Transcriptome Analysis of Heterosis in Survival in the Hybrid Progenies of‘Haida No.1’and Orange-Shelled Lines of the Pacific Oyster Crassostrea gigas

Heterosis has been exploited to enhance the yield and adaptability in various shellfish species;however,the molecular basis of it remains unclear.The Pacific oyster Crassostrea gigas is one of the most economically important aquaculture species,and its productive traits can be improved by hybridization.Here,an intraspecific cross between orange shell(O,10th generation)and‘Haida No.1’(H,13th generation)of C.gigas was performed to assess the heterosis of survival trait.Survival rates of hybrid family(OH)and inbred families(HH and OO)were compared at larval stage,and eyed-pediveliger larvae of three families were subjected to transcriptome analysis.The analysis results of best-parent heterosis and mid-parent heterosis showed that the hybrid family exhi-bited a high heterosis in survival relative to the parental families.The OH-M(OH vs.OO)and OH-P(OH vs.HH)had 425 and 512 dif-ferentially expressed genes(DEGs),respectively.Functional enrichment analysis of these DEGs revealed that the significantly enrich-ed genes function in virion binding,C-type lectin receptor signaling pathway,cellular defense response and other immune-related pro-cesses,which involves perlucin-like protein,CD209 antigen-like protein,ZNFX1,caspase-3 and acan genes.These differentially ex-pressed genes in OH-M and OH-P,together with the immune-related processes mentioned above may play an important role in the larval survival of C.gigas.In addition,three genes(CYP450,fucolectin and perlucin-like)are associated with the orange shell and low survival of maternal oyster OO.These findings provide support for the application of hybrid with superior survival and will facilitate the understanding of heterosis formation in the Pacific oyster.

Effects of polyamines on the early development of cystocarps,spore release,survival,and germination rate of Gracilariopsis lemaneiformis

Three polyamines(PAs)(spermidine(Spd),spermine(Spm),and putrescine(Put))were used as growth regulators to the marine macroalgae Gracilariopsis lemaneiformis and to female gametophyte and reproductive tissues(cystocarps were constructed),which led to early maturation of cystocarps and spore release.Laboratory cultivation revealed that exogenous PA application accelerated the development of cystocarps,and the mean sporeling growth rate was 20%–50%/d during the initial week of cultivation.The spore count(SC),survival rate(SR),and germination rate(GR)of G.lemaneiformis showed different responses to PA(10-6 mol/L and 10-3 mol/L)treatments under different temperatures(18,26,and 34℃),light intensities(30,60,and 90μmol photons/(m^(2)·s)),salinities(25,30,and 35),and nutrient levels(25꞉2.5,50꞉5.0,and 75꞉7.5μmol/L NH4Cl꞉K2HPO4),and the optimal conditions were 26℃,light intensity of 60μmol/(m^(2)·s),salinity of 35,and nutrient level of 50꞉5.0μmol/L NH4Cl꞉K2HPO4.Under the optimum conditions,the SC per cystocarp increased by 82.38%,and the spore SR and GR increased by 33.07%and 46.44%,respectively.Each experiment lasted for 7 days,with the highest SC on Day 4 and plateauing on Day 7.The results indicate that PAs could promote the early maturation,spore release,survival,and germination of G.lemaneiformis under laboratory conditions.

Effects of indole-3-butyric acid and age of stem cuttings on root morphology,growth,and survival of Cornus sericea

Red osier dogwood(Cornus sericea L.),widely distributed throughout North America,is essential for wildlife,thus biodiversity.It is recommended for reclamation or revegetation of sites disturbed by oil and gas extraction because it tolerates a wide range of soil types and high pH levels.Since germination of this species is extremely difficult with long stratification requirements and poor germination,cuttings facilitate propagation.In this study,to develop techniques to propagate the species from stem cuttings,four concentrations of indole-3-butyric acid(IBA)and two cutting ages previous year’s growth(PYG)and current year’s growth(CYG)were investigated for survival and growth.After 4 months,survival rate,height growth,and shoot biomass from PYG cuttings were enhanced with IB A.In contrast,IB A did not affect these parameters in CYG cuttings.Root morphology was significantly affected by IB A concentration and cutting age.IBA,at higher concentrations,increased root surface and length.Total root surface area and length of PYG cuttings were increased,which may facilitate the absorption of essential resources and consequently increase growth.The results indicate that increasing the concentration of IB A may be an effective way to have better plant survival and growth of previous year’s cuttings in red osier dogwood.

