Green tides caused by the bloom of Ulva prolifera have affected the Yellow Sea annually since 2007.To explore the intrinsic causes of successive blooms,field investigations and indoor simulation experiments were condu...Green tides caused by the bloom of Ulva prolifera have affected the Yellow Sea annually since 2007.To explore the intrinsic causes of successive blooms,field investigations and indoor simulation experiments were conducted using micro-propagules of U.prolifera.From January to February 2014,micro-propagules of various green algae,including U.prolifera,Ulva flexuosa,and Ulva linza,were prevalent in the coastal waters of Rudong,Lianyungang,and Qingdao.However,in March 2014,micro-propagules of U.prolifera were not detected in the coastal waters of Lianyungang and Qingdao.Neither the spores nor gametes of U.prolifera can germinate at temperatures below 5℃.At 2℃and 5℃,U.prolifera spores and gametes could survive for 1-3 months at a light intensity range of 0-30μmol m^(-2)s^(-1)and for less than 1 month if the light intensity exceeded 30μmol m^(-2)s^(-1).By integrating indoor experiments and field investigations,this study found that U.prolifera spores and gametes could overwinter in the Rudong coastal area,which is an important factor for the annual emergence of recurring green tides in the Yellow Sea.展开更多
Peeling trunk,binding insect-attracting belt,cleaning orchard and soil-covering under the crown were the control methods on overwintering generation of oriental fruit moth.However,they had not been applied widely on t...Peeling trunk,binding insect-attracting belt,cleaning orchard and soil-covering under the crown were the control methods on overwintering generation of oriental fruit moth.However,they had not been applied widely on the production because of the lack of systematic quantitative evaluation.Aiming at this fact,the control effects of these technical measures were studied in peach with different ripening period.The results showed that peeling trunk was the best with the control effect of88.64%.The control effect of binding insect-attracting belt of grass bundle was74.13%,which was the most economical and efficient.Covering with soil layer of 3cm under the crown during the middle ten days of March could holdback the adult getting out from soil.Cleaning deadwood could clean out the overwintering larvae on the ground.展开更多
Chilo suppressalis （Walker） is one of the important pests in rice produc-tion. ln this paper, the spawning condition of Chilo suppressalis on rice seedlings in Wuxue, Qichun, Chongyang and Xiaogan of Hubei Province ...Chilo suppressalis （Walker） is one of the important pests in rice produc-tion. ln this paper, the spawning condition of Chilo suppressalis on rice seedlings in Wuxue, Qichun, Chongyang and Xiaogan of Hubei Province was investigated, and the spawning habit of overwintering-generation Chilo suppressalis on rice seedlings was analyzed. The results showed the overwintering-generation Chilo suppressalis prefers to spawn on verdant rice leaf blades （face, upper part）. The investigation on spawning habit of Chilo suppressalis would provide a theoretical basis for the fore-casting and control of Chilo suppressalis.展开更多
The ground-cover chrysanthemum （Dendranthemaxgrandiflorum Kitamura） ＇Zixunzhang＇ was used as the experimental material in this study. The physiological and biochemical indexes of leaves, emergent rhizomes and root...The ground-cover chrysanthemum （Dendranthemaxgrandiflorum Kitamura） ＇Zixunzhang＇ was used as the experimental material in this study. The physiological and biochemical indexes of leaves, emergent rhizomes and roots from ＇Zixunzhang＇ growing in the open field during the autumn and winter in Beijing area were deter- mined. These indexes showed that root activities decreased slowly with the drop in temperature. The relative water contents of leaves and emergent rhizomes, and the water content of roots decreased. The activities of SOD, CAT and POD from leaves and emergent rhizomes were affected significantly by low temperature, but their change trends were different, which suggested that these 3 enzymes might play an interacted role in the formation of the cold tolerance of ＇Zixunzhang＇ mum, while the changes of the three enzyme activities in roots were little when the tem- perature dropped. With the significant increasing of the content of soluble sugar from leaves, the contents of soluble protein and proline declined overall; and the contents of osmotic regulation substances of emergent rhizomes and roots increased at first and then decreased. The correlation analysis indicated that the cold toler- ance of ground-cover mum ＇Zixunzhang＇ was related closely to relative water con- tents, SOD enzyme activity, soluble protein, soluble sugar and root activity. The morphological observation of leaves, emergent rhizomes and roots also showed that the survival of the ground-cover mum mainly depended on the cold tolerance of roots during the overwintering.展开更多
We analyzed the relationships linking overwintering death and frost cracking to temperature and sunlight as well as the effects of low temperatures and freeze–thaw cycles on bud-burst rates,relative electrical conduc...We analyzed the relationships linking overwintering death and frost cracking to temperature and sunlight as well as the effects of low temperatures and freeze–thaw cycles on bud-burst rates,relative electrical conductivity,and phloem and cambial ultrastructures of poplar.Overwintering death rates of poplar were not correlated with negative accumulated temperature or winter minimum temperature.Freeze–thaw cycles caused more bud damage than constant exposure to low temperatures.Resistance to freeze–thaw cycles differed among clones,and the budburst rate decreased with increasing exposure to freeze–thaw cycles.Cold-resistant clones had the lowest relative electrical conductivity.Chloroplasts exhibited the fastest and the most obvious reaction to freeze–thaw damage,whereas a single freeze–thaw cycle caused little damage to cambium ultrastructure.Several such cycles resulted in damage to plasma membranes,severe damage to organelles,dehydration of cells and cell death.We conclude that overwintering death of poplar is mainly attributed to the accumulation of effective freeze–thaw damage beyond the limits of freeze–thaw resistance.展开更多
In order to select severe overwintering abilitied blueberry cultivars for cold resistance of annual branches, promoting breeding high quality cultivars, a study had been conducted into field-planting shoots overwinter...In order to select severe overwintering abilitied blueberry cultivars for cold resistance of annual branches, promoting breeding high quality cultivars, a study had been conducted into field-planting shoots overwintering ability and the relative conductivity, MDA content, SOD of 7 different kinds of blueberries under artificial cooling process. According to survey results, under field conditions, Different cultivars of blueberries showed significantly difference, ranging from 56.67% of Bluegold to 12.80% of Darrow. With the temperature decreasing, changes of relative conductivity, MDA content and SOD in annual branches had a strong regularity and the hardiness of these cultivars is: Northland > Chippewa > Coville > Bluecroup > Darrow > Bluegold > Powderblue.展开更多
