寄生橡胶树叶上的头孢藻

由头孢藻引起的藻斑病在世界各国热带和亚热带地区的很多植物物种上均有报道。弄清寄生橡胶树叶上寄生藻的种类、为害症状以及不同橡胶树品系和环境对寄生藻发生为害的影响，为橡胶树藻斑病防治提供参考依据。通过田间调查、观察其为害特性症状；采集藻斑病标本，切片显微观察寄生藻在宿主组织内和表面的寄生习性；提取寄生藻的DNA，分析比对其核糖体小亚基基因序列。结合寄生藻的形态和核糖体小亚基(18S rRNA)基因序列分析结果，将本研究发现的橡胶树藻类叶斑病原物鉴定为茂盛头孢藻，这是首次在我国大陆橡胶树上发现由该寄生藻引起的橡胶树叶斑病。结果表明，种植于不同坡向、相同品系的橡胶树受害程度不一样，种植在阴坡的病害级别要高于阳坡的；同一株橡胶树上层树冠叶受害最轻，下层树冠叶受害最重；相比较而言橡胶树品系云研272较为抗病。     

Notch1 promotes renal tubulointerstitial fibrosis in renal tissues of diabetic mice by inhibiting autophagy through Akt/mTOR signaling pathway

AIM: To observe the changes of Notch1 expression and autophagy in the renal tissues of diabetic mice, and to explore the regulatory effect of Notch1 on tubulointerstitial fibrosis by inhibiting autophagy in diabetic nephro-pathy. METHODS: The mice were randomly divided into normal control group (db/m mice) and diabetes group (db/db mice), with 8 rats in each group. After 12 weeks of feeding, the mice were sacrificed and the corresponding biochemical indexes were measured. The protein expression of Notch1 in the renal tubular epithelial cells was observed by immunohistochemical staining. The protein levels of Notch1, PTEN, p-Akt (Thr308), Akt, p-mTOR (Ser2448), mTOR, LC3, P62, collagen type Ⅰ (Col-Ⅰ) and collagen type Ⅲ (Col-Ⅲ) were determined by Western blot. RESULTS: Compared with the db/m mice, the blood glucose, glycosylated hemoglobin, serum creatinine, triglyceride and total cholesterol were increased in the db/db mice (P<0.01). Renal tubular epithelial cell vacuolar degeneration, renal tubular expansion and interstitial inflammatory cell infiltration in db/db mouse renal tissues with HE staining were observed. The images of Masson staining showed collagenous fiber-like substance deposition in the glomerular capillaries and renal interstitium, and disarrangement of tubular structure in the renal tissues of db/db mice. The protein expression levels of PTEN and LC3-Ⅱ were decreased (P<0.01 or P<0.05), while the protein levels of Notch1, P62, p-mTOR (Ser2448), p-Akt (Thr308), Col-I and Col-III were increased in the db/db mice as compared with the db/m mice (P<0.01). However, no significant change of total mTOR and Akt proteins between the 2 groups was found. CONCLUSION: Notch1 protein expression was increased, PTEN expression was significantly reduced, Akt/mTOR pathway was activated, autophagy was inhibited, and fibrosis was aggravated in the renal tissues of the diabetic mice.     