The Effect of Modified Postoperative Treatment on Finger Replantation Survival Rate

Objective:To explore the clinical effect of modified treatment after finger replantation and its impact on the survival rate of replantation.Methods:The research was conducted from March 2022 to March 2023.A total of 58 patients who underwent finger replantation at our hospital were selected.These patients were divided into two groups using the digital table grouping method:the research group(n=29)and the control group(n=29).Patients in the control group received standard treatment following finger replantation,while patients in the study group received modified treatment after the procedure.The incidence of vascular crisis and the survival rate of replantation were compared between the two groups.Results:The incidence of vascular crisis in the study group was lower than that in the control group(P<0.05);the replantation survival rate in the study group was higher than that in the control group(P<0.05).Conclusion:Modified treatment after replantation of severed fingers can reduce the incidence of vascular crisis replantation and improve the survival rate of replantation,so it should be popularized and applied in medical institutions.

Colorectal cancer screening:The value of early detection and modern challenges

The screening of colorectal cancer(CRC)is pivotal for both the prevention and treatment of this disease,significantly improving early-stage tumor detection rates.This advancement not only boosts survival rates and quality of life for patients but also reduces the costs associated with treatment.However,the adoption of CRC screening methods faces numerous challenges,including the technical limitations of both noninvasive and invasive methods in terms of sensitivity and specificity.Moreover,socioeconomic factors such as regional disparities,economic conditions,and varying levels of awareness affect screening uptake.The coronavirus disease 2019 pandemic further intensified these challenges,leading to reduced screening participation and increased waiting periods.Additionally,the growing prevalence of early-onset CRC necessitates innovative screening approaches.In response,research into new methodologies,including artificial intelligence-based systems,aims to improve the precision and accessibility of screening.Proactive measures by governments and health organizations to enhance CRC screening efforts are underway,including increased advocacy,improved service delivery,and international cooperation.The role of technological innovation and global health collaboration in advancing CRC screening is undeniable.Technologies such as artificial intelligence and gene sequencing are set to revolutionize CRC screening,making a significant impact on the fight against this disease.Given the rise in early-onset CRC,it is crucial for screening strategies to continually evolve,ensuring their effectiveness and applicability.

Effects of acute kidney injury on acute pancreatitis patients’ survival rate in intensive care unit: A retrospective study

BACKGROUND Acute kidney injury(AKI)is one of the most common acute pancreatitis(AP)-associated complications that has a significant effect on AP,but the factors affecting the AP patients’survival rate remains unclear.AIM To assess the influences of AKI on the survival rate in AP patients.METHODS A total of 139 AP patients were included in this retrospective study.Patients were divided into AKI group(n=72)and non-AKI group(n=67)according to the occurrence of AKI.Data were collected from medical records of hospitalized patients.Then,these data were compared between the two groups and further analysis was performed.RESULTS AKI is more likely to occur in male AP patients(P=0.009).AP patients in AKI group exhibited a significantly higher acute physiologic assessment and chronic health evaluation II score,higher Sequential Organ Failure Assessment score,lower Glasgow Coma Scale score,and higher demand for mechanical ventilation,infusion of vasopressors,and renal replacement therapy than AP patients in non-AKI group(P<0.01,P<0.01,P=0.01,P=0.001,P<0.01,P<0.01,respectively).Significant differences were noted in dose of norepinephrine and adrenaline,duration of mechanical ventilation,maximum and mean values of intra-peritoneal pressure(IPP),maximum and mean values of procalcitonin,maximum and mean serum levels of creatinine,minimum platelet count,and length of hospitalization.Among AP patients with AKI,the survival rate of surgical intensive care unit and in-hospital were only 23%and 21%of the corresponding rates in AP patients without AKI,respectively.The factors that influenced the AP patients’survival rate included body mass index(BMI),mean values of IPP,minimum platelet count,and hospital day,of which mean values of IPP showed the greatest impact.CONCLUSION AP patients with AKI had a lower survival rate and worse relevant clinical outcomes than AP patients without AKI,which necessitates further attention to AP patients with AKI in surgical intensive care unit.