312 recombinant inbred lines （RILs） in F9 from a cross between a overwintering cold-tolerant germplasm resource Glutinous rice 89-1（Gr 89-1） and a cold-sensitive variety Shuhui 527 was used for quantitative trait ...312 recombinant inbred lines （RILs） in F9 from a cross between a overwintering cold-tolerant germplasm resource Glutinous rice 89-1（Gr 89-1） and a cold-sensitive variety Shuhui 527 was used for quantitative trait locus （QTL） analysis. The scores of percent ratooning germinability （PRG） and overwintering germinability （POG） were evaluated. The overwintering germination rate of axillary buds was scored to represent the overwintering germinability. Two significant QTLs （qPRG-4 and qPRG-7） on chromosomes 4 and 7 were detected and explained 8.3 and 7.2% of the total phenotypic variation, respectively. Three significant QTLs （qPOG-2, qPOG-3 and qPOG-7） were identified and mapped on chromosomes 2, 3, and 7, respectively. These QTLs contributed 9.6, 6.7, and 17.8% of phenotypic variations, respectively. A comparative analysis using SSR markers closely linked to the three QTLs for the overwintering revealed cold-tolerant individuals, which harbour the Glutinous rice 89-1 alleles at RM7110, RM250, RM418, and RM232, had a high percent overwintering germinability, while cold-sensitive individuals, which carry Shuhui 527 alleles at these loci, had a low percent overwintering germinability in the F2 population of Shuhui 527/Glutinous rice 89-1. This study demonstrated the utility of these SSR markers for selection of overwintering germinability genotypes.展开更多
Background: Understanding how overwintering birds choose foraging habitats is very important for conservation management. The overwintering Black-necked Crane(Grus nigricollis) feeds on crop remains in farmlands;thus,...Background: Understanding how overwintering birds choose foraging habitats is very important for conservation management. The overwintering Black-necked Crane(Grus nigricollis) feeds on crop remains in farmlands;thus, reasonable conservation management of this type of farmland that surrounds wetlands is critical for the overwintering populations of the Black-necked Crane;however, it is not clear how the Black-necked Crane chooses the foraging land in the farmland.Methods: A thorough field positioning survey of all foraging sites in farmland areas around the Caohai Wetland and a-sampling analysis of habitat selection by the Black-necked Crane were conducted during the winters from 20162017 and 2017-2018.Results: Multiple factors contributed to the selection of foraging habitat in farmlands, i.e., food factors(crop remains and tillage methods) > human disturbance factors(distance to road and settlement) > topography factors(slope aspect), listed according to the strength of influence. Additionally, Black-necked Cranes tend to choose farmland sites where there was no machine tillage, the crop remains were > 500 g/m^2, the distance to residences ranged from 100 to 500 m, the distance to roads ranged from 50 to 100 m, and the slopes exhibited western or eastern aspects. As the winters progressed, the volume of the edible crop remains declined, and the influences of the other main factors also changed, i.e., the factors of human disturbance(distance to road and settlement) became less important, while the effect of the food factor(crop remains) was strengthened. Thus, the foraging sites near the road became more important.Conclusion: The farming area surrounding the Caohai Wetland is very important for the overwintering Black-necked Crane. Food factors and human disturbance factors are the main factors that influence the choice of feeding ground.展开更多
This article discusses the overwintering ability and genetic variation of the main agronomic traits in a new germplasm resource, glutinous rice 89-1. Survival rates of overwintering axillary buds and stems were observ...This article discusses the overwintering ability and genetic variation of the main agronomic traits in a new germplasm resource, glutinous rice 89-1. Survival rates of overwintering axillary buds and stems were observed in different altitudes. The F1, backcross F1 and F2 populations were constructed from sexual crossing between glutinous rice 89-1 and Hongmangnuo, Fuhui 838, Minghui 63, Ce 64. The overwintering ability and genetic variation of the main agronomic traits were analyzed in different seasons. Results showed that glutinous rice 89-1 could overwinter by axillary buds in low temperatures at different altitudes. Axillary buds would ratoon in the following year. The survival rates of rice stem and axillary buds were 82.6 and 29%, respectively. The grain yields were 6 291.0 kg ha^-1 in the overwintering ratooning season, and corresponded in the main season. Genetic analysis and chi-square test showed that the overwintering ability of glutinous rice 89-1 was likely controlled by polygene, and heritabilities showed diversity in different hybrid combinations. The highest heritabilities of 1 000-grain weight and plant height were in the main crop season, whereas the lowest were in the overwintering season, and the heritabilities of grain numbers per panicle and the seed setting rate reached the highest in the ratooning season. The spikelets per panicle, the seed setting rate, the 1 000-grain weight, the plant height, and the spikelet length had nearly normal distribution in F2 populations of glutinous rice 89-1/Minghui 63, but the seed setting rate had bimodal distribution. Overwintering glutinous rice 89-1 was a useful new genetic germplasm resource.展开更多
[Objective] In this study,the climatic features and overwintering sage storage methods of seed-stem of cassava in cassava-planting areas were investigated aiming at providing a technical guidance for sustainable devel...[Objective] In this study,the climatic features and overwintering sage storage methods of seed-stem of cassava in cassava-planting areas were investigated aiming at providing a technical guidance for sustainable development of cassava industry in China.[Method] The seed-stem of cassava was overwintered through keeping in field,piling up in the open air,burying in soil or piling up in greenhouses in Hepu,Nanning and Laibin of Guangxi,Hunan and Zhejiang.After the beginning of spring,the survival buds in seed stem of cassava were counted.And then the survival rates of buds were calculated for different storage methods.[Result] In Hepu,where the seed-stem of cassava was piled up in the open air for overwintering,the survival rates of buds were all higher than 90.00%.In particular,the survival rate of buds in seed-stem of cassava that was buried shallowly in the open field was highest（94.38%）.In Nanning,the seed-stem of cassava that was stored in greenhouses had the highest survival rate（94.98%） of buds.In Laibin,the seed-stem of cassava was usually stacked in greenhouses.Thus the survival rates of buds were almost all higher than 89.60%.Particularly,the survival rate of buds in seed-stem of cassava that was buried horizontally in soil and covered with sugarcane leaves reached the peak（98.79%）.In Jiangyong and Hangzhou,the seedstem of cassava was stored in specific facilities.So the survival rates of buds were relatively high.[Conclusion] In the frost-free areas south of 21.6° N（south of Maoming（Guangdong）-Hepu（Guangxi）-Jinghong（Yunnan））,the seed-stem of cassava can be buried shallowly in the open air or stacked and covered with film.In the light to heavy-frost areas（21.6° N-23.8° N,south of Qingyuan（Guangdong）-Laibin（Guangxi）-Lincang（Yunnan））,the seed-stem of cassava can be stacked in greenhouses,stacked and covered with film in the open air or buried vertically in greenhouses.In the heavy-frost areas and low-temperature areas north of 23.8° N（north of Qingyuan（Guangdong）-Laibin（Guangxi）-Lincang（Yunnan） to HunanJiangxi-Zhejiang）,the seed-stem of cassava can be stored in coldness-resistant caves or cellars or stacked vertically in greenhouses along with small sheds.展开更多
[ Objective] To understand the overwintering of Rana dybowskii under four overwintering modes in northern Guangdong＇s mountainous areas. [Method] The overwintering management of Rana dybowskii was performed under fou...[ Objective] To understand the overwintering of Rana dybowskii under four overwintering modes in northern Guangdong＇s mountainous areas. [Method] The overwintering management of Rana dybowskii was performed under four overwintering modes which were outdoor overwintering in water-land, outdoor overwintering in water, indoor overwintering in dryness, and indoor overwintering in freezer, respectively. The time, temperature and overwintering status were recorded. The Rana dybowskii in each group was weighed before and after overwintering, and the body weight loss and the survival rate were calculated. [ Result] Under the outdoor overwintering in water-land, outdoor overwintedng in water, indoor overwintering in dryness, and indoor overwintering in freezer, the survival rate of Rana dybowskii was 40.0%, 41.5%, 82.0% and 84.5%, respectively. [Conclusion] The temperature, overwintering mode and fatness are the important factors affecting the safe overwintering of Rana dybowskii in northern Guangdong.展开更多
