为探寻八角炭疽病Colletotrichum horii绿色防控途径,研究采用单因素完全区组随机设计,在发病林区施用不同配方肥料,测定对病害控制效果、叶片生理生化指标变化以及在生产上扩大试验示范.结果表明:不同配方肥料对病害的控制效果不同,配方1(N+P2O5+K2O 35％,有机质15％,有效钙、镁、硼、锌、铜含量3902 mg/kg,含生防菌、肥料增效剂及复合杀菌剂)的病情指数最低,防治效果达65.65％;配方1处理的POD、SOD活性、百叶鲜质量和MDA含量与其它处理差异显著;配方1在4个不同区域点大面积试验示范,病害控制效果在79.65％以上.通过不同肥料配方处理后,对八角炭疽病的防治均有一定效果,以配方1效果最为明显,具有应用价值.

Eucalyptus citriodora is a wood and oil dual-purpose tree with strong growth adaptability and high ornamental value. Recent years, it has been widely planted in Guangxi in China. In Nov. 2021, branch blight was found to be widespread on E. citriodora in Qinzhou in China (21°57'57"N, 108°42'6"E). The occurrence area was over 7000 m2, and the disease incidence was 23% (23/100). Twigs were withered in most of infected plants, and only top branch died in few plants. The lesions started from branch tips, then expanded and caused 5-20 cm branches died in final. The lesions were tiny and brown at early stage, then turned dark brown or black. Ten diseased branches were sampled randomly in field and were cut into 1 cm pieces. After surface disinfecting with 75% ethanol for 3 min, 0.1% HgCl2 for 5 min, washing with sterile water three times, samples were placed onto Potato Dextrose Agar (PDA) medium. Hyphae appeared after incubating for 5 days at 28 ℃. The diameter of colonies reached 64-71 mm after 7 days incubation. The colonies were white and felt-like, and then turned yellowish gradually with flourish aerial hyphae. Two weeks later, pycnidia appeared, which were nearly spherical, initial pale yellow and later black. Sometimes secretions overflowed from the aperture on pycnidia. There were 2 types of conidia (α and β type), which were unicellular and hyaline. The α type was spindle to ellipse and had 1-2 oil globule, with 5.56±0.50 × 2.67±0.39 μm (n=100) in size. The β type was linear and one end bent in hook shape, with 17.10±2.54 × 1.55±0.32 μm (n=50) in size. Three isolates (LEQZ01, LEQZ02, LEQZ03) were selected for further study. The internal transcribed spacers (ITS) region of rDNA, translation elongation factor 1-α (tef1 α) and β-tubulin (tub2) genes were amplified using primer pairs ITS1/ITS4 (White et al. 1990), EF1-983F/EF1-1567R (Rehner et al. 2005) and Tub1/ Tub2 (Chauhan et al. 2007), respectively. BLASTn searches showed that the ITS (OM339849, ON075781, ON075782), tef1 α (ON093807-ON093809) and tub2 (ON093810-ON093812) sequences had the highest similarity with Diaporthe ueckerae strains, with 99% (543/549, 544/549, 544/549) identity for ITS (NR 147543.1), with 99% (350/351, 353/353, 349/350) identity for tef1 α (KY569388.1), with 99% (754/754, 753/754, 754/754) identity for tub2 (MW514128.1). A neighbor-joining tree constructed by combining 3 sequenced loci. Three isolates clustered in the D. ueckerae clade with 100% bootstrap support. Based on morphological (Yi et al. 2018) and molecular evidences, the pathogen was identified as D. ueckerae. In a pathogenicity test, 20 healthy E. citriodora seedlings were divided into 4 groups. Before inoculation, twigs were surface disinfected with 75% ethanol followed by washing 3 times using sterile water. Tiny artificial wounds at 5 cm below the seedling top were inoculated by hyphae taken from colonies incubated for 7 days at 25 ℃ in the dark, and covered with damp cotton in 1-3 groups (Yi et al. 2018). Yet the wounds were covered with damp cotton in control group. Two days later, wounds started to turn brown in test groups, and symptoms similar to field were obtained after 10 days. But no lesion emerged in control group. Then germs were re-isolated from symptomatic twigs and identified as D. ueckerae following the methods above. To our knowledge, this is the first report of branch blight caused by D. ueckerae on E. citriodora in China. Further researches on disease epidemiology would help to prevent spread to more locations.

