共查询到20条相似文献，搜索用时 46 毫秒
1.
Jan Suszka Beata P. Plitta Marcin Michalak Barbara Bujarska-Borkowska Tadeusz Tylkowski Paweł Chmielarz 《Annals of Forest Science》2014,71(5):543-549
Context
Black poplar (Populus nigra L.) is an alluvial forest tree species whose genetic pool is decreasing in Europe. Poplar trees produce short-lived seeds that do not store well.Aim
The feasibility of seed storage in conventional and cryogenic conditions after their desiccation from water content (WC) of 0.15 to 0.07 g H2O g?1 dry mass (g g?1) was investigated.Methods
Seed germinability was evaluated (seeds with a radicle and green cotyledons were counted) after storage of seeds for a period of 3 to 24 months at different temperatures: 20°, 10°, 3°, ?3°, ?10°, ?20° or ?196°C.Results
Seeds desiccated to a 0.07 g g?1 WC can be stored successfully at ?10 °C and ?20 °C for at least 2 years. A significant decrease in germination was observed only after 12 months of seed storage (WC 0.15 g g?1) at temperatures above 0 °C. We demonstrated that both fresh (0.15 g g?1 WC) and desiccated (0.07 g g?1 WC) seeds can be preserved at ?196 °C for at least 2 years.Conclusions
Seed storage temperature and time of storage were statistically significant factors affecting seed storability. The presented data provide a foundation for the successful gene banking of P. nigra seeds. 相似文献2.
? Context
Soil temperature can limit tree growth and function, but it is often unaddressed in understanding the successional status of trees.? Aims
We tested how soil temperature affected carbon allocation strategies of two dominant co-occurring boreal conifer species, Pinus contorta and Picea mariana.? Methods
We measured nonstructural carbon (NSC) concentrations, biomass, and photosynthesis of dormant and actively growing 2-year-old seedlings in response to three soil temperatures (5, 10, and 20 °C) under a common ambient air temperature.? Results
For both species, variation in carbon reserves with soil temperature was more pronounced following seedling growth than during dormancy. For both species and all organ types (roots, needles, and stems), NSC concentrations were highest when seedlings were grown at 5 than 20 °C. Mass adjusted for NSC content was negatively correlated with NSC concentration for all organ types of both species. Soil temperature had a marginally significant effect on photosynthesis of pine; seedlings grown at 10 or 20 °C acquired more carbon than seedlings grown at 5 °C. Spruce seedlings photosynthesized more when grown at 20 °C than at 5 or 10 °C.? Conclusion
Interspecific differences in allocation of carbon may underlie the responses of P. mariana and P. contorta to cold soils and consequently their successional status. 相似文献3.
Phenology,life table analysis and temperature requirements of the invasive brown marmorated stink bug,Halyomorpha halys,in Europe 总被引：1，自引：0，他引：1
The invasive Halyomorpha halys was accidentally introduced into Switzerland around 2004 and has recently established in the neighbouring countries of France and Italy. To better understand the population dynamics of this pest in Europe, the phenology, reproductive biology and temperature requirements of Swiss H. halys populations were investigated. Overwintered adults became active in April, but peak oviposition was not observed before early July. Individual females laid on average 79 eggs (maximum of 160). The oviposition period lasted from mid-June to end of September. Eggs laid in August and September did not result in offspring due to the low temperatures in autumn. Under natural fluctuating temperatures, development from egg to adult lasted between 60 and 131 days. The first new generation of adults did not occur before mid-August when the photoperiod was already below 15 h, which likely initiated diapause and suppressed the reproductive activity of new generation adults. Under controlled conditions of 20, 25 and 30 °C, Swiss H. halys populations developed within 75.8, 42.3 and 33.2 days from egg to adult, respectively. No development was possible at or below 15 and at or above 35 °C. The number of degree days required for completion of development from egg to adult was 588.24 DD. Under semi-natural conditions, total mortality of Swiss H. halys populations was 86.7 % with a net reproductive rate of 5.69, indicating growing populations. In Switzerland, H. halys is univoltine, but if it continues to spread into the Mediterranean area two generations per year could be expected. 相似文献
4.
