黄淮麦区Fhb1基因的育种应用

小麦赤霉病是由禾谷镰孢菌引起的一种世界性重要病害,严重威胁小麦生产安全。黄淮麦区作为我国小麦主产区,赤霉病危害日趋严重,因缺乏半冬性抗源,抗赤霉病育种进展缓慢。Fhb1基因是迄今发现的效应最大、抗性最稳定,也是被广泛应用于全球小麦赤霉病抗性育种的主效基因,但Fhb1基因在黄淮麦区尚未被广泛应用。本研究以感病品种矮抗58为轮回亲本, H35为Fhb1基因供体亲本,通过有限回交和分子标记辅助选择,同时利用双单倍体育种和传统系谱选育两种方法,培育出了一批综合性状较好、具有Fhb1基因的优良新品系,其中徐麦DH9和徐麦17252经多年鉴定均达到中抗水平。在以徐麦36和徐麦2023为杂交父本的后代品系中,含Fhb1基因的家系赤霉病平均抗性明显优于感病对照。Fhb1基因的导入显著提高了赤霉病抗性,但部分家系对赤霉病仍旧表现出高感水平,说明赤霉病抗性还受到Fhb1基因以外其他遗传因素的显著影响。本研究为Fhb1基因在黄淮麦区抗赤霉病小麦育种中的应用提供了成功的经验。     

利用小麦单染色体代换系研究赤霉病抗性和抑制毒素产生的基因

由赤霉菌引起的小麦赤霉病是小麦生产的主要病害之一,小麦赤霉病抗源十分贫乏,而且多数表现为多基因遗传,在小麦育种中较难应用。从小麦近缘属种中寻求赤霉病抗性基因并把它引入栽培品种中,有重要的学术意义和经济价值。本研究以来自抗病小麦材料PI481521和栽培小麦Langdon杂交得到的14个4倍体小麦单条染色体代换系为试验材料,进行室内赤霉病的抗性鉴定,同时用脱氧雪腐镰刀菌烯醇(DON)试剂盒来测定接种后籽粒中的毒素含量。表型鉴定结果表明,14个代换系的抗病性存在较大的差异,其中代换系LDN(PI481521-3A)和LDN(PI481521-7B)分别在感染小穗数和小穗感染百分率上与抗性亲本无显著性差异,不存在抗病性高于抗性亲本的类型;毒素含量分析表明,2个亲本的毒素含量没有显著差异,各代换系的毒素含量均高于抗性亲本PI481521、LDN(PI481521-1A)、LDN(PI481521-2A)及LDN(PI481521-6A)的毒素含量较高,与2个亲本存在显著差异。这一鉴定结果为下一步抗性基因和毒素基因的定位研究提供了基础材料,对赤霉病抗性指标进行相关性分析,发现小穗感染百分率与麦粒毒素含量呈显著正相关。因此,在田间进行抗赤霉病种质筛选及抗病育种后代选择时,可以小穗感染百分率作为衡量指标以简化操作程序。     

小麦Fhb1基因定位、克隆及其在抗赤霉病育种中利用的研究进展

赤霉病已成为小麦第一大病害,严重影响小麦的产量和品质。目前,抗性品种结合化学防治的方法成为当前防治赤霉病的最有效途径。小麦赤霉病抗性受多种基因控制,其中,Fhb1基因抗性效应最大,且抗性稳定,在小麦赤霉病抗性方面具有重要作用。本文综述了赤霉病主效抗性基因Fhb1的定位、分子标记和克隆技术的最新研究进展。利用选择性回交技术和矮败小麦平台将Fhb1基因导入当地小麦中可提升赤霉病抗性,进而结合化学防治方法为我国小麦安全生产提供保障。     