DPC~+化学封顶对不同施氮量下棉花叶片光合生理特性的影响

在北疆气候条件下,为明确棉花对不同施氮量下增效缩节胺[DPC+,25%甲哌鎓(1,1-dimethylpiperidinium chloride, DPC)水剂]化学封顶效应的响应,以新陆早53号为试验材料,在150(N1)、300(N2)和450(N3) kg hm~(–2)施氮水平下,以人工打顶(P0)为对照,研究DPC+剂量[450(P1)、750(P2)和1050(P3) mL hm~(–2)]对棉花叶绿素含量(Chl)、叶面积(LA)、气体交换参数、叶绿素荧光参数及干物质累积与分配的影响。结果表明,同一DPC+剂量下,随施氮量增加, Chl、LA、气体交换参数、叶绿素荧光参数和生殖器官干物质(RODM)均呈现先上升后下降的趋势;同一施氮量下,上述参数因DPC+剂量不同呈不同变化趋势,其中N1水平下以P1处理、N2水平下以P2处理、N3水平下以P3处理表现出较高的RODM、Chl、净光合速率(Pn)、实际光化学效率(ФPSII)、电子传递速率(ETR),较低的非光化学淬灭(NPQ)。DPC+与施氮量互作表现为,与其他处理相比, Chl、Pn、蒸腾速率(Tr)、气孔导度(Gs)、ФPSII、ETR、RODM在N2P2处理下分别提高了15.52%、29.39%、27.97%、36.77%、23.28%、23.55%、8.41%～22.24%, NPQ降低了34.54%。相关分析表明,干物质累积和Chl、LA、Pn、Gs、ФPSII均呈显著正相关,与NPQ呈极显著负相关。因此,在喷施DPC+(750 mL hm~(–2))条件下,适量追施氮肥(300kghm~(–2))能改善棉花光合性能,在增加干物质累积的基础上,促进了光合产物向生殖器官分配。     

马铃薯块茎淀粉组分高效检测体系的建立及应用

马铃薯块茎淀粉组分(直链/支链淀粉比AM/AP)影响淀粉特性以及决定其在食品和其他工业上的应用。AM/AP的测定对其合理利用以及选育特异淀粉组分的专用品种等具有重要意义。采用96孔板双波长法对马铃薯不同AM/AP比率标准样品进行测试,发现当测试样品AM/AP比率超过制作标准曲线的AM/AP比率(33.3%)时,测试结果明显高估直链淀粉含量。基于96孔板的碘染分析,建立了马铃薯AM/AP比率和最大吸收峰下波长的标准曲线:y=601.88x0.0215,R2=0.9999。该方法进一步提高了测试准确度和应用范围。利用该方法测试了198个马铃薯品种(系)以及高直链淀粉组分的转基因块茎,明确了收集的马铃薯品种(系)的直链淀粉组成范围为17.4%~33.3%。新建立的马铃薯淀粉组分测试方法为高效准确筛选遗传育种材料以及改良淀粉组分株系提供了方便。     

籽用南瓜育种研究进展

南瓜种子含有丰富的营养成分，具有较高的保健价值。我国籽用南瓜产业规模逐年扩大，但目前种质创制和新品种 选育尚有待开展较为系统的研究。本文从籽用南瓜种质资源的鉴定评价和遗传多样性研究、籽用南瓜产量、抗性、种皮颜色、 营养成分等重要农艺性状的遗传定位及调控研究等方面进行综述，同时，对籽用南瓜的研究方向进行展望，以期为籽用南瓜 种质创制和新品种选育提供一定的理论参考。     

Protective efficacy of an H5/H7 trivalent inactivated vaccine produced from Re-11, Re-12, and H7-Re2 strains against challenge with different H5 and H7 viruses in chickens

We developed an H5/H7 trivalent inactivated vaccine by using Re-11, Re-12, and H7-Re2 vaccine seed viruses, which were generated by reverse genetics and derived their HA genes from A/duck/Guizhou/S4184/2017(H5 N6)(DK/GZ/S4184/17)(a clade 2.3.4.4 d virus), A/chicken/Liaoning/SD007/2017(H5 N1)(CK/LN/SD007/17)(a clade 2.3.2.1 d virus), and A/chicken/Guangxi/SD098/2017(H7 N9)(CK/GX/SD098/17), respectively. The protective efficacy of this novel vaccine and that of the recently used H5/H7 bivalent inactivated vaccine against different H5 and H7 N9 viruses was evaluated in chickens. We found that the H5/H7 bivalent vaccine provided solid protection against the H7 N9 virus CK/GX/SD098/17, but only 50–60% protection against different H5 viruses. In contrast, the novel H5/H7 trivalent vaccine provided complete protection against the H5 and H7 viruses tested. Our study underscores the importance of timely updating of vaccines for avian influenza control.     