Global pattern and trends of colorectal cancer survival: a systematic review of population-based registration data

This review will describe the global patterns and trends of colorectal cancer survival,using data from the population-based studies or cancer registration.We performed a systematic search of China National Knowledge Infrastructure(CNKI),Wanfang Data,PubMed,Web of Science,EMBASE,and SEER and collected all population-based survival studies of colorectal cancer(up to June 2020).Estimates of observed and relative survival rates of colorectal cancer by sex,period,and country were extracted from original studies to describe the temporal patterns and trends from the late 1990s to the early 21st century.Globally,5-year observed survival rates were higher in Seoul,Republic of Korea(1993–1997;56.8%and 54.3%for colon and rectum cancers,respectively),Zhejiang province(2005–2010;52.9%for colon cancer),Tianjin(1991–1999;52.5%for colon cancer),Shanghai(2002–2006;50.0%for rectum cancer)of China,and in Japan(1993–1996,59.6%for colorectal cancer).Five-year relative survival rates of colorectal cancer in the Republic of Korea(2010–2014),Queensland,Australia(2005–2012),and the USA(2005–2009)ranked at relatively higher positions compared to other countries.In general,colorectal cancer survival rates are improving over time worldwide.Sex disparities in survival rates were also observed in the colon,rectum,and colorectal cancers in most countries or regions.The poorest age-specific 5-year relative survival rate was observed in patients>75 years of age.In conclusion,over the past 3 decades,colorectal cancer survival has gradually improved.Geographic variations,sex differences,and age gradients were also observed globally in colorectal cancer survival.Further studies are therefore warranted to investigate the prognostic factors of colorectal cancer.

Predictors of patient survival following living donor liver transplantation

BACKGROUND: Living donor liver transplantation (LDLT) is considered to be the alterative choice in light of the great shortage of cadaveric donors. However, the characteristics of the patients who will benefit from LDLT have not been well identified. The aim of this study was to define the pre- and intra-operative factors that may influence patient outcome. METHODS: The data from 102 LDLT patients who had operations between 2002 and 2009 were collected and analyzed retrospectively. Data were analyzed using uni- and multi-variate analysis according to factors that are known to be associated with outcome in these patients. RESULTS: Overall, the accurate survival rate of recipients at 1, 3, and 5 years was 84%, 76%, and 70%, respectively. The independent risk factors, preoperative renal dysfunction, intraoperative red blood cell transfusions of greater than 5 units, and female to male match (donor to recipient matching), were identified by Cox regression analysis. The pre-transplant model for end-stage liver disease score and a graft to recipient weight ratio of less than 0.8% were not predictive of outcome. The overall 1-, 3-, and 5-year survival of patients with one or no risk factors and two or more risk factors were 91%, 86%, and 83% and 67%, 56%, and 47%, respectively (P<0.0001). CONCLUSIONS: In our retrospective study, preoperative renal dysfunction, intraoperative red blood cell transfusions of greater than 5 units, and female to male gender match were independent risk factors for LDLT recipient outcome. Two or more of these risk factors may contribute to poor outcome.

