Sugarcane smut, a serious disease caused by the fungus Sporosorium scitamineum, can result in 30% to 100% cane loss. The most affordable and efficient measure of preventing and handling sugarcane smut disease is to select disease-resistant varieties. A comprehensive evaluation of disease resistance based on the incidence of smut disease is essential during the selection process, necessitating the rapid and accurate identification of sugarcane smut. Traditional identification methods, which rely on visual observation of symptoms, are time-consuming, costly, and inefficient. To address these limitations, we present the lightweight sugarcane smut detection model (YOLOv5s-ECCW), which incorporates several innovative features. Specifically, the EfficientNetV2 is incorporated into the YOLOv5 network to achieve model compression while maintaining high detection accuracy. The convolutional block attention mechanism (CBAM) is added to the backbone network to improve its feature extraction capability and suppress irrelevant information. The C3STR module is used to replace the C3 module, enhancing the ability to capture global large targets. The WIoU loss function is used in place of the CIoU one to improve the bounding box regression’s accuracy. The experimental results demonstrate that the YOLOv5s-ECCW model achieves a mean average precision (mAP) of 97.8% with only 4.9 G FLOPs and 3.25 M parameters. Compared with the original YOLOv5, our improvements include a 0.2% increase in mAP, a 54% reduction in parameters, and a 70.3% decrease in computational requirements. The proposed model outperforms YOLOv4, SSD, YOLOv5, and YOLOv8 in terms of accuracy, efficiency, and model size. The YOLOv5s-ECCW model meets the urgent need for the accurate real-time identification of sugarcane smut, supporting better disease management and selection of resistant varieties.

甘蔗黑穗病是我国蔗区危害最严重的甘蔗病害之一,引起甘蔗产量的严重损失,培育和筛选抗黑穗病品种是防控黑穗病最有效途径之一.本研究采用人工浸渍法,对 10 个优良甘蔗品种进行黑穗病抗性鉴定,同时记录甘蔗黑穗病潜伏期幼苗生长情况.结果表明:10 个优良品种中高抗品种 3 个,抗病 2 级品种 4 个,中抗品种 2 个,中感品种 1 个,各品种的黑穗病发病潜伏期为 97～158 天.在黑穗病潜伏期内,桂糖 46 号的株高均较小,桂糖 55 号的株高均较大,桂糖 58 号的假茎粗均较大,而ROC22的假茎粗均较小.以上结果为筛选抗黑穗病品种和甘蔗品种合理布局及推广提供了科学依据.

Sugarcane smut is the most severe sugarcane disease in China. The typical symptom is the emerging of a long, black whip from the top of the plant cane. However, in 2018, for the first time we observed the floral structures of sugarcane infected by smut fungus in the planting fields of China. Such smut-associated inflorescence in sugarcane was generally curved and short, with small black whips emerging from glumes of a single floret on the cane stalk. Compatible haploid strains, named Ssf1-7 (MAT-1) and Ssf1-8 (MAT-2), isolated from teliospores that formed black whips in inflorescence of sugarcane were selected for sexual mating assay, ITS DNA sequencing analysis and pathogenicity assessment. The isolates Ssf1-7 and Ssf1-8 showed stronger sexual mating capability than the reported Sporisorium scitamineum strains Ss17 and Ss18. The ITS DNA sequence of the isolates Ssf1-7 and Ssf1-8 reached 100% similarity to the isolates of S. scitamineum strains available in GenBank. Inoculating Ssf1-7 + Ssf1-8 to six sugarcane varieties, i.e., GT42, GT44, GT49, GT55, LC05-136 and ROC22, resulted in different smut morphological modifications. The symptoms of floral structure only occurred in LC05-136, indicating that the flowering induction by S. scitamineum is variety-specific. Furthermore, six selected flowering-related genes were found to be differentially expressed in infected Ssf1-7 + Ssf1-8 LC05-13 plantlets compared to uninfected ones. It is concluded that the flowering induction by S. scitamineum depends on specific fungal race and sugarcane variety, suggesting a specific pathogen–host interaction and expression of some flowering-related genes.

