正交实验法在香果树种质离体保存中的应用

以香果树带芽茎段为外植体,采用正交实验法研究活性炭、琼脂、封口材料和培养容器对香果树试管苗离体保存的影响.结果表明,香果树带芽茎段用200 ml三角瓶,无菌培养容器封口膜封口,保存于MS + KT 2.0 mg/L + 6-BA 2.0 mg/L + NAA 0.1 mg/L + 30 g/L蔗糖 + 0.5 g/L活性炭 + 7.5 g/L琼脂培养基上6个月后,成活率可达86.3%.离体保存的试管苗没有发生遗传变异.     

枇杷种质资源的离体保存研究Ⅱ生长抑制剂的影响

在枇杷种质资源离体保存中,加入植物生长抑制剂可以延缓枇杷试管苗的生长速度,延长保存时间。实验结果表明,有利于枇杷种质保存的35种生长抑制剂浓度分别是：多效唑（PP333）2-5mg/L、矮壮素（CCC）25mg/L、脱落酸（ABA）10mg/L;其中浓度为5mg/L的多效唑效果最为理想。高浓度的甘露醇（＞5g/L）对试管苗会造成毒害,不利于枇杷种质的保存;5g/L甘露醇保存效果较好。     

‘神马’菊花的离体保存及遗传稳定性

用添加不同蔗糖与甘露醇配比的培养基对切花菊品种‘神马’(Jinba)试管苗进行离体保存,并对保存材料再生后代的遗传稳定性进行了研究。结果表明,在温度(23±2)℃、光照强度2 000~3 000 lx、光照时间12 h/d的培养条件下,MS 0.3 mg.L-16-BA 0.1 mg.L-1NAA培养基中分别添加10 g.L-1蔗糖和10 g.L-1甘露醇、10 g.L-1蔗糖和20 g.L-1甘露醇、20 g.L-1蔗糖和20 g.L-1甘露醇或30 g.L-1蔗糖和10 g.L-1甘露醇均能使菊花试管苗连续保存12个月,其中10 g.L-1蔗糖和20 g.L-1甘露醇、20 g.L-1蔗糖和20 g.L-1甘露醇组合处理保存12个月后成活率较高,分别达到50.00%和60.00%,且均保持最高的增殖倍数2.67。保存12个月的试管苗在增殖、生根培养基上均能正常恢复生长,且其再生后代的田间生物学性状、过氧化物酶(POD)及酯酶(EST)同工酶酶谱、ISSR扩增图谱与对照株无差异,保持了良好的遗传稳定性,说明利用上述方法保存‘神马’种质是可行的。     

5种植物生长抑制剂对香果树种质离体保存的影响

以香果树带芽茎段为外植体,采用单因子实验法研究了5种植物生长抑制剂在不同温度、不同光照条件下对香果树试管苗离体保存的影响。结果表明,在25℃条件下,香果树种质离体保存的最佳CCC、MH、B9、S3307和ABA浓度分别为4、4、2、1和4mg／L;在9℃条件下,香果树种质离体保存的最佳CCC、MH、B9、S3307和ABA浓度分别为2、1、1、0．5和2mg／L。在光照和黑暗条件下,香果树种质离体保存的最佳CCC、MH、B9、S3307和ABA浓度分别为4、4、2、1和4mg／L。与常温条件相比,低温条件下5种植物生长抑制剂的成活率更高,最佳浓度普遍降低。与光照培养比较,在黑暗条件下5种植物生长抑制剂的成活率也更高,但处理的最佳浓度相同。离体保存后的试管苗没有发生遗传变异。     

珍稀濒危植物香果树种质离体保存技术的研究

以香果树(Emmenopterys henryiOliv.)带芽茎段为外植体,以MS为基本培养基,采用正交实验和单因子实验方法研究了培养温度、无机盐水平、蔗糖、甘露醇和植物生长抑制剂PP333对香果树试管苗离体保存的影响。结果表明,香果树带芽茎段在9℃低温下保存于附加2.0 mg.L-1KT、2.0 mg.L-16-BA、0.1 mg.L-1NAA、50 g.L-1蔗糖和10 g.L-1甘露醇的1/2MS培养基上,180 d后其成活率可达80%。PP333对香果树的离体保存也有显著影响,其中最适合的PP333浓度为6 mg.L-1,180 d后其成活率可达95%以上。离体保存后的试管苗经形态指标和生理生化指标测定以及RAPD分析检测没有发生遗传变异。本实验结果为珍稀濒危植物香果树的种质保存提供了一条简单有效的途径。     