The joint analysis of the mixed genetic model of major gene and polygene was conducted to study the inheritance of cryotolerance in cotton during the overwintering period.H077（G.hirsutum L.,weak cryotolerance） and H...The joint analysis of the mixed genetic model of major gene and polygene was conducted to study the inheritance of cryotolerance in cotton during the overwintering period.H077（G.hirsutum L.,weak cryotolerance） and H113（G.barbadence L.,strong cryotolerance） were used as parents.Cryotolerance of six generation populations including P1,P2,F1,B1,B2,and F2,from each of the two reciprocal crosses H077×H113 and H113×H077 were all investigated.The results showed that cryotolerance in cotton during the overwintering period was accorded with two additive major genes and additivedominance polygene genetic model.For cross H077×H113,the heritabilities of major genes in B1,B2,and F2 were 83.62,76.84,and 90.56%,respectively;and the heritability of polygene could only be detected in B2,which was 7.76%.For cross H113×H077,the heritabilities of major genes in B1,B2,and F2 were 67.42,68.95,and 83.40%,respectively;and the heritability of polygene was only detected in F2,which was 6.51%.In addition,the whole heritability in F2 was always higher than that in B1 and B2 in each cross.Therefore,for the cryotolerance breeding of perennial cotton,the method of single cross recombination or single backcross should be adopted to transfer major genes,and the selection in F2 would be more efficient than that in other generations.展开更多
Rice stripe mosaic virus(RSMV)is an emerging pathogen which significantly reduces rice yields in the southern region of China.It is transmitted by the leafhopper Recilia dorsalis,which overwinters in rice fields.Our f...Rice stripe mosaic virus(RSMV)is an emerging pathogen which significantly reduces rice yields in the southern region of China.It is transmitted by the leafhopper Recilia dorsalis,which overwinters in rice fields.Our field investigations revealed that RSMV infection causes delayed rice heading,resulting in a large number of green diseased plants remaining in winter rice fields.This creates a favorable environment for leafhoppers and viruses to overwinter,potentially contributing to the rapid spread and epidemic of the disease.Next,we explored the mechanism by which RSMV manipulates the developmental processes of the rice plant.A rice heading‐related E3 ubiquitin ligase,Heading date Associated Factor 1(HAF1),was found to be hijacked by the RSMV‐encoded P6.The impairment of HAF1 function affects the ubiquitination and degradation of downstream proteins,HEADING DATE 1 and EARLY FLOWERING3,leading to a delay in rice heading.Our results provide new insights into the development regulation‐based molecular interactions between virus and plant,and highlights the importance of understanding virus‐vector‐plant tripartite interactions for effective disease management strategies.展开更多
In northwest China,where winter is extremely cold and the grapevine is vulnerable to freezing damage,the application of soil covering has promoted the vigorous development of the local grape and wine industries.Howeve...In northwest China,where winter is extremely cold and the grapevine is vulnerable to freezing damage,the application of soil covering has promoted the vigorous development of the local grape and wine industries.However,in recent years,the negative effects of burying soil for cold protection on the environment have gradually emerged.In some viticultural regions,the phenomenon of"summer forest,winter desert"has appeared.Therefore,it is urgent for the Chinese grape industry to find a better solution to overwinter safely and environmentally friendly.This review summarizes the advantages and disadvantages of widely used solutions to overwinter such as covering vines with soil,breeding of cold-resistant grapes,cold-resistant cultivation model,physical and chemical covering materials,and protected grape facilities were reviewed.Future overwintering measures were proposed which avoid burial and grape overwintering research directions.It also provides a theoretical foundation and technical support to improve grape yield and quality in northwest China.展开更多
The Pearl River Delta,where Aedes albopictus(Ae.albopictus)is the only vector for dengue transmission,has exhibited one of the highest dengue burdens in southern China in recent decades.However,whether dengue virus(DE...The Pearl River Delta,where Aedes albopictus(Ae.albopictus)is the only vector for dengue transmission,has exhibited one of the highest dengue burdens in southern China in recent decades.However,whether dengue virus(DENV)can overwinter in Ae.albopictus in the Pearl River Delta has not been determined to date.In this study,300 field-derived Ae.albopictus mosquitoes from Guangzhou that were infected with the predominant endemic DENV-1 strain were investigated under simulated urban balcony environment from October 16,2016,to June 16,2017.The vertical transmission of DENV in the infected overwintering Ae.albopictus was analyzed.The DENV infected overwintering mosquitoes were evaluated for viral load at nine-time points using reverse transcription-quantitative PCR.The vector competence of the infected overwintering Ae.albopictus was also investigated by using suckling mice.Adult mosquitoes and larvae were found during the observation period.The vertical transmission of DENV-1 was documented.The DENV-1-positive rates between overwintering males and females had no difference.The proportion of DENV-1-positive overwintering mosquitoes decreased over time and had no difference beyond three months after the experiment.Overwintering mosquitoes can spread DENV-1 to hosts.No engorged mosquitoes at an ambient temperature below 15℃were observed.The ratio of engorged mosquitoes was positively correlated with the ambient temperature ranging from 15 to 30℃.Our results demonstrated that DENV can overwinter in Ae.albopictus in the Pearl River Delta,Ae.albopictus is the competent vector for DENV,and maintain autochthonous dengue outbreaks in the Pearl River Delta through vertical transmission.展开更多
Wheat stripe rust caused by Puccinia striiformis f.sp.tritici occurs widely in China and seriously affects wheat production.Global warming could profoundly impact the incidence and prevalence of lowtemperature disease...Wheat stripe rust caused by Puccinia striiformis f.sp.tritici occurs widely in China and seriously affects wheat production.Global warming could profoundly impact the incidence and prevalence of lowtemperature diseases such as stripe rust.Studies on the effects of temperature on the distribution of overwintering stripe rust could help us understand the incidence and prevalence of the disease and could also provide support for monitoring,forecasting and developing control strategies.An exponential model and a spherical model of the ordinary Kriging method in the ArcGIS platform were used to predict the overwintering regions of stripe rust based on the probability that the average temperature of the coldest month from December to February was higher than–6 or–7°C from 2001 to 2012.The results showed that the areas with a probability between 70%and 90%were transition regions for the overwintering of stripe rust.Based on annual mean temperature of the coldest month from December to February for 2001 to 2012,overwintering distribution of stripe rust was likewise evaluated.The boundary for overwintering of stripe rust was consistent with the areas where the probability was predicted to be 70%to 90%for the overwintering distribution of stripe rust,but the boundary was shifted northward toward Beijing in North China.Some areas in Xinjiang,including Akto,Pishan,Hotan and Yutian,were also predicted to be suitable for the overwintering of stripe rust.展开更多
