Screening of antagonistic Trichoderma strains and their application for controlling stalk rot in maize

Maize is one of the major crops in China, but maize stalk rot occurs nationwide and has become one of the major challenges in maize production in China. In order to find an environment-friendly and feasible technology to control this disease, a Trichoderma-based biocontrol agent was selected. Forty-eight strains with various inhibition activities to Fusarium graminearum, and Fusarium verticillioides were tested. A group of Trichoderma strains(DLY31, SG3403, DLY1303 and GDFS1009) were found to provide an inhibition rate to pathogen growth in vitro of over 70%. These strains also prevented pathogen infection over 65% and promoted the maize seedling growth for the main root in vivo by over 50%. Due to its advantage in antifungal activity against pathogens and promotion activity to maize, Trichoderma asperellum GDSF1009 was selected as the most promising strain of the biocontrol agent in the Trichoderma spectrum. Pot experiments showed that the Trichoderma agent at 2–3 g/pot could achieve the best control of seedling stalk rot and promotion of maize seedling growth. In the field experiments, 8–10 g/hole was able to achieve over 65% control to stalk rot, and yield increased by 2–11%. In the case of natural morbidity, the control efficiency ranged from 27.23 to 48.84%, and the rate of yield increase reached 11.70%, with a dosage of Trichoderma granules at 75 kg ha~(-1). Based on these results, we concluded that the Trichoderma agent is a promising biocontrol approach to stalk rot in maize.     

玉米对镰刀菌茎腐病抗性的生化反应

在抽雄期用禾谷镰刀菌孢子悬浮液接种抗病品种陕单931和感病品种西农11号,于接种后测定茎秆髓部组织内苯丙氨酸解氨酶、过氧化物酶活性变化、木质素和绿原酸的变化。结果表明,玉米植株受镰刀菌侵染后,抗病品种的苯丙氨酸解氨酶酶活上升快,活性强,且形成两个活性高峰,高活性时间持续长;感病品种苯丙氨酸解氨酶酶活上升慢,活性相对较弱,且只形成一个峰,高活性持续时间短。抗病品种过氧化物酶酶活峰值高,感病品种过氧化物酶酶活峰值低,且抗病品种高酶活持续的时间长,感病品种高酶活持续的短。研究还表明,植株原生的木质素对玉米的抗性贡献不大,而诱导的木质素在玉米的抗病性中起着主导作用。同时,无论抗、感品种,其组织诱导提取液对镰刀菌都有一定的抑制作用。     

分离自小麦赤霉病和玉米茎基腐病的禾谷镰孢菌的致病性研究

采用单花滴注方法和注射法交互接种,分别对8株分离自小麦赤霉病穗和11株分离自玉米茎基腐病茎的禾谷镰孢菌进行致病力测定。结果表明,所有供试菌株均能够成功交互侵染小麦和玉米,二者致病能力不同,存在明显差异。小麦赤霉病和玉米茎基腐病都是土传病害,染病作物病残体会造成跨寄主侵染,在小麦玉米轮作区两种病害可能会出现日渐严重的趋势。     

玉米镰孢菌穗腐病和茎腐病侵染规律相互关系的研究

通过温室内串珠镰孢菌（Ｆｕｓａｒｉｕｍ ｍｏｎｉｌｉｆｏｒｍｅ）和禾谷镰孢菌（Ｆｕｓａｒｉｕｍ ｇｒａｍｉｎｅａｒｕｍ）接种、植株体内病菌的系统分离和田间自然病圃内植株体外病原菌的捕捉和致病性测定,明确了玉米镰孢菌穗腐病和茎腐病侵染规律的相互关系。研究表明：串珠镰孢菌和禾谷镰孢菌均能沿植株体内向上扩展,串珠镰孢菌能够扩展到穗部籽粒,但当年未能引起穗腐症状,禾谷镰孢菌难以扩展到穗部。体外气流传播是两种镰孢菌引起穗腐病的主要途径。     

