文冠果优良无性系授粉组合选择及结实性状分析

  目的  探究文冠果Xanthoceras sorbifolium优良无性系最佳授粉组合，提高其坐果率、种实产量，为科学配置授粉树及优良种质资源无性系化推广提供参考。  方法  以文冠果5个优良无性系为材料，进行花期物候观测、柱头可授性及花粉活力检测。进行控制授粉，分析各授粉组合受精率、坐果率、种实产量及种实性状。  结果  ① 5个无性系开花时间在4月27日至5月14日。②雌能花开花当天及花后1 d柱头可授性较强。③雄能花初开放和完全开放当天花粉活力较高。④综合考虑各授粉组合受精率、最终坐果率、产量及种实性状得出，10号无性系较佳授粉组合为10×16、10×119，14号、15号、16号最佳授粉组合分别为14×15、15×16、16×15，10号、14号、15号、16号均不适合做119号的授粉无性系。  结论  科学的授粉树配置可以提高文冠果坐果率及种实产量。     

新疆吐鲁番产区‘美乐’葡萄成熟度指标体系研究

为确定新疆吐鲁番产区酿酒葡萄的最佳采收期，对不同成熟期‘美乐’（Merlot，ML）果实和葡萄酒的基本理化指标和多酚指标进行测定，运用主成分分析和感官分析法确定果实中各项成熟指标的相关性，筛选对品质影响最大的指标，并确定最佳采收期。结果显示：8月14日及之后的葡萄达到技术成熟；8月28日的‘美乐’葡萄果皮、果籽、葡萄酒中酚类物质总量达到最高，且酿造的葡萄酒质量最佳；主成分分析筛选出一级指标总酸，二级指标皮总单宁，三级指标籽总酚的‘美乐’葡萄最佳采收期判定的指标体系；不同采收期‘美乐’果实主成分综合得分结果显示，8月28日的‘美乐’葡萄品质最好。可见，‘美乐’葡萄适宜在8月28日前后 采收。     

玉米pTAC2影响苗期叶片叶绿素合成的转录组分析

【目的】叶绿素是参与光合途径最为重要的光合色素。叶绿体的发育及叶绿素的合成在很大程度上依赖于质体基因组与核基因组之间的双向信号传导来精确协调基因表达。通过对白化表型的CRISPR/Cas9-ZmpTAC2转基因阳性纯合突变材料进行RNA-seq研究,筛选和鉴定参与叶绿素合成的相关基因,为明确叶绿素的合成途径奠定基础。【方法】以CRISPR/Cas9-ZmpTAC2玉米转基因编辑纯合突变株系为研究材料,使用透射电镜观察叶绿体超微结构和分光光度法测定叶片叶绿素含量,确定叶绿体发育状态及叶绿素合成情况。对转基因阴性材料（CK）和CRISPR/Cas9-ZmpTAC2转基因纯合编辑材料（zmptac2）苗期叶片取样进行转录组测序。通过生物信息学分析,寻找CK与zmptac2间差异表达的基因;qRT-PCR对差异表达基因进行验证。通过酵母双杂交筛选与玉米pTAC2互作的蛋白质。【结果】共获得15株T₀转基因植株,包括绿色植株（7株）和白色植株（8株）。绿色幼苗中3株为转基因阴性材料,4株为转基因阳性（2株为未编辑,2株为杂合编辑突变）,白色植株(8株)均为转基因阳性纯合编辑。与CK相比,突变体（zmptac2）叶绿体发异常,叶绿素含量显著降低。RNA-seq的结果显示,CK与zmptac2之间共检测到1 367个基因差异表达,其中618个基因上调表达（zmptac2/CK）,749个基因下调表达（zmptac2/CK）。GO富集分析显示,下调基因显著富集到叶绿体和质体中。KEGG分析表明下调表达基因显著富集在苯丙氨酸代谢、酪氨酸代谢和异喹啉生物碱生物合成等途径。选取的15个差异基因表达模式均与测序数据相一致,表明测序结果是可靠的。与CK相比,zmptac2中依赖PEP（plastid-encoded RNA polymerase）转录的基因表达量显著降低,而依赖NEP（nuclear gene-encoded RNA polymerase）转录的基因表达量则显著上升。通过对玉米cDNA文库筛选和互作验证,鉴定出ZmpTAC3与ZmpTAC2存在互作。【结论】ZmpTAC2突变会导致叶绿体早期生物合成受阻,该基因参与叶绿体发育及叶绿素合成,且该种作用是由ZmpTAC2调控PEP相关基因表达而实现的。     

高光谱技术检测农产品成熟度研究进展

高光谱技术作为近年来兴起的一项融合传统成像技术的新型三维光谱检测技术,能够同时获得目标物的光谱信息和图像信息,具有无损、快速等特点,在农产品成熟度检测方面应用潜力巨大。综述了近年来高光谱技术在水果、番茄、烟草等农产品成熟度检测中的研究现状和进展,指出了目前在应用方面存在的问题,并提出了改进措施。     

醚苯磺隆·异丙隆防除单双子叶杂草及对养分的影响

进行了50%醚苯磺隆·异丙隆可湿性粉剂(WP)对小麦田杂草的防除效果试验。结果表明,施药后30、90 d,防除杂草的综合株防效分别为96.08%～99.46%、98.31%～100%;施药后90 d,综合鲜重防效为99.94%～100%;对照药剂50%醚苯磺隆WP和50%异丙隆WP防除杂草的综合株防效分别为97.37%、97.09%和100%、98.99%,鲜重防效分别为100%、99.97%。     

Minimally invasive evaluation of the anaesthetic efficacy of MS‐222 for ornamental discus fish using skin mucus biomarkers

