抗玉米丝黑穗病转基因株系的分子检测及抗病株系选育

采用花粉介导方法将质粒pGL II_RC_1导入玉米自交系海92_1中,获得了T0种子128粒,种子经潮霉素抗性筛选得到抗潮霉素植株16株。对抗性植株分离的统计分析表明,多数情况下几丁质酶基因以单拷贝形式导入转基因植株,后代分离比约为3∶1。抗性苗移栽到大田后,5~6叶期取样进行PCR扩增、PCR Southern blot杂交分析,对T1的分析结果表明,几丁质酶基因已导入转基因植物细胞中。对T2,T3植株的检测结果显示,目的基因已整合到转化植株基因组中并可随植株世代稳定遗传。田间抗病鉴定结果表明,转基因植株及后代的玉米丝黑穗病发病率明显比对照降低。根据分子检测及田间抗病鉴定结果,得到GH05024,GH05028 2个抗丝黑穗病的纯合转基因株系。     

玉米苗期抗丝黑穗病快速鉴定的初步研究

建立玉米苗期抗丝黑穗病快速鉴定方法,对开展抗病种质资源收集,加快玉米育种进程,保障玉米质量安全有重要意义。丁布(DIMBOA)是玉米植株重要的抗菌、抗虫次生代谢物。本试验测定了12个对丝黑穗病抗性不同的玉米材料播种后7 d幼苗丁布含量,结果表明,玉米幼苗丁布含量与丝黑穗病发病率呈极显著负相关(r=-0.955 4,p=0.000 1),表明通过丁布含量可初步鉴定玉米对丝黑穗病抗性。     

不同种衣剂对玉米丝黑穗病防治效果研究

本试验利用目前市场上常见的3种用于防治玉米丝黑穗病的种衣剂对该病进行防治效果的对比试验。结果表明：3种种衣剂防治玉米丝黑穗病效果显著；种衣剂能有效地控制丝黑穗病的发生，降低发病率，提高玉米产量，与对照差异显著。黑败种衣剂的防效最佳，黑虫双全次之，立克秀最差。     

玉米抗丝黑穗病的基因效应

利用2个抗玉米丝黑穗病自交系（齐319和Mo17）与2个感病系（E28和黄早四）,组配4个抗感杂交组合。2004年,对4个组合的亲本、F₁、F₂、BCR（F₁与抗病亲本回交1代）和BCS（F₁与感病亲本回交1代）6个世代群体分别在北京和黑龙江进行丝黑穗病的人工接种鉴定,采用世代平均值分析玉米抗丝黑穗病的遗传特点。研究表明,各杂交组合的抗病性均含有显著的加性效应,其中3个组合有显著的显性效应。不同杂交组合的抗病遗传模式表现不同,用感病亲本E28组配的2个组合（齐319×E28）和（Mo17×E28）的抗病性基本符合加性-显性遗传模型;而用另一个感病亲本黄早四组配的组合（齐319×黄早四）和（Mo17×黄早四）的抗病性存在明显的上位性效应。这说明玉米对丝黑穗病的抗性呈现较复杂的遗传模式。因此,在抗玉米丝黑穗病育种中既要重视对自交系抗病水平的鉴定,也要加强杂种F₁的合理组配及抗病性评估。     

玉米黑穗病和丝黑穗病的发生与防治

玉米黑穗病和丝黑穗病都是真菌性病害,但是两种病害的病原菌不同,症状不同,防治药物不同。介绍了玉米黑穗病和丝黑穗病的发生时期。危害症状、发病条件及防治措施,以期为农业生产提供帮助与参考。     

Mo17抗玉米丝黑穗病的基因效应分析

在人工接种条件下研究了玉米丝黑穗病重要抗源Mo17在不同感病背景下的基因效应差异。两背景下不同世代间玉米抗丝黑穗病程度存在极显著差异，F1和F2的病株率介于双亲之间，偏向与抗病亲本，均无超亲优势，F1与双亲回交，后代的病株率基本偏向于回交亲本；玉米抗丝黑穗病的遗传分别符合六参数和四参数模型，其遗传贡献中主要以加性和显性效应为主，但在黄早四背景下表现为超显性且存在明显的上位效应，而3788背景下加性、显性效应相当，且仅存在加性、显性上位效应；以Mo17为抗病亲本组合的抗病性至少由1对抗性基因控制，估计的基因对数为0.48~1.03。     