我国部分常用玉米种质资源对镰孢菌病害的抗性评价

【目的】玉米穗腐病、茎腐病和鞘腐病是我国玉米产区普遍发生的三大镰孢菌（Fusarium spp.）病害,近年来有严重混和发生的趋势,三大病害主要致病菌分别为拟轮枝镰孢（F. verticillioides）、禾谷镰孢（F. graminearum）和层出镰孢（F. proliferatum）。种植抗病品种是控制该类病害最经济有效的方法,本研究旨在筛选出单抗或兼抗穗腐病、茎腐病和鞘腐病的玉米种质,为玉米品种的科学选育和合理布局提供参考。【方法】选取我国玉米种质B73、B37、郑58、昌7-2、齐319等16个常用育种自交系,将玉米穗腐病主要病原菌拟轮枝镰孢、茎腐病主要病原菌禾谷镰孢及鞘腐病主要病原菌层出镰孢分别接种于玉米果穗、茎秆及叶鞘,具体方法为待整株长到吐丝期用连动注射器将拟轮枝镰孢孢子悬浮液沿花丝通道注射到健康玉米果穗;将健康玉米地上第一节的茎部用针扎孔后向其中注射禾谷镰孢孢子悬浮液;将层出镰孢孢子悬浮液沿健康玉米植株叶基部接种到地上2—5节间的叶鞘内。以上各种接种方式均使用无菌水作为对照。在2016年和2018年度进行人工田间接种试验,通过评价穗腐病、鞘腐病的病情指数以及茎腐病发病面积,评估所选自交系对以上镰孢菌引起的穗腐病、茎腐病和鞘腐病的抗性级别。【结果】供试自交系中吉853、OH43和X178对穗腐病表现为中抗,B73、B37、PH6WC、掖478、郑58、9058、昌7-2、浚928、Mo17、A619、PH4CV、齐319和13-1077共13份材料为感病或高感;齐319、PH4CV、Mo17、9058、B37、B73、昌7-2和13-1077共8份材料对茎腐病表现为中抗或高抗,郑58、掖478、PH6WC、浚928、吉853、A619和OH43共7份材料表现为感病或高感;B73、B37、郑58、掖478、PH6WC、9058、昌7-2、吉853、浚928、Mo17、A619、PH4CV、OH43、齐319和13-1077共15份材料对鞘腐病表现为中抗或抗病。从16个自交系所在种群来看,瑞德群对穗腐病表现为感病,兰卡斯特群和唐四平头群对鞘腐病表现为抗病,其他群对3种镰孢菌病害抗性水平的离散程度较大,无明显规律。【结论】供试自交系吉853和OH43对鞘腐病和穗腐病表现为中抗或抗性,齐319、PH4CV、Mo17、9058、B37、B73、昌7-2和13-1077共8份材料对鞘腐病和茎腐病表现为中抗、抗性或高抗,但尚未筛选到对3种病害均有较好抗性的材料,有待于进一步筛选其他种质资源。     

Resistance Evaluation of Some Commonly Used Maize Germplasm Resources to Fusarium Diseases in China

