化肥减施下土壤改良剂DK-1对设施丝瓜生长及土壤性状的影响

为研究DK-1型土壤改良剂对设施蔬菜生长及土壤性状的影响,进行了本次田间试验。本研究共设置4个处理,分别为:T1(不施用任何肥料)、T2(常规施肥处理)、T3(常规施肥处理配施土壤改良剂)和T4(化肥减施20%并配施土壤改良剂)。试验结果表明,土壤改良剂的施用具有促进丝瓜产量提升的潜力,T3较T2处理丝瓜产量增加9.89%;T3处理作物茎粗也有所增加,较T2和T4处理分别增加了13.22%和14.56%;各处理对丝瓜SPAD值的影响不大;土壤改良剂的添加可以显著促进土壤pH值的增加,T3和T4处理土壤pH值分别比T1处理土壤pH值增加了4.79%和5.39%;同时DK-1的添加可以显著降低土壤EC值,T3和T4处理土壤EC值均显著小于T2处理,分别降低了32.26%和23.66%。综上所述,化肥减施并配施DK-1型土壤改良剂,促进丝瓜植株生长、产量的提升和土壤理化性质的改善,均具有较强的可操作性,是设施蔬菜连作障碍防控的有效手段之一。     

花生品种主要脂肪酸含量在不同生态区的稳定性

花生是主要的油料作物,脂肪酸组成受环境等的影响而不稳定。本研究选取60份黄淮及长江流域产区主推的花生品种,连续2年在湖北武汉、河北石家庄、河南濮阳和河南周口4个环境下种植,利用GB/T5510-2011法检测种子脂肪酸含量。结果表明,高油酸花生品种油酸含量比普通油酸品种稳定,普通油酸品种棕榈酸和亚油酸含量比高油酸品种稳定;武汉种植环境有利于花生油酸含量的提高,2年60份品种的平均油酸含量均最高,分别为52.93%和52.64%;高油酸花生品种除油酸含量显著提高外,花生烯酸含量也提高了54.1%;而棕榈酸和亚油酸含量分别降低了45.20%和90.44%。结合前期SSR研究结果,本研究涉及的6份高油酸品种属于不同的类群(G1、G2c和G2e),其遗传背景差异较大。本研究结果为花生品种的合理布局和进一步的遗传改良提供了理论依据。     

49种山茶在低温和盐胁迫下的双抗能力分析

根据杜鹃红山茶(Camellia azalea)抗坏血酸过氧化物酶(ascorbate peroxidase,APX)基因(CaAPX1,GenBank登录号:KP635267)序列,设计实时荧光定量PCR引物,并对4℃低温和200 mg·L~(-1)NaCl胁迫下杜鹃红山茶CaAPX1表达量进行分析,发现该基因能够在低温和NaCl胁迫下应激上调表达。实时荧光定量PCR分析发现,CaAPX1在49个山茶品种中均得到表达,但表达量有差异。通过田间抗寒耐盐指数和APX1表达量隶属函数值对49个山茶品种抗寒和耐盐双抗能力进行分析,其中Ⅰ类抗寒和耐盐能力强的有4个品种,Ⅱ类抗寒和耐盐能力中等的有11个品种,Ⅲ类抗寒和耐盐能力弱的有34个品种。     

Attraction of bruchid beetles Callosobruchus chinensis (L.) (Coleoptera: Bruchidae) to host plant volatiles

Host-plant volatiles play an important role as cues for herbivores in search of resources, mates and oviposition sites in complex environments. Plant volatile-based attractants can be developed for pest monitoring and control. Previously, we indicated that mated female adults of Callosobruchus chinensis showed choice preference behavior toward 2-hexenal and benzaldehyde. Our objective here was to investigate the synergistic effect of host-derived attractive volatiles in attracting C. chinensis under laboratory and field conditions in Shanxi Province, China. We hypothesized that the ratio and concentration of volatiles derived from Vigna radiata play critical roles for C. chinensis in locating this host. Therefore, we collected and identified the volatiles of mungbean by using headspace collection and GC-MS. The effectiveness of different ratios and concentrations of two compounds (2-hexenal and benzaldehyde) that elicit C. chinensis searching behavior were examined in Y-tube olfactometer assays. The combination of 300 μg μL⁻¹ 2-hexenal and 180 μg μL⁻¹ benzaldehyde loadings exhibited a synergistic effect on attracting C. chinensis (82.35%). Compared to control traps, the adults were significantly attracted to traps baited with blends, and more attraction to females than males was found for blend traps in the field experiments. Our results suggest that blends of this specific concentration and ratio of benzaldehyde and 2-hexenal can be used in traps as attractants for C. chinensis monitoring and control in the field.     

