Development and Molecular Cytogenetic Identification of Two Wheat-Aegilops geniculata Roth 7Mg Chromosome Substitution Lines with Resistance to Fusarium Head Blight,Powdery Mildew and Stripe Rust

Fusarium head blight (Fhb), powdery mildew, and stripe rust are major wheat diseases globally. Aegilops geniculata Roth (U^gU^gM^gM^g, 2n = 4x = 28), a wild relative of common wheat, is valuable germplasm of disease resistance for wheat improvement and breeding. Here, we report the development and characterization of two substitution accessions with high resistance to powdery mildew, stripe rust and Fhb (W623 and W637) derived from hybrid progenies between Ae. geniculata and hexaploid wheat Chinese Spring (CS). Fluorescence in situ hybridization (FISH), Genomic in situ hybridizations (GISH), and sequential FISH-GISH studies indicated that the two substitution lines possess 40 wheat chromosomes and 2 Ae. geniculata chromosomes. Furthermore, compared that the wheat addition line parent W166, the 2 alien chromosomes from W623 and W637 belong to the 7M^g chromosomes of Ae. geniculata via sequential FISH-GISH and molecular marker analysis. Nullisomic-tetrasomic analysis for homoeologous group-7 of wheat and FISH revealed that the common wheat chromosomes 7A and 7B were replaced in W623 and W637, respectively. Consequently, lines W623, in which wheat chromosomes 7A were replaced by a pair of Ae. geniculata 7M^g chromosomes, and W637, which chromosomes 7B were substituted by chromosomes 7M^g, with resistance to Fhb, powdery mildew, and stripe rust. This study has determined that the chromosome 7M^g from Ae. geniculata exists genes resistant to Fhb and powdery mildew.     

Fine Mapping and Identification of a Candidate Gene of Downy Mildew Resistance,RPF2, in Spinach (Spinacia oleracea L.)

Downy mildew is a major threat to the economic value of spinach. The most effective approach to managing spinach downy mildew is breeding cultivars with resistance genes. The resistance allele RPF2 is effective against races 1–10 and 15 of Peronospora farinosa f. sp. Spinaciae (P. effusa) and is widely used as a resistance gene. However, the gene and the linked marker of RPF2 remain unclear, which limit its utilization. Herein, we located the RPF2 gene in a 0.61 Mb region using a BC₁ population derived from Sp39 (rr) and Sp62 (RR) cultivars via kompetitive allele specific PCR (KASP) markers. Within this region, only one R gene, Spo12821, was identified based on annotation information. The amino acid sequence analysis showed that there were large differences in the length of the LRR domain between the parents. Additionally, a molecular marker, RPF2-IN12821, was developed based on the sequence variation in the Spo12821, and the evaluation in the BC₁ population produced a 100% match with resistance/susceptibility. The finding of the study could be valuable for improving our understanding of the genetic basis of resistance against the downy mildew pathogen and breeding resistance lines in the future.     

霉变玉米气体传感器阵列快速检测

玉米易受霉菌感染发生霉变,影响食用安全。快速测定玉米霉变程度是控制其危害的前提。本研究拟利用基于气体传感器阵列的电子鼻技术,获取不同霉变程度玉米的特征气味信息,建立玉米霉变程度快速检测方法。辐照灭菌玉米分别接种5种谷物中常见有害霉菌,并于28 ℃和85%相对湿度环境中储藏15 d直至严重霉变。在第0、6、9、12和15 d,采集样品的气味信息的电子鼻特征响应信号,建立了玉米霉变程度的定性定量模型。结果表明,主成分分析(PCA)法可成功区分不同霉变程度的玉米样品。线性判别分析(LDA)对受单一霉菌侵染的不同霉变程度玉米样品的平均识别率达93.3%以上,全部样品达76.7%。样品中菌落总数的偏最小二乘回归分析(PLSR)模型的预测决定系数(R_p²)达0.777,预测均方根误差和相对分析偏差(RPD)分别为0.981 log CFU/g和2.12。结果表明,应用电子鼻技术快速检测玉米霉变具有一定可行性,下一步需要不断扩大样本量以提高方法的精度和可靠性。     