玉米抗丝黑穗病QTL分析

以Mo17（抗）×黄早四（感）的F₂分离群体（191个单株）为作图群体,构建了含有84个SSR位点和48个AFLP位点的遗传连锁图谱,全长1 542.9 cM,平均图距11.7 cM。在吉林省公主岭和黑龙江省哈尔滨2个地点通过人工接种方法对184个相应的F₃家系（缺失7个）进行抗病鉴定。采用复合区间作图法对抗丝黑穗病数量性状位点（QTL）进行定位及遗传效应分析。在吉林公主岭地区检测到5个QTL,分别位于第1、2、3、8、9染色体上,解释的表型方差为10.0%~16.3%。在黑龙江哈尔滨地区也检测到5个QTL,分别位于第1、2、3、4、7染色体上,解释的表型方差为4.6%~13.4%。比较分析发现,两地一致在第2、3染色体上各检测到1个QTL,其中第2染色体上的表现为超显性效应,第3染色体上的表现为加性效应。研究结果为玉米抗丝黑穗病种质改良提供了重要信息。     

抗4,抗7高粱品种选育及对丝黑穗病抗性的遗传

抗４，抗７高粱杂交种是由Ｔｘ６２２Ａ不育系和晋粱５号，忻粱７号恢复系杂交选育而成。具有高产，高抗至免疫丝黑穗病和适应性广等特点，增产１５％－１８％，在人工接菌条件下发病率为０，对照种为８２．４％，是目前山西，河北，陕西，甘肃和天津等省市生产上推广的骨干品种。     

玉米丝黑穗病的发生与防治

玉米丝黑穗病，农民称为“乌霉”或“乌米”，是由孢子菌侵染所引起的玉米系统性病害。近两年，此病在吉林省发生普遍且严重，并有明显的上升趋势，今年，许多地区出现了丝黑穗病爆发的情况，造成了玉米产量的大幅度减产，已引起各级领玉米丝黑穗病，农民称为“乌霉”或“乌米”，是由孢子菌侵染所引起的玉米系统性病害。近两年，此病在吉林省发生普遍且严重，并有明显的上升趋势，今年，许多地区出现了丝黑穗病爆发的情况，造成了玉米产量的大幅度减产，已引起各级领导和学术界的高度重视。１表现症状玉米丝黑穗病在种子萌动到五叶期都能感…     

对玉米丝黑穗病危害的思考

玉米丝黑穗病年年都有发生,惟有2003年确实让我们大吃一惊:田间调查发病率高的点达到52%,低的点也达到29%,平均41%,减产严重.难怪农民反应强烈,四处告状,要求种子公司赔偿.我们作为调查组的成员,面对大田玉米受危害的事实与受害农民一脸的苦涩和无奈,心里也很不是滋味.秋天本来是收获的季节,而眼前的景象与这个季节实在太不相称了.     

玉米丝黑穗病分子标记辅助选择育种中前景引物与背景引物的筛选

前景选择和背景选择是抗丝黑穗病分子标记辅助育种中的关键一步.本研究选用吉1037为供体亲本,京24为受体亲本,利用SSR分子标记,基于荧光毛细管电泳检测系统,最终筛选出两对前景引物(MZAI,661)和45对背景引物.对回交二代(BC2)群体鉴定结果表明,携带主效抗病QTL的植株比不带主效QTL的植株抗病率提高约22%...     

高粱不育系3197A抗丝黑穗病性丧失原因

利用从美国引进的高粱3197A原原种组配了晋杂一号(原)、晋杂四号(原)和晋杂五号(原)3个杂交种.并用这些原种与我国目前生产上使用的3197A、晋杂一号、晋杂四号、晋杂五号在人工接种条件下做了对丝黑穗病敏感性的比较试验.结果表明,3197A自身对丝黑穗病的敏感性和这一特性的遗传能力没有发生显著变化,其抗病性丧失是由于我国丝黑穗病菌生理小种变化所致.     

