Objective The soil seed bank is the basis of aboveground vegetation regeneration,which plays a decisive role in the formation and damage of invasive plants population. Methods In this paper,the relationship between soil seed bank and aboveground population quantity of Ambrosia artemisiifolia and A. trifida invading for 1 ～ 6 years was studied,and the effects of soil seed bank on population establishment,growth and persistence were analyzed. Results The results show that:( 1) The density of soil seed bank decreased with the increase of soil depth and increased with the extension of invasion time. Seeds were mainly concentrated in 0 ～ 10 cm soil layer,and the maximum seed bank density of Ambrosia artemisiifolia and A. trifida were 525 seeds·m-2 and 11868 seeds·m-2 respectively in this soil layer of six years invasion habitat.( 2) Withered,Eaten by insects and moldy seeds accounted for 25% of the total A. artemisiifolia seed bank at 0 to 10 cm,it’s about 23%,34% and 15% in A. trifida seed bank from different habitats.( 3) The population density decreased with the prolongation of growth period and increased with the extension of invasion time. Density decreases most rapidly during the nutritional and reproductive stages,the maximum reduction of A. artemisiifolia and A. trifidawas was 343 plants·m-2 and 637 plants·m-2,respectively. The longer the population settlement,the greater the seed bank accumulation was input and the more seed was germination in spring. Conclusion Therefore in oder to control the invasion of A. artemisifolia and A. trifida,the seed back should the regarded as a key point,and the control chould be carried out from the two aspects of reducing the seed production and controlling seed germination.
研究以红龙23色素板椒为试材,在盆栽条件下设置中性盐(NaCl,pH= 6.99)、碱性盐(NaHCO3∶Na2CO3 =9 ∶ 1,pH = 9.30)、中性盐+碱性盐混合胁迫(NaCl ∶ NaHCO3 ∶ Na2CO3 = 9 ∶ 9 ∶ 1,pH = 8.88)等处理.利用分光光度计、液相色谱等方法对青果期、转色期、红熟期的辣椒果实进行品质分析,结果表明:3种胁迫下青果期、转色期及红熟期辣椒果实的Vc和有机酸含量均较对照显著下降,盐处理后3个时期果实糖酸均较对照显著提高;3种胁迫下绿熟期果实可溶性糖、可溶性蛋白含量较对照显著下降,而转色期和红熟期二者的含量却较对照显著升高;3种胁迫均能提高各阶段果实中的辣椒碱和二氢辣椒碱含量,其中碱性盐胁迫对辣椒素的促进作用更显著;3种胁迫可在一定程度上提高绿熟期、转色期果实的辣椒红素含量,但却使红熟期果实的红色素含量下降,其中碱性盐对辣椒红素的影响显著.表明碱性盐对辣椒品质的影响最大,其次为混合胁迫,中性盐的影响较小.
Objective Echinococcus granulosus scoleces was injected into the mouse liver capsule to construct the animal mode of echinococcosis granulosa.Methods Echinococcus granulosus scoleces were extracted from goat liver infected with Echinococcus granulosus,and cultured in cell culture medium for 3 ～ 5 days in vitro,and its activity was detected by eosin staining. The mice were anesthetized with 5% chloral hydrate,and then fixed on the operation table.After the abdominal skin was disinfected,the skin was cut with disinfected scissors.The activity of extracting more than 90% of the scoleces t was injected into the liver capsule of C57 mice( 6 ～ 8 weeks old,weighing 18 ～ 22 g) with a 1 ml syringe,and then the skin was sutured. The mice ’s liver tissue was harvested at 30 days,60 days,90 days,120 days,and 150 days,respectively.After the liver tissue was fixed,the sections were stained with HE staining to observe the basic pathological changes of inflammation.Sirius red staining was used to observe the collagen fiber proliferation in the lesion tissue.Results The success rate of 60 mice was 95%.In the pathological section,a large number of lymphocytes infiltrated and loose collagen fibers were observed in the liver tissue for 30 days.With the extension of the infection time,the lymphocytes infiltration decreased,multinucleated giant cells and epithelioid cells increased,collagen fibers increased and densified.Conclusion The animal model constructed in this experiment can be used to construct an animal model of Echinococcus granulosus,which lays a foundation for the study of treatment of Echinococcus granulosus.
To explore the inductive effect of Escherichia coli,Staphylococcus and theirmixture on its biochemical characteristics of antimicrobial peptide(AMPs) extracted from Locusta migratoria L.larva,Locust larva was induced by E.coli, staphylococcus and its mixture at the concentration of 1×108CFU/m L,then antimicrobial peptide was extracted after24 hours respectively.Theirconcentration were detected by coomassie brilliant blue method.Next,otherfeatures,as thermostability,multigelation stability and different p H were measured.The results showed that the concentration of locusk antimicrobial peptide concentration which were induced by bacteria was notably higherthan those not(P0.05).Meanwhile,the concentration of antimicrobial peptide which were induced by staphylococcus was notably higherthan that by E.coli and mixed bacteria induced.Analysis result of biochemical characteristic showed that the locusts antimicrobial peptide have betterheat stability(the antibacterial rate reached to 82.65%when temperature was 100 ℃),p H stability(its antibacterial rate was higherthan 92.97% when pH rangeed from 1 to 7),multigelation stability and low temperature storability(there was no difference between AMPs that frizzed and thawed within 6times ornot(P0.05)).
To estimate the heritability for body weight at 280 day-old in Rugao Yellow chicken,to evaluate the influence of different models on genetic effects.The data were collected from Rugao Yellow chicken population from 2009 to 2013.A total of 8116 body weight records from laying hen were evaluated.The records at different day-olds were standardized to280 day-old body weights.Variance components were obtained by WOMBAT software.The influences from year,batches and dam age were considered during evaluation of heritability.Models were compared using AIC and BIC values.The results suggested that the influences from batches and dam ages should be included in the fix effects.The heritability of 280day-old body weight was 0.52 ±0.03 with animal model, and 0.56 ±0.02 with sire model.The heritability for the body weight at 40 weeks were moderate.In the future,Expected Breeding Value(EBV) predict with BLUP able to improve the uniform of the body weight.
