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。     

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。     

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。     

Molecular insights into brown rust resistance and potential epidemic based on the <Emphasis Type="Italic">Bru</Emphasis>1 gene in sugarcane varieties and new elite clones

In most sugarcane cultivation areas, sugarcane brown rust (SBR), caused by Puccinia melanocephala, is an economically important fungal disease that leads to severe yield loss in susceptible cultivars. Bru1, which is the major dominant SBR resistance gene, has been widely used in the prediction of brown rust resistance in sugarcane. In this study, three panels of sugarcane germplasms, the major varieties approved over the past 10 years and new elite clones in the current national regional trial, together with one panel of Saccharum spontaneum, were employed in estimating the possibility of SBR epidemic and to assess the efficiency of 9O20-F4-HaeIII in eliminating false positives. Among the current top five varieties used as sucrose feedstock, accounting for more than 68.9% of the total cultivated area, all were highly resistant to SBR, although only three harboring Bru1. Two major varieties Yuetang60 and Guitang46 without harboring Bru1 were highly susceptible to SBR, together with highly susceptible Funong41, which need prudent promotion. Approximately 60.5% of the 38 new elite clones were Bru1 positive. Considering the susceptibility of Liucheng03-1137, which exhibits a strong promotion momentum, together with Funong41, Guitang46, Yuetang60, and Yunzhe06-47, four were favored by the enterprise due to their superior sucrose content and good stalk yield, despite their high susceptibility to SBR, and additional Yuetang93-159, one current top five varieties with declining resistance, which results in a potential risk for brown rust epidemic. Furthermore, low frequency of the wild germplasm of S. spontaneum from five different countries was Bru1 positive. In addition, a perfect molecular diagnostic result was observed in all modern sugarcane clones using two dominant markers, and HaeIII can prevent the occurrence of false positive results when the 9O20-F4 PCR products of S. spontaneum are digested by RsaI. The prevalent chewing cane Badila without Bru1 is highly resistant to SBR. Our results provide valuable information for the extension of sugarcane varieties and a batch of novel SBR resistance sources with superior comprehensive characters for crossbreeding, and for SBR-resistant gene pyramiding by crossing or through mining and using of new SBR-resistant genes.     

甘蔗新品种苗期抗螟虫性评价

为明确新甘蔗品种对甘蔗螟虫的抗性水平,以期为抗虫品种的推广应用和抗性基因