采用菌丝生长速率法,测定了苯醚甲环唑ME和吡唑醚菌酯EC及其混配剂对八角炭疽病菌(Colletotrichum ho-rii)室内毒力.结果表明,2种单剂对八角炭疽病菌具有较强的抑制作用,吡唑醚菌酯EC的EC50值为0.3516 mg/L,苯醚甲环唑ME的EC50值为0.3594 mg/L.将2种杀菌剂以不同浓度混配后,其中具有增效作用的2个组合分别是苯醚甲环唑ME与吡唑醚菌酯EC的3:2混剂和1:1混剂,共毒系数分别为189和134.

害虫是影响油茶(Camellia spp.)产量的主要因素之一,对其进行准确识别有助于及时防控,减少损失.目前,油茶害虫识别研究缺少相关的数据集,限制了深度学习技术在油茶害虫识别中的应用.为给在生态环境下准确识别油茶害虫提供1种新范式,构建包含1116张7类害虫的油茶害虫识别图像数据集,采用4种目标检测算法(SSD、YOLOv3、YOLOX和RetinaNet)在该数据集上进行试验.结果表明,IOU阈值为0.5时,SSD的平均精度为93.50%,YOLOX为93.50%,RetinaNet为86.80%,YOLOv3为96.60%;SSD的平均召回率为73.20%,YOLOX为75.10%,RetinaNet为78.00%,YOLOv3为76.80%.综合分析,YOLOv3的检测和分类能力最优.

Aniseed (Illicium verum) is a woody spice tree that has been grown in China for a long time. Anthracnose is an important disease of aniseed, which can cause severe leaf drop. In Sep. 2020, severe anthracnose was observed in Shanglin (23°35'5"N, 108°19'51"E), Nanning, Guangxi in China, and the incidence was 85%. The symptoms at the early stage were small, round and watery, then became larger and gradually turned brown. The acervuli would appear at the later stage, and contain many conidia. Leaves with disease were randomly sampled from 10 plants, and were cut into small rectangular pieces of 0.5×1 cm, and disinfected with 75% alcohol 1 min, with 0.1% HgCl2 3 min. After washing with sterile water 3 times, they were placed onto potato dextrose agar (PDA) medium and incubated at 25°C for 5 days. The average colony growth rate was 11.85 mm/d in 7 days. The colony was white or light gray in the initial stage, with dense aerial mycelium, and the central mycelium of the colony was dark grey in the later stage. Conidia were colorless, single spore, smooth, cylindrical, both ends obtuse, with an average size of 14.95 ± 0.97 μm × 5.46 ± 0.44 μm (n = 100). The conidial appressorium was oval or club-shaped, brown, margin intact, with an average size of 7.83 ± 1.21 μm × 5.82 ± 0.58μm (n = 50). Three strains GXNN02, GXNN03 and GXNN05 were selected for further study. Primer pairs T1/βt2b, ACT512/ACT783, GDF/GDR, CHS1-79F / CHS1-354R and ITS1/ITS4 (Weir et al. 2012) were used to amplify tubulin (TUB), actin (ACT), 3-phosphate glyceraldehyde dehydrogenase (GAPDH), chitinase (CHS1) and the internal transcribed spacers of rDNA (ITS) respectively. BLASTn searches showed that the TUB (ON619861-63 ), ACT (ON619852-54), GAPDH (ON619855-57), CHS1 (ON619858-60) and ITS (ON573028-30) sequences had the highest similarity to Colletotrichum siamense with up to 99% (699/702, 676/679, 699/702) identity for TUB (JX010404.1); 99% (281/282, 253/254, 249/250) identity for ACT (JX009518.1); 99% (275/277, 275/277, 239/241) identity for GAPDH (JX009924.1); 99% (296/299, 296/299, 259/262) identity for CHS1 (JX009865.1); up to 99% (527/530, 485/487, 527/530) identity for ITS (JX010171.1) of ex-type ICMP 18578. A ML tree was constructed by combining 5 sequenced loci, and three isolates clustered in the C. siamense clade with 94% bootstrap support. Therefore, combined with the morphological characteristics, the pathogens were identified as C. siamense. In a pathogenicity test, these three isolates were tested on 9 healthy aniseed seedlings with at least 10 leaves, and 3 seedlings as control. The leaves were surface disinfected with 75% alcohol, and then wiped with sterilized water three times. Holes were made near the edge of the leaves and were sprayed with conidial solution (6×106 spores/mL) in test groups, and use sterilized water as control. Then the leaves were sealed inside a plastic bag for 48 h to retain moisture. Brown spot and black acervuli, similar to the symptoms in the field, were observed on the leaves in test groups within 10-15 days. No symptoms were observed on the negative control leaves. The pathogens were reisolated from the treated infected leaves and were identified as C. siamense, thus fulfilling Koch's postulates. The pathogenicity test was confirmed by repeating in triplicate. The isolation frequency of C. siamense in our samples was 82.50%. To our knowledge, this is the first report of C. siamense in China. Further research on the occurrence of the disease will help prevent the spread of the disease.

