Latency of Botrytis cinerea Pers.: Fr. and Biochemical Studies During Growth and Ripening of Two Grape Berry Cultivars, Respectively Susceptible and Resistant to Grey Mould

Latency and development of Botrytis cinerea were assessed under field conditions and after artificial inoculation of two grape varieties, Gamay (susceptible) and Gamaret (resistant). When the percentage of latent Botrytis was the same for both varieties, severity of visible grey mould remained very low in Gamaret berries, while Gamay clusters were destroyed by the disease to a high percentage. Some biochemical parameters were measured in berries, such as constitutive and induced anti‐fungal compounds, polymeric proanthocyanidins and lipid peroxidation products as markers of senescence. Differences were observed in polymeric proanthocyanidins (PPRA) of Gamaret compared with those of Gamay. Concentration and mean degree of polymerization (mDP) of PPRA were always higher in the berries of the resistant variety. The inhibitory effect of Gamaret PPRA on enzyme activity remained until harvest whereas Gamay PPRA lost their inhibitory activity at the beginning of véraison. Based on these results, resistance to B. cinerea seems to be linked to the maintainance of the fungus in its latent form in berries, mainly due to the ability of Gamaret PPRA to inhibit macerating fungal enzyme activities.     

Presence of corazonin in three insect species, and isolation and identification of [His7]corazonin from Schistocerca americana.

An ELISA for corazonin, a cardioactive neuropeptide from the American cockroach, Periplaneta americana, was developed. It was used to isolate corazonin from the cockroach Nauphoeta cinerea, the locust Schistocerca americana, and the hawkmoth Manduca sexta. The peptides from Nauphoeta and Manduca had the same retention times as Periplaneta corazonin, and their amino acid compositions also suggested that these peptides are identical with corazonin. The corazonin-immunoreactive peptide from Schistocerca eluted slightly earlier on HPLC than corazonin, and its structure was determined to be [His⁷]corazonin, or pGlu-Thr-Phe-Gln-Tyr-Ser-His-Gly-Trp-Thr-Asn-amide. These results indicate that corazonin is generally present in insects and that its structure has been well conserved.     

灰葡萄孢侵染垫缺失突变体的筛选及其相关生物学特性的研究

【目的】从农杆菌介导获得的灰葡萄孢RoseBC-3的突变体库中筛选侵染垫缺失突变体菌株,并明确其相关生物学特性。【方法】将菌株接种于洋葱表皮,利用棉兰染色观察侵染垫形成情况,筛选得到一个侵染垫缺失突变体(AT19)。采用形态学方法、离体叶片接种法、钌红染色法、小麦种子幼芽生长抑制法分别对该菌株的菌落培养性状、侵染垫产生情况、致病力、产果胶酶能力以及产植物毒性代谢产物能力进行测定。【结果】筛选灰葡萄孢突变体168株,根据侵染垫形成可分为三类：快速形成侵染垫型(158株)、缓慢形成侵染垫型(9株)和侵染垫形成缺陷型(1株,AT19)。AT19在接种洋葱120 h后依然无法形成成熟侵染垫。该菌株生长较为缓慢,菌落扩展均匀,可以产生分生孢子,对烟草、草莓、蚕豆和豌豆叶片均不能致病,可以产生果胶酶和植物代谢毒性物质。【结论】突变体菌株AT19可以产生果胶酶和植物代谢毒性物质,其致病力缺失与侵染垫产生缺陷相关。研究结果为了解灰葡萄孢侵染垫形成分子机制提供基础材料。     

生防细菌CNY-04筛选、鉴定及其对灰霉病菌的防效

【目的】为研究土壤细菌对蔬菜灰霉病的生防价值, 从辽宁、山东等地区的蔬菜种植基地采集土壤样本56份, 分离、筛选出对灰霉病具有稳定拮抗作用的细菌9株。【方法】采用平板对峙培养法进行初筛、复筛, 用抑菌圈法测定其抑菌效果, 并进行离体果实试验验证其对蔬菜灰霉病的防治效果, 通过形态学特征、生理生化特征及16S rRNA基因序列分析研究其分类地位。【结果】细菌CNY-04对蔬菜灰霉病的拮抗能力最强且遗传稳定, 抑菌圈直径达到34 mm; 初步鉴定该菌株为格氏沙雷菌(Serratia grimesii), 尚未见该菌在生防上的报道; CNY-04液体菌剂对离体番茄果实灰霉病的防效为69.23%, 50%多菌灵防效为75.39%, 24 h时接种CNY-04处理的番茄发病率为40.0%, 而48 h时接种处理的发病率为51.1%。【结论】CNY-04是一株较为理想的拮抗菌, 丰富了生防资源。     

番茄内生菌St24的鉴定及其对灰霉病的生防作用

从番茄植株根茎部分离到1株有抑菌活性的植物内生放线菌菌株St24,对其分类地位以及对灰霉病菌的防治效果进行研究.结果表明: 菌株St24为酒红链霉菌.St24发酵液经石油醚萃取得到的粗提物对多种病原菌有抑制作用,其中对灰霉病菌的抑制作用最强,抑制菌丝生长的EC₅₀为11.78 mg·L^-1.粗提物处理灰霉菌后,菌丝量减少,菌丝体皱缩、断裂、原生质外渗,菌体细胞表面有许多瘤状畸形.处理后的灰霉病菌培养液在260 nm处比对照多出现一吸收峰,说明粗提物对病原菌的细胞膜透性有影响.经盆栽试验, St24发酵液对番茄灰霉病有保护和治疗的作用,100 mg·L^-1粗提物叶面喷雾的保护作用效果最好,24 h后防效达到94.3%,120 h后为85.4%.     

