为明确在贵州发现的山茶花灰斑病的致病菌.采用组织分离法和离体接种法分别对其病原菌进行分离和致病性测定,利用形态学及ITS基因序列分析对病原菌进行鉴定.鉴定结果表明:分离得到的致病菌菌株(编号为schb1),在PDA培养基上菌落边缘缺刻状,呈现出很明显的褶皱微凸面,气生菌丝呈白色,背面黄褐色.根据显微观察结果,分生孢子较多,呈纺锤形,分生孢子顶生附着丝1～2根.在以ITS基因序列构建的系统发育树中,schb1与葡萄牙拟盘多毛孢菌(Pestalotiopsis portugallica)聚于一支,且支持率达100％,结合形态特征与系统发育分析将其鉴定为葡萄牙拟盘多毛孢菌.

为明确贵州省山茶花葡萄牙拟盘多毛孢菌灰斑病(Pestalotio psisportugalica)病原的生物学特性,针对从种植地采集感病样品中分离出的菌株(编号为schb1),研究碳源、氮源、pH、温度和光照对病原菌菌丝生长的影响.结果表明,该菌菌丝最适生长温度为25℃,最适pH值为6,对碳源蔗糖、氮源酵母膏的利用最高,菌丝生长对光暗交替敏感.研究结果为进一步了解山茶花葡萄牙拟盘多毛孢菌灰斑病发生规律和开展病害综合防治提供了重要参考.

Zanthoxylum bungeanum (family Rutaceae) is an economically important deciduous shrub that is widely distributed across Asia. The leaves of this plant are rich in chemical compounds and have a variety of biological activities. However, a spot disease was discovered on Z. bungeanum leaves in Zunyi, China, in 2020. In the present study, a fungal isolate (YY-815) was obtained from Z. bungeanum leaves with leaf spot symptoms and identified as Didymella segeticola based on its morphological characteristics and phylogenetic analysis. This isolate could cause leaf spot disease and be re-isolated, fulfilling Koch's postulates. The fungicides boscalid, penthiopyrad and pydiflumetofen significantly inhibited hyphal growth of D. segeticola under in vitro conditions. This is the first study to report a leaf spot disease on Z. bungeanum caused by D. segeticola.

以22种常见植物为研究对象,采用浸渍法,研究了植物乙醇粗提物对猕猴桃根结线虫2龄幼虫(J2)室内活性的影响,并开展了蕺菜、万寿菊和蓖麻粗提物对猕猴桃根结线虫的田间防效试验,以期为猕猴桃根结线虫绿色防控提供参考依据.结果表明:22种植物粗提物对猕猴桃根结线虫2龄幼虫均有不同程度的毒杀活性,其中,以蕺菜、万寿菊和蓖麻粗提物对J2的毒杀活性最佳,48 h后的校正死亡率分别为88.54％、90.97％和87.50％,LC50值分别为2.711、3.096、3.679 g·L-1;用药180 d后,万寿菊和蕺菜粗提物的田间防效分别为63.01％和54.79％,与药剂对照无显著差异,蓖麻粗提物的田间防效为41.10％,与空白对照差异显著.万寿菊、蕺菜和蓖麻粗提物均可作为防治猕猴桃根结线虫的绿色药剂.

以"小铁球"甘蓝为试材,选用缓释型氮肥、微生物菌肥和有机肥部分替代化肥,采用全程化肥减量施肥与常规施肥对比试验,研究不同施肥处理对甘蓝的农艺性状和产量影响,以期为建立经济效益明显的甘蓝化肥减施增效技术模式奠定理论基础.结果表明:一次性施缓释肥处理的甘蓝叶片开展度和株高分别为54.44 cm和36.5 cm,相较常规施肥处理分别高出12 cm和4.5 cm,说明一次性施缓释肥应用效果优于常规施肥.在总化肥减施率达50.88％的条件下,全程化肥减量施肥处理的N、P、K肥利用率分别为37.19％、33.25％和35.41％,相比常规施肥的肥料利用率提高18.44％～22.73％.全程化肥减量施肥处理甘蓝每667m2的产量为6450 kg,相较常规施肥每667 m2增产12.17％,增收280元.综上,全程化肥减量施肥处理在产量和收益上都优于常规施肥,在甘蓝生长期减少50％化肥用量,并且采用腐殖酸水溶肥、氨基酸水溶肥、海藻酸甲壳螯合钾和缓释型氮肥替代化肥施用,为甘蓝化肥减施增效技术的实际应用提供科学参考依据.