为获得对八角叶甲(Oides duporti)具有高致病力的白僵菌(Beauveria spp.)菌株,为利用白僵菌防治八角叶甲提供理论依据,采用组织分离法从感病的八角叶甲幼虫体内分离获得5株白僵菌菌株,测定其菌落直径、产孢量和孢子萌发率,采用浸虫法测定5个菌株对八角叶甲的毒力,并结合形态学与分子生物学,对菌株进行鉴定.结果表明,菌落直径最大的为菌株YJ-43;菌株YJ-22的产孢量和孢子萌发率均最高,毒力最强.形态学及rDNA-ITS序列分析结果显示,5个菌株均为球孢白僵菌(B.bassiana).

Eucalypt species are among the most important for timber production worldwide. Eucalyptus cloeziana is increasingly culticated due to its desirable structural properties. Leaf blight is one of the most devastating diseases of E. cloeziana in China. In May 2019, leaf blight samples were collected from E. cloeziana in Chongzuo, Guangxi, China (22°20'37.70"N, 107°49'29.29"E). Lesions began at the leaf margin and extended to 1/4-3/4 of the total leaf surface area. Lesions (26.76±12.64 mm diameter) were round, yellow, and withered in appearance, and sometimes many black, round pycnidia were observed. Leaves with blight were collected randomly from 10 E. cloeziana plants. Tissue blocks (3 mm×3 mm) were sampled from diseased and healthy leaf portions, then surface disinfected with 75% ethanol for 20 s and 0.1% HgCl2 for 3 min. After washing with sterile water three times, dry tissue blocks were placed on potato dextrose agar (PDA) medium and incubated at 28°C for 5 days. Hyphae were milky white or whitish, and sparse. The colonies had petal-shaped edges and the conidiophores were clustered, branched and transparent. Spore-forming cells were solitary and smooth; conidia were smooth, fusiform or oblong, transparent, blunt-based, mostly erect, and 16.54±2.19 × 3.38±0.77 μm (n=100 in each isolate) in size. Three representative isolates (AB-6, AB-9, AB-16) were selected for further study. For molecular identification, the internal transcribed spacer (ITS) region of rDNA, translation elongation factor 1-α (TEF1), and large subunit ribosomal RNA (LSU) were amplified with primers ITS1/ITS4 (White et al. 1990), EF1-983F/EF1-1567R (Rehner and Buckleyet al. 2005), and LR0R/LR5 (Vilgalys and Hesteret al. 1990), respectively. BLASTn searches showed that the ITS (OM280456, ON026088-89), TEF1 (ON055278-80) and LSU (OM281346, ON026097-98) sequences had the highest similarity to Coniella quercicola strains with: 99% (600/605, 600/605, 600/604) identity for ITS (MH859478.1); 98% (326/333, 327/334, 325/332) identity for TEF1 (KX833698.1); 99% (870/872, 833/834, 830/831) identity for LSU (MH871258.1) of ex-type CBS 904.69. A Neighbor-Joining phylogenetic tree was constructed by combining 3 sequenced loci. Three isolates clustered in the C. quercicola clade with 100% bootstrap support. Thus, based on morphological (Maas et al. 1979; Wang and Lin et al. 2004) and molecular characteristics, the pathogen was identified as C. quercicola. In a pathogenicity test, 20 healthy E. cloeziana seedlings with at least 5 leaves were divided into 4 groups: groups 1-3 were used to inoculate three isolates respectively, and the fourth group acted as control. After surface disinfection with 75% ethanol and wiping with sterile water, tiny wounds were maked made by inoculation needle on each leaf. Fungal culture plugsblocks cut from 3 isolates were placed on wounds in groups 1-3 respectively,. withWarter- agar blockplugs served as control in group 4. The leaves were covered with wet cotton and sealed in airtight bags to retain moisture at room temperature with natural light. After 3 days, light brown lesions were observed in groups 1-3, with no symptoms present in the control group. The pathogenicity test was confirmed by repeating in triplicate and fungi re-isolated from symptomatic leaves were identified as C. quercicola. To our knowledge, this is the first report of leaf blight on E. cloeziana caused by C. quercicola in China. This study increases our understanding of E. cloeziana leaf blight and future research may allow the development of targeted prevention methods for more effective disease controls.