灰葡萄孢丝裂原活化蛋白激酶编码基因bmp1和bmp3的功能

【背景】植物病原真菌丝裂原活化蛋白激酶(Mitogen-activated protein kinase,MAPK)信号途径参与病菌有性生殖、细胞壁完整、菌丝侵染、致病力、胁迫响应等过程,灰葡萄孢MAPK信号途径参与病菌生长发育、致病力以及胁迫响应,但MAPK信号途径基因在灰葡萄孢中的功能尚未完全阐明,该信号途径对灰葡萄孢的生长发育和致病力的调控机制尚不明确。【目的】明确灰葡萄孢MAPK编码基因bmp1、bmp3在病菌生长发育、致病力以及氧化胁迫响应过程的功能,为进一步阐明MAPK信号途径调控灰葡萄孢生长发育和致病力的分子机制奠定基础。【方法】利用RNAi技术构建灰葡萄孢MAPK编码基因bmp1和bmp3的RNAi突变体,并以野生型BC22菌株为对照,对bmp1和bmp3基因的RNAi突变体的表型、致病力以及对氧化胁迫的敏感性进行分析。【结果】灰葡萄孢bmp1和bmp3基因的RNAi突变体其菌落形态、菌丝形态均与野生型BC22菌株没有明显差别;bmp1基因的RNAi突变体生长速率明显减慢,分生孢子产量明显降低;bmp3基因的RNAi突变体的生长速率与野生型BC22菌株没有明显差别,不能产生分生孢子。bmp1和bmp3基因的RNAi突变体在番茄果实的表面均不能产生明显的致病症状,而且不能穿透玻璃纸。bmp1基因的RNAi突变体在含有H_2O_2的培养基上受抑制的程度显著低于野生型,而在含甲萘醌的培养基上受抑制的程度显著高于野生型;bmp3基因的RNAi突变体在含有H_2O_2和甲萘醌的培养基受抑制的程度均显著高于野生型。【结论】灰葡萄孢bmp1基因正调控病菌生长、分生孢子形成、致病力和穿透能力,参与调控病菌对氧化胁迫的响应;灰葡萄孢bmp3基因正调控病菌分生孢子形成、致病力、穿透能力以及对氧化胁迫的响应。     

Characterisation of the yeast Pichia membranifaciens and its possible use in the biological control of Botrytis cinerea, causing the grey mould disease of grapevine

Pichia membranifaciens strain FY-101, isolated from grape skins, was found to be antagonistic to Botrytis cinerea, the causal organism of the grey mould disease of the grapevine. When grown together on solid as well as liquid media, the yeast brings about the inhibition of this parasitic fungus, coagulation and leakage of its cytoplasm, and suppression of its ability to produce the characteristic grey mould symptoms on the grapevine plantlets. In vitro experiments confirm that this yeast can be used as a biological control organism against B. cinerea. An account of the molecular characterisation of P. membranifaciens (complete sequence of the ITS region of its ribosomal DNA, GenBank accession No. AF 270935), as well as the interaction between B. cinerea and the yeast, are given here.     

不同营养物质对脱落酸液体发酵产量的影响

考察了不同营养添加物及前体对脱落酸 (abscisicacid ,ABA)液体发酵的影响。在玉米粉、黄豆饼粉、燕麦、小米粉等不同营养添加物中 ,以添加玉米粉效果较好 ,产量可提高 35 .8% ;将碳源由单一的葡萄糖改变为蔗糖∶葡萄糖 =3∶2 ,可使产量提高 6 8.8% ;而在乙酸钠等二碳至五碳原子的不同前体添加物中 ,乙酸钠、丙酮酸钠、丁二酸钠、柠檬酸三钠盐等能提高脱落酸产量 ,而丙酸钙、氨基乙酸对脱落酸的生成有抑制作用 ,尤其是柠檬酸三钠盐对脱落酸产量影响最为显著 ,可使产量比对照提高 81.0 %。     

核盘菌和灰葡萄孢基因组中的简单重复序列分析

利用公共的真菌基因组数据库资源, 对核盘菌（Sclerotinia sclerotiorum）和灰葡萄孢（Botrytis cinerea）基因组中SSRs的结构类型、分布、丰度及最长序列等进行了系统分析, 并与已经研究过的禾谷镰孢菌（Fusarium graminearum）, 稻瘟病菌（Magnaporthe grisea）和黑粉菌（Ustilago maydis）等几种植物病原真菌基因组中的SSRs进行了比较。结果表明: 核盘菌和灰葡萄孢基因组中的SSRs非常丰富, 分别为6 539和8 627个, 并且在结构类型和分布规律上具有一定的相似性; 与其他几种病原真菌相比, 核盘菌和灰葡萄孢基因组中长重复的四、五、六核苷酸基序更为丰富, 从而使得这两种真菌具有更高的变异性。同时, 我们发现真菌基因组中SSRs的丰度与基因组的大小及GC含量没有必然的关系。文章对核盘菌和灰葡萄孢基因组中SSRs的丰度、出现频率及最长基序的分析为快速、便捷地设计多态性丰富的SSRs引物提供了有益的信息。