培养条件对澳蜡花‘舞后’试管苗玻璃化的影响

以澳蜡花‘舞后’的试管苗为试验材料,研究了培养条件对其试管苗玻璃化的影响。结果表明,当以1/2MS为基本培养基,附加0.2mg·L-16-BA、0.01mg·L-1IBA、4%蔗糖、0.8%琼脂并在以塑料封口膜为封口材料的三角瓶内培养时,试管苗的增殖系数较高,玻璃化率较低。     

铁皮石斛快速繁殖和离体种质保存的研究

对铁皮石斛种子发芽、原球茎增殖、丛芽分化和壮苗培育进行了试验、观察和分析,研究了培养基、植物激素、光强和添加剂等对其分化和生长的影响。结果显示种子在1/2MS+蔗糖2%的培养基上,30d萌发95%以上。原球茎在1/2MS+椰子汁25%+蔗糖3%的培养基上,45~60d原球茎增殖速度可达1∶10。丛芽分化较适宜的培养基为1/2MS+BA2mg·L-1+NAA0.2mg·L-1+IBA0.1mg·L-1+蔗糖3%,45~60d芽丛增殖速度为1∶4~5。试管苗在MS+香蕉泥20%+蔗糖2%培养基上,大约60d苗快速长高,茎粗壮且根系发达。离体保存材料可采用试管丛芽和原球茎两种方式,以保持其遗传多样性。保存方法是在15℃左右条件下,保存离体材料,继代间隔期为12~18个月;也可以采用室温保存,在1/2MS+蔗糖1%培养基上,继代间隔期可延长至10~12个月。     

纪伊潮菊离体保存及其遗传稳定性分析

通过在基本培养基中添加不同浓度配比的蔗糖和矮壮素(CCC)对纪伊潮菊(Chrysanthemum shiwogiku var.kinokuniense)离体保存的影响进行研究,并对保存材料再生后代的遗传稳定性进行分子标记鉴定与分析.结果表明:在(23±2)℃、2 000～3 000 lx光照强度、12 h/d的光照培养条件下,MS+0.5 mg·L~(-1) BA+0.1 mg·L~(-1) NAA+琼脂6.5 g·L~(-1)培养基中添加30 g·L~(-1)蔗糖和1 500～2 000 mg·L~(-1)的CCC能够保存试管苗12个月,存活率为92.86%~96.43%,且恢复生长后试管苗长势良好,其再生后代的形态特征、过氧化物酶(POD)活性和ISSR分子标记扩增图谱与对照株无差异.     

室温下保存的小鼠屠体卵巢GV卵的发育能力

将ICR系雌性小鼠处死并在10℃、15℃、20℃和25℃下依次保存8、14、24和48 h后,采集其体内的卵巢GV期卵,采用常规方法进行体外成熟和体外受精,获得的2细胞期胚经体外培养或胚胎移植观察其发育能力.其结果,在10℃下保存24 h、15℃下保存14 h、20℃下保存8h和25℃下保存4 h后,其体内附有卵丘细胞的GV卵的体外成熟-体外受精后的2细胞率分别为14%、9%、10%和10%,随着保存温度的提高和保存时间的延长,带有颗粒细胞GV期卵的比率明显降低,同时其GV期卵经体外成熟及体外受精后的2细胞率明显降低.在20℃下保存24 h和25℃下保存14 h时,难以获得形态正常的GV期卵;体外受精获得的2细胞期胚经体外培养,总体上有64%的胚胎发育至扩张囊胚,未见有保存温度和保存时间的显著影响,且利用在15℃保存8 h后的GV卵获得2细胞期胚的移植获得正常新生小鼠.上述结果表明,雌性动物室温条件下死亡后,若能短时间及时采集其体内GV期卵并体外成熟、体外受精,体外培养及胚胎移植技术,就有可能获得新生后代.     

果实成熟度和贮藏条件对枇杷种子无菌萌发的影响

为探讨影响枇杷(Eriobotrya japonica Lindl.)种子萌发的因素,将种子播种于1/2MS培养基80 d,研究了成熟度和贮藏条件对枇杷种子萌发的影响。结果表明,‘软条白沙’、‘宁海白’、‘塘科白沙’和‘大红袍’转色期和完熟期采收的种子的萌发率和苗高无显著差异;而‘大房’完熟期采收种子的萌发率较高。‘洛阳青’枇杷果实或种子经4℃贮藏5 d和10 d,萌发率和苗高与未贮藏种子的无显著差异,而贮藏期达20 d或更长时,贮藏种子的萌发率和苗高显著下降。在不同温度下贮藏的枇杷种子萌发率和苗高存在差异,‘早钟6号’和‘太平白’枇杷在15℃和4℃的优于25℃的,但适宜贮藏时间分别不超过15 d和30 d。因此,在转色期采收果实以及适度贮藏果实或种子可以保持枇杷种子的萌发能力。     