小麦外源抗条锈病基因及染色体定位研究进展

小麦条锈病(Wheat stripe rust or yellow rust)是小麦生产中重要流行病害之一。挖掘抗病基因,培育抗病品种是防治该病害最有效的措施。中国小麦条锈菌抗源单一,且具高度变异性,抗病品种极易丧失抗性。不断挖掘,筛选新的抗条锈病基因,对中国小麦抗病育种工作极为重要。小麦抗条锈病基因主要来源于普通小麦和小麦近缘属植物,而小麦近缘属植物蕴含丰富的抗病基因。本综述主要对目前已正式命名的,暂命名的外源抗条锈病基因进行总结,并对其染色体具体位置分布进行归纳,对优异抗病资源利用进行简要分析和展望,以期在育种工作中进一步高效利用外源抗条锈病基因。     

小麦野生近缘植物抗病性鉴定研究进展

小麦野生近缘植物具有优良的抗病特性,是改良普通小麦的宝贵遗传资源,是基因改良和培育高产、优质和高抗病性小麦的基础。为此,主要对小麦赤霉病、白粉病、叶锈病、条锈病、秆锈病等小麦主要病害的发生及危害情况进行简述,阐述了利用小麦野生近缘植物进行小麦主要病害的抗病性鉴定研究进展,包括苗期及成株期鉴定、温室及田间试验、分子标记辅助鉴定等,指出了小麦近缘野生植物与普通小麦直接或间接杂交转移优异基因情况,并对其发展前景进行了展望。     

小麦种质纹枯病抗性评价

近年来 ,小麦纹枯病在我国广大麦区 ,特别是主产和高产的黄淮冬麦区迅速蔓延、危害严重 ,已上升为小麦的主要病害 ,1998年 ,河北省主要粮食作物普遍发生较重 ,现已成为危害该省粮食生产的主要障碍之一。众所周知 ,小麦纹枯病是土传病害 ,药剂防治难度大 ,因此迫切需要选育和推广抗病品种 ,这是小麦产量进一步提高所必须解决的关键问题之一 ,拥有数量多、质量好的种质是抗纹枯病育种成功的关键 ,但目前普通小麦中筛选出的抗源过硬的尚未发现免疫材料 ,急需鉴定、选拔抗源材料或抗病品种 ,另外通过远缘杂交 ,将小麦近缘属的抗性基因导入普通小…     

啤酒大麦品种的抗赤霉病基因的分子标记多样性

赤霉病是由镰刀菌(Fusarium spp.)引起的世界性病害,大麦感染赤霉病后,不仅减产严重,而且病菌产生的毒素污染籽粒后会使啤酒酿造品质变劣,还会对人畜健康产生危害。遗传改良是控制赤霉病的最有效措施。为了明确长江中下游地区啤酒大麦品种的赤霉病抗性及其与国外主要抗源赤霉病抗性基因的遗传关系,选择了12个啤酒大麦栽培品种或育种品系、5个国外引进的赤霉病抗源,以2个感病品种为对照,进行赤霉病抗性鉴定,以均匀覆盖基因组的分子标记对品种型基因型分析数据为基础探讨品种间的遗传关系,依据已报道的大麦赤霉病抗性QTL的连锁标记,比较抗性品种的抗性基因的遗传多样性。结果表明,供试的啤酒大麦品种具有良好的赤霉病抗性,优于国外引进的抗源;以平均遗传相似系数0.51为阈值,19个大麦品种可以分为国外引进品种与国内品种2大类群,表明国内大麦品种与引自于其他国家的大麦品种存在较明显的遗传差异,本地区的抗感品种可归于不同亚类群。11个抗病品种携带1-3个与已知抗性QTL一致的位点,检测到的QTL位点多少与赤霉病抗性无明显相关性,说明本地区抗赤霉病品种可能存在多个新的抗病基因,是啤酒大麦抗赤霉病育种的优异材料。     

十年来小麦抗白粉病基因资源的抗性变化及抗源的利用策略

１９８３年以来，小麦抗白粉病基因资源的抗性鉴定表明，包含二个或二个以上基因联合及多基因抗源的抗性一直表现强而稳定；而单基因抗源抗性容易丧失；包含Ｐｍ８抗病基因的抗源及其衍生种在近几年丧失抗性。我国小麦白粉病抗源单一化是导致小麦白粉病流行及日趋严重的主要原因。当前采用多基因、多源化新抗源是克服抗源单一的主要措施。进一步加强微效、多基因抗源的发掘和利用，把主效基因和微效基因结合起来，以维持抗性的持久和稳定。     