广西是我国八角主产区,为了解为害八角的有害生物主要种类及其为害情况,为生产防控提供参考,2018-2021年笔者在广西八角产区开展了实地调查研究.结果表明:为害广西八角的主要有害生物有30种,其中病害6种,害虫18种,有害植物5种,害鼠1种.当前对八角为害较严重且对生产影响最大的种类是八角尺蠖(Dilophodes elegans subsp.sinica)、八角叶甲(Oides duporti)和八角炭疽病(Colletotrichium horii).茶堆沙蛀蛾、矢尖蚧、煤烟病、中华简管蓟马和野葛等在一些区域亦出现偏重发生的情况.

为获得八角炭疽病高效生防菌,利用组织分离法从八角叶片分离出芽胞杆菌菌株,通过与八角炭疽病病原菌哈锐炭疽菌Colletotrichum horii对峙培养筛选出拮抗菌株L0517.利用拮抗菌株的发酵滤液来验证其对八角炭疽病的防治效果,并研究菌株的发酵条件.结合形态学、生理生化及16SrDNA和gyrB序列分析,将菌株L0517鉴定为贝莱斯芽胞杆菌Bacillusvelezensis.菌株L0517发酵滤液可显著抑制哈锐炭疽菌菌丝生长,并引起菌丝形成囊泡状结构.用含0.1％吐温-80和10％L0517发酵滤液处理八角叶片可显著降低哈锐炭疽菌的致病能力,且对八角安全无致病性.发酵条件研究表明,当发酵温度为25℃,培养液pH为7,碳源和氮源分别为麦芽糖和酵母粉时菌株生长最快,其发酵液的抑菌活性也最强.

为明确香花油茶(Camellia osmantha)不同无性系苗期炭疽病发生情况及其病菌致病力分化状况,为香花油茶苗期炭疽病的综合防治和抗病育种提供理论依据,采用平行线取样法,对27个香花油茶无性系苗期炭疽病进行调查与统计,通过形态特征和分子系统学分析对炭疽病病菌进行鉴定,并采用离体叶片接种法对所获菌株进行致病性及致病力测定,明确各菌株的致病力等级.结果表明,2019—2021年,不同无性系炭疽病发病率及病情指数均呈上升趋势,均在2019—2020年增长较快;27个菌株的培养性状及形态特征均相似,鉴定为Colletotrichum fructicola;来自6和12号无性系的炭疽病菌株为强致病力菌株,其他25个无性系的炭疽病菌株均为中等致病力菌株.香花油茶无性系苗期炭疽病菌C.fructicola致病力分化明显,以中等致病力菌株为优势群体.