No long-term survival benefit with sustained-release 5-fluorouracil implants in patients with stages Ⅱ and Ⅲ gastric cancer

BACKGROUND The prognosis of gastric cancer in an advanced stage remains poor. The exact efficacy of the use of intraoperative sustained-release chemotherapy with 5-fluorouracil(5-FU) in advanced-stage gastric cancer is still unelucidated.AIM To explore the long-term survival benefit of using sustained-release 5-FU implants in stage Ⅱ and stage Ⅲ gastric cancer patients.METHODS Patients with gastric cancer in a locally advanced stage and who underwent an R0 radical resection between Jan 2014, to Dec 2016, in this single institution were included. Patients with pathological diagnoses other than adenocarcinoma were excluded. All included patients were grouped according to whether intraoperative sustained-release(SR) chemotherapy with 5-FU was used or not(NSR). The primary end-point was 5-year overall survival. Kaplan–Meier method with logrank test was used to analyze the overall survival of patients and Cox analysis was used to analyze prognosis factors of these patients.RESULTS In total, there were 563 patients with gastric cancer with locally advanced stage, who underwent an R0 radical resection. 309 patients were included in the final analysis. 219(70.9%) were men, with an average age of 58.25 years. Furthermore, 56(18.1%) received neoadjuvant chemotherapy, and 191(61.8%) were in TNM stage Ⅲ. In addition, 158 patients received intraoperative sustainedrelease chemotherapy with 5-FU and were included in the SR group, while the other 161 patients were included in the NSR group. The overall complication rate was 12.94% in the whole group and 10.81%, 16.46% in SR and NSR groups, respectively. There were no significant differences between the two groups in overall survival and complication rate(P > 0.05). The multivariate cox analysis indicated that only N Stage and neoadjuvant therapy were independent influencing factors of survival.CONCLUSION Intraoperative sustained-release chemotherapy usage with 5-FU, did not improve the survival of patients who underwent an R0 radical resection in locally advanced stage of gastric cancer.

Nest survival rate of Reeves＇s pheasant(Syrmaticus reevesii) based on artificial nest experiments

To explore the nest survival rate of Reeves＇ s pheasant（Syrmaticus reevesii） and the nest-site factors that affect it, we conducted artificial nest experiments with reference to natural nests at Dongzhai National Nature Reserve（DNNR）, Henan Province and Pingjingguan, Hubei Province from April to June 2014 simulating the situation in its early and later breeding season. We also determined distance characteristics of the nest sites by Arc GIS 10.0. Nest survival models were constructed in Program MARK for data analysis. Results indicated that in the early breeding season, the apparent survival rate（ASR） in DNNR（52.4%） was significantly greater than that in Pingjingguan（13.5%）, and the ASR in the later breeding season in DNNR（26.7%） was not indistinctively correlated with Pingjingguan（3.2%）. The daily survival rate（DSR） in the later breeding season was 93.8% in DNNR and 92.0% in Pingjingguan, respectively. The DSRs were both negatively correlated with nest distance to forest edges and settlements. The DSR in Pingjingguan was positively correlated with nest distance to paths and negatively correlated with nest distance to water sources. However, the DSR in DNNR was negatively correlated with nest distance to paths but positively correlated with nest distance to water sources.

The Influence of Shock Treatment on Survival Rate of Intestinal Probiotics during Freezing

Probiotics which can provide potential health benefits for consumers and prevent disease, is the most important research field for functional food in the future. It is the key point that how much the count of bacteria and how long it can preserve. Freeze-drying skill is one of the best preservation methods, but it＇s defect that damage to biological systems can be attributed to changes in the physical state of membrane lipids or/and changes in the structure of sensitive proteins and the decreased survival rate. This work used pretreatment methods-cold shock and hot shock to reduce the damage to bacteria during freeze-drying. Using unpretreated samples as control, aspects of cold shock or heat shock. The response of Enterococcous faecalis A31 was investigated during lag phase, the middle of exponential growth phase and the terminal of exponential growth phase. The results suggested that when cold shock, the shock protein concentration produced by treated sample within 2 h during the middle of exponential growth phase was higher than 4, 8, 24 h, The concentration of shock protein produced by treated sample at 10 ℃ was higher than 20℃, The concentration of sample protein at the middle of exponential growth phase was higher than that at the terminal of exponential growth phase. After one-month storage, the survival rate at 10℃ was better than 20 ℃ and 4 ℃comparatively. The survival rate at （6 h） 4 ℃/24 h （lag period） was higher than （10 h） 4 ℃/24 h （the middle of exponential growth phase）, and the effect of 10℃/8 h shock treatments was best during the middle of exponential growth phase, when hot shock, The concentration of heat shock proteins produced was not obvious, and survival rate was higher at 45 ℃, 30 min than at 45 ℃, 60 min.