The reproductive potential of overwintering boll weevil, Anthonomus grandis grandis （Boheman）, females collected from pheromone traps in September, November and January, fed for 1, 3, and 5 weeks on plant pollens, a...The reproductive potential of overwintering boll weevil, Anthonomus grandis grandis （Boheman）, females collected from pheromone traps in September, November and January, fed for 1, 3, and 5 weeks on plant pollens, and then provided cotton squares, was determined in the laboratory at 27 ~ I^C, 65% RH, and a photoperiod 13 ： 11 （L ： D） h. Duration of pollen feeding by overwintering boll weevils did not significantly influence egg and feeding punctures, or puncture ratios （egg to total punctures） for any of the three months of parent weevil collections when provided cotton squares on a daily basis. However, punctures and puncture ratios are significantly different when comparing mean data between months of boll weevil collections. When boll weevils were provided with cotton squares daily, the pre-ovipositional periods of female parents captured in September, November and January were 5, 9 and 14 days, respectively. The rate of eggs by females was significantly lower during November and January than September. Female parents collected in September produced a significantly higher percentage of eggs yielding adult progeny than those collected in November and January. Life table parameters indicated that net reproductive rate （Ro） of boll weevil females collected in September was 1.2- fold higher than those collected in November and 10.7-fold higher than those collected in January. Except for testes size, no differences in male reproductive parameters were observed during the cotton-free period compared with males captured during mid-cotton （June）. The number of oocytes in the ovarioles and the number of ooeytes containing yolk were significantly lower during September, November and January compared with June. The reproductive potential ofoverwintering boll weevil females collected in different months is an important consideration in determining the success of any control strategy.展开更多
Harsh environmental conditions often impose strong selection on the phenotype of natural populations through impacts on their fitness.For overwintering birds,winter is an important period for survival because the weat...Harsh environmental conditions often impose strong selection on the phenotype of natural populations through impacts on their fitness.For overwintering birds,winter is an important period for survival because the weather conditions in winter is usually severer than in other seasons and birds often suffer more thermoregulation costs while food is in short supply.Thus,the selective effect of weather conditions on phenotype in winter is expected to be strong.In this study,we examined the relationship of overwinter survival of Silver-throated Tits(Aegithalos glaucogularis)with their morphological traits under different levels of winter conditions(winters with and without snowstorms)to explore the differential selective effect of winter weather on their morphology.We found that regardless of whether the winter experienced a snowstorm,the female Silver-throated Tits with a smaller bill surface area or smaller bill depth and a smaller surface area:volume ratio were more likely to survive during the winter,which supported the hypothesis of selection for heat retention.Furthermore,the females with a smaller body length survived better than the larger females,indicating that the lesser food requirements for smaller body sizes may confer advantages during the winter when food availability was reduced.In addition,in agreement with the finding in many short-lived birds that survival rate increases with the increase of age,older(≥2-year-old)female Silver-throated Tits had higher overwinter survival than 1-year-old females.However,we did not find any correlation of morphological traits and age with survival in male Silver-throated Tits.These results illustrate differential selective effects of winter weather on female and male Silver-throated Tits and contribute to the knowledge of sex-specific selection on the phenotype of natural populations.展开更多
In order to take advantage of the climate resources more effectively ac- cording to the local circumstances and to plan and develop the citrus industry in Southern Shaanxi more reasonably. On the basis of the investig...In order to take advantage of the climate resources more effectively ac- cording to the local circumstances and to plan and develop the citrus industry in Southern Shaanxi more reasonably. On the basis of the investigation of freeze dam- age to citrus occurring in Southern Shaanxi in the winter of 2010, the climatic back- ground for the formation of this freeze damage was analyzed. In combination with the freeze damage indicators during the overwintering period and the harmful accu- mulated cold during the cold wave, indexes for grading the freeze damage in southern Shaanxi were analyzed and verified, and the perspective of grading the freeze damage using the harmful accumulated cold during the cold wave was also presented. Through analyzing the extremely lowest temperature and the harmful ac- cumulated cold in the winter of 2010 and in history at 12 citrus growing counties （districts） in Ankang area and Hanzhong area, the reasons why the freeze damage to citrus during the overwintering period was severer in the west than in the east of Southern Shaanxi were discussed, and the results obtained were basically consistent with the actual situation observed from investigation. Finally, defensive countermea- sures against the freeze damage to citrus during the overwintering period were put forward from several aspects.展开更多
Antarctic krill is thought to undergo an annual cycle of biological processes to cope with seasonal changes in their environment. The question of whether, and to what degree, seasonal environmental parameters such as ...Antarctic krill is thought to undergo an annual cycle of biological processes to cope with seasonal changes in their environment. The question of whether, and to what degree, seasonal environmental parameters such as photoperiod, food availability and temperature govern metabolism in krill is not clear. In this long-term laboratory study, respiration rates were determined in krill incubated under simulated natural light cycle or total darkness, subjected to fed or starved conditions and on krill kept at different temperatures (-1°C, 1°C and 3°C). There was a strong and significant increasing trend of respiration rates with month in all experimental treatments. In August (late winter), the mean respiration rates ranged between 0.22 - 0.35 μL O2 mg.DW-1.hr-1 for krill in both simulated seasonal light and complete darkness, and 0.25 - 0.26 μL O2 mg.DW-1.hr-1 for both fed and starved krill. Mean maximal respiration rates were recorded in October and December for all light and feeding treatments (0.46 - 0.56 μL O2 mg.DW-1.hr-1). Mean respiration rates for krill in the temperature treatments ranged between 0.24 - 0.30 μL O2 mg.DW-1.hr-1 in September reaching mean maximal rates in November and February (0.60 - 0.71 μL O2 mg.DW-1.hr-1). The covariate total length of krill was found to be non-significant and there was generally no significant interaction of experimental treatment with month and only for photoperiod comparison was the treatment main effect significant. The dark treatment gave higher respiration rates, and this needs careful interpretation. Results here suggest that, although light, food availability and temperature significantly affect metabolic rates,展开更多
基金The work was supported by the Key Laboratory of Ecological Prewarning,Protection and Restoration of Bohai Sea,Ministry of Natural Resources(No.2022107)the Qingdao Postdoctoral Applied Research Project(No.QDBSH202001).