【Objective】 Maize ear rot, stalk rot and sheath rot are the three common Fusarium diseases in maize producing areas in China, and there is a trend of serious mixing occurrence in recent years. The main pathogens of the three major diseases are F. verticillioides, F. graminearum and F. proliferatum. Planting resistant varieties is the most economical and effective method to control this kind of diseases. The objective of this study is to screen out the maize resistant germplasms to ear rot, stalk rot and sheath rot, and to provide references for scientific breeding and rational layout of maize varieties.【Method】 Sixteen common inbred lines of maize including B73, B37, Zheng 58, Chang 7-2, Qi 319 and so on were selected to inoculate F. verticillioides, F. graminearum, and F. proliferatum on maize ears, stalks and sheaths, respectively. The suspension spores of F. verticillioides were injected into healthy maize ears along the filament channel with a continuous syringe at silk stage. The stem of the first aboveground segment of healthy maize was pinned and then injected with the suspension spores of F. graminearum. The suspension spores of F. proliferatum were injected into the sheath of the aboveground 2-5 internodes along the base of healthy maize sheath. Sterile water was used as control. In 2016 and 2018, experiments were conducted in fields to evaluate the disease index of ear rot, sheath rot and the lesion areas of stalk rot, so as to evaluate the resistance level to the ear rot, stalk rot and sheath rot.【Result】 The tested inbred lines Ji 853, OH43 and X178 were moderate resistance to ear rot, 13 of the tested inbred lines such as B73, B37, PH6WC, Ye 478, Zheng 58, 9058, Chang 7-2, Xun 928, Mo17, A619, PH4CV, Qi 319 and 13-1077 were sensitivity or high sensitivity to ear rot; 8 of the tested inbred lines including Qi 319, PH4CV, Mo17, 9058, B37, B73, Chang 7-2 and 13-1077 were moderate resistance and high resistance to stalk rot, 7 of the tested inbred lines such as Zheng 58, Ye 478, PH6WC, Xun 928, Ji 853, A619 and OH43 were sensitivity or high sensitivity to stalk rot; 15 of the tested inbred lines such as B73, B37, Zheng 58, Ye 478, PH6WC, 9058, Chang 7-2, Ji 853, Xun 928, Mo17, A619, PH4CV, OH43, Qi 319 and 13-1077 were moderate resistance or resistance to sheath rot. According to the population of 16 inbred lines, Reid group was susceptible to ear rot. Lancaster group and Tangsipingtou group were resistant to sheath rot. The resistant levels of other groups to Fusarium diseases dispersed to a large extent, and there was no obvious regularity.【Conclusion】 The tested inbred lines Ji 853 and OH43 showed moderate resistance or resistance to sheath rot and ear rot, 8 of the tested inbred lines including Qi 319, PH4CV, Mo17, 9058, B37, B73, Chang 7-2 and 13-1077 showed moderate resistance, resistance or high resistance to sheath rot and stalk rot, but the materials with good resistance to all three diseases had not yet been screened, and other germplasm resources needed to be further screened.     

玉米穗,茎腐病禾谷镰孢菌和串珠镰孢菌同工酶分析

对沈阳、河北、吉林、北京等地区玉米穗、茎腐病禾谷镰孢菌和串珠镰孢菌进行了可溶性蛋白和同工酶聚丙烯酰胺凝胶电泳,以研究玉米穗、茎腐病同种镰孢菌是否存在寄生专化性或生理分化现象。结果表明：各地区的玉米穗、茎腐病串珠镰孢菌同源性高,亲缘关系近,相似性系数在0．86～0．98之间,菌株间差异仅表现为个体间多样性。而两种病害禾谷镰孢菌亲缘关系困地区不同而有差异,河北、吉林两地区穗、茎腐禾谷镰孢菌间均具有很近的亲缘关系,相似性系数在0．93以上;但沈阳地区禾谷镰孢菌亲缘关系相对较远,相似性系数仅为0．65～0．67。     

Mechanisms involved in biocontrol and plant induced resistance by richoderma. asperellum (T. harzianum T-203)

Growing awareness of the environmental damage caused by the use of chemical substances for plant disease control in agriculture has raised the need to study biological alternatives, such as activating the defense response of plant crops by inducers not toxic to the environment. Trichoderma spp. are effective biocontrol agents for a number of soilborne pathogens, and are also known for their ability to enhance plant growth and to induce systemic resistance (ISR) in plants. In our laborator…     