小麦白粉病抗性基因的研究与利用

小麦白粉病是小麦中的一种重要病害,广泛分布于世界各产麦区,造成了小麦产量的重大损失,因此,如何挖掘抗源.提高抗白粉病育种的成效,减轻白粉病的流行、危害,是育种家一直研究的重要问题。本文概述了世界上已鉴定出的19个白粉病抗性基因的来源,携带该基因的有关品种和部分抗性基因的抗性表现及在育种上的应用。其中,P_(m2)、P_(m4)、P_(m6)等抗性基因在我国为高效抗性基因,特别是含有P_(m2)、p_(m6)基因的CI_(12632)、CI_(12633)、TP_(114)等是良好的抗源,有很高的利用价值。本文还论述了小麦抗白粉病育种中的几个问题。     

小麦抗条锈病基因来源及染色体定位的研究进展

条锈病是小麦生产的重要病害之一,选育抗病品种是防治该病最为经济、安全和有效的途径。由于小麦条锈菌具有高度变异性且抗源的单一化,抗病品种抗性很容易丧失。因此,不断发掘新的抗条锈病基因资源,扩大抗源选择利用范围,对中国小麦抗病育种工作极为重要。本研究对已命名的57个条锈病基因进行了总结分析,着重介绍了源于小麦一级、二级和三级基因源的各个抗条锈病基因的来源及其在染色体上的分布,并对条锈病抗源利用方面进行了分析及展望。     

Utilization of alien genes to enhance Fusarium head blight resistance in wheat – A review

Fusarium head blight (FHB) is a destructive disease of wheat worldwide. Sources of resistance to FHB are limited in wheat. Search for novel sources of effective resistance to this disease has been an urgent need in wheat breeding. Fusarium head blight resistance has been identified in relatives of wheat. Alien chromatin carrying FHB resistance genes has been incorporated into wheat through chromosome addition, substitution, and translocation. Relatives of wheat demonstrate a great potential to enhance resistance of wheat to FHB.     

过表达TaJRL53基因提高了小麦赤霉病抗性

Jacalin-related lectins(JRLs)是一种含有Jacalin结构域的植物凝集素,在植物应对生物胁迫和非生物胁迫过程中发挥重要作用。根据其糖结合特性被划分为半乳糖特异性JRL(gJRLs)和甘露糖或葡萄糖特异性JRL(mJRLs)两类。前期研究表明普通小麦TaJRL53编码一个具有Jacalin结构域和Dirigent结构域的蛋白,并能在赤霉菌的诱导下上调表达。由赤霉菌侵染引起的小麦赤霉病是一种毁灭性的病害,它不仅能够导致大幅度减产,而且使感病的麦粒品质下降。受真菌毒素污染的籽粒,严重影响人畜健康。为分析该基因在抗赤霉病方面的作用,本研究利用VIGS系统在小麦中沉默TaJRL53,导致了其对赤霉病的抗性减弱。通过基因枪的方法将该基因的过量表达载体导入到感赤霉病小麦品种中,增强了赤霉病抗性,其病小穗数,病轴长都明显缩短。在赤霉菌侵染后,ROS合成途径相关基因、JA信号通路中的主要标志基因、JA合成基因及病程相关蛋白基因在TaJRL53过量表达的转基因植株中明显高于它们在野生型中的表达量,因此推测TaJRL53提高小麦赤霉病抗性可能跟ROS和JA合成,JA信号转导途径有关。本研究增进了对小麦JRLs家族基因功能的了解,为解析TaJRL53抗赤霉病机制奠定了基础。     