Kieren D. Rix Alistair J. Gracie Bradley M. Potts Phillip H. Brown Cameron J. Spurr Peter L. Gore 《Annals of Forest Science》2012,69(6):673-679
Context
High temperature stress in nurseries germinating Eucalyptus globulus seed is an important problem affecting germination synchrony and rate. Where there is a risk of high-temperature stress, then the choice of female parent may be important. This issue is particularly relevant to the production of full-sib families from mass-supplementary pollination where there may be opportunities for seed producers to manipulate the directionality of the crossing done in seed orchards.Aims
This study aimed to quantify the maternal versus paternal influence of seed sensitivity to high temperature stress during germination.Methods
A diallel crossing scheme involving four genotypes was used to test the relative importance of male and female genetic influences on the germination and development of E. globulus seed and their response to high temperature stress. Seed was germinated at optimum (25°C) and supra-optimal (32°C and 37°C) temperatures, and six traits describing the proportion and rate of seed germination and early seedling development were assessed.Results
Both paternal and maternal effects affected the germination response, arguing for at least some influence of the nuclear genotype of the embryo. However, the response to high temperature stress was more influenced by the maternal than paternal parent.Conclusion
Both the male and female genotype may affect various aspects of seed germination and early seedling development independent of seed size; however, some facets of the germination response will be mainly affected by the female parent. 相似文献5.
The mortality of adults, eggs, larvae and pupae of the cowpea storage bruchid,Callosobruchus maculatus (Fab.) was observed in four different high carbon dioxide (CO2) in air atmospheres (88% CO2, 70% CO2, 60% CO2 and 50% CO2) at 25°C and 32°C respectively, and 70% RH. All the developmental stages ofC. maculatus were completely killed within 5 days in the 88% CO2 in air atmosphere and within 12 days in the other high CO2 atmospheres tested. The adult and egg stages were most susceptible, and the old larvae and pupae, the least susceptible to the high CO2 atmospheres. Mortality ofC. maculatus was significantly influenced by the level of CO2, stage of insect development, exposure period and temperature. 相似文献
6.
Dr. Mahmoud Sabri Lababidi 《Journal of pest science》1989,62(1):14-18
The development, longevity, fecundity and sex ratio of the predatory miteAmblyseius longispinosus (Evans) were studied at different constant and alternating temperatures withTetranychus cinnabarinus as prey. Alternating temperatures had no significant effect on the developmental times, in comparison with optimal constant temperature. At the alternating temperature of 33/23°C the mean duration of the life cycle from egg to adult was obvious longer with 5.0 and 4.4 days forA. longispinosus females and males than at alternating temperature of 30/20°C with 4.2 and 4.1 days for females and males. At 25°C constantly the egg stage was the longest during development and required a mean of 2.2 days.A. longispinosus females and males remained in larval stage for 0.5 and 0.6 days. The protonymphal and deutonymphal stage lasted for 0.7 and 1.1 for females and for 0.7 days for males, respectively. At all temperatures the development of females required significantly longer than of males. Longevity ofA. longispinosus adults was variable to tested temperatures: At 25°C females lived for 33.1 days, at 30/20°C for 30.6 days and at 33/23°C for 29.9 days. At 25°CA. longispinosus females produced a mean total progeny of 48.8 eggs and the mean duration of oviposition period was 21 days; at 30/20°C and at 33/23°C a mean number of 49.1 and 48.2 eggs was laid during an oviposition period of 20 days. Temperature had no effect on the sex ratio of predatory mites, about 70% of mites became females at all temperatures. 相似文献
7.