[目的]为筛选对八角炭疽病具有较好防治效果的杀菌剂.[方法]采用菌丝生长速率法,测定了 7种杀菌剂对八角炭疽病菌室内生物活性.采用针刺法接种病菌至八角苗,测定了45％咪鲜胺EW、30％苯醚·啶氧SC和10％苯醚甲环唑WG对感病苗木的防治效果.[结果]抑制作用较强的杀菌剂是30％苯醚·啶氧SC,10％苯醚甲环唑WG和45％咪鲜胺EW,EC50值分别为0.0424、0.0441、0.0738 mg/L.当质量浓度为150、300 mg/L时,3种杀菌剂的防治效果为60％～70％,当杀菌剂的质量浓度为600 mg/L时,防治效果达到70％以上.[结论]30％苯醚·啶氧SC、10％苯醚甲环唑WG和45％咪鲜胺EW均可作为防治八角炭疽病的备选药剂.

[目的]轮斑病是桉树的常见叶部真菌病害.本研究探讨健康和轮斑病害桉树叶内生真菌群落的结构差异,并筛选对轮班病菌具有拮抗作用的菌株.[方法]采用Illumina Miseq技术对健康和轮斑病害桉树叶内生真菌ITS rDNA进行测序,分析两组样品内生真菌的多样性和丰度.采用平板对峙法检测本实验室保存菌株对轮斑病菌生长的影响,并用PCR法验证抗病菌株是否存在于健康和病害叶片中.[结果]生物信息学分析结果表明健康桉树叶的内生真菌共注释到2门、15纲、55目、139科、238属、300种;轮斑病害桉树叶共注释到2门、12纲、55目、88科、130属、183种.轮斑病害桉树叶内生真菌群落多样性和优势菌种的集中程度均较健康叶片无显著改变,处于相对稳定的状态.而轮斑病害桉树叶内生真菌群落丰度较健康叶显著降低,两组叶片中真菌群落结构和组成存在较大差异.病害和健康桉树叶内均存在轮斑病菌Coniella eucalyptorum、花斑病菌Aureo-basidium pullulans和枝枯病菌Lasiodiplodia theobromae,其中轮斑病菌为病害叶内的优势真菌.平板对峙试验结果发现,本实验室保存的菌种中,仅有贝莱斯芽孢杆菌Bacillus velezensis对轮班病菌具有较强的拮抗作用.用PCR分别扩增轮斑病害和健康桉树叶基因组DNA中的GyrA基因片段,PCR产物的琼脂糖凝胶电泳结果表明B.velezensis仅存在于健康桉树叶内,而在轮斑病害桉树叶中未能检测到.[结论]桉树叶部内生真菌的群落结构可能受轮斑病菌侵染的影响,导致染病叶内生真菌群落的丰度下降;而贝莱斯芽孢杆菌对桉树轮斑病菌的生长具有一定的拮抗作用,有望成为一种新的针对桉树轮斑病的生物防治方法.本研究为明确桉树轮斑病的成因和开发轮斑病生防制剂提供了一定的理论和实验依据.

为明确引起贵州八角叶枯病的病原种类及其生物学特性,本研究采用单孢分离法获得3个菌株,经形态学特征鉴定结合ITS、tef1和TUB多基因序列分析,3个菌株均被鉴定为庐山拟盘多毛孢Pestalotiopsis lushanensis,这是该菌在八角上引起叶枯病的首次报道.生物学特性研究表明,该菌菌丝生长和孢子萌发最佳温度为25℃,最适pH为6～7,菌丝致死温度为50℃处理10 min,分生孢子致死温度为55℃处理10 min.