文摘Green tides caused by the bloom of Ulva prolifera have affected the Yellow Sea annually since 2007.To explore the intrinsic causes of successive blooms,field investigations and indoor simulation experiments were conducted using micro-propagules of U.prolifera.From January to February 2014,micro-propagules of various green algae,including U.prolifera,Ulva flexuosa,and Ulva linza,were prevalent in the coastal waters of Rudong,Lianyungang,and Qingdao.However,in March 2014,micro-propagules of U.prolifera were not detected in the coastal waters of Lianyungang and Qingdao.Neither the spores nor gametes of U.prolifera can germinate at temperatures below 5℃.At 2℃and 5℃,U.prolifera spores and gametes could survive for 1-3 months at a light intensity range of 0-30μmol m^(-2)s^(-1)and for less than 1 month if the light intensity exceeded 30μmol m^(-2)s^(-1).By integrating indoor experiments and field investigations,this study found that U.prolifera spores and gametes could overwinter in the Rudong coastal area,which is an important factor for the annual emergence of recurring green tides in the Yellow Sea.
文摘Peeling trunk,binding insect-attracting belt,cleaning orchard and soil-covering under the crown were the control methods on overwintering generation of oriental fruit moth.However,they had not been applied widely on the production because of the lack of systematic quantitative evaluation.Aiming at this fact,the control effects of these technical measures were studied in peach with different ripening period.The results showed that peeling trunk was the best with the control effect of88.64%.The control effect of binding insect-attracting belt of grass bundle was74.13%,which was the most economical and efficient.Covering with soil layer of 3cm under the crown during the middle ten days of March could holdback the adult getting out from soil.Cleaning deadwood could clean out the overwintering larvae on the ground.
基金Supported by National Five-year Science&Technology Support Program(2012BAD19B03)Special Scientific Research Fund of Agricultural Public Welfare Profession of China(201303017)~~
文摘Chilo suppressalis （Walker） is one of the important pests in rice produc-tion. ln this paper, the spawning condition of Chilo suppressalis on rice seedlings in Wuxue, Qichun, Chongyang and Xiaogan of Hubei Province was investigated, and the spawning habit of overwintering-generation Chilo suppressalis on rice seedlings was analyzed. The results showed the overwintering-generation Chilo suppressalis prefers to spawn on verdant rice leaf blades （face, upper part）. The investigation on spawning habit of Chilo suppressalis would provide a theoretical basis for the fore-casting and control of Chilo suppressalis.
基金Supported by the Key Project under Beijing Municipal Education Commission(KM20150020021)the Project of Construction of Innovative Teams and Teacher Career Development for Universities and Colleges under Beijing Municipal Education Commission(IDHT20150503)~~
文摘The ground-cover chrysanthemum （Dendranthemaxgrandiflorum Kitamura） ＇Zixunzhang＇ was used as the experimental material in this study. The physiological and biochemical indexes of leaves, emergent rhizomes and roots from ＇Zixunzhang＇ growing in the open field during the autumn and winter in Beijing area were deter- mined. These indexes showed that root activities decreased slowly with the drop in temperature. The relative water contents of leaves and emergent rhizomes, and the water content of roots decreased. The activities of SOD, CAT and POD from leaves and emergent rhizomes were affected significantly by low temperature, but their change trends were different, which suggested that these 3 enzymes might play an interacted role in the formation of the cold tolerance of ＇Zixunzhang＇ mum, while the changes of the three enzyme activities in roots were little when the tem- perature dropped. With the significant increasing of the content of soluble sugar from leaves, the contents of soluble protein and proline declined overall; and the contents of osmotic regulation substances of emergent rhizomes and roots increased at first and then decreased. The correlation analysis indicated that the cold toler- ance of ground-cover mum ＇Zixunzhang＇ was related closely to relative water con- tents, SOD enzyme activity, soluble protein, soluble sugar and root activity. The morphological observation of leaves, emergent rhizomes and roots also showed that the survival of the ground-cover mum mainly depended on the cold tolerance of roots during the overwintering.
基金supported by grants from the National Key Research and Development Program of China(Grant No.2016YFD0600401)the Liaoning Provincial Key Research Project for Agriculture(Grant No.2015103002)
文摘We analyzed the relationships linking overwintering death and frost cracking to temperature and sunlight as well as the effects of low temperatures and freeze–thaw cycles on bud-burst rates,relative electrical conductivity,and phloem and cambial ultrastructures of poplar.Overwintering death rates of poplar were not correlated with negative accumulated temperature or winter minimum temperature.Freeze–thaw cycles caused more bud damage than constant exposure to low temperatures.Resistance to freeze–thaw cycles differed among clones,and the budburst rate decreased with increasing exposure to freeze–thaw cycles.Cold-resistant clones had the lowest relative electrical conductivity.Chloroplasts exhibited the fastest and the most obvious reaction to freeze–thaw damage,whereas a single freeze–thaw cycle caused little damage to cambium ultrastructure.Several such cycles resulted in damage to plasma membranes,severe damage to organelles,dehydration of cells and cell death.We conclude that overwintering death of poplar is mainly attributed to the accumulation of effective freeze–thaw damage beyond the limits of freeze–thaw resistance.
文摘In order to select severe overwintering abilitied blueberry cultivars for cold resistance of annual branches, promoting breeding high quality cultivars, a study had been conducted into field-planting shoots overwintering ability and the relative conductivity, MDA content, SOD of 7 different kinds of blueberries under artificial cooling process. According to survey results, under field conditions, Different cultivars of blueberries showed significantly difference, ranging from 56.67% of Bluegold to 12.80% of Darrow. With the temperature decreasing, changes of relative conductivity, MDA content and SOD in annual branches had a strong regularity and the hardiness of these cultivars is: Northland > Chippewa > Coville > Bluecroup > Darrow > Bluegold > Powderblue.