Entwicklungsgeschichte und Ultrastruktur von Pollenkitt und Exine bei nahe verwandten entomophilen und anemophilen Angiospermensippen derAlismataceae,Liliaceae, Juncaceae,Cyperaceae, Poaceae undAraceae

Some closely related members of the monocotyledonous familiesAlismataceae, Liliaceae, Juncaceae, Cyperaceae, Poaceae andAraceae with variable modes of pollination (insect- and wind-pollination) were studied in relation to the ultrastructure of pollenkitt and exine (amount, consistency and distribution of pollenkitt on the surface of pollen grains). The character syndromes of pollen cementing in entomophilous, anemophilous and intermediate (ambophilous or amphiphilous) monocotyledons are the same in principal as in dicotyledons. Comparing present with former results one can summarize: 1) The pollenkitt is always produced in the same manner by the anther tapetum in all angiosperm sub-classes. 2) The variable stickiness of entomophilous and anemophilous pollen always depends on the particular distribution and consistency of the pollenkitt, but not its amount on the pollen surface. 3) The mostly dry and powdery pollen of anemophilous plants always contains a variable amount of inactive pollenkitt in its exine cavities. 4) A step-by step change of the pollen cementing syndrome can be observed from entomophily towards anemophily. 5) From the omnipresence of pollenkitt in all wind-pollinated angiosperms studied one can conclude that the ancestors of anemophilous angiosperms probably have been zoophilous (i.e. entomophilous) throughout.

     

Identification and Characterization of the First Equine Parainfluenza Virus 5

正Dear Editor,Parainfluenza virus 5 (PIV5), known as canine parainfluenza virus in the veterinary field, is a negative-sense,nonsegmented, single-stranded RNA virus belonging to the Paramyxoviridae family (Chen 2018). The virus was first reported in primary monkey kidney cells in 1954 (Hsiung1972), then it has been frequently discovered in various     

Pathogenic Characterization and Full Length Genome Sequence of a Reassortant Infectious Bursal Disease Virus Newly Isolated in Pakistan

<正>Dear Editor,Infectious bursal disease (IBD) is one of the most important diseases of the poultry. The IBD virus (IBDV), a nonenveloped virus belonging to the Birnaviridae family with a genome consisting of two segments of double-stranded RNA (segments A and B), targets B lymphocytes of bursa of Fabricious leading to immunosuppression. In Pakistan,poultry farming is the second biggest industry and IBD is the second biggest disease threating the poultry sector.However, there is limited genome information of IBDV     

Mink Circovirus Can Infect Minks,Foxes and Raccoon Dogs

正Dear Editor,Mink circovirus (MiCV), which is clustered in the genus Circovirus of the family Circoviridae, was first described in minks from farms in Dalian, China in 2013 (Lian et al.2014). The complete single-stranded circular genome of the virus is 1,753 nucleotides long and contains two major open reading frames (ORFs), designated ORF1 (Rep gene)and ORF2 (Cap gene)(Lian et al. 2014; Ge et al. 2018).Sequence analysis has shown that MiCV is most closely     

CypA Regulates AIP4-Mediated M1 Ubiquitination of Influenza A Virus

Cyclophilin A (CypA) is a peptidyl-prolyl cis/trans isomerase that interacts with the matrix protein (M1) of influenza A virus (IAV) and restricts virus replication by regulating the ubiquitin–proteasome-mediated degradation of M1. However,the mechanism by which CypA regulates M1 ubiquitination remains unknown. In this study, we reported that E3 ubiquitin ligase AIP4 promoted K48-linked ubiquitination of M1 at K102 and K104, and accelerated ubiquitin–proteasome-mediated degradation of M1. The recombinant IAV with mutant M1 (K102 R/K104 R) could not be rescued, suggesting that the ubiquitination of M1 at K102/K104 was essential for IAV replication. Furthermore, CypA inhibited AIP4-mediated M1 ubiquitination by impairing the interaction between AIP4 and M1. More importantly, both the mutations of M1 (K102 R/K104 R) and CypA inhibited the nuclear export of M1, indicating that CypA regulates the cellular localization of M1 via inhibition of AIP4-mediated M1 ubiquitination at K102 and K104, which results in the reduced replication of IAV.Collectively, our findings reveal a novel ubiquitination-based mechanism by which CypA regulates the replication of IAV.