甘薯基因组NBS-LRR类抗病家族基因挖掘与分析

NBS-LRR类基因家族是植物抗病R基因(Resistance gene)数量最多的一类,具有NBS (Nucleotide-binding site)和LRR (Leucine-leucine-repeat)结构域。甘薯(Ipomoea batatas)栽培种基因组已完成测序,但尚未注释,本研究对甘薯基因组序列进行外显子预测,得到甘薯染色体组全基因组蛋白序列,在此基础上进一步对NBS-LRR家族基因鉴定和分析表明,甘薯基因组中含有379个NBS-LRR家族基因,占全基因组基因总数的0.212%,其中N型亚家族120个,NL型103个, CNL型133个, TNL型22个, PN型1个。所有染色体上均有NBS-LRR家族基因分布,但数量明显不同,其中有60.9%的NBS-LRR基因序列呈簇状分布。NBS-LRR基因序列有15个保守结构域,在N端较为保守。研究结果为甘薯进一步开展NBS-LRR家族基因的功能研究和抗性育种提供了参考。     

茶树CsSNAT基因的克隆与表达分析

为明确茶树SNAT基因的序列特征和表达特点,在茶树转录组测序的基础上以茶树(Camellia sinensis)品种舒茶早为试验材料,通过SMART^TM RACE技术克隆茶树褪黑素合成途径中关键限速酶5-羟色胺-N-乙酰转移酶CsSNAT基因的cDNA全长序列,并分析其基因结构和表达模式。结果表明,CsSNAT基因序列全长1 014 bp,其中包含742 bp的完整开放阅读框(ORF),编码247个氨基酸,预测等电点7.64,蛋白分子量27.36 kDa。氨基酸序列比对显示,CsSNAT蛋白与其他高等植物的SNAT蛋白具有较高同源性,与葡萄 VvSNAT(CBI31163)同源性最高,为66.19%。诱导蛋白最佳条件为温度28℃,异丙基-β-D-硫代半乳糖苷(IPTG)浓度0.5 mg·L^-1,诱导时间6 h,在上清液中可获得大量分子量为66 kDa的可溶性融合蛋白。实时定量 PCR 分析表明,CsSNAT在褪黑素处理6 h后表达量最高,为对照的3倍;茶尺蠖取食6 h后,CsSNAT表达显著上调。不同激素处理结果显示,CsSNAT受脱落酸(ABA)、茉莉酸甲酯(MeJA)和水杨酸(SA)诱导表达。本研究结果为5-羟色胺-N-乙酰转移酶功能研究奠定了一定的基础。     

60Co-γ射线对睡莲生物学效应的影响

为探究辐射对睡莲的生物学效应,对2个睡莲品种弗吉尼亚(Nymphaea Virginia)和奥毛斯特(N.Almost black)的块茎进行不同剂量的⁶⁰Co-γ射线辐射处理。结果表明,2个睡莲品种的存活率均随辐射剂量的增加而下降,半致死剂量分别为24.342和27.671 Gy。5~10 Gy 剂量⁶⁰Co-γ辐射处理使睡莲叶面积和浮叶数显著增加,20~40 Gy剂量⁶⁰Co-γ辐射处理使叶面积和浮叶数显著减少。2个睡莲品种的开花时间均随辐射剂量的增加而延迟,但整个花期长度无显著变化。10~40 Gy剂量⁶⁰Co-γ辐射处理显著降低了睡莲花径,但对睡莲开花率无显著影响。辐射处理导致2个睡莲品种的叶片均出现红棕色斑块、锯齿、皱缩、小孔、卷曲、黄化等变异,且红棕色斑块的面积随着辐射剂量的增加而增大。辐射处理使黑红色花品种奥毛斯特出现普遍的褪色现象,而白色花品种弗吉尼亚的花色未发生变异。此外,经⁶⁰Co-γ射线辐射处理后2个睡莲品种均出现了花型变异的现象。本研究结果为利用辐射诱变技术选育睡莲新品种奠定了基础。