基金supported by the Rice Key Project of Chongqing,China (CSTC2011AB1076)the Foundation Project of Chongqing Education Commission (KJ110623)+1 种基金the Doctor Foundation of Chongqing Normal University,China (10LR028)the Plants Breeding Project of Chongqing,China (CSTC2010AA1033)
文摘312 recombinant inbred lines （RILs） in F9 from a cross between a overwintering cold-tolerant germplasm resource Glutinous rice 89-1（Gr 89-1） and a cold-sensitive variety Shuhui 527 was used for quantitative trait locus （QTL） analysis. The scores of percent ratooning germinability （PRG） and overwintering germinability （POG） were evaluated. The overwintering germination rate of axillary buds was scored to represent the overwintering germinability. Two significant QTLs （qPRG-4 and qPRG-7） on chromosomes 4 and 7 were detected and explained 8.3 and 7.2% of the total phenotypic variation, respectively. Three significant QTLs （qPOG-2, qPOG-3 and qPOG-7） were identified and mapped on chromosomes 2, 3, and 7, respectively. These QTLs contributed 9.6, 6.7, and 17.8% of phenotypic variations, respectively. A comparative analysis using SSR markers closely linked to the three QTLs for the overwintering revealed cold-tolerant individuals, which harbour the Glutinous rice 89-1 alleles at RM7110, RM250, RM418, and RM232, had a high percent overwintering germinability, while cold-sensitive individuals, which carry Shuhui 527 alleles at these loci, had a low percent overwintering germinability in the F2 population of Shuhui 527/Glutinous rice 89-1. This study demonstrated the utility of these SSR markers for selection of overwintering germinability genotypes.
基金following projects:National Natural Science Foundation of China(NSFC)(31860610,31400353)Provincial Key Science and Technology Project of Guizhou([2016]3022-1)+3 种基金Provincial Science and Technology Plan of Guizhou([2014]7682[2019]1068)Science and Technology Plan of Education Administration of Guizhou Province([2018]102[2015]354).
文摘Background: Understanding how overwintering birds choose foraging habitats is very important for conservation management. The overwintering Black-necked Crane(Grus nigricollis) feeds on crop remains in farmlands;thus, reasonable conservation management of this type of farmland that surrounds wetlands is critical for the overwintering populations of the Black-necked Crane;however, it is not clear how the Black-necked Crane chooses the foraging land in the farmland.Methods: A thorough field positioning survey of all foraging sites in farmland areas around the Caohai Wetland and a-sampling analysis of habitat selection by the Black-necked Crane were conducted during the winters from 20162017 and 2017-2018.Results: Multiple factors contributed to the selection of foraging habitat in farmlands, i.e., food factors(crop remains and tillage methods) > human disturbance factors(distance to road and settlement) > topography factors(slope aspect), listed according to the strength of influence. Additionally, Black-necked Cranes tend to choose farmland sites where there was no machine tillage, the crop remains were > 500 g/m^2, the distance to residences ranged from 100 to 500 m, the distance to roads ranged from 50 to 100 m, and the slopes exhibited western or eastern aspects. As the winters progressed, the volume of the edible crop remains declined, and the influences of the other main factors also changed, i.e., the factors of human disturbance(distance to road and settlement) became less important, while the effect of the food factor(crop remains) was strengthened. Thus, the foraging sites near the road became more important.Conclusion: The farming area surrounding the Caohai Wetland is very important for the overwintering Black-necked Crane. Food factors and human disturbance factors are the main factors that influence the choice of feeding ground.
文摘This article discusses the overwintering ability and genetic variation of the main agronomic traits in a new germplasm resource, glutinous rice 89-1. Survival rates of overwintering axillary buds and stems were observed in different altitudes. The F1, backcross F1 and F2 populations were constructed from sexual crossing between glutinous rice 89-1 and Hongmangnuo, Fuhui 838, Minghui 63, Ce 64. The overwintering ability and genetic variation of the main agronomic traits were analyzed in different seasons. Results showed that glutinous rice 89-1 could overwinter by axillary buds in low temperatures at different altitudes. Axillary buds would ratoon in the following year. The survival rates of rice stem and axillary buds were 82.6 and 29%, respectively. The grain yields were 6 291.0 kg ha^-1 in the overwintering ratooning season, and corresponded in the main season. Genetic analysis and chi-square test showed that the overwintering ability of glutinous rice 89-1 was likely controlled by polygene, and heritabilities showed diversity in different hybrid combinations. The highest heritabilities of 1 000-grain weight and plant height were in the main crop season, whereas the lowest were in the overwintering season, and the heritabilities of grain numbers per panicle and the seed setting rate reached the highest in the ratooning season. The spikelets per panicle, the seed setting rate, the 1 000-grain weight, the plant height, and the spikelet length had nearly normal distribution in F2 populations of glutinous rice 89-1/Minghui 63, but the seed setting rate had bimodal distribution. Overwintering glutinous rice 89-1 was a useful new genetic germplasm resource.
基金Supported by Scientist Program for Seedling Breeding of National Cassava IndustryTechnology System(CARS-12-gxwbh)Key Science and Technology Program ofGuangxi Province(1222014-2C)~~
文摘[Objective] In this study,the climatic features and overwintering sage storage methods of seed-stem of cassava in cassava-planting areas were investigated aiming at providing a technical guidance for sustainable development of cassava industry in China.[Method] The seed-stem of cassava was overwintered through keeping in field,piling up in the open air,burying in soil or piling up in greenhouses in Hepu,Nanning and Laibin of Guangxi,Hunan and Zhejiang.After the beginning of spring,the survival buds in seed stem of cassava were counted.And then the survival rates of buds were calculated for different storage methods.[Result] In Hepu,where the seed-stem of cassava was piled up in the open air for overwintering,the survival rates of buds were all higher than 90.00%.In particular,the survival rate of buds in seed-stem of cassava that was buried shallowly in the open field was highest（94.38%）.In Nanning,the seed-stem of cassava that was stored in greenhouses had the highest survival rate（94.98%） of buds.In Laibin,the seed-stem of cassava was usually stacked in greenhouses.Thus the survival rates of buds were almost all higher than 89.60%.Particularly,the survival rate of buds in seed-stem of cassava that was buried horizontally in soil and covered with sugarcane leaves reached the peak（98.79%）.In Jiangyong and Hangzhou,the seedstem of cassava was stored in specific facilities.So the survival rates of buds were relatively high.[Conclusion] In the frost-free areas south of 21.6° N（south of Maoming（Guangdong）-Hepu（Guangxi）-Jinghong（Yunnan））,the seed-stem of cassava can be buried shallowly in the open air or stacked and covered with film.In the light to heavy-frost areas（21.6° N-23.8° N,south of Qingyuan（Guangdong）-Laibin（Guangxi）-Lincang（Yunnan））,the seed-stem of cassava can be stacked in greenhouses,stacked and covered with film in the open air or buried vertically in greenhouses.In the heavy-frost areas and low-temperature areas north of 23.8° N（north of Qingyuan（Guangdong）-Laibin（Guangxi）-Lincang（Yunnan） to HunanJiangxi-Zhejiang）,the seed-stem of cassava can be stored in coldness-resistant caves or cellars or stacked vertically in greenhouses along with small sheds.