Eucalypt GL-9 (Eucalyptus grandis × Eucalyptus urophylla) is one of the most widely grown genotypes of Eucalyptus in China. Each year, leaf blight causes serious economic losses in the eucalyptus industry in the south of China. In December 2019, a leaf blight disease was found to be widespread on eucalyptus GL-9 in Hechi in Guangxi, China (25°22'17"N, 108°15'32"E). Symptomatic lesions were usually brown at the early stage of infection and then turned off-white at the late stage. They had a large number of black round pycnidia randomly dispersed on the surface. Most of the lesions initially started from the leaf tip and then gradually expanded to the base of the leaf. Three randomly sampled leaves were washed using sterile water. Next, small pieces of tissue (5×10 mm) were removed from the margins of the lesions, surface disinfected with 75% ethanol for 1 min and 0.1% HgCl2 for 3 min, and then washed three times with sterile water. The tissues were placed on potato dextrose agar (PDA) and incubated at 28°C for 5 days to observe the fungus morphological characteristics. The hyphae on the PDA were milky yellow, and the PDA was light yellow when viewed from the bottom, with few aerial hyphae. The colonies had petal-like edges. In the later stage, hyphae in the center of the colonies turned brown. Three representative isolate (EC7, EC8, EC10) were selected for further study. Their conidia were olive-shaped, spindle-shaped, or obliquely globose, 8.80-11.93 μm in length (10.35 μm in average), 4.69-7.33 μm in width (6.06 μm in average) (n=100 in each isolate), with a conical apiculus and a hyaline basal appendage that was tubular, smooth, and thin-walled. For molecular identification, their genomic DNA was extracted using a Genomic DNA Kit (Tiangen, China). The internal transcribed spacer (ITS) region of rDNA and β-tubulin (TUB) genes were amplified using ITS5/ITS4 and βt2a/βt2b primer sets, respectively (White et al. 1990). BLASTn searches showed that the ITS and TUB sequences had the highest identity with Apoharknessia eucalyptorum strains, with 100% (586/586 in EC7 and EC8, 590/590 in EC10) identity for ITS (KY979752.1) and 99% (502/505 in EC7, 506/508 in EC8 and 504/507 in EC10) identity for TUB (KY979919.1) of ex-type CBS 142519. The ITS and TUB sequences of three isolates were submitted to GenBank (EC7: OM060439 and OM103586, EC8: OM679378 and OM715153, EC10: OM679377 and OM715152). A maximum likelihood phylogenetic tree was constructed by combining the two sequenced loci in MEGA7. Three isolates clustered in the A. eucalyptorum clade with 92% bootstrap support. Thus, based on morphological (Crous et al. 2017; Garrett et al. 2018) and molecular characteristics, the pathogen was identified as A. eucalyptorum. In a pathogenicity test, twenty healthy GL-9 seedlings were collected, and were divided into four groups. Seedlings from groups 1-3 were used to inoculate three isolates respectively, and seedlings from another group were sprayed distilled water as control. Before test, leaves were washed with sterile water, surface disinfected with 75% ethanol, and then rinsed with sterile water. After drying, an inoculation needle was used to make tiny wounds near the leaf margin on each leaf. Next, conidia solution (1×107 conidia/ml) and sterile water were sprayed to leaves in different groups and moistened with airtight bags. After 3 days, airtight bags were moved. Lesions appeared on all the pathogen-inoculated leaves, whereas only the inoculation point turned brown on the control leaves. The pathogenicity test was repeated three times and the same results were obtained. Fungi were re-isolated from symptomatic leaves and identified as A. eucalyptorum following the same methodologies used for the initial identification. To our knowledge, this is the first report of A. eucalyptorum causing leaf blight on E. grandis × E. urophylla in China. This study expands the understanding of the pathogen of leaf blight on E. grandis × E. urophylla. More research is needed to develop effective strategies to manage this disease.

