甘蔗抗褐锈病新基因定位遗传群体的构建

为发掘甘蔗抗褐锈病新基因,本研究以4个高抗褐锈病不含Bru1基因的甘蔗品种为父本,4个高感褐锈病的甘蔗品种为母本配置杂交组合,对获得的5个杂交组合F1代群体进行SSR真实性鉴定、人工接种褐锈病抗性表型鉴定和Bru1基因分子检测。结果显示:‘粤糖03-393’בROC24’和‘柳城03-1137’ב德蔗93-88’的F1代群体分别符合3R:1S和1R:3S的遗传分离比例,且都未检测出Bru1基因;表明‘粤糖03-393’בROC24’群体的褐锈病抗性由一对显性未知新抗病基因控制,而‘柳城03-1137’ב德蔗93-88’群体的褐锈病抗性由一对隐形未知新抗病基因控制。本研究成功构建了2个能用于甘蔗抗褐锈病新基因定位的遗传分离群体,为今后的褐锈病抗性遗传分析,遗传图谱构建和抗褐锈病新基因定位和开发与其紧密连锁的分子标记提供了科学的参考数据。     

101份中国甘蔗主要育种亲本褐锈病抗性鉴定及Bru1基因的分子检测

由黑顶柄锈菌引起的甘蔗褐锈病是一种重要的世界性甘蔗病害,Bru1是甘蔗抗褐锈病主效基因,该基因对不同地区的褐锈病分离物具有广谱抗性。为明确中国甘蔗主要育种亲本对黑顶柄锈菌的抗性水平,了解Bru1基因在这些亲本中的分布情况,本研究于2014年对中国国家甘蔗种质资源圃保存的101份甘蔗主要育种亲本进行苗期抗褐锈病鉴定和抗褐锈病基因Bru1的分子检测。结果显示,供试亲本中,共48份抗病材料含有抗褐锈病基因Bru1,频率为47.5%,表明中国甘蔗主要育种亲本中褐锈病抗性主要由Bru1控制;其余29份抗病材料和24份感病材料均不含抗褐锈病基因Bru1,暗示除了Bru1外,可能还有其他抗褐锈病基因存在。研究结果为深入开展甘蔗抗褐锈病育种,选育和推广优良抗病品种,有效防控甘蔗褐锈病提供了科学依据和优良抗性亲本。     

甘蔗抗褐锈病新基因抗感病池构建及SSR多态性引物筛选

由黑顶柄锈菌(Puccinia melanocephala H. Sydow ＆ P. Sydow)引起的甘蔗褐锈病是危害中国甘蔗生产的主要病害之一。为了鉴定和发掘抗褐锈病新基因,防止褐锈病爆发流行和保证甘蔗安全生产,本研究以杂交组合‘粤糖03-393’× ‘ROC 24’抗感分离真实性F₁代群体为材料,构建抗感基因池,合成449对引物对抗感亲本及抗感基因池进行抗、感连锁SSR分子标记筛选。结果表明,25对引物在抗感亲本间有多态性,其中4对引物(SMC236CG、SCESSR0928、SCESSR0636、SCESSR2551)在抗感亲本及抗感池间有多态性,初步判定这4个SSR标记在染色体上的位点可能与抗褐锈病新基因存在连锁关系。研究结果为后续开展抗褐锈病新基因定位、为中国甘蔗褐锈病防控及抗病育种奠定了良好的基础。     