基金supported by the Science and Technology Program Projects of Guangdong Province (2007B020805002)the Combination Projects of Production,Teaching & Research of Ministry of Education of Guangdong Province(2008B090500122)
文摘[ Objective] To understand the overwintering of Rana dybowskii under four overwintering modes in northern Guangdong＇s mountainous areas. [Method] The overwintering management of Rana dybowskii was performed under four overwintering modes which were outdoor overwintering in water-land, outdoor overwintering in water, indoor overwintering in dryness, and indoor overwintering in freezer, respectively. The time, temperature and overwintering status were recorded. The Rana dybowskii in each group was weighed before and after overwintering, and the body weight loss and the survival rate were calculated. [ Result] Under the outdoor overwintering in water-land, outdoor overwintedng in water, indoor overwintering in dryness, and indoor overwintering in freezer, the survival rate of Rana dybowskii was 40.0%, 41.5%, 82.0% and 84.5%, respectively. [Conclusion] The temperature, overwintering mode and fatness are the important factors affecting the safe overwintering of Rana dybowskii in northern Guangdong.
基金supported by the Innovation Project of Guangxi Postgraduate Education,China(2008105930901D015)
文摘The joint analysis of the mixed genetic model of major gene and polygene was conducted to study the inheritance of cryotolerance in cotton during the overwintering period.H077（G.hirsutum L.,weak cryotolerance） and H113（G.barbadence L.,strong cryotolerance） were used as parents.Cryotolerance of six generation populations including P1,P2,F1,B1,B2,and F2,from each of the two reciprocal crosses H077×H113 and H113×H077 were all investigated.The results showed that cryotolerance in cotton during the overwintering period was accorded with two additive major genes and additivedominance polygene genetic model.For cross H077×H113,the heritabilities of major genes in B1,B2,and F2 were 83.62,76.84,and 90.56%,respectively;and the heritability of polygene could only be detected in B2,which was 7.76%.For cross H113×H077,the heritabilities of major genes in B1,B2,and F2 were 67.42,68.95,and 83.40%,respectively;and the heritability of polygene was only detected in F2,which was 6.51%.In addition,the whole heritability in F2 was always higher than that in B1 and B2 in each cross.Therefore,for the cryotolerance breeding of perennial cotton,the method of single cross recombination or single backcross should be adopted to transfer major genes,and the selection in F2 would be more efficient than that in other generations.
基金supported by the National Natural Science Foundation of China(32222071,32072388)the National Key Research and Development Program of China(2022YFA1304400)+1 种基金the Natural Science Foundation of Guangdong Province(2021A1515110363,2022A1515010770,2023A1515012030)the Guangzhou Science and Technology Program(2023B03J1313).
文摘Rice stripe mosaic virus(RSMV)is an emerging pathogen which significantly reduces rice yields in the southern region of China.It is transmitted by the leafhopper Recilia dorsalis,which overwinters in rice fields.Our field investigations revealed that RSMV infection causes delayed rice heading,resulting in a large number of green diseased plants remaining in winter rice fields.This creates a favorable environment for leafhoppers and viruses to overwinter,potentially contributing to the rapid spread and epidemic of the disease.Next,we explored the mechanism by which RSMV manipulates the developmental processes of the rice plant.A rice heading‐related E3 ubiquitin ligase,Heading date Associated Factor 1(HAF1),was found to be hijacked by the RSMV‐encoded P6.The impairment of HAF1 function affects the ubiquitination and degradation of downstream proteins,HEADING DATE 1 and EARLY FLOWERING3,leading to a delay in rice heading.Our results provide new insights into the development regulation‐based molecular interactions between virus and plant,and highlights the importance of understanding virus‐vector‐plant tripartite interactions for effective disease management strategies.
基金supported by the National key research and development program(2022YFD1602000)the Innovation Capacity Support Plan of Shaanxi Province(2022NY-039,2022ZDLNY04-04,2023-YBNY-176,2023KXJ-171).
文摘In northwest China,where winter is extremely cold and the grapevine is vulnerable to freezing damage,the application of soil covering has promoted the vigorous development of the local grape and wine industries.However,in recent years,the negative effects of burying soil for cold protection on the environment have gradually emerged.In some viticultural regions,the phenomenon of"summer forest,winter desert"has appeared.Therefore,it is urgent for the Chinese grape industry to find a better solution to overwinter safely and environmentally friendly.This review summarizes the advantages and disadvantages of widely used solutions to overwinter such as covering vines with soil,breeding of cold-resistant grapes,cold-resistant cultivation model,physical and chemical covering materials,and protected grape facilities were reviewed.Future overwintering measures were proposed which avoid burial and grape overwintering research directions.It also provides a theoretical foundation and technical support to improve grape yield and quality in northwest China.
基金This project was supported by the Provincial Science and Technology Projects of Guangdong Province,China(Grant numbers:2014A020219007,2015A020218003,2016A020219006 and 2017A020215101)the Medical Scientific Research Foundation of Guangdong Province,China(Grant numbers:A2018167).
文摘The Pearl River Delta,where Aedes albopictus(Ae.albopictus)is the only vector for dengue transmission,has exhibited one of the highest dengue burdens in southern China in recent decades.However,whether dengue virus(DENV)can overwinter in Ae.albopictus in the Pearl River Delta has not been determined to date.In this study,300 field-derived Ae.albopictus mosquitoes from Guangzhou that were infected with the predominant endemic DENV-1 strain were investigated under simulated urban balcony environment from October 16,2016,to June 16,2017.The vertical transmission of DENV in the infected overwintering Ae.albopictus was analyzed.The DENV infected overwintering mosquitoes were evaluated for viral load at nine-time points using reverse transcription-quantitative PCR.The vector competence of the infected overwintering Ae.albopictus was also investigated by using suckling mice.Adult mosquitoes and larvae were found during the observation period.The vertical transmission of DENV-1 was documented.The DENV-1-positive rates between overwintering males and females had no difference.The proportion of DENV-1-positive overwintering mosquitoes decreased over time and had no difference beyond three months after the experiment.Overwintering mosquitoes can spread DENV-1 to hosts.No engorged mosquitoes at an ambient temperature below 15℃were observed.The ratio of engorged mosquitoes was positively correlated with the ambient temperature ranging from 15 to 30℃.Our results demonstrated that DENV can overwinter in Ae.albopictus in the Pearl River Delta,Ae.albopictus is the competent vector for DENV,and maintain autochthonous dengue outbreaks in the Pearl River Delta through vertical transmission.
基金This study was supported by the National Natural Science Foundation of China(31101393)the National Key Technologies Research and Development Program(2012BAD19BA04).