[目的]鉴定广西香花油茶炭疽病病原菌,掌握其生物学特性,为抗病油茶品种选育提供参考依据.[方法]采集广西南宁市、来宾市和崇左市香花油茶林地典型炭疽病样品,以组织分离法和柯赫氏法获得致病菌株,依据病原菌形态特征描述和病原菌核糖体内转录间隔区(ITS)、肌动蛋白(ACT)、几丁质合成酶(CHS1)和3-磷酸甘油醛脱氢酶(GPDH)多基因分子系统学分析结果进行鉴定,并采用平板法测定病原菌的生物学特性.[结果]从广西南宁市、来宾市和崇左市3个地区香花油茶林地采集典型炭疽病样品中分离获得的76株炭疽菌属真菌,对健康香花油茶叶片均具有致病性,但致病力略有差异;代表菌株CXNN02、CXLB08和CXCZ09的离体接种病斑平均直径分别为6.48、6.39和5.20 mm,活体接种病斑比前者略小,分别为5.53、5.33和4.97 mm,以CX-NN02菌株的致病力略强.菌株CXNN02在PDA培养基上菌落呈圆形,菌丝灰色至深灰色,气生菌丝茂盛,绒毛状,背面产生黑色色素;菌丝生长较快,平均生长速率为11.75 mm/d;分生孢子光滑,无色,单胞,圆柱状,顶端钝圆或略尖,大小为(13.30～20.67)μm×(3.39～7.48)μm;分生孢子附着胞浅褐色至褐色,单个或多个,圆形或近圆形,边缘完整,大小为(6.50～10.69)μm×(5.17～9.50)μm.对菌株CXNN02、CXLB08和CXCZ09进行形态学结合病原菌多位点基因系统发育进化树分析,确定核果炭疽菌(Colle-totrichum fructicola)是广西香花油茶炭疽病病原菌.生物学特性测定结果显示,香花油茶炭疽病病原菌菌丝生长和产孢的最佳温度均为28℃,最适菌丝生长pH为4～5,最适产孢pH为6,菌丝生长的较佳碳源为D-麦芽糖、D-葡萄糖、D-果糖和D-木糖,最佳产孢碳源为乳糖,较佳氮源为牛肉膏、蛋白胨和酵母粉3种有机氮源,最佳产孢氮源为酵母粉;完全黑暗有利于香花油茶炭疽病病原菌菌丝生长和产孢.[结论]广西香花油茶炭疽病病原菌为核果炭疽菌,其菌丝生长和产孢受温度、pH、碳氮源和光照条件影响明显.香花油茶是核果炭疽菌的新寄主,进行香花油茶抗病品种选育及制定炭疽病防治措施时需充分了解该菌的生物学特性.

为掌握广西杉木(Cunninghamia lanceolata)主要有害生物种类和分布情况,采用线路踏查和标准地调查为主,定点监测、不定期调查和室内饲养观察为辅的调查方法,对广西杉木人工林和苗圃等地的主要有害生物种类进行调查.结果显示,广西杉木主要有害生物种类有37种;其中,害虫26种,分别隶属于等翅目(Isoptera)(5种)、直翅目(Orthoptera)(1种)、同翅目(Homoptera)(1种)、鞘翅目(Coleoptera)(14种)和鳞翅目(Lepidopter)(5种),主要危害枝干和根部;病害7种,发病部位为枝干和叶片;有害动植物4种.