罗非鱼中红霉素残留量的高效液相色谱法的测定

建立了以高效液相色谱法测定罗非鱼中红霉素残留量的方法。提出了以乙腈为提取剂,经过液-液萃取、固相萃取、反萃取等步骤对样品进行分离净化的样品处理方法,该方法准确、灵敏度高。方法的检出限为400μg/kg。     

不同质地土壤玉米出苗适宜墒情研究

通过室内盆栽试验,研究不同质地土壤、不同底墒(即初始含水量,下同)、不同底墒增加量下玉米的出苗率,分别就砂土、壤土和黏土三种质地给出了底墒、底墒增加量和出苗率之间的回归方程,并通过方程计算得出三种质地土壤在不同底墒的条件下,达到80%的出苗率所需的底墒增加量。     

Anti-Larval and Anti-Algal Natural Products from Marine Microorganisms as Sources of Anti-Biofilm Agents

Bacteria growing inside biofilms are more resistant to hostile environments, conventional antibiotics, and mechanical stresses than their planktonic counterparts. It is estimated that more than 80% of microbial infections in human patients are biofilm-based, and biofouling induced by the biofilms of some bacteria causes serious ecological and economic problems throughout the world. Therefore, exploring highly effective anti-biofilm compounds has become an urgent demand for the medical and marine industries. Marine microorganisms, a well-documented and prolific source of natural products, provide an array of structurally distinct secondary metabolites with diverse biological activities. However, up to date, only a handful of anti-biofilm natural products derived from marine microorganisms have been reported. Meanwhile, it is worth noting that some promising antifouling (AF) compounds from marine microbes, particularly those that inhibit settlement of fouling invertebrate larvae and algal spores, can be considered as potential anti-biofilm agents owing to the well-known knowledge of the correlations between biofilm formation and the biofouling process of fouling organisms. In this review, a total of 112 anti-biofilm, anti-larval, and anti-algal natural products from marine microbes and 26 of their synthetic analogues are highlighted from 2000 to 2021. These compounds are introduced based on their microbial origins, and then categorized into the following different structural groups: fatty acids, butenolides, terpenoids, steroids, phenols, phenyl ethers, polyketides, alkaloids, flavonoids, amines, nucleosides, and peptides. The preliminary structure-activity relationships (SAR) of some important compounds are also briefly discussed. Finally, current challenges and future research perspectives are proposed based on opinions from many previous reviews.     

油菜的源库关系研究Ⅲ.油菜库容变化对粒重的影响

分析不同密度、不同角果大小和植株不同部位角果的籽粒体积、单位角果皮面积上承担的籽粒数(SNPA)、单位角果皮面积上承担的籽粒体积(SVPA)等与粒重的关系,探讨油菜库容量的变化对粒重的影响,结果表明:①主序、上部第2分枝和上部第5分枝上角果的粒重与籽粒体积都呈极显著的正相关关系,但粒重随籽粒体积增大而增加的幅度不同;②籽粒体积、SNPA、SVPA和粒重都随种植密度增加而呈先增后减的趋势,通径分析显示,调节密度主要是通过改变籽粒体积而影响粒重;③籽粒体积与角果长度呈极显著的正相关关系,SNPA和SVPA随角果增大而呈指数函数的下降趋势。通径分析显示,角果大小对粒重的直接效应较小,主要是通过影响籽粒体积而影响粒重。     

杏鲍菇子实体多糖提取的均匀设计试验

采用均匀设计试验,研究了温度、时间、料液比对杏鲍菇子实体中多糖提取得率的影响,结果显示:提取温度是影响多糖提取得率的主要因素,最佳提取工艺为料液比1:50、温度100℃、时间240min,在此条件下,杏鲍菇多糖提取得率为4.35%;通过乙醇沉淀、透析、DE-52柱层析对提取的杏鲍菇多糖进行纯化,纯化的杏鲍菇多糖经紫外光谱分析不合蛋白质和核酸,最大吸收峰在192 nm.     

低温环境下辣根素对三种仓储害虫熏蒸效果

在10℃下,利用三角瓶密闭熏蒸法研究了辣根素对赤拟谷盗、谷蠹和长角扁谷盗成虫的熏蒸作用。结果表明,辣根素对三种仓储害虫成虫均具有较强的熏蒸活性。其中,辣根素Ⅱ的熏蒸效果更好,剂量达到5．797μL／L时,处理48h后,赤拟谷盗校正死亡率达到100%;剂量达到1．449μL／L时,处理48h后,谷蠹校正死亡率达到100％;剂量达到0．725μL／L时,处理24h后,长角扁谷盗校正死亡率达到100%。