34份甘蔗栽培原种抗褐锈病性鉴定及Bru1基因的分子检测

明确甘蔗栽培原种对黑顶柄锈菌的抗性水平,了解Bru1基因在甘蔗栽培原种资源中的分布状况,可以帮助筛选甘蔗原种抗源种质,提高抗褐锈病育种效率。本研究于2013年对中国国家甘蔗种质资源圃保存的34份甘蔗栽培原种进行苗期抗褐锈病鉴定和抗褐锈病基因Bru1的分子检测。苗期抗性鉴定结果表明,34份供试材料中,1级高抗至3级中抗的有26份,占76.5%。其中13份材料表现1级高抗,占38.2%,6份材料表现2级抗病,占17.6%,7份材料表现3级中抗,占20.6%。分子检测结果显示:34份供试材料中25份抗病材料含有抗褐锈病基因Bru1,出现频率为73.5%;其余1份抗病材料和8份感病材料不含抗褐锈病基因Bru1。本研究结果显示了中国国家甘蔗种质资源圃保存的甘蔗栽培原种资源中褐锈病抗性主要由Bru1控制,这一发现为利用Bru1防治由黑顶柄锈菌引起的甘蔗褐锈病提供了重要信息和参考依据。     

甘蔗新品种及主栽品种对褐锈病抗性与Bru1基因分子检测

为明确近年我国各甘蔗育种单位育成的新品种及各蔗区主栽品种对甘蔗褐锈病的抗性,筛选抗褐锈病优良新品种供生产上推广应用,本研究结合全国甘蔗新品种联合区域试验,选择甘蔗褐锈病高发的云南临沧、云南普洱、云南玉溪和广西宜州蔗区,在田间自然发病下,对我国近年来选育的60个新品种和34个主栽品种进行抗性评价,并对抗褐锈病基因Bru1进行分子检测。结果表明,94个新品种及主栽品种中,66个表现高抗到中抗,占70.21%;28个表现为感病到高感,占29.79%。分子检测结果显示,共54个抗病新品种及主栽品种含有抗褐锈病基因Bru1,频率为57.45%。目前大面积种植的桂糖29号、桂糖44号、德蔗03-83、柳城03-1137、粤糖60号、桂糖46号等主栽品种高度感病,而粤甘48号、福农09-2201、桂糖08-120、柳城09-15、中蔗1号、云蔗08-1609、云瑞10-187、中糖1201等31个新品种抗病性强。建议多雨湿润褐锈病高发蔗区,应加大淘汰感病主栽品种和推广应用抗病新品种力度,以期达到品种合理布局,从根本上控制褐锈病暴发流行,为甘蔗产业高质量发展提供安全保障。     

小麦核质互作抗条锈类型的发现及其遗传机制分析

在西宁小麦“天然锈病圃”,辅以人工接种天然锈菌的条件下,杂交组合冬独1号/运83—2正反交F_2对条锈抗性显著不同。正交抗性分离,反交全部感病4级。3个冬独1号作母本的组合,F_2抗条锈分离;3个冬独1号作父本的组合,F_2全部感病4级。表明冬独1号的抗条锈性具有显著的细胞质遗传特点。对冬独1号/津丰1号F_2抗条锈分离研究结果是,其抗感比经X~2测验符合孟德尔一对显性基因3:1的分离规律(P>0.8)。其互作遗传方式遵循孟德尔规律。     

中国小麦LB0288中抗叶锈病基因的鉴定

明确中国小麦LB0288中所含的抗叶锈病基因,找到与其紧密连锁的DNA分子标记。将小麦LB0288和感病小麦品种Thatcher杂交,获得F1、F2代群体,用叶锈菌小FHTT分别对双亲及其杂交后代进行叶锈鉴定并进行标记分析。抗性鉴定结果表明F2代群体时呈现一对显性基因的抗感分离比例,经过亲本和抗感池间标记筛选以及F2代群体的标记检测,位于5DL的SSR标记barc144与抗病基因连锁,遗传距离为5.3 cM,同时Lr1的STS标记与之共分离,根据该基因的抗性特点和染色体位置推断为Lr1。此实验通过抗性鉴定、遗传分析和分子标记等手段确定LB0288中含有小麦抗叶锈病基因Lr1。     

