity level are decreased by rain. The production of different foliage colours by B. cycloptera seems to be an adaptative strategy which increases the possibility for establishment in unpredictable environments by producing seeds with different germination requirements and salinity tolerance.     

Photosystem 2 is more tolerant to high temperature in apple (<Emphasis Type="Italic">Malus domestica</Emphasis> Borkh.) leaves than in fruit peel

Tolerance of photosystem 2 (PS2) to high temperature in apple (Malus domestica Borkh. cv. Cortland) leaves and peel was investigated by chlorophyll a fluorescence (OJIP) transient after exposure to 25 (control), 40, 42, 44, and 46 °C in the dark for 30 min. The positive L-step was more pronounced in a peel than in leaves when exposed to 44 °C. Heat-induced K-step became less pronounced in leaves than in peel when exposed to 42 °C or higher temperature. Leaves had negative L-and K-steps relative to the peel. The decrease of oxygen-evolving complex (OEC) by heat stress was higher in the peel than in the leaves. OJIP transient from the 46 °C treated peel could not reach the maximum fluorescence (F_m). The striking thermoeffect was the big decrease in the relative variable fluorescence at 30 ms (V_I), especially in the leaves. Compared with the peel, the leaves had less decreased maximum PS2 quantum efficiency (F_v/F_m), photochemical rate constant (K_P), F_m and performance index (PI) on absorption basis (PI_abs) and less increased minimum fluorescence (F₀) and non-photochemical rate constant (K_N), but more increased reduction of end acceptors at PS1 electron acceptor side per cross section (RE₀/CS₀) and per reaction center (RE₀/RC₀), quantum yield of electron transport from Q_A ⁻ to the end acceptors (ϕ _R0) and total PI (PI_abs,total) when exposed to 44 °C. In conclusion, PS2 is more thermally labile than PS1. The reduction of PS2 activity by heat stress primarily results from an inactivation of OEC. PS2 was more tolerant to high temperature in the leaves than in the peel.     

Temperature-dependent development and immature survival of an aphidophagous ladybeetle, Propylea dissecta (Mulsant)

Development and survival of the immature stages of an aphidophagous ladybeetle, Propylea dissecta (Mulsant) was investigated at five constant temperatures, viz. 20, 25, 27, 30 and 35°C, using Aphis gossypii Glover as prey. Developmental period of all the life stages were significantly affected with change in constant temperature and developmental rate increased with increase in temperature. Theoretical lower thermal threshold for complete development and thermal constant was 10.39°C and 465.11 Day‐degrees, respectively. Of the various life stages, first instar larvae were most susceptible to mortality at temperatures between 20 and 30°C, whilst pre‐pupae suffered least mortality. Egg‐mortality was maximum at 35°C. Female biased sex ratios were obtained at all five temperatures tested with higher proportion of females at the extremes of temperature, thus suggesting that females are more thermal‐tolerant. Lowest mortality of immature stages with maximum larval survival and adult emergence was recorded at 27°C, while reverse was the case at 35°C. Thus, 27°C may be considered best for the laboratory rearing of P. dissecta.     

Thermal Dependence of Tongue-flicking and Comments on Use of Tongue-flicking as an Index of Squamate Behavior

Tongue-flicking rate has often been used as a dependent variable or a component of a dependent variable taken as a measure of responsiveness to chemical stimuli by lizards and snakes. Because temperature has been controlled in most studies, effects of temperature have been largely overlooked. In this study, a constant stimulus, the adult cloacal odor of a conspecific female, was presented to adult scincid lizards (Eumeces laticeps) and temperature was from 15 ° to 35 °C. Tongue-flicking rates by adult Eumeces laticeps in response to cloacal odors of conspecific females were strongly thermally dependent in 20 s and 60 s trial periods. The tongue-flick-temperature curve appears to be roughly quadratic over the entire 15 °-35 °C range studied, with very low rates at 15 ° and 20 °C followed by a rapid rise to maximum tongue-flicking rate at 30 ° and rapid decline to 35 °C. Presumably, similar relationships apply to other lizards and snakes with modifications related to ecological characteristics such as diel activity cycle and foraging mode, to relative position on a scale of eurythermy-stenothermy, and to taxon. Thermal response curves for other stimuli, especially prey odors, are likely to have the same basic form, but have not been determined.     

Influence of temperature and daylength on population development ofAphis gossypii onCucurbita pepo

The life table parameters ofAphis gossypii Glover were evaluated in tow sets of experiments onCucurbita pepo. The first set was conducted at six constant temperatures (5°C increments from 10–35°C) with 12 h photophase. The second set of experiments was conducted at 6, 12, and 18 h photophase at 25°C. Nymphal survivorship was 100% at 15, 20, 25 and 30°C. However, it was 80 and 0% at 10 and 35°C, respectively. The optimum temperature for body length was 10°C, and body length decreased with increasing temperature.A. gossypii attained its optimum growth and reproduction at 25°C. At this temperature, the net reproductive rate (79.7), intrinsic rate of increase (0.496) and finite rate of increase (1.6) were largest while generation time (6.6 d) and population doubling time (1.4 d) were smallest. Temperatures above and below 25°C reduced the net reproductive rate, and the intrinsic and finite rates of increase. The intrinsic and finite rates of increase ofA. gossypii reared at 18 h photophase (0.53 and 1.7) were significantly higher than at 12 (0.43 and 1.5) and 6 h daylength (0.49 and 1.6).     