The allocation between egg size and clutch size depends on local nest survival rate in a mean of bet-hedging in a shorebird

Background:The allocation of resources between offspring size and number is a central question of life-history theory.Although several studies have tested the existence of this trade-off,few studies have investigated how environmental variation influences the allocation of resources to offspring size and offspring number.Additionally,the relationship between population dynamics and the offspring size and number allocation is far less understood.Methods:We investigate whether resource allocation between egg size and clutch size is influenced by the ambient temperature and whether it may be related to apparent nest survival rate.We measured 1548 eggs from 541 nests of two closely related shorebird species,the Kentish Plover(Charadrius alexandrinus)and the White-faced Plover(C.dealbatus)in China,in four populations that exhibit contrasting ambient environments.We weighed females,monitored nest survival,and calculated the variance of ambient temperature.Results:Although we found that egg size and clutch size were all different between the four breeding populations,the reproductive investment(i.e.total clutch volume)was similar between populations.We also found that populations with a high survival rate had relatively larger eggs and a smaller clutch than populations with a low nest survival rate.The latter result is in line with a conservative/diversified bet-hedging strategy.Conclusions:Our findings suggest that plovers may increasing fitness by investing fewer,larger or many,small according local nest survival rate to make a similar investment in reproduction,and thereby may have an impact on population demography.

Feeding Broodstocks Different Starfish Diets Affect Growth and Survival of Larvae of Trumpet Shell(Charonia lampas sauliae Reeve 1844)

Trumpet shell(Charonia lampas sauliae)(Mollusca, Heterogastropoda, Cymatidae) has extensive economic value. Studies on the artificial larval development of C. lampas sauliae for aquaculture utilization have become especially important due to the finite natural resources. In the present study, the growth and survival rate of the larvae of C. lampas sauliae broodstocks fed three types of starfish diets, Asterina pectinifera Müller & Troschel 1842, A. amurensis Lütken 1871 and their mixture were compared. The larval size increased gradually between day 10 and day 20 after hatching at 15℃ and 20℃. No difference was found in body size and specific growth rate(SGR)(two-way ANOVA; P > 0.05). However, during transition from trochophore to veliger stage 20 days after hatching, significant increases in larval survival and growth rates were observed. The maximum survival rate was observed on day 10. The mean survival rate was 0.463, 0.730 and 0.515 at 15℃, and 0.369, 0.713 and 0.444 at 20 when ℃ A. pectinifera, A. amurensis and their mixture were fed, respectively. The SGR and survival rate of the larvae were definitely influenced by the diets(P < 0.05), and the effect of A. amurensis alone was higher than that of A. pectinifera alone and their mixture.

SURVIVAL ANALYSIS OF CANCER CASES FROM QIDONGCANCER REGISTRY

Objective: 16,922 patients with cancers from 15 sites of Qidong population-based cancer registry in the period of 1982–1991 were analyzed for evaluation of cancer survival as well as different cancer control measures. Methods: Observed survival rate (OS) was computed by the Kaplan-Meier method using EGRET statistical software package. Relative survival (RS) which is the ratio of the OS to the expected rate was calculated by using Qidong life table with respect to sex, age and calendar period of observation. Results: The five-year OS for the 5 leading sites of cancers, liver, stomach, lung, oesophagus, and rectum were 1.8%, 11.6%, 3.0% 3.3%, and 19.9%, respectively. The five-year RS for the 5 sites were 1.9%, 14.0%, 3.6%, 4.2%, and 23.7%, respectively, in which, 1.7%, 14.8%, 3.4%, 4.2%, and 26.0% for males, and 2.7%, 12.7%, 4.1%, 4.0%, and 22.0% for females, respectively. Female patients with breast cancer and cervix cancer had 5-year RS of 54.6% and 33.0%. Conclusion: Cancer survival rates for all sites are poor, in which that of the liver is the lowest, while that of the breast, the highest. The survivals of cancers for all sites, especially for breast, cervix, and leukemia are seen to be lower than those of European countries except for oesophagus, pancreas and lung cancer which do not achieve improved survival both in developing and developed countries. There will be a long way to improve the total cancer survival, as well as the cancer treatment in the developing countries.