以“京丰1号”甘蓝为试材,采用喷施和浸根方法,分别在贵州省息烽县、威宁县和余庆县甘蓝主产区调查根肿病的发生情况,并选择发生较重基地开展3种不同施药处理对根肿病的防效试验,以期为贵州省甘蓝根肿病的防控技术提供参考依据.结果 表明:甘蓝根肿病在息烽县、威宁县和余庆县3个不同种植区域均有不同程度发生,平均病株率为30.00％～60.00％,发病严重的地区为息烽县,病株率高达60.00％,病情指数为45.93;相同区域不同处理间以T2处理的田间防效最好,息烽县、威宁县和余庆县3个试验地,T2处理的防效在73.40％～75.80％,其次是T1处理,防效在68.00％～70.10％,最低为T3处理,防效在61.10％～63.70％;不同处理间甘蓝和白菜的防效不同,同样以T2处理的防效最高,分别为74.40％和71.06％;通过对甘蓝实产实收,T2处理的平均产量最高,为123 511.80kg·hm-2,按照当地市场平均收购价0.50元·kg-1计算,与CK相比,采用T2处理防治根肿病,可以增收30 040.05元·hm-2.

李是助力贵州扶贫攻坚的主要水果产业之一,随着种植规模不断扩大,病虫害发生为害逐年加重.通过多次实地调查贵州李主产区病虫害发生现状,结合目前李病虫害研究进展,本文综述了李褐腐病、细菌性穿孔病、红点病、蚧壳虫、蚜虫、李小食心虫等主要病虫害的为害症状、发生特点与防治措施,旨在为优质李生产提供技术参考.

[目的] 明确李果斑病病原菌(Fusarium fujikuroi)的生物学特性并筛选出对李果斑病有效的防治药剂.[方法] 测定不同培养基、光照、温度、pH和碳、氮源对病原菌生长的影响,并采用菌丝生长速率法测定7种杀菌剂对该病原菌的室内毒力.[结果] 该病原菌最适生长温度25 ℃,pH为7～8,最适培养基为Czapek和PDA,最适碳源为淀粉和葡糖糖,最适氮源为蛋白胨和硝酸钠,不同光照条件对菌丝生长无显著影响;室内毒力测定结果表明7种杀菌剂对病原菌菌丝生长均有抑制效果,其中45％咪鲜胺WDG、20％吡噻菌胺SC和30％丙硫菌唑OD对该菌室内毒力较强,其EC50值分别为0.8914、0.9436、1.0220 μg·mL?1.[结论] 明确了对李果斑病病原菌生长的最适温度、pH、光照及营养物质等,筛选对该病原菌有较好抑制作用的杀菌剂,为李果斑病的后续研究提供基础数据及有效防控措施的选择提供参考.

Plum is commercially cultivated worldwide for the rich nutrient in its fruit. In May 2019, plum with symptoms of fruit rot were collected from fields located in Liuma town, Guizhou Province, China. The incidence of the disease varied from 10 to 20%, which was observed in 15 plum orchards (18 hectares) surveyed. Estimated yield loss was~5 to 10% for each field. Diseased fruits showed deformity, wilting and sunken lesions, and subsequenly became melanized and rotted. Diseased tissues were surface disinfected with 70% ethanol for 45 s and rinsed with sterile distilled water three times. Four morphologically similar colonies with white fluffy aerial mycelium and a reddish pigment were obtained after 3 days incubation on potato dextrose agar (PDA) at 25°C. Four single-spore isolates produced conidia with 1 to 2 septa that were sickle-shaped, thin-walled with a tapering and curved apical cell, measuring 15.6 to 29.6 × 4.8 to 8.7 μm (average 19.5×5.9 μm, n=50). Based on the cultural and conidial morphology, the isolates were identified as Fusarium (Mun et al. 2012; Leslie and Summerell 2006). DNA of two isolates was extracted using the Ezup Column Fungal Genomic DNA Extraction Kit (Sangon Bioengineering Shanghai, LTD.). To confirm the morphological diagnosis, DNA sequence data from three loci were obtained. PCR amplification was carried out with universal primers ITS1/ITS4 (White et al. 1990), translation elongation factor (EF-1α), EF1-H (5'-ATGGGTAAGGAAGACAAGAC-3') and EF2-T (5'-GGAAGTACCAGTGATCATGTT-3') (O'Donnell et al. 1998) and the second largest subunit of RNA polymerase II (RPB2), 5F2(5'-GGGGWGAYCAGAAGAAGGC-3') and 7cR (5'-CCCATRGCTTGYTTRCCCAT-3') (O'Donnell et al. 2007). Primers ITS1 and ITS4 produced a 559-bp amplicon (GenBank accession. MW085028). BLAST analysis showed 100% sequence identity to sequences of several species, deposited in GenBank, including F. fujikuroi. The EF-1α sequence (MW086868) was 100% identical to that of Fusarium fujikuroi (MN193860.1). The RPB2 primers amplified a fragment (MW086869) that was 99.9% identical to that of F. fujikuroi (MN193888.1). The BLASTn results based on the partial EF-1α and RPB2 sequences suggest isolate HJGF1 is F. fujikuroi. A pathogenicity assay was conducted using an agar disk inoculation method on plum. Fruits were stab inoculated with HJGF1 by piercing 1-mm at 3 points using a sterile needle, and fruits were mock inoculated with sterile PDA, each fruit was inoculated with three disks. (Fig. 1). The treated fruit were maintained in a growth chamber with 90% relative humidity at 25°C, and a daily 12-h photoperiod. After 5 days, the artificially inoculated fruit showed blotches with sunken lesions similar to those observed in the orchards, whereas no symptoms were observed on the control fruit. The experiment was repeated twice with similar results. F. fujikuroi was reisolated from infected tissues and confirmed by sequence analysis. To our knowledge, this is the first report of F. fujikuroi causing fruit blotch of plum in China. Considering the economic importance of plum in China and throughout the world, F. fujikuroi may be an emerging problem for plum cultivation. Thus, further study of fruit blotch of plum is warranted.