哈茨木霉对禾谷镰孢病原菌的抑菌活性研究

用3种实验方法研究了哈茨木霉对禾谷镰孢菌的抑制效果,分别是哈茨木霉和禾谷镰孢菌在PDA培养基上的对峙培养,哈茨木霉和禾谷镰孢菌在载玻片上对峙培养,哈茨木霉发酵液的上清液对禾谷镰孢菌的抑菌圈实验,并对培养基、pH值、温度3种培养条件进行了优化。3种实验方法的结果均表明哈茨木霉对禾谷镰孢菌有较强的抑制作用,哈茨木霉适宜生长的条件为培养基PDB,pH值6.0,30℃。     

玉米植株抗倒伏性状的遗传分析

以2个茎秆强度不同的自交系82 -3和W1为基础材料,通过杂交与自交,对双亲、F1及F2等不同群体株高、穗位高、茎秆强度等植株性状进行田间调查和遗传分析.结果表明,双亲及其杂交后代各性状差异明显,与W1相比,亲本82 -3表现株矮、穗位低,但根系差,茎秆强度也低;杂种F1除穗位节的节间强度表现负向杂种优势外,其它性状均...     

Key indicators affecting maize stalk lodging resistance of different growth periods under different sowing dates

The accurate evaluation of maize stalk lodging resistance in different growth periods enables timely management of lodging risks and ensures stable and high maize yields. Here, we established five different sowing dates to create different conditions for maize growth. We evaluated the effects of the different growth conditions on lodging resistance by determining stalk morphology, moisture content, mechanical strength and dry matter, and the relationship between stalk breaking force and these indicators during the silking stage(R1), milk stage(R3), physiological maturity stage(R6), and 20 days after R6. Plant height at R1 positively affected stalk breaking force. At R3, the coefficient of ear height and the dry weight per unit length of basal internodes were key indicators of stalk lodging resistance. At R6, the key indicators were the coefficient of the center of gravity height and plant fresh weight. After R6, the key indicator was the coefficient of the center of gravity height. The crushing strength of the fourth internode correlated significantly and positively with the stalk breaking force from R1 to R6, which indicates that crushing strength is a reliable indicator of stalk mechanical strength. These results suggest that high stalk strength and low ear height benefit lodging resistance prior to R6. During and after R6, the coefficient of the center of gravity height and the mechanical strength of basal internodes can be used to evaluate plant lodging resistance and the appropriate time for harvesting in fields with a high lodging risk.     

冬小麦秸秆还田对夏玉米生长发育及产量的影响

【目的】探讨不同品种冬小麦秸秆、秸秆覆盖量和覆盖方式对夏玉米生长发育和产量的影响。【方法】于2012年在陕西关中一年两熟典型地区,采用随机区组设计,选用小偃22和小偃216 2个冬小麦品种秸秆,设秸秆混入耕层、秸秆带状覆盖、秸秆全面覆盖3种秸秆还田方式,以及4 500,7 500和10 500kg/hm2 3个秸秆还田量,以秸秆不还田为对照,于夏玉米幼苗期和发育中期测定株高、茎粗、次生根数、叶片颜色、单株干质量,并于成熟期测定株高、穗位高及产量构成因素,研究各处理对夏玉米生长发育及产量的影响。【结果】2012年夏玉米播种后由于较长时期干旱少雨,冬小麦秸秆覆盖的保墒作用大于其化感作用,各秸秆还田处理夏玉米生长发育及产量总体优于对照。在2个小麦品种秸秆中,以小偃216秸秆对夏玉米诸性状的表现较好;在3种秸秆还田量中,以7 500kg/hm2秸秆还田量较为适宜;3种秸秆还田方式中,则以秸秆带状覆盖方式对夏玉米生长发育影响较小;在此组合下,夏玉米幼苗和植株生长健壮,成熟期产量最高。【结论】对夏玉米进行秸秆覆盖时,以冬小麦秸秆覆盖量为7 500kg/hm2的带状覆盖方式最好。     

Preparation on the basis of Trichoderma asperellum in the system of biological protection of wheat from Fusarium ear scab