Fhb1基因改良‘周麦’品种赤霉病抗性研究

为加快‘周麦’品种赤霉病抗性改良,利用当地主栽‘周麦’品种（系）‘周麦22号’、‘周麦32号’、‘周11550’为母本,‘宁麦9号’、‘生选6号’、‘扬麦21号’等长江中下游地区抗赤霉病材料为父本配制一系列杂交组合,经过选择获得621份F₃~F₆后代材料。在田间选用来源于江苏和河南两地不同的赤霉病菌株,通过单花滴注法接种小穗进行赤霉病抗性鉴定,同时利用抗赤霉病主效基因Fhb1紧密连锁的诊断性标记His-InDel对后代材料进行分子检测。结果表明,江苏的赤霉病菌株接种后代材料田间鉴定为高抗和中抗的占总数的23.9%,而河南的赤霉病菌株感染后代材料田间鉴定为高抗和中抗占比为35.1%,说明后代材料的赤霉病抗性比感病亲本有明显的改良,而且材料对江苏的赤霉菌菌株的抗性比河南的赤霉菌菌株的抗性低。分子检测结果显示,携带Fhb1和不携带Fhb1的材料之间赤霉病抗性差异极显著。这表明利用Fhb1基因分子标记辅助选择技术可用于改良‘周麦’品种的赤霉病抗性。     

大豆对胞囊线虫的抗性及分子标记研究

本文首次利用我国特有的抗病品种小粒黑豆与辽宁省的主栽品种辽豆10配制杂交组合,以F2代群体为试验材料,系统地应用分离群体分组分析法(Bulked Segregant Analysis,BSA)寻找与大豆胞囊线虫3号生理小种抗性基因相关的DNA分子标记以及同工酶标记和低分子肽/氨基酸标记,为我国的大豆抗胞囊线虫病育种提供理论指导.主要研究结果如下:1.利用杂交技术构建了大豆胞囊线虫抗性的分子表达平台.本研究配制了辽豆10×小粒黑豆的杂交组合,并利用海南加代快速繁殖,应用毒力最弱的大豆胞囊线虫3号生理小种对F2代群体进行抗性鉴定和移栽,为大豆对胞囊线虫抗性分子标记的筛选提供了均一遗传背景的试验材料.对该组合进行田间抗性鉴定,结果表明符合抗感分离1∶3的比率,表明在辽豆10背景下小粒黑豆对大豆胞囊线虫3号生理小种的抗性是由一对以上的隐性基因控制的.2.应用分离群体分组分析法在辽豆10和抗大豆胞囊线虫的核心抗源中获得了一个与感病性密切相关的RAPD标记S11700.应用143个随机引物,对由小粒黑豆和辽豆10配制的杂交组合的抗感亲本和构建的抗感池进行筛选,有92个引物产生了RAPD扩增产物,25个引物产生了RAPD多态性,其中一个引物产生了与抗大豆胞囊线虫基因密切相关的特异性DNA片段S11700,经多次重复验证,该片段在感病亲本及感病池中被特异性扩增,而在抗病亲本及抗病池中未产生该片段.利用S11700对不同抗性大豆品种进行分子标记鉴定和辅助选择,验证了该特异性片段与大豆胞囊线虫3号生理小种抗性紧密相关,可以用于抗胞囊线虫大豆新品种的分子辅助选择育种.3.利用BSA法对11个黑色种皮的大豆品种和12个黄色种皮的大豆材料的基因组DNA进行RAPD分析,获得一个与大豆黄色种皮相关的特异DNA片段S79500.