为明确伴生植物对猕猴桃根结线虫的调控效果及对猕猴桃品质和产量的影响,本研究采用猕猴桃园伴生植物多种处理,以清耕栽培为对照,测定了猕猴桃园根结线虫发病率、杂草种类、土壤物理性质及猕猴桃果实品质和产量的变化.结果 表明,伴生植物对根结线虫具有较好的调控效果,可降低猕猴桃园根结线虫发生率和减少果园杂草种类,并提高了猕猴桃果实品质及产量.其中,蕺菜伴生的猕猴桃果园根结线虫发病率最低,为27.78％,相对防效达64.28％;其次为鼠茅草伴生处理,根结线虫发病率为33.33％,防效为59.52％.蕺菜伴生的果园土壤毛管孔隙度和含水量显著提高,分别较对照增加25.55％和26.75％.数据显示,蕺菜和蚕豆伴生可明显提高猕猴桃外观品质和产量,单果体积分别较对照增加24.76％和18.24％,折算667 m2产量分别较对照增加11.94％和11.52％.蕺菜伴生对猕猴桃果实品质改善效果最佳,其果实维生素C、可溶性固形物和可溶性总糖分别比对照提高24.60％、22.79％和33.33％.

根肿病和褐斑病是影响甘蓝产量和品质的两大主要病害.为明确贵州主栽甘蓝品种对根肿病和褐斑病的抗性,采用田间自然鉴定法,在贵州威宁县、息烽县和修文县对10个甘蓝主栽品种进行根肿病和褐斑病抗性鉴定.结果表明:抗根肿病的甘蓝品种缺乏,冬丰8号在威宁和息烽对根肿病表现为耐病,中甘21号在威宁表现为耐病,其余品种均表现为感病;小铁球在3个县对甘蓝褐斑病均表现为中抗,铁球3号、中甘21号和冬丰8号在威宁和息烽表现为中抗,其余品种均表现为感病.部分相同品种在不同区域的抗感表现有差异,抗感表现一致的品种在不同县病情指数也存在较大差异,试验结果将为应用和选育甘蓝抗病品种提供参考.

为明确低温对戊唑醇包衣高粱种子的影响,指导科学合理用药,防止药害产生,研究低温胁迫对戊唑醇包衣高粱种子出苗和幼苗生理生化的指标影响.结果表明,戊唑醇4个包衣浓度0.06、0.12、0.24、0.48 g ai·kg-1种子,在适宜温度下(15～30℃)对高粱种子发芽及出苗无不良影响,均表现促进作用,发芽率提高13.33％～16.67％,出苗率均提高13.33％;幼苗叶绿素含量提高8.7％～9.7％;对高粱幼苗根长、株高、鲜重及根重无抑制作用.在低温胁迫(0～10℃)下,适量戊唑醇包衣浓度(0.06～0.12 g ai·kg-1种子)对高粱幼苗生长发育无抑制作用,而过量浓度包衣(0.24～0.48 g ai·kg-1种子)处理均表现低温药害,出苗率显著降低76.67％,叶绿素含量降低、细胞电解质外渗、过氧化氢积累及氧自由基增加,生长发育状态变差.因此,在推荐使用的浓度(0.06～0.12 g ai·kg-1种子)范围内,戊唑醇包衣不会使高粱种子产生低温药害.