Carbon storage in biomass,litter, and soil of different plantations in a semiarid temperate region of northwest China 总被引：1，自引：0，他引：1
? Context
A large area of abandoned land in the semiarid temperate region of China has been converted into plantations over the past decades. However, little information is available about the ecosystem C storage in different plantations.? Aim and methods
Our objective was to estimate the C storage in biomass, litter, and soil of four different plantations (monospecific stands of Larix gmelinii, Pinus tabuliformis, Picea crassifolia, and Populus simonii). Tree component biomass was estimated using allometric equations. The biomasses of understory vegetation and litter were determined by harvesting all the components. C fractions of plant, litter, and soil were measured.? Results
The ecosystem C storage were as follows: Picea crassifolia (469 t C/ha)?>?Larix gmelinii (375 t C/ha), Populus simonii (330 t C/ha)?>?Pinus tabuliformis (281 t C/ha) (P?<?0.05), 59.5–91.1 % of which was in the soil. The highest tree and understory C storage were found in the plantation of Pinus tabuliformis (247 t/ha) and Larix gmelinii (1.2 t/ha) respectively. The difference in tree C fraction was significant among tree components (P?<?0.05), following the order: leaf?>?branch?>?trunk?>?root. The highest soil C (SC) was stored in Picea crassifolia plantation (411 t C/ha), while Populus simonii plantation had a higher SC sequestration rate than others.? Conclusion
C storage and distribution varied among different plantation ecosystems. Coniferous forests had a higher live biomass and litter C storage. Broadleaf forests had considerable SC sequestration potential after 40 years establishment. 相似文献8.
The development time, survival and fecundity of the generalist predatory mite, Neoseiulus umbraticus Chant, were determined at 20, 25, and 30?°C and 65?±?10?% RH. N. umbraticus females completed development in 9.7, 8.0 and 5.9 days, respectively, using a diet of all life stages of Tetranychus cinnabarinus Boisduval. Total developmental times of males were relatively shorter at 25 and 30?°C than at 20?°C. In general, preoviposition, oviposition, and postoviposition periods of N. umbraticus shortened as temperature increased. The longest survival rate of N. umbraticus of 80.5 days occurred at 20?°C, followed by 67.0 and 57.6 days at 25 and 30?°C, respectively. Mated females laid an average 0.9, 1.3 and 1.4 eggs per female per day and 33.1, 44.0 and 43.6 eggs over their entire lives at 20, 25 and 30?°C, respectively. The sex ratios of this species were 0.57, 0.57 and 0.54 female (female+male) at 20, 25 and 30?°C, respectively. The intrinsic rate of increase (rm) became greater with rising temperatures from 0.123 at 20?°C to 0.180 at 30?°C. The net reproduction rate (Ro) was highest at 25?°C (25.0 females/female) and lowest at 20?°C (18.8 females/female), while To decreased with increasing temperatures, from 23.8 days at 20?°C to 17.5 days at 30?°C. 相似文献
9.
Yuhua Bai Ming Zhao Liming Bai Ryo Hasegawa Jun-ichi Sakai Toshiaki Hasegawa Tomokazu Mitsui Hirotsugu Ogura Takao Kataoka Katsutoshi Hirose Masayoshi Ando 《Journal of Wood Science》2011,57(1):56-65
Sixteen cardenolide triglycosides (1?C16) were isolated from stems, twigs, and leaves of Nerium oleander. Among them, 3??-O-(4-O-gentiobiosyl-d-diginosyl)-7??,8-epoxy-14-hydroxy-5??,14??-card-20(22)-enolide, named cardenolide B-3 (16), was isolated from natural sources for the first time. The in vitro anti-inflammatory activities of compounds 1?C16 were examined on the basis of inhibitory activity against the induction of intercellular adhesion molecule-1 (ICAM-1). Compounds 1?C5 were active at an IC50 value of less than 7 ??M. The cytotoxic activity of isolated compounds was evaluated against three human cell lines: normal human fibroblast cells (W-38), malignant tumor cells induced from WI-38 (VA-13), and human liver tumor cells (HepG2). Compounds 1?C5 were active toward WI-38 cells; compounds 1, 3, and 5 were active toward VA-13 cells; and compounds 1?C5 were active toward HepG2 cells at IC50 values of less than 10 ??M. The multidrug-resistant (MDR) cancer-reversal activity of compounds 1?C16 was evaluated on the basis of the amount of calcein accumulated in MDR human ovarian cancer 2780AD cells in the presence of each compound. Compounds 13 and 14 showed significant effects on calcein accumulation. 相似文献
10.