[目的]明确广西杉木炭疽病的病原种类及生物学特性,为杉木抗病育种及杉木炭疽病的防治技术研究提供科学依据.[方法]采集广西河池、百色、桂林、柳州、贺州和南宁市杉木种子园及林地炭疽病样品,采用常规组织和单孢分离法获得杉木炭疽病病原菌菌株,通过形态特征结合病原菌核糖体内转录间隔区(ITS)、几丁质合成酶(CHS1)、3-磷酸甘油醛脱氢酶(GPDH)、微管蛋白(TUB2)和肌动蛋白(ACT)多基因分子系统学分析,对获得的炭疽病菌菌株进行鉴定;采用平板培养法测定病原菌生物学特性.[结果]从杉木炭疽病样品中共分离获得60株炭疽菌属真菌,均具有致病性,但致病力存在差异.通过形态学结合病原菌多位点基因系统发育分析,确定广西杉木炭疽病病原菌种类为核果炭疽菌(Colletotrichum fructicola)和山茶炭疽菌(C.camelliae).生物学特性测定结果显示,C.fruc-ticola和C.camelliae菌丝生长及产孢最适温度分别为28和25℃;光照对C.fructicola菌丝生长无明显影响,但有利于C.camealliae菌丝生长,黑暗有利于2种病原菌产孢;pH 4时最适宜2种病原菌菌丝生长,pH 4最适宜C.fructicola产孢,pH 5最适宜C.camealliae产孢;2种病原菌对D-麦芽糖利用最好,乳糖和D-山梨醇最有利于C.fructicola产孢,可溶性淀粉和阿拉伯糖最有利于C.camelliae产孢;蛋白胨和酵母粉均有利于2种病原菌菌丝生长,酵母粉有利于C.fructi-colaz产孢,酵母粉和牛肉膏有利于C.camelliae产孢.[结论]广西杉木炭疽病病原为核果炭疽菌(C.fructicola)和山茶炭疽菌(C.camelliae).温度、pH和碳氮源对2种病原菌菌丝生长及产孢影响明显,光照对2种病原的影响略有不同.

采用菌丝生长速率法测定9种杀菌剂对桉树轮斑病原菌(Pilidiella eucalyptorum、P.diplodiella)的室内毒力.结果表明,供试的杀菌剂对病原菌具有不同程度的抑制作用.对P.eucalyptorum毒力最强的杀菌剂是10％苯醚甲环唑ME,EC50值为0.0116 mg/L;其次是25％吡唑醚菌酯SC,EC50值为0.0453 mg/L;毒力最弱的是80％乙蒜素EC,EC50值为6.8393 mg/L.对P.diplodiella毒力最强的杀菌剂是43％戊唑醇SC,EC50值为0.0473 mg/L;其次是20％丙环唑ME,EC50值为0.0857 mg/L;毒力最弱的是80％乙蒜素EC,EC50值为2.8099 mg/L.

The plant U-box (PUB) gene family, one of the major ubiquitin ligase families in plants, plays important roles in multiple cellular processes including environmental stress responses and resistance. The function of U-box genes has been well characterized in Arabidopsis and other plants. However, little is known about the tea plant (Camellia sinensis) PUB genes. Here, 89 U-box proteins were identified from the chromosome-scale referenced genome of tea plant. According to the domain organization and phylogenetic analysis, the tea plant PUB family were classified into ten classes, named Class I to X, respectively. Using previously released stress-related RNA-seq data in tea plant, we identified 34 stress-inducible CsPUB genes. Specifically, eight CsPUB genes were expressed differentially under both anthracnose pathogen and drought stresses. Moreover, six of the eight CsPUBs were upregulated in response to these two stresses. Expression profiling performed by qRT-PCR was consistent with the RNA-seq analysis, and stress-related cis-acting elements were identified in the promoter regions of the six upregulated CsPUB genes. These results strongly implied the putative functions of U-box ligase genes in response to biotic and abiotic stresses in tea plant.

采用平板培养法和液体培养法研究桉树轮斑病原菌(Pilidiella eucalyptorum)的生物学特性,为桉树轮斑病的监测及防治技术提供理论基础.结果表明,该菌菌丝在10～35℃及pH 2～12的环境里均能生长,最适温度为28℃,最适pH值为6;6 h/18 h紫外光光暗交替与12 h日光灯光暗交替有利于菌丝生长;乳糖和蔗糖是菌丝生长最佳碳源;蛋白胨和酵母粉是菌丝生长最佳氮源;分生孢子在20～30℃均可萌发,以28℃萌发率最高;在饱和湿度且有水滴条件下分生孢子萌发率最高;病原菌菌丝和分生孢子的致死温度分别为48和50℃.