Influences of Culture Temperature on the Growth, Lipid Content and Fatty Acid Composition of Aurantiochytrium sp. Strain mh0186

The growth, lipid content, and fatty acid composition of Aurantiochytrium sp. strain mh0186 at different temperatures were investigated. Strain mh0186 grew well at 15–30°C, but weakly at 10°C. The biomass at 15–30°C was significantly higher than at 10 and 35°C, and the total lipid at 15–35°C was significantly higher than that at 10°C. The amount of DHA in the total fatty acid was highest at 10°C and decreased in response to temperature increase. The content of DHA (mg/g-dry cell weight) at 15–30°C were significantly higher than those at 35°C and those at 15–25°C were significantly higher than those at 10 and 35°C. The DHA yield at 15–35°C was significantly higher than those at 10 and 35°C. Unsaturation of fatty acid was regulated by temperature and was enhanced in response to temperature decrease. The ratio of DHA to DPA varied at different temperatures.     

Biocide application for increasing storage periods and maintaining quality and chemical constituents of banana fruits

Banana fruits were treated with biocides formulated from essential oils of anise, coriander or black cumin seeds. Treated and non-treated fruits were stored at temperatures of 5, 10, 15 and 20°C. Samples were stored for periods of 10, 20, 30, 40, 50 and 60 days. The collected samples in each interval were subjected to estimation of decay development and quality degree, in addition to the chemical constituents of starch, sugars, vitamin C of pulp and peel chlorophyll content. Results reveal that non-treated banana fruits decayed continuously by lapse of storage periods. However, this decay was significantly delayed by lowering the storage temperature. Soaking banana fruits in the tested biocides showed a positive potential for interrupting the decay in stored banana fruits and this promising impact was much more pronounced at lower storage temperature. Further, biocide treated banana fruits kept their good quality for longer storage periods compared to non-treated fruits, due to lower ripening rates which promisingly prolonged shelf-life. As the starch content gradually decreased during storage, the total sugar content increased. On the other hand, biocide application retarded the conversion of starch into simple sugars, especially at the low temperature rate. Additionally, the imposed treatments maintained vitamin C in banana pulp and lowered the decline in peel chlorophyll content.     

The influence of temperature,sexual condition,and season on the metabolic rate of the lizardPsammodromus hispanicus

Summary Male and femalePsammodromus hispanicus from southern Europe were acclimated to four seasonal conditions of photoperiod and night time temperature. During the dark period, the lizards' body temperatures fell to ambient air temperature but during the light period the lizards were allowed to thermoregulate behaviourally and at such times the lizards' mean body temperature varied from 29.0°C to 32.6°C. The resting metabolic rate of these lizards was measured in 5°C steps from 5°C to 30°C or 35°C. Sexual condition had little effect on resting metabolic rate, but at low temperatures lizards acclimated to winter or spring seasonal conditions had lower resting metabolic rates than those acclimated to summer or autumn conditions. At temperatures above 20°C seasonal acclimation had no effect on resting metabolic rate. It is considered that the reduction in low temperature metabolic rate in spring and winter is induced by low night time temperatures and serves to conserve energy during those seasons when lizards must spend long periods at low temperature without being able to feed.     

Lipases obtained from orange wastes: Commercialization potential and biochemical properties of different varieties and fractions

Brazil is the world's leading orange supplier for juice production purposes. However, the production process generates high amount of wastes, which leads to disposal problems. Orange wastes can be used for lipases production, incorporating the biorefinery concept into juice industries. Thus, the aim of the present study was to investigate the wastes of orange production chain as source of lipases based on different varieties (Pera, Hamlin, Valencia, and Natal), as well as on different fractions of wastes. The mass balance of the juice/wastes (2007–2016 crops) was evaluated, and lipases from different varieties and fraction were biochemically characterized. Overall, the wastes corresponded to approximately 43% of the fruit mass. All the fractions of all varieties showed lipase activity in emulsified olive oil and in p-nitrophenyl substrates. The highest lipase activities were obtained by Natal pulp in emulsified olive oil, Natal frit, and Hamlin peel in p-NPB and Hamlin frit in p-NPL and p-NPP. The bagasse, peel, and frit lipases from the different orange varieties showed optimum pH from 6.0 to 8.0 and optimal temperature from 30 °C to 60 °C. Thus, it is possible concluding that the orange processing for juice production purposes generates a large amount of wastes, which can be destined to profitable purposes as lipases production. Lipases produced by different fractions and varieties are biochemically diverse, enabling the application a wide range of processes. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 35: e2734, 2019