Jianfen Guo Guangshui Chen Jinsheng Xie Zhijie Yang Yusheng Yang 《Annals of Forest Science》2014,71(5):585-594
? Context
Coarse woody debris (CWD, ≥10 cm in diameter) is an important structural and functional component of forests. There are few studies that have estimated the mass and carbon (C) and nitrogen (N) stocks of CWD in subtropical forests. Evergreen broad-leaved forests are distributed widely in subtropical zones in China.? Aims
This study aimed to evaluate the pools of mass, C and N in CWD in five natural forests of Altingia gracilipes Hemsl., Tsoongiodendron odorum Chun, Castanopsis carlesii (Hemsl.) Hayata, Cinnamomum chekiangense Nakai and Castanopsis fabri Hance in southern China.? Methods
The mass of CWD was determined using the fixed-area plot method. All types of CWD (logs, snags, stumps and large branches) within the plot were measured. The species, length, diameter and decay class of each piece of CWD were recorded. The C and N pools of CWD were calculated by multiplying the concentrations of C and N by the estimated mass in each forest and decay category.? Results
Total mass of CWD varied from 16.75 Mg ha?1 in the C. fabri forest to 40.60 Mg ha?1 in the A. gracilipes forest; of this CWD, the log contribution ranged from 54.75 to 94.86 %. The largest CWD (≥60 cm diameter) was found only in the A. gracilipes forest. CWD in the 40–60 cm size class represented above 65 % of total mass, while most of CWD accumulations in the C. carlesii, C. chekiangense and C. fabri forests were composed of pieces with diameter less than 40 cm. The A. gracilipes, T. odorum, C. carlesii and C. chekiangense forests contained the full decay classes (from 1 to 5 classes) of CWD. In the C. fabri forest, the CWD in decay classes 2–3 accounted for about 90 % of the total CWD mass. Increasing N concentrations and decreasing densities, C concentrations, and C:N ratios were found with stage of decay. Linear regression showed a strong correlation between the density and C:N ratio (R 2?=?0.821). CWD C-stock ranged from 7.62 to 17.74 Mg ha?1, while the N stock varied from 85.05 to 204.49 kg ha?1. The highest overall pools of C and N in CWD were noted in the A. gracilipes forest.? Conclusion
Differences among five forests can be attributed mainly to characteristics of the tree species. It is very important to preserve the current natural evergreen broad-leaved forest and maintain the structural and functional integrity of CWD. 相似文献11.
Tree exudates play an important role in the defense system of trees. In this study, the composition of exudates secreted from the wound site of Cryptomeria japonica was examined. Seven diterpenoids, including ferruginol (1), cryptojaponol (2), isopimaric acid (3), 7β-hydroxydeoxocryptojaponol (4), isopimarol (5), sandaracopimarinol (6) and phyllocladan-16α-ol (7), were identified through chromatographic separation and spectroscopic analyses. Among them, ferruginol was the most abundant compound, accounting for 76.6 % of the total content in exudates. Exudates, ferruginol and isopimaric acid possessed the strongest antibacterial activity and had MIC values of 25–250, 12.5–100 and 6.25–100 μg/mL, respectively, against one strain of Gram-negative bacteria (Escherichia coli) and four strains of Gram-positive bacteria (Staphylococcus aureus, methicillin-resistant S. aureus, S. epidermidis and Enterococcus faecalis). In addition, exudates and ferruginol presented 79 and 53 % at 100 μg/mL, respectively, of antioxidant activities against 1,1-dipheny1-2-picrylhydrazyl radical. C. japonica bark exudates and their diterpenes exhibit the strongest antioxidant activity and can inhibit bacterial growth and thus have the potential to be developed into natural antioxidants and bactericides. 相似文献
12.