Skin mucus has been demonstrated to provide stress biomarkers for evaluating the physiological status, providing new convenient and non‐invasive methods to detect stress response in fish. Here, we investigated the anaesthetic efficacy of tricaine methanesulphonate (MS‐222; 75–115 mg/L) for discus Symphysodon aequifasciata (34.27 ± 4.46 g; 8.10 ± 0.59 cm) using skin mucus stress biomarkers. The induction time, recovery time and respiratory frequency were also determined. According to the criteria for anaesthesia and recovery, discus fish to reach stage A3 (deep anaesthesia) within 3 min and to reach stage R4 (full recovery of normal behaviour) within 5 min were observed at 95–105 mg/L MS‐222. Respiratory frequency increased first and then decreased during MS‐222 exposure and increased after recovery. At 10 min after deep anaesthesia, a lower mucus glucose was only observed at 115 mg/L MS‐222. No change in mucus cortisol and increased lactate were observed in all treatments. Increased mucus protein was observed at 75, 85 and 95 mg/L MS‐222. At 10 min after recovery, increased mucus glucose and decreased mucus protein were observed at 85, 95 and 115 mg/L MS‐222, but increased mucus cortisol only at 115 mg/L and lactate only at 75 and 105 mg/L MS‐222. At 24 hr after recovery, mucus glucose returned to the initial level only at 75, 95 and 105 mg/L MS‐222, while cortisol at 75 and 85 mg/L and protein and lactate at 75 mg/L respectively. Overall, the effective dose of MS‐222 for discus fish has been suggested to be 95–105 mg/L.     

日本米虾胚胎发育及离体孵化

本研究采用自制离体孵化装置，对日本米虾(Caridina japonica)不同发育期胚胎进行离体孵化研究，结果显示，水温为25.5℃时，日本米虾受精卵孵化大约需要25 d，发育积温为637.5℃。胚胎发育历经受精卵、卵裂期、囊胚期、原肠胚期、前无节幼体期、后无幼体期、前溞状幼体期和膜内溞状幼体期8个时期。各期离体胚胎均能孵化出幼体，膜内溞状幼体期离体胚胎孵化率最高，为(80.7±2.4)%，非离体孵化的对照组为(79.1±4.9)%，二者差异不显著；卵裂期离体胚胎孵化率最低，为(28.2±2.6)%，与对照组差异显著。各组离体胚胎所孵化出的Ⅰ期(ZⅠ)和Ⅱ期溞状幼体(ZⅡ)的变态率无显著差异。温度对日本米虾前溞状幼体期胚胎离体孵化影响显著，在15.0℃~32.5℃范围内，随水温升高孵化时间逐渐缩短，15.0℃时，前溞状幼体离体孵化时间为(436.8±124.8) h，32.5℃时缩短至(228.0±88.8) h，但温度高于29.0℃时，孵化出的幼体变态率开始下降。本研究可为日本米虾繁殖生物学及甲壳动物胚胎离体孵化技术研究提供参考。     

Spatiotemporal heterogeneity of PPARγ expression in porcine uteroplacenta for regulating of placental angiogenesis through VEGF-mediated signalling

Non-infectious prenatal mortality severely affects the porcine industry, with pathological placentation as a likely key reason. Previous studies have demonstrated that peroxisome proliferator-activated receptor gamma (PPARγ) deficiency causes defects in the uteroplacental vasculature and induces embryonic losses in mice. However, its role in porcine placental angiogenesis remains unclear. In the present study, PPARγ expression was investigated in porcine uteroplacental tissues at gestational day (GD) 25, GD40 and GD70 via quantitative polymerase chain reaction (qPCR), Western blot and immunohistochemistry (IHC). Moreover, the roles of PPARγ in porcine placental angiogenesis were investigated using a cell model of porcine umbilical vein endothelial cells (PUVECs) to conduct proliferation, migration and tube formation assays in vitro and a mouse xenograft model to assess capillary formation in vivo. The results showed that PPARγ was mainly located in the glandular epithelium, trophoblast, amniotic chorion epithelium and vascular endothelium, as indicated by the higher expression levels at GD25 and GD40 than at GD70 in endometrium and by higher expression levels at GD40 and GD70 than at GD25 in placenta. Moreover, PPARγ expression was significantly downregulated in placenta with dead foetus. In PUVECs, knocking out PPARγ significantly inhibited proliferation, migration and tube formation in vitro and inhibited capillary formation in mouse xenografts in vivo by blocking S-phase, promoting apoptosis and downregulating the angiogenic factors of VEGF and its receptors. Overall, the spatiotemporal heterogeneity of PPARγ expression in porcine uteroplacental tissue suggests its vital role in endometrial remodelling and placental angiogenesis, and PPARγ regulates placental angiogenesis through VEGF-mediated signalling.     

苜蓿青贮乳酸菌的筛选及其对苜蓿青贮发酵的影响

为获得苜蓿青贮用乳酸菌,本研究从苜蓿附生乳酸菌中通过抑菌活性、酸化苜蓿粉及结构性糖代谢中间产物的性能指标筛选优良菌株,并研究其对苜蓿(Medicago sativa)青贮发酵的影响。结果表明,1)筛选到抑菌活性较高、酸化苜蓿粉及结构性糖代谢中间产物综合性能较好的菌株ZZU A341,被鉴定为植物乳杆菌(Lactobacillus plantarum);2)青贮90 d,添加该菌株的处理组pH、氨态氮含量低于添加商业菌株(YX)的处理组,显著低于自然青贮(P<0.05)。综上所述,使用该筛选方法获得的优良乳酸菌可有效改善苜蓿发酵品质。