为明确不同杀菌剂对甘蔗梢腐病病原菌的抑菌效果以便后续科学地指导病害防治,本文分别使用42.4％唑醚·氟酰胺悬浮剂,62.5 g/L精甲·咯菌腈悬浮种衣剂,250 g/L苯醚甲环唑乳油,325 g/L苯甲·嘧菌酯悬浮剂,25％吡唑醚菌酯乳油,43％氟菌·肟菌酯悬浮剂,60％唑醚·代森联水分散粒剂和19％啶氧·丙环唑悬浮剂对甘蔗梢腐病病原菌拟轮枝镰孢菌(Fusarium verticillioides)采用菌丝生长速率法进行室内药剂筛选,并通过扫描电镜(SEM)观测不同杀菌剂对病原菌孢子与菌丝的影响.结果表明,不同杀菌剂对病原菌菌丝生长均有一定抑制作用.扫描电镜结果表明,经不同杀菌剂处理后,病原菌孢子和菌丝均有不同程度的溃烂、畸形、干瘪甚至穿孔.其中,19％啶氧·丙环唑悬浮剂和325 g/L苯甲·嘧菌酯悬浮剂的抑菌效果较好,抑制中浓度(EC50)分别为0.260μg/mL和0.042μg/mL;而62.5 g/L精甲·咯菌腈悬浮种衣剂的抑菌效果较差,EC50高达2504.060μg/mL.供试药剂中,三唑类杀菌剂与甲氧基丙烯酸酯类杀菌剂的复配剂抑菌效果最好,其EC50均小于1.000μg/mL.

由甘蔗鞭黑粉菌引起的甘蔗黑穗病是我国甘蔗生产中危害最大的病害,给甘蔗产业造成严重的产量和经济损失.化学防治是作物病害综合防治的重要措施之一,开展甘蔗黑穗病高效、低毒、低残留防治药剂的筛选,进行田间防治试验,对甘蔗黑穗病的有效防治和提高甘蔗产量具有重要意义.为筛选适合大田防治甘蔗黑穗病的推荐化学药剂,通过测定11种杀菌剂对甘蔗鞭黑粉菌的抑菌试验,采用扫描电镜解析有效杀菌剂的抑菌机理,通过新植蔗和宿根蔗的甘蔗黑穗病大田防治试验,评价杀菌剂的防治效果和对产量、株高、茎径、公顷有效茎数、锤度、单茎重等甘蔗主要农艺性状的影响.结果表明,经室内生物活性测定,获得4种杀菌剂对甘蔗鞭黑粉菌单倍体生长、有性配合、冬孢子萌发有抑制作用,分别是42.4％唑醚·氟酰胺悬浮剂、75％肟菌·戊唑醇水分散粒剂、250 g/L吡唑醚菌酯乳油和325 g/L苯甲·嘧菌酯悬浮剂.扫描电镜显示,这4种杀菌剂均对甘蔗鞭黑粉菌冬孢子和单倍体孢子细胞组织造成不同程度的破坏,使甘蔗鞭黑粉菌失活.在大田新植蔗的甘蔗黑穗病防治试验中,42.4％唑醚·氟酰胺悬浮剂、75％肟菌·戊唑醇水分散粒剂、250 g/L吡唑醚菌酯乳油和325 g/L苯甲·嘧菌酯悬浮剂的防治效果分别为91.81％、82.84％、81.76％、70.92％,各药剂防治区产量分别比对照增产20.84％、17.13％、15.92％、13.35％.在宿根蔗的甘蔗黑穗病防治试验中,以上杀菌剂防治效果分别为89.35％、82.21％、81.51％、70.18％,其产量分别比对照增产30.15％、24.05％、20.33％、16.58％.新植蔗和宿根蔗药剂防治区的甘蔗其他农艺性状均优于对照区.这4种杀菌剂对甘蔗黑穗病均有良好的防治效果和增产作用,可作为大田防治甘蔗黑穗病的推荐杀菌剂.

从广西荔浦槟榔芋栽培区患芋软腐病的发病植株中分离纯化获得一株优势明显的菌株.电镜显微下,该菌菌体为短杆状,无芽孢产生,具鞭毛.致病性测定试验发现该菌株发病症状与田间芋软腐病症状一致.对该菌株进行生理生化分析,发现其符合胡萝卜果胶杆菌Pectobacterium carotovorum subsp.carotovorum的特性.16S rDNA、icdA、mdh、mtld、proA多基因联合分析结果表明该菌株与P.carotovorum subsp.carotovorum PC1(GenBank Accession No.CP001657.1)相似.综合该菌株致病性、形态学、生理生化等特征特性及多基因序列分析,将引起槟榔芋软腐病的病原菌鉴定为Pectobacterium carotovorum subsp.carotovorum.