采用该标记对辽豆10×PI437654杂交后代种皮颜色有分化的群体进行检测,结果表明这个RAPD标记具有较高的重复性和稳定性,可用于辅助选育优良的黄色种皮的大豆新品种.4.获得了一个与大豆胞囊线虫3号生理小种抗性基因相关的SSR分子标记Satt187.应用204对SSR引物对辽豆10×小粒黑豆进行SSR分析,31对引物产生了扩增产物,其中15对具有多态性,从中筛选到一个与大豆胞囊线虫3号生理小种抗性基因相关的分子标记Satt187,其片段大小为172 bp和176 bp,为共显性标记,在F2代分离群体中的分离比为1∶2∶1,呈孟德尔式遗传.应用该标记对辽豆10x小粒黑豆F2代分离群体进行分子标记鉴定和辅助选择,在抗病单株中均检测到标记带Satt187-176 bp的存在,而在感病单株中检测到有Satt187-176 bp和Satt187-172 bp两种标记带或仅有Satt187-172 bp的标记带存在,分析表明该标记具有抗胞囊线虫分子标记辅助选择应用的前景.5.系统地研究了辽豆10×小粒黑豆和辽豆10×PI437654两对组合的亲本及其杂交后代植株体内防卫反应酶系,包括多酚氧化酶(PPO)、过氧化物酶(POD)、过氧化氢酶(CAT)和超氧化物歧化酶(SOD)酶活及根内可溶性蛋白含量的动态变化.研究结果表明,抗感亲本、子代在大豆胞囊线虫侵染后各种防御酶系和可溶性蛋白含量均产生相应的变化,表现出酶活及可溶性蛋白的变化与抗病性密切相关,可作为鉴定大豆抗源抗性强弱的一项辅助生化指标,在抗胞囊线虫病抗源筛选辅助选择中起到一定的作用.6.采用电泳技术,系统地研究了大豆胞囊线虫侵染后,抗感亲本及子代中PPO、POD、CAT、SOD等几种同工酶酶谱,获得了一条与大豆胞囊线虫抗性相关的特异性SOD谱带.研究结果表明,线虫侵染后,诱导植株体内PPO、POD、CAT、SOD及可溶性蛋白量的增加,抗病亲本诱导产生的酶蛋白及可溶性蛋白量均多于感病亲本,对于杂交后代,出现不同于亲本的新的同工酶和可溶性蛋白谱带.在两对组合的SOD酶谱中,分别出现一条特异性谱带(Rf=0.365和Rf=0.381),利用两对杂交组合F2代抗感单株进行SOD同工酶电泳分析,证明该带可以作为大豆抗胞囊线虫的一项较为可靠的生化标记.7.探讨了不同抗性大豆品种及杂交后代根系分泌物中低分子肽/氨基酸与抗性的相关性.应用简便快速的聚酰胺薄膜层析检测技术对不同抗性大豆品种及杂交后代根系分泌物中低分子肽/氨基酸与抗胞囊线虫的相关性进行了研究.结果表明,大豆胞囊线虫侵染后,抗感亲本和子代在出苗后不同时期根系分泌物中的低分子肽/氨基酸的种类和数量有所差异,出苗后1～6 d的变化明显,感病亲本及感病子代在D区和E区存在共有的荧光斑点,而抗病亲本及抗病子代则无,可将该项检测技术作为一种辅助手段,用于大豆对胞囊线虫3号生理小种的抗性鉴定.     