During the last century, as the area of wheat grown under advanced grain husbandry has increased worldwide, so too has the importance of Fusarium ear scab (FES) (synonym, Fusarium head blight) caused by several species of the fungus Fusarium. Yield losses due to FES can total 20%-40% and more depending on climatic conditions. During the last twenty years epidemics of FES in cereals have become chronic all over the world, including the United States and Russia. The most destructive of t…     

防治玉米茎腐病的一种新型木霉菌复合种衣剂

主要由禾谷镰刀菌引起的玉米茎腐病是一种重要的土传病害并能导致玉米严重减产。本研究通过筛选拮抗木霉菌,优化发酵工艺与改进配方,研制出一种新的木霉菌剂,同时为了提高防治的稳定性与持效性,筛选出了几种低毒的化学农药,并把它们加入到木霉菌种衣剂中配制成一种复合种衣剂。试验结果显示,无论是单一木霉菌种衣剂还是复合种衣剂都能有效地控制玉米苗期茎腐病,其中用木霉菌ZJSX5003菌株制成的种衣剂对病害的防效最高可达98.50%,并且对玉米种子的胚根、胚芽生长促进作用最大。同时,我们发现用木霉菌发酵液浸种6 h和将发酵液稀释50倍是促进玉米幼苗生长的最佳条件。此外,我们发现30%敌委丹、35%满适金和20%辛硫磷对于木霉菌的生长无抑制作用,而且木霉菌与35%满适金复合后对茎腐病有最高的防效且达到83%。     

玉米穗腐病致病禾谷镰孢复合种的遗传多样性、致病力与毒素化学型分析

【目的】明确中国玉米穗腐病致病禾谷镰孢复合种(Fusarium graminearum species complex,FGSC)的菌群遗传结构、致病力、毒素化学型及其相互关系,为玉米镰孢穗腐病防控提供参考信息。【方法】从中国玉米主产区采集玉米穗腐病样本,经单孢分离鉴定,选取代表性的禾谷镰孢复合种,利用22对SSR和10对VNTR引物,使用Popgen32、NTsys2.1、STRUCTURE2.3.4群体遗传学研究软件进行数据分析,结合TEF-1α、β-tubulin和RPB2基因测序构建系统发育树,分析7个地理区域禾谷镰孢复合种的遗传多样性,采用花丝通道注射接种法测定各镰孢菌的致病力,利用产毒基因特异性引物进行毒素化学型的检测。【结果】在禾谷镰孢复合种中共检测到等位位点数48个,多态性位点数39个,多态性条带比率为81.25%,每对引物扩增出多态性条带2—4条;禾谷镰孢复合种7个地理群体平均Shannon’s信息指数和Nei’s遗传多样性指数分别为0.41和0.29,7个地理区域遗传相似度集中在0.6677—0.8797,遗传距离为0.1282—0.4039,表明菌群间具有较丰富的...     

钾素对玉米茎髓和幼根超微结构的影响及其与茎腐病抗性的关系

【目的】从细胞水平探讨钾素营养提高玉米茎腐病抗性的机制。【方法】采用扫描电镜和透射电镜分别观察施钾后玉米茎髓组织和接菌后施钾与不施钾幼根根尖细胞超微结构的变化。【结果】缺钾处理的玉米茎髓薄壁细胞,结构不规则,长边较长。而不缺钾处理茎髓细胞结构规则,呈长方形,整齐排列。缺钾导致维管束间的薄壁细胞破裂,致使茎髓中维管束间失去连接细胞,支撑能力变差。另外,施钾有利于寄主幼根表皮细胞排列紧密而整齐,细胞壁增厚,有效阻碍病原菌的入侵。而且施钾处理细胞中拥有丰富的高尔基体,可以产生大量分泌物将菌丝降解。钾素还有利于菌丝入侵部位乳突的形成及高电子致密物的积累,以阻止菌丝的扩展。【结论】钾素能通过稳定细胞结构,防止细胞间隙的扩大,加固细胞壁,来降低病原菌侵入的机率;通过形成位于胞间及胞内的闭塞物来限制病原物在寄主细胞的进一步发展。     