Fusarium head blight-resistant wheat line 'Bizel' does not contain rye chromatin

Fusarium head blight (FHB), primarily caused by Fusarium graminearum in North America can result in significant losses in the yield and quality of wheat (Triticum aestivum L). Resistance sources have been largely limited to Chinese germplasm and, in particular, Sumai 3 or its derivatives. In recent years, resistance has been identified in Europe. Previous studies using the wheat line ‘Bizel’, developed in France, have shown that it has resistance to Fusarium head blight. Pedigree information shows that one of its progenitors is rye. This experiment was conducted to determine if ‘Bizel’ has rye chromatin, with the goal of developing a strategy for mapping FHB resistance genes. Two methods based on repetitive DNA sequences specific to rye were implemented. With both approaches, it was demonstrated that ‘Bizel’ does not contain rye chromatin. Consequently, wheat SSRs can be used to map ‘Bizel’ resistance genes for FHB.     

Molecular cytogenetic analysis of a durum wheat ×Thinopyrum distichum hybrid used as a new source of resistance to Fusarium head blight in the greenhouse

Fusarium head blight (FHB, scab), caused by Fusarium graminearum Schwabe, is a serious and damaging disease of wheat. Although some hexaploid wheat lines express a good level of resistance to FHB, the resistance available in hexaploid wheat has not yet been transferred to durum wheat. A germplasm collection of Triticum durum× alien hybrid lines was tested as a potential source of resistance to FHB under controlled conditions. Their FHB reaction was evaluated in three tests against conidial suspensions of three strains of F. graminearum at the flowering stage. Two T. durum×Thinopyrum distichum hybrid lines, ‘AFR4’ and ‘AFR5′, expressed a significantly higher level of resistance to the spread of FHB than other durum‐alien hybrid lines and a resistant common wheat line ‘Nyu‐Bay’. Genomic in situ hybridization using total genomic DNA from alien grass species demonstrated that ‘AFR5’ had 13 or 14 alien genome chromosomes plus 27 or 28 wheat chromosomes, while ‘AFR4’ had 22 alien genome and 28 wheat chromosomes. All of the alien chromosomes present in these two lines belonged to the J genome. ‘AFR5’ is likely to be more useful as a source of FHB resistance than ‘AFR4’ because of its relatively normal meiotic behaviour, high fertility and fewer number of alien chromosomes. ‘AFR5’ shows good potential as a source for transferring FHB resistance gene into wheat. The development of T. durum addition lines carrying resistance genes from ‘AFR5’ is underway.     

小麦品种赤霉病抗性的遗传研究

利用8个不同抗性小麦品种双列杂交的F1及其亲本,以赤霉病病粒率为抗性指标,研究了小麦赤霉病抗性的遗传。结果表明,参试品种间存在3～4对赤霉病抗性基因的差异,苏麦3号、宁麦9号和扬麦158具有较多控制赤霉病抗性遗传的显性基因,对于减少它们杂交后代的病粒率有较高的一般配合力。小麦赤霉病抗性符合加性-显性模型。赤霉     

Combining ability of resistance to head blight caused by Fusarium culmorum (W.G. Smith) in the F1 of a seven parent diallel of winter wheat (Triticum aestivum L.)

Fusarium head blight (FHB, scab) caused by Fusarium spp. is a widespread disease of cereals causing relevant yield and quality losses and contaminating cereal products with mycotoxins. Breeding resistant cultivars is the method of choice for controlling the disease. Resistance to FHB is a quantitative trait and is most likely governed by several genes. We present the results of an F₁ diallel analysis of FHB resistance involving six resistant and one susceptible European winter wheat genotypes of diverse origin in order to identify promising combinations for the selection of improved cultivars. Parents and F₁s including reciprocals were evaluated for FHB resistance in an artificially inoculated field trial. Two traits were assessed: visual disease symptoms on the heads and the percentage of Fusarium damaged kernels in a harvested sample. General combining ability (GCA) and specific combining ability (SCA) effects were statistically significant for visual symptoms and kernel damage, whereas reciprocal effects were small or not significant. Heterosis for resistance was common, indicating that the parental genotypes possess different resistance genes. Selection of transgressive segregates should be feasible from such heterotic combinations. This revised version was published online in August 2006 with corrections to the Cover Date.     