Carmen Sotelo Montes John C. Weber Dimas A. Silva Clarice Andrade Graciela I. B. Mu?iz Rosilei A. Garcia Antoine Kalinganire 《Annals of Forest Science》2012,69(6):747-756
? Context
There is little information about inter- and intra-specific variation in fuelwood properties of trees/shrubs in West Africa.? Aims
We studied variation in fuelwood properties of Balanites aegyptiaca, Combretum glutinosum, Guiera senegalensis, Piliostigma reticulatum, and Zizyphus mauritiana in the Sahelian and Sudanian ecozones of Mali.? Methods
Trees were sampled on different soil (sandy, sandy/loam, or rocky), land use (parkland agroforest or woodland), and terrain (flat, temporarily flooded, or hill slope) types in five regions extending from the drier eastern to the more humid western parts of Mali. Basic density, volatile matter, fixed carbon, ash content, moisture content, gross calorific value, and fuel value index were measured for each tree and adjusted for tree age.? Results
All fuelwood properties differed significantly among species, but there were significant species by region interactions. Most fuelwood properties of four species differed significantly among regions. Soil and/or land use type had significant effects on a few fuelwood properties of four species.? Conclusion
In general, fuelwood production is recommended in all regions for G. senegalensis, in drier regions for B. aegyptiaca and C. glutinosum, in more humid regions for Z. mauritiana, and on rocky soils for all species. Fuelwood production of P. reticulatum is not recommended. 相似文献13.
Ai-Fang Wang Marja Roitto Tarja Lehto Janusz J Zwiazek Mónica Calvo-Polanco Tapani Repo 《Annals of Forest Science》2013,70(8):781-790
Context
Waterlogging is predicted to become more common in boreal forests during winter and early spring with climate change. So far, little is known about the waterlogging tolerance of boreal tree species during their winter dormancy.Aim
The aim was to quantify the degree of waterlogging tolerance of 1-year-old dormant Norway spruce (Picea abies (L.) Karst.) seedlings.Methods
The seedlings were exposed to waterlogging in a growth chamber at temperature of 2 °C for 4 weeks and then allowed to recover for 6 weeks during the growth stage. Shoot and root responses were monitored by physiological and growth measurements.Results
No effect was found in the seedling biomass, but root mortality increased slightly during the early growth stage following waterlogging. The water potential of the needles became less negative at the end of the waterlogging and the early growth stage. The ratio of apoplastic to symplastic electrical resistance (R e/R i) of the needles was lower after waterlogging, indicating changes in the proportions of symplastic and apoplastic space. No differences were found between the treatments in the dark-acclimated chlorophyll fluorescence (F v/F m) of the needles. Slightly greater accumulation of starch and temporary reductions of some mineral nutrients in needles were found after waterlogging.Conclusions
We conclude that in late winter and early spring, Norway spruce seedlings potentially tolerate short periods of waterlogging. 相似文献14.
Context
Although adventitious shoots are produced in many tree species in response to injury, little is known about the effects of salinity on sprouting.Aims
The main objective was to examine the sprouting capacity of Pinus leiophylla seedlings in relation to injury and physiological changes induced by NaCl.Methods
Seedlings were grown in controlled-environment growth rooms and treated with 0, 100, 150, and 200 mM NaCl. Numbers of adventitious shoots were recorded and growth and physiological parameters measured after 64 days of treatments and following a 30-day recovery period.Results
NaCl treatments triggered sprouting of adventitious shoots, mainly in the lower parts of the stems. However, fewer sprouts were induced by 200 mM NaCl compared with the lower concentration treatments. These changes were accompanied by needle necrosis, decreased chlorophyll concentrations, seedling dry mass, and stem diameter. Stomatal conductance, net photosynthesis, and root hydraulic conductance decreased with increasing NaCl concentrations and did not return to the control levels after 30 days of stress relief.Conclusions
Pinus leiophylla has the regeneration potential when exposed to salinity. However, very high salt concentrations induce severe physiological impairments and, consequently, a decrease of this regeneration potential. 相似文献15.