玉米种质资源抗腐霉茎腐病和镰孢茎腐病精准鉴定

[目的]建立和完善玉米种质抗腐霉茎腐病和镰孢茎腐病精准鉴定的方法,对遗传背景丰富的玉米种质资源进行腐霉茎腐病和镰孢茎腐病的抗性精准鉴定,筛选出对2种茎腐病具有稳定抗性的种质资源,为玉米抗病育种奠定基础.[方法]对2004份具有广泛遗传背景的玉米种质进行多年多点的自然发病抗性鉴定,初步筛选出抗茎腐病或综合性状优良的代表性...     

玉米种质对腐霉茎腐病和镰孢茎腐病抗性鉴定与评价

【目的】 系统评价新疆玉米种质资源对玉米茎腐病优势病原菌的抗性水平,为玉米抗茎腐病遗传育种及防治提供科学依据。【方法】 采用田间人工土壤埋接法,对62份玉米种质资源进行抗肿囊腐霉(P. inflatum)茎腐病水平鉴定,鉴定及评价100份玉米种质资源的抗镰孢茎腐病水平。【结果】 62份种质资源抗肿囊腐霉(P. inflatum)茎腐病达到高抗(HR)7份,占比11.29%,抗(R)、中抗(MR)、感(S)、高感(MS)材料分别为5份、18份、5份和27份,依次占比8%、29%、8%和24%。100份种质资源抗镰孢茎腐病鉴定与评价则筛选出高抗(HR)、抗(R)、中抗(MR)、感(S)、高感(MS)材料分别为14份、16份、37份、15份和18份。病株率与株高、穗长、穗粗呈极显著负相关,高杆穗粗的玉米品种具有良好的抗病基础。而干穗重、粒重、百粒重与病株率呈显著或极显著负相关,病株率对产量指标具有极大的影响。21KBL054抽雄期、吐丝期、散粉期受影响程度较小,分别推迟2、2和4 d,21KBL096受影响程度严重,抽雄期、吐丝期、散粉期则分别推迟13、12和8 d。21KBL058病株平均株高(224.80cm)、穗位(83.09 cm)较对照相比分别增长(22.15%、51.76%),而处于同一抗性水平的21KBL045病株平均株高、穗位为186.50和72.64 cm,较对照相比增幅仅为(-0.40%、3.04%)受影响程度较小。【结论】 筛选出21KBL096、21KBL030、21KBL033等优异抗病性且田间性状稳定的抗病品种。     

我国玉米穗、茎腐病病害研究现状与展望

详述了中国在玉米穗腐病和茎腐病的病原学、发生规律、致病与抗病机理及综合防治理论与实践方面主要研究进展。介绍了国内关于玉米穗、茎腐病病原学和发生规律研究规律研究方面的主要学术观点,并进行了讨论;在系统研究的基础上,提出了茎腐病抗机制的基本模式;从侵染循环、血清学、可溶性蛋白、同工酶谱和ＤＮＡ多态性分析等不同水平上,阐述了玉米穗腐病与茎腐病在病原学和发生规律方面的内在关系,为两种病害的综合防治奠定了重要理论的基础。     

微贮玉米秸秆对猪生长及饲粮养分利用的影响

在18头15~30 kg阶段生长育肥猪饲料中分别添加15%2、5%微贮玉米秸秆,研究微贮玉米秸秆对猪育肥效果及养分利用的影响.试验结果表明,在饲粮中分别添加15%和25%的微贮玉米秸秆,猪采食率下降了11.3%和18.9%;日增重下降了31.4%和42.4%;饲料转化率也随微贮玉米秸秆添加量增大而下降;同时饲粮添加微贮玉米秸秆还会影响生长猪对Ca、P的利用.据此认为在猪饲料中添加微贮玉米秸秆降低了猪的生长性能,不利于饲粮养分的利用.