棉花种间杂交渐渗系抗黄萎病性状遗传分析

利用抗黄萎病棉花种间渐渗系冀79作父本,高感病陆地棉品系1096作母本,配制杂交组合。感病对照、亲本及F1、F2在田间混生病圃鉴定。对亲本、F1及F2分离群体的抗性表现进行调查、统计,分析该抗源抗黄萎病性状的遗传方式,结果表明,该抗源抗性是由1个显性抗(耐)病基因和2个加性基因共同起作用,其中加性基因起主要作用。并且2个加性基因是独立遗传的,当2个加性基因同时存在并且纯合时,植株表现为高抗;当2个加性基因同时存在并且杂合时,植株表现为抗病;当只有1个加性基因存在时,不论纯合还是杂合,植株都表现为耐病;当2个加性基因不存在时,植株表现为感病。     

甘蔗新品种及主栽品种对褐锈病抗性与Bru1基因分子检测

The aim of this study was to assess brown rust resistance of new sugarcane varieties bred in China and main cultivated varieties in sugarcane planting area, and screen the elite new brown rust resistant varieties for popularization and application in production. In total, 60 new varieties in the national regional test of new sugarcane varieties were tested in Kaiyuan and Lincang, and 34 main cultivated varieties were studied in Lincang, Puer, and Yuxi, Yunnan province, and Yizhou, Guangxi province, China, where the incidence of brown rust was particularly high. The resistance of these sugarcane varieties to brown rust was investigated under natural inoculation and molecular marker-assisted identification was used to detect the brown rust resistance gene Bru1. The results of field survey showed that 66 (70.21%) of the 94 new and main cultivated varieties were highly resistant to moderately resistant, and 28 (29.79%) were susceptible to highly susceptible. Molecular detection indicated that Bru1 gene was found among 54 (57.45%) of the 94 new and main cultivated varieties. Some main cultivated varieties that were currently planted across large areas such as Guitang 29, Guitang 44, Dezhe 03-83, Liucheng 03-1137, Yuetang 60, and Guitang 46 were highly susceptible to brown rust, and 31 new varieties such as Yuegan 48, Funong 09-2201, Guitang 08-120, Liucheng 09-15, Zhongzhe 1, Yunzhe 08-1609, Yunrui 10-187, and Zhongtang 1201 were resistant. Therefore, in the sugarcane planting areas with high incidence of brown rust and wet and rainy climates, more effort should be eliminated the main susceptible varieties and promoted the application of new resistant varieties. This will help to achieve a reasonable distribution of varieties, fundamentally control the outbreak of disease in sugarcane planting areas, and provide security for the high-quality development of sugarcane industry in China in the future.     

Bru1 gene and potential alternative sources of resistance to sugarcane brown rust disease

Brown rust, caused by the fungus Puccinia melanocephala, is responsible for important yield losses in sugarcane production globally and it is therefore an important objective to introduce resistance to this disease in breeding programs. A major gene, Bru1, has been shown to confer resistance to P. melanocephala strains from different parts of the world and two molecular markers, R12H16 and 9O20-F4, closely associated to this gene have been previously reported. The usefulness of these molecular diagnostic markers in order to predict a rust resistant phenotype under natural high pressure inoculums conditions was analyzed. A total of 129 sugarcane accessions were evaluated under field infection for resistance or susceptibility to brown rust and subsequently screened for presence or absence of the two Bru1 diagnostic markers. A total of 49 genotypes (38 %) were phenotyped as resistant to brown rust but only eight (16.3 %) of them were harboring the Bru1 gene. To determine overall frequency of the Bru1 in the local sugarcane germplasm collection, 190 additional genotypes were examined. Presence of Bru1, as determined by the diagnostic markers, was detected in only 7 % of the genotypes evaluated. In conclusion, Bru1 diagnostic markers enable positive selection for brown rust resistance in sugarcane and moreover allowed detecting at least one additional source(s) of resistance. Interestingly, whilst only little genetic variability of rust resistance independent of Bru1 has been reported previously, this alternative genetic resource(s) found in our local germplasm constitutes the predominant one and should be helpful in order to amplify the narrow genetic basis for brown rust resistance in sugarcane.     

Survey of the Bru1 gene for brown rust resistance in Brazilian local and basic sugarcane germplasm

Bru1 is currently the major gene conferring brown rust resistance in sugarcane, and diagnostic markers are available. A survey for the presence of this gene was conducted on 391 genotypes including Brazilian cultivars, clones and basic germplasm. The efficiency of these markers for identifying resistant cultivars and artificially inoculated basic germplasm was also evaluated. The Bru1 frequency among cultivars (73.5%) suggests this gene is the prevalent source of brown rust resistance in Brazilian sugarcane breeding programmes. Most of the cultivars known to be resistant were positive for Bru1, although other genes for resistance could be present in lines not having Bru1. Only 17.8% of the basic germplasm accessions were positive for the Bru1 gene, and a low correlation between Bru1 diagnostic markers and brown rust severity was observed for basic germplasm accessions. Overall, Bru1 diagnostic markers proved to be efficient identifying resistant cultivars and clones and have potential to be in screening brown rust resistance in Brazilian breeding programmes.     