Daniele Castagneri Assunta Esposito Giovanni Bovio Stefano Mazzoleni Umberto Seneca Ambra Elena Catalanotti Davide Ascoli 《Annals of Forest Science》2013,70(8):863-871
? Context
Prescribed burning is increasingly recommended to control encroaching shrublands in the Mediterranean area.? Aims
The aims of this paper are to analyze the fuel structural characteristics of Spartium junceum and how they influence fire behaviour during prescribed burning.? Methods
Two winter–spring prescribed burns were conducted in 2009 and 2011. Fuel load and structure of S. junceum shrubs were assessed using the Cube Method, and shrub 3-D models were built using the FIRE PARADOX FUEL MANAGER software. Allometric equations to estimate S. junceum fuel load were developed. During burning, thermocouples measured temperature variations, which were then analyzed relative to fuel characteristics.? Results
Fuel load components and distribution were strictly related to shrub height; in tall shrubs, most of the fine fuel was more than 1.5 m aboveground. Due to fuel vertical discontinuity, not all shrubs were burned in the fires, but wind increased fire sustainment and fuel consumption. Maximum temperatures (over 800 °C) and residence times were positively related to fuel load.? Conclusion
S. junceum tall shrublands represent high hazard formations due to their elevated fuel load, mostly in fine fuel fractions. Vertical discontinuity among fuel strata limits fire propagation in mild weather conditions. Winter–spring prescribed burning cannot eliminate S. junceum shrublands, but do create shrub cover discontinuity. As S. junceum has fire-adapted morphological traits, a single burn is insufficient to control it. 相似文献16.
Context
Bark beetles are known to be associated with fungi, especially the ophiostomatoid fungi. However, very little is known about role of pine weevils, e.g., Hylobius abietis, as a vector of these fungi in Europe.Aims
The aims of our study were to demonstrate the effectiveness of H. abietis as a vector of ophiostomatoid fungi in Poland and to identify these fungi in Scots pine seedlings damaged by weevil maturation feeding.Methods
Insects and damaged Scots pine seedlings were collected from 21 reforestation sites in Poland. The fungi were identified based on morphology, DNA sequence comparisons for two gene regions (ITS, β-tubulin) and phylogenetic analyses.Results
Sixteen of the ophiostomatoid species were isolated and identified. In all insect populations, Leptographium procerum was the most commonly isolated fungus (84 %). Ophiostoma quercus was also found at a relatively high frequency (16 %). Other ophiostomatoid fungi were found only rarely. Among these rarer fungi, four species, Leptographium lundbergii, Ophiostoma floccosum, Ophiostoma piliferum and Sporothrix inflata, were isolated above 3 %. L. procerum was isolated most frequently and was found in 88 % of the damaged seedlings. S. inflata was isolated from 26 %, while O. quercus occurred in 10 % of the seedlings.Conclusion
This study confirmed that L. procerum and O. quercus were common associates of H. abietis, while others species were found inconsistently and in low numbers, indicating causal associations. H. abietis also acted as an effective vector transmitting ophiostomatoid species, especially L. procerum and S. inflata, to Scots pine seedlings. 相似文献17.