以覆膜增温为主的综合技术对玉米丝黑穗病控制的初步研究

2005~2006年,在玉米丝黑穗病发生较为严重的山西省寿阳县,开展了以覆盖农膜为主,结合抗病品种和杀菌剂处理对玉米丝黑穗病控制效果以及玉米生长和产量影响的初步研究。结果显示,2005年和2006年,覆膜使玉米丝黑穗病的平均发病率分别从15.5%和8.9%降低到6.3%和6.5%,防治效果分别达59.4%和27.0%;使玉米产量分别提高746.2kg/hm²和1410.0kg/hm²。选种抗丝黑穗病品种能显著降低丝黑穗病的发病率。晋单34号在2005年和2006年较宽诚1号和张玉1号丝黑穗病的发病率分别从17.3%和9.5%降低到4.5%和6.0%。本研究所选用的杀菌剂15%三唑酮、CAM和黑虫双全均未显著降低丝黑穗病的发病率。     

Maize Smut Induced by Ustilago maydis (D. C.) Corda – Specific Effect of Smut Intensity and Location of Galls on Yield Losses

Seventeen maize hybrids were used in this study to estimate the damage effects of smut intensity and location of galls on yield during the growing seasons 1982, 1983 and 1984. The term "relative yield" was introduced to give an indication about the variation in yield of each maize hybrids among years in accordance with the proposed system of grade classification. Additional calculations were also applied to give quantitative measurements of the specific effect of grade and location of galls on yield losses. The results showed that:
1. In most cases, the relative yield followed up the grade classification, being the highest for the highly resistant group (99.0 %) and the lowest for the highly susceptible ones (82.0 %).
2. Small galls, as expressed in grade 2 and 3 did not appreciably reduce the yield, but the losses resulted from grade 4 up to grade 8 were more destructive and the losses ranged from 11.0 to 95.0 %, respectively.
3. The loss in yield associated with smut galls located on ear, stem + ear, stem + tassel, stem and tassel were 57.1, 48.9, 38.6, 24.3 and 9.3 %, respectively.
4. Yield losses were greatly influenced by increasing smut infection and/or smut location among years, due to the changes of climatical conditions.
5. The loss in yield at any specific smut location tended to increase exponentially with increasing smut intensity, but the degree of severity was, however, greater when the galls were located on the ear.     

Maize Smut Induced by Ustilago maydis (D. C.) Corda – Reaction of Maize Hybrids and Lines to Smut Disease

A field experiment was carried out during the growing seasons 1982, 1983 and 1984 to evaluate the reaction of different maize hybrids and lines to smut disease and to give further informations on the effect of environmental factors on smut incidence.
The kernels of 17 different maize hybrids and 17 inbred line were planted in the field and the stand was maintained constant of 30 plants per row during the respective years. Each plant was subjected to an artificial infection by dropping 2 ml of U. maydis -spore suspension into the leaf whorl at 6–8 leaf stage. Field observations, concerning the number, the size and location of smut galls were recorded for each individual plant whenever the symptoms appeared. The reaction of maize genotypes was evaluated on a new classified system and the differential response was correlated with the changes ol meteorological data.
The results indicated that hybrids: Circe LG9, E1, Kaceplns, Limac-LG11 and RA 94A x RA 320 as well as lines: F2, L1, L2, L8, RA 94A, RA 320, W33 and W401 were highly resistant; while the hybrids E2, F7 x EP1.J and Giga as well as lines: EP1J, F115, L5 and L6 were highly susceptible. The reaction of these genotypes exhibited an identical behaviour during the 3 years. The remaining genotypes were unstable and showed differential response to degree of infection and location of smut galls. The increase of smut infection in 1982 relative to that recorded in 1984, under the same wet weather conditions, was attributed to the increase of air temperature and sunshine duration. Under dry weather condition, as in 1983, increasing temperature and sunshine duration had little effect on smut incidence.     

转AtHDG11基因玉米的获得及抗旱性鉴定

培育抗除草剂和抗旱的转基因玉米种质,通过超声波辅助农杆菌介导花粉非组培法将拟南芥抗旱基因At HDG11导入玉米自交系昌7-2中,获得转基因植株。通过逐代除草剂筛选、分子检测对获得的转基因植株进行检测,获得5株转基因株系。在此基础上,以非转基因自交系昌7-2为对照,对5个转基因株系进行抗旱性鉴测;对苗期和十叶期玉米植株进行干旱胁迫处理,测定转基因植株生理活性物质和光合参数。结果表明,在干旱胁迫条件下,转基因玉米叶片的Pro含量高于非转基因玉米,MDA含量低于非转基因玉米;不论在正常生长条件下还是干旱条件下,转基因株系的光合速率和水分利用率都明显高于对照植株;而转基因株系的蒸腾速率和气孔导度则明显低于对照植株。综合室内与田间的抗旱检测结果表明,超声波辅助农杆菌介导花粉的非组培转基因方法在玉米上是可行的。将拟南芥HDG11基因导入玉米,同样可以有效地提高玉米的抗旱性,为玉米的抗旱育种提供新的种质资源和新的转基因方法。