蜂胶在蜜饯奈李中防霉防腐效果研究

目的:将蜂胶作为一种纯天然食品防霉防腐保鲜剂应用于蜜饯产品加工中,替代化学防腐剂苯甲酸钠。方法:选择0.05%～0.2%的蜂胶应用于蜜饯奈李产品加工中,同时与常规用量0.05%化学防腐剂苯甲酸钠对比。结果:0.05%蜂胶产品组抑菌效果优于0.05%苯甲酸钠组。加入0.05%～0.2%蜂胶对蜜饯奈李产品中霉菌及细菌繁殖体有较好的抑菌作用,而且对产品风味及品质无影响。      

Fine Mapping and Candidate Gene Analysis of Pm36, a Wild Emmer-Derived Powdery Mildew Resistance Locus in Durum Wheat

Powdery mildew (PM) is an economically important foliar disease of cultivated cereals worldwide. The cultivation of disease-resistant varieties is considered the most efficient, sustainable and economical strategy for disease management. The objectives of the current study were to fine map the chromosomal region harboring the wild emmer PM resistance locus Pm36 and to identify candidate genes by exploiting the improved tetraploid wheat genomic resources. A set of backcross inbred lines (BILs) of durum wheat were genotyped with the SNP 25K chip array and comparison of the PM-resistant and susceptible lines defined a 1.5 cM region (physical interval of 1.08 Mb) harboring Pm36. The genetic map constructed with F_2:3 progenies derived by crossing the PM resistant line 5BIL-42 and the durum parent Latino, restricted to 0.3 cM the genetic distance between Pm36 and the SNP marker IWB22904 (physical distance 0.515 Mb). The distribution of the marker interval including Pm36 in a tetraploid wheat collection indicated that the positive allele was largely present in the domesticated and wild emmer Triticum turgidum spp. dicoccum and ssp. dicoccoides. Ten high-confidence protein coding genes were identified in the Pm36 region of the emmer, durum and bread wheat reference genomes, while three added genes showed no homologous in the emmer genome. The tightly linked markers can be used for marker-assisted selection in wheat breeding programs, and as starting point for the Pm36 map-based cloning.     

新型烟酰胺类杀菌剂-啶酰菌胺

介绍了新型烟酰胺类杀菌剂啶酰菌胺,内容涉及化学名称、理化性质、毒性、创制经纬、作用机理、药效结果、专利概况与合成方法等.     

小麦白粉病抗性基因的研究进展

综述了小麦白粉病抗病研究的最新进展，介绍了抗白粉病基因的来源、定位及代表品种，简述了分子标记在小麦白粉病抗性研究中的应用，并对小麦白粉病抗性基因的应用前景进行了预测。     

防治卵菌纲病害的新型杀菌剂氟啶酰菌胺

介绍了防治卵菌纲病害如霜霉病和晚疫病的杀菌剂氟啶酰菌胺，内容涉及化学名称、理化性质、毒性、创制经纬、作用机理、药效结果、专利概况与合成方法等。     

新型杀菌剂四唑吡氨酯对黄瓜霜霉病的田间防治效果评价

[目的]明确新型杀菌剂10%四唑吡氨酯悬浮剂对黄瓜霜霉病的防治效果,为生产上应用提供科学依据。[方法]采用喷雾法于2016—2017年在山东省烟台市进行了田间药效试验。[结果]10%四唑吡氨酯悬浮剂对黄瓜霜霉病防治效果良好,第3次施药后14 d,30~90 g a.i./hm2处理防效仍在88.62%以上,优于对照药剂50%烯酰吗啉水分散粒剂(225 g a.i./hm2)。[结论]10%四唑吡氨酯悬浮剂是一种防治黄瓜霜霉病较为理想的新型药剂,值得在黄瓜生产中推广应用。