Liming Bai Ming Zhao Asami Toki Toshiaki Hasegawa Jun-ichi Sakai Xiao-yang Yang Yuhua Bai Hirotsugu Ogura Tomokazu Mitsui Takao Kataoka Mariko Ando Katsutoshi Hirose Masayoshi Ando 《Journal of Wood Science》2011,57(1):47-55
Twelve polar cardenolide monoglycosides, 1, 2, 4?C13, and oleagenin (3) were isolated from the methanol extract of stems and twigs of Nerium oleander. Among these, oleagenin (3) and cardenolide monoglycosides named cardenolide B-1 (1) and cardenolide B-2 (2) were isolated from natural sources for the first time. The in vitro antiinflammatory activity of compounds 1?C13 was examined on the basis of inhibitory activity against the induction of the intercellular adhesion molecule-1 (ICAM-1). Compounds 4?C7 were active at an IC50 value of less than 0.4 ??M. The cytotoxic activity of compounds 1?C13 was evaluated against three human cell lines: normal human fibroblast cells (WI-38), malignant tumor cells derived from WI-38 (VA-13), and human liver tumor cells (HepG2). Compounds 4, 6, and 7 were active toward these three cell lines at IC50 values of less than 0.7 ??M, and compounds 5 and 8 were active toward the cell lines at IC50 values of less than 1.5 ??M. The multidrug resistance (MDR) cancer-reversal activity of compounds 1?C13 was evaluated on the basis of the amount of calcein accumulated in MDR human ovarian cancer 2780AD cells in the presence of each compound. Compound 1 and 12 showed significant effects on calcein accumulation. 相似文献
18.
Shi-Yong Yang Hai-Xia Zhan Feng Zhang Dirk Babendreier Yong-Zhi Zhong Qiao-Zhe Lou Yi Zhong Jin-Ping Zhang 《Journal of pest science》2018,91(4):1335-1343
Halyomorpha halys, the brown marmorated stink bug, is a serious agricultural and horticultural pest native to East Asia, which became an invasive pest in northern temperate parts of other regions in the mid-1990s. Trissolcus japonicus is a dominant egg parasitoid of H. halys in its native range. In this paper, we investigated mating, oviposition and fecundity of both virgin and mated females of H. halys. Virgin H. halys females produced unfertilized eggs, while mated females produced fertilized eggs, but mating states of adult females did not affect the number of eggs produced. We further compared the development and fecundity of T. japonicus on fertilized or unfertilized eggs of various ages. Fertilized eggs were tested continuously for up to 5 days (time to hatch), while unfertilized eggs were tested for up to 11 days (time to egg collapse). The fertilization status of the host egg had a significant effect on the development, emergence success, and sex ratio of T. japonicus progeny. A small increase in development time was observed for T. japonicus in fertilized eggs, fewer T. japonicus emerged from fertilized eggs than unfertilized eggs, and the proportion of female progeny was lower on fertilized eggs. The age of host eggs also significantly affected the development rate and fecundity of T. japonicus, with unfertilized eggs becoming more favorable than fertilized eggs as egg age increased. In summary, unfertilized H. halys eggs were better suited for T. japonicus development and fecundity, indicating their potential use in T. japonicus mass rearing. 相似文献
19.
Context
Although drought is generally considered the main environmental constraint in Mediterranean environments, the ability to acclimate to and tolerate frost in early developmental stages can be a determinant for seedling survival of many Mediterranean tree species like stone pine (Pinus pinea L.).Aims
The aim of this study was to assess the impact of the developmental stage of naturally regenerated stone pine individuals on tolerance to low temperature (LT) from summer to late autumn and in spring, at a highly continental site in central Spain. Specifically, we tested to what extent the differences in tolerance are related to shoot heteroblasty.Methods
We assessed LT tolerance of needles from individuals at three age classes (class C1: seedlings, class C2: 4- to 8-year-old saplings and class C3: >9-year-old saplings) over nine dates from summer to spring.Results
LT tolerance displayed severe seasonal trends and differed between age classes. It usually increased with sapling age. Such differences were tightly related to heteroblasty of the shoots. Our results point to a higher LT tolerance associated with larger leaf dry mass per unit area (LMA) values. No impact of late frosts on shoot growth rates was detected during this study.Conclusions
Developmental changes during early plant growth seem to play a role in frost tolerance of stone pine seedlings, a finding which furthers our understanding of regeneration dynamics in this species in areas with continental influence. 相似文献20.
Douglas Godbold Arvo Tullus Priit Kupper Jaak Sõber Ivika Ostonen Jasmin A. Godbold Martin Lukac Iftekhar U. Ahmed Andrew R. Smith 《Annals of Forest Science》2014,71(8):831-842