31份甘蔗野生核心种质资源褐锈病抗性鉴定及Bru1基因的分子检测

为明确甘蔗野生资源对黑顶柄锈菌的抗性水平,了解Bru1基因在甘蔗野生资源中的分布状况,于2013年对中国国家甘蔗种质资源圃保存的31份野生核心种质资源进行苗期抗褐锈病鉴定和抗褐锈病基因Bru1的分子检测。结果表明,31份供试材料中,高抗(1级)至中抗(3级)的有28份,占90.3%。其中19份材料表现高抗(1级),占61.3%,3份材料表现抗病(2级),占9.7%,6份材料表现中抗(3级),占19.4%。31份供试材料中只有贵州78-2-12、云南97-4、E.rockii95-19、E.rockii 95-20、云南83-224、广西79-8、云南95-35和广西89-13含抗褐锈病基因Bru1,占参试材料的25.8%;其余20份抗病材料和3份感病材料均不含抗褐锈病基因Bru1,表明除Bru1外,可能还有其他抗褐锈病基因存在。结果暗示中国国家甘蔗种质资源圃保存的野生核心种质资源中蕴藏着优良的抗褐锈病基因,是选育抗褐锈病甘蔗品种很有利用前景的抗源种质。     

甘蔗(Saccharum species hybrid)种质资源褐锈病和黄锈病抗性位点分子检测

开展种质资源抗锈病分子检测,对甘蔗筛选抗性资源和抗锈病育种具有重要意义。本研究利用已报道的褐锈病抗性位点Bru1和黄锈病抗性位点G1对中国甘蔗育种中的亲本资源和创新材料进行分析。在164份材料中共检测到‘粤糖07-913’、‘桂糖02-281’、‘赣南05-352’等23份带有Bru1抗性标记的材料,占参试材料的14%。在180份材料中共检测到‘粤糖96-86’、‘桂糖03-8’、‘赣南81-1035’等10份带有黄锈病抗性位点G1的材料,占参试材料的5.56%。‘粤糖96-86’、‘ROC16’、‘ROC22’等6份材料同时带有Bru1和G1位点,可能兼具褐锈病和黄锈病两种抗性。本研究结果可为选择优异抗锈病基因资源,开展杂交育种提供科学依据。     

Frequency and distribution of the brown rust resistance gene Bru1 and implications for the Louisiana sugarcane breeding programme

Brown rust, caused by the fungus Puccinia melanocephala, poses an increasing threat to sugarcane industries worldwide. Recently, markers R12H16 and 9020‐F4 were developed for a major resistance gene Bru1 that contributes to a significant proportion of brown rust resistance in multiple sugarcane industries. Marker‐assisted screening of Louisiana sugarcane germplasm showed a low frequency (4.3%, five out of 117 clones) of Bru1 among sugarcane cultivars and elite breeding clones. Likewise, among progeny of crosses involving wild/exotic germplasm, only 14 of 208 clones (6.7%) tested Bru1 positive. However, Bru1 frequency was higher (28.7%, 52 of 181 clones) in wild/exotic germplasm, which indicated that diverse genetic resources are available for Bru1 introgression. Commercial Bru1‐positive cultivar, ‘L 01‐299', was resistant to brown rust. However, Bru1‐positive cultivar, ‘L 10‐146’, was susceptible while Bru1‐negative cultivars, such as ‘L 99‐233’, showed resistance to brown rust. Bru1‐negative clones with brown rust resistance offer an opportunity to identify alternate sources of resistance, which can be pyramided with Bru1 for effective and durable resistance in sugarcane against the changing pathogen.     

Enhanced leaf rust resistance in wheat conditioned by resistance gene pairs with Lr13

Summary Leaf rust resistance gene Lr13 is present in many North American hard red spring wheat cultivars that have shown durable resistance to leaf rust. Fifteen pair-wise combinations of Lr13 and seedling leaf rust resistance genes were developed by intercrossing near isogenic Thatcher lines. In both seedling and adult plant tests, homozygous paired combinations of specific resistance genes with Lr13 had enhanced resistance relative to either parent to rust isolates that had intermediate avirulent infection types to the additional genes. In field tests, homozygous lines were more resistant than either parent if the additional leaf rust gene conditioned an effective level of resistance when present singly.