Assessment of Prognostic Factors of Racial Disparities in Testicular Germ Cell Tumor Survival in the United States(1992–2015)

Objective Testicular germ cell tumors(TGCT) are the most common cancer among men aged 15 to 39 years. Previous studies have considered factors related to TGCT survival rate and race/ethnicity, but histological type of the diagnosed cancer has not yet been thoroughly assessed.Methods The data came from 42,854 eligible patients from 1992 to 2015 in the Surveillance Epidemiology and End Results 18. Frequencies and column percent by seminoma and nonseminoma subtypes were determined for each covariates. We used Cox proportional hazard regression to assess the impact of multiple factors on post-diagnostic mortality of TGCT.Results Black males were diagnosed at a later stage, more commonly with local or distant metastases.The incidence of TGCT in black non-seminoma tumors increased most significantly. The difference in survival rates between different ethnic and histological subtypes, overall survival(OS) in patients with non-seminoma was significantly worse than in patients with seminoma. The most important quantitative predictor of death was the stage at the time of diagnosis, and older diagnostic age is also important factor affecting mortality.Conclusion Histological type of testicular germ cell tumor is an important factor in determining the prognosis of testicular cancer in males of different ethnic groups.

Heritability estimations of ammonia tolerance and survival of ridgetail white prawn Exopalaemon carinicauda

Ridgetail white prawn Exopalaemon carinicauda is an important economic marine species in China.To improve the germplasm quality of cultured E.carinicauda,for the fi rst time,we estimated the heritability of ammonia tolerance and survival of E.carinicauda,covering 263 full-sib families in multiple generations.Analysis models including binary linear animal model(BLA),binary linear sire-dam model(BLSD),probit threshold animal model(PTA),and probit threshold sire-dam model(PTSD)were used.The estimated heritability of tolerance to ammonia in diff erent models ranged from 0.09 to 0.22,and that of survival rate ranged from 0.06 to 0.16.Concerning the tolerance to ammonia,both the PTSD and BLSD models showed comparatively better prediction accuracies(0.48 and 0.47,respectively)than PTA and BLA models(0.40 and 0.26,respectively),while to the survival rate,all four models presented relatively low predictive abilities(0.16-0.26).This study provided important information for the future breeding program of E.carinicauda.

Impact of Long-term Exposure to Air Particulate Matter on Life Expectancy and Survival Rate of Shanghai Residents

Objective To evaluate the impact of long-term air particulate matter exposure on the life expectancy and survival rate of Shanghai residents. Methods Epidemiology - based exposure-response function was used for the calculation of attributable deaths to air particulate matter in Shanghai, and the effect of long-term exposure to particulate matter on life expectancy and survival rate was estimated using the life table of Shanghai residents in 1999. Results It was shown that in 1999, the long-term air particulate matter exposure caused 1.34-1.69 years reduction of life expectancy and a decrease of survival rate for each age group of Shanghai residents. Conclusion The effect of long-term exposure to air particulate matter on life expectancy is substantial in Shanghai.