文摘Wheat stripe rust caused by Puccinia striiformis f.sp.tritici occurs widely in China and seriously affects wheat production.Global warming could profoundly impact the incidence and prevalence of lowtemperature diseases such as stripe rust.Studies on the effects of temperature on the distribution of overwintering stripe rust could help us understand the incidence and prevalence of the disease and could also provide support for monitoring,forecasting and developing control strategies.An exponential model and a spherical model of the ordinary Kriging method in the ArcGIS platform were used to predict the overwintering regions of stripe rust based on the probability that the average temperature of the coldest month from December to February was higher than–6 or–7°C from 2001 to 2012.The results showed that the areas with a probability between 70%and 90%were transition regions for the overwintering of stripe rust.Based on annual mean temperature of the coldest month from December to February for 2001 to 2012,overwintering distribution of stripe rust was likewise evaluated.The boundary for overwintering of stripe rust was consistent with the areas where the probability was predicted to be 70%to 90%for the overwintering distribution of stripe rust,but the boundary was shifted northward toward Beijing in North China.Some areas in Xinjiang,including Akto,Pishan,Hotan and Yutian,were also predicted to be suitable for the overwintering of stripe rust.
文摘The reproductive potential of overwintering boll weevil, Anthonomus grandis grandis （Boheman）, females collected from pheromone traps in September, November and January, fed for 1, 3, and 5 weeks on plant pollens, and then provided cotton squares, was determined in the laboratory at 27 ~ I^C, 65% RH, and a photoperiod 13 ： 11 （L ： D） h. Duration of pollen feeding by overwintering boll weevils did not significantly influence egg and feeding punctures, or puncture ratios （egg to total punctures） for any of the three months of parent weevil collections when provided cotton squares on a daily basis. However, punctures and puncture ratios are significantly different when comparing mean data between months of boll weevil collections. When boll weevils were provided with cotton squares daily, the pre-ovipositional periods of female parents captured in September, November and January were 5, 9 and 14 days, respectively. The rate of eggs by females was significantly lower during November and January than September. Female parents collected in September produced a significantly higher percentage of eggs yielding adult progeny than those collected in November and January. Life table parameters indicated that net reproductive rate （Ro） of boll weevil females collected in September was 1.2- fold higher than those collected in November and 10.7-fold higher than those collected in January. Except for testes size, no differences in male reproductive parameters were observed during the cotton-free period compared with males captured during mid-cotton （June）. The number of oocytes in the ovarioles and the number of ooeytes containing yolk were significantly lower during September, November and January compared with June. The reproductive potential ofoverwintering boll weevil females collected in different months is an important consideration in determining the success of any control strategy.
基金supported by the National Natural Science Foundation of China(31970421,31472011,31101644)。
文摘Harsh environmental conditions often impose strong selection on the phenotype of natural populations through impacts on their fitness.For overwintering birds,winter is an important period for survival because the weather conditions in winter is usually severer than in other seasons and birds often suffer more thermoregulation costs while food is in short supply.Thus,the selective effect of weather conditions on phenotype in winter is expected to be strong.In this study,we examined the relationship of overwinter survival of Silver-throated Tits(Aegithalos glaucogularis)with their morphological traits under different levels of winter conditions(winters with and without snowstorms)to explore the differential selective effect of winter weather on their morphology.We found that regardless of whether the winter experienced a snowstorm,the female Silver-throated Tits with a smaller bill surface area or smaller bill depth and a smaller surface area:volume ratio were more likely to survive during the winter,which supported the hypothesis of selection for heat retention.Furthermore,the females with a smaller body length survived better than the larger females,indicating that the lesser food requirements for smaller body sizes may confer advantages during the winter when food availability was reduced.In addition,in agreement with the finding in many short-lived birds that survival rate increases with the increase of age,older(≥2-year-old)female Silver-throated Tits had higher overwinter survival than 1-year-old females.However,we did not find any correlation of morphological traits and age with survival in male Silver-throated Tits.These results illustrate differential selective effects of winter weather on female and male Silver-throated Tits and contribute to the knowledge of sex-specific selection on the phenotype of natural populations.
基金Supported by Shaanxi"13115"Public Service Platform Construction Program for Science&Technology Innovation Projects(2010FWPT-17)~~
文摘In order to take advantage of the climate resources more effectively ac- cording to the local circumstances and to plan and develop the citrus industry in Southern Shaanxi more reasonably. On the basis of the investigation of freeze dam- age to citrus occurring in Southern Shaanxi in the winter of 2010, the climatic back- ground for the formation of this freeze damage was analyzed. In combination with the freeze damage indicators during the overwintering period and the harmful accu- mulated cold during the cold wave, indexes for grading the freeze damage in southern Shaanxi were analyzed and verified, and the perspective of grading the freeze damage using the harmful accumulated cold during the cold wave was also presented. Through analyzing the extremely lowest temperature and the harmful ac- cumulated cold in the winter of 2010 and in history at 12 citrus growing counties （districts） in Ankang area and Hanzhong area, the reasons why the freeze damage to citrus during the overwintering period was severer in the west than in the east of Southern Shaanxi were discussed, and the results obtained were basically consistent with the actual situation observed from investigation. Finally, defensive countermea- sures against the freeze damage to citrus during the overwintering period were put forward from several aspects.
文摘Antarctic krill is thought to undergo an annual cycle of biological processes to cope with seasonal changes in their environment. The question of whether, and to what degree, seasonal environmental parameters such as photoperiod, food availability and temperature govern metabolism in krill is not clear. In this long-term laboratory study, respiration rates were determined in krill incubated under simulated natural light cycle or total darkness, subjected to fed or starved conditions and on krill kept at different temperatures (-1°C, 1°C and 3°C). There was a strong and significant increasing trend of respiration rates with month in all experimental treatments. In August (late winter), the mean respiration rates ranged between 0.22 - 0.35 μL O2 mg.DW-1.hr-1 for krill in both simulated seasonal light and complete darkness, and 0.25 - 0.26 μL O2 mg.DW-1.hr-1 for both fed and starved krill. Mean maximal respiration rates were recorded in October and December for all light and feeding treatments (0.46 - 0.56 μL O2 mg.DW-1.hr-1). Mean respiration rates for krill in the temperature treatments ranged between 0.24 - 0.30 μL O2 mg.DW-1.hr-1 in September reaching mean maximal rates in November and February (0.60 - 0.71 μL O2 mg.DW-1.hr-1). The covariate total length of krill was found to be non-significant and there was generally no significant interaction of experimental treatment with month and only for photoperiod comparison was the treatment main effect significant. The dark treatment gave higher respiration rates, and this needs careful interpretation. Results here suggest that, although light, food availability and temperature significantly affect metabolic rates,