Diallel analysis of Fusarium head blight resistance in genetically diverse winter wheat germplasm

New sources of partial resistance to Fusarium head blight (FHB) in wheat have been identified over the past decade; however, little is known of their breeding value. A 20 parent partial diallel that included resistant genotypes from the U.S., Europe, China and South America was used to evaluate the potential of these sources of resistance as parents in wheat breeding programs. Eight plants replication⁻¹ of each of 190 crosses and 20 parents were point-inoculated with Fusarium graminearum under greenhouse conditions in two replicated experiments. Both general (GCA) and specific combining ability (SCA) were significant. Most of the variance for FHB severity was associated with additive genes; however, estimates for SCA ranged from highly negative to highly positive in both resistant × resistant and resistant × susceptible crosses which suggest that improving FHB resistance through gene pyramiding strategies based on additive genetic variation may be complicated by interaction effects that condition FHB resistance.     

Characterization of Chinese wheat germplasm for resistance to Fusarium head blight at CIMMYT, Mexico

Fusarium head blight (FHB) poses a challenge for wheat breeders worldwide; there are limited sources of resistance and the genetic basis for resistance is not well understood. In the mid-1980s, a shuttle breeding and germplasm exchange program launched between CIMMYT-Mexico and China, enabled the incorporation of FHB resistance from Chinese bread wheat germplasm into CIMMYT wheat. Most of the Chinese wheat materials conserved in the CIMMYT germplasm bank had not been fully characterized for FHB reaction under Mexican environments, until 2009, when 491 Chinese bread wheat lines were evaluated in a FHB screening nursery in Mexico, and 304 (61.9 %) showed FHB indices below 10 %. Subsequent testing occurred in 2010 for plant height (PH), days to heading (DH), and leaf rust response. In 2012, 140 elite lines with good agronomic types were further evaluated for field FHB reaction and deoxynivalenol (DON) accumulation. Most of the tested lines showed good resistance: 116 (82.9 %) entries displayed FHB indices lower than 10 %, while 89 (63.6 %) had DON contents lower than 1.0 ppm. Significant negative correlations were observed between FHB traits (FHB index, DON content, and Fusarium damaged kernels) and PH, DH, and anther extrusion. A subset of 102 elite entries was selected for haplotyping using markers linked to 10 well known FHB quantitative trait loci (QTL). 57 % of the lines possessed the same 2DL QTL marker alleles as Wuhan 1 or CJ 9306, and 26.5 % had the same 3BS QTL allele as Sumai 3. The remaining known QTL were of low frequency. These materials, especially those with none of the above tested resistance QTL (26.5 %), could be used in breeding programs as new resistance sources possessing novel genes for FHB resistance and DON tolerance.     

Gene expression analysis of four WIR1-like genes in floret tissues of European winter wheat after challenge with <Emphasis Type="Italic">G. zeae</Emphasis>

Fusarium head blight (FHB) is a highly destructive disease of wheat and other cereals which causes serious mycotoxin contaminations of grain. A number of molecular mapping studies led to the detection of QTL with small to moderate effects on FHB resistance in European winter wheat. Genes involved in the defence reaction of these genotypes remain largely unknown. WIR1 (wheat induced resistance 1) genes have been shown to be upregulated in cereals during attack of various fungal pathogens; however, their role in resistance is ambiguous. In this study, the expression of three WIR1 genes and a gene with high sequence similarity to WIR1 was investigated in European winter wheat genotypes after inoculation with Giberella zeae. Floret tissues of four winter wheat genotypes (Dream, Lynx, G16-92, Hussar) were challenged with G. zeae conidia or water (control) and sampled six times during 0–96 h after inoculation. Quantitative real-time PCR showed that all four genes were highly upregulated in the resistant genotypes compared to the susceptible ones. WIR1b and a gene with sequence similarity to WIR1 genes mapped to chromosome 5DS in the G16-92/Hussar mapping population. Two genes annotated as WIR1a mapped in the interval of a FHB resistance QTL on chromosome 7BS in the Dream/Lynx mapping population. These could be considered possible candidate genes for quantitative FHB resistance.