Effects of sand burial on survival and growth of Artemisia halodendron and its physiological response

There is a great deal of literature on the effects of sand burial upon the survival and growth of desert plants, but the physiological adaption mechanisms of desert plants to sand burial have as yet rarely been studied. Artemisia halodendron is widely distributed in the semi-arid deserts of China and is a dominant species in semi-moving dune vegetation. The growth and physiological properties ofA. halodendron seedlings under different sand burial depths were studied in 2010 and 2011 in the Horqin Sand Land, Inner Mongolia, to better understand the ability and physiological mechanism by which desert plants withstand sand burial. The results showed that A. halodendron as a prammophyte species had a stronger ability to withstand sand burial compared to non-prammophytes, with some plants still surviving even if buried to a depth reaching 225% of seedling height. Although seedling growth was inhibited significantly once the depth of sand burial reached 50% of the seedling height, seedling survival did not decrease significantly until the burial depth exceeded 100% of the seedling height. Sand burial did not result in significant water stress or MDA （Malondialdehyde） accumulation in the seedlings, but membrane permeability increased significantly when the burial depth exceeded 100% of the seedling height. After being subjected to sand burial stress, POD （Peroxidase） activity and proline content increased significantly, but SOD （Superoxide Dismutase） and POD activities and soluble sugar content did not. The primary mechanism resulting in in- creased mortality and growth inhibition were that cell membranes were damaged and photosynthetic area decreased when subjected to the severe stress of sand burial, while proline and POD played key roles in osmotic adjustment and protecting cell membranes from damage, respectively.

STUDY ON RELATIONSHIPS AMONG SEEDLING QUALITY AND SURVIVAL RATE, STOCKING PERCENTAGE AND GROWTH

Effects of various seedling classes and root cutting treatments on the survival rate, stocking Percentage and the growth of height and collar diameter in young stands of korean pine (Pinus koraiensis), mongolian scots pine (Pin us sylvestris var.mangolica),Dahurian larch (Larix gmelini), korean spruce (Picea koraiensis), anur cork tree(Phellodendron amurensis). manchurian ash (Fradinus mandshurica) and anur linden (Tilia amurensis) were studied in this paper. The results show that the survival rate, stocking Percentage and the growth of height and collar diameter of the I class seedlings are better than that of the n and III classes seedlings. so it is very important to select I class seedlings for increasing the quality of afforestation.

Effect of Different Diet Combinations on WSSV Load and Survival Rate of Fenneropenaeus chinensis Larvae

Using microalgae( SA),artificial feed( AF),Brachionus plicatilis( BP) and brine shrimp larvae( BS),four diets including SA + AF,SA + AF + BP,SA + AF + BS and SA + AF + BP + BS were formulated and used to rear Fenneropenaeus chinensis larvae. The fertilized eggs fed with SA + AF were divided into disinfection group with iodophor and untreated group,and the fertilized eggs fed with other diets were all disinfected with iodophor. The survival rates,body weight and WSSV load of post larvae at each stage were compared. The results showed that there was no significant difference in the survival rate of prawns at the N-Z stage by feeding with different diets( P > 0. 05),but the survival rate of prawns fed with BP was higher than others( P < 0. 01) at the Z-P stage. The body weight of post larvae( P10) fed with SA + AF + BP was less than that fed with SA + AF + BP + BS( P <0. 01). The WSSV load of prawns( 10. 52 ±3. 3 copies/ng DNA) fed with SA + AF were significantly lower than that of other treatments( P < 0. 05) at the P10 stage. During the P11- P60 stage,four kinds of diets,including Ruditapes philippinarum foot muscle( CF) + artificial feed( AF),R. philippinarum foot muscle radiated by60 Co γ-ray( RCF) + artificial feed( AF),potassium permanganate-disinfected R. philippinarum foot muscle( DCF) + artificial feed( AF) and artificial feed( AF),were used to feed prawns. The prawns fed with CF + AF gained the greatest increase of body weight and body length,but had no significant difference with that fed with AF( P > 0. 05); prawns fed with CF + AF and AF had significant difference with the other two groups( P < 0. 05). The survival rates of prawns fed with four different diets had no significant difference with each other( P > 0. 05). WSSV artificial infection test showed that the accumulated mortality of prawns fed with four diets were higher than 90%,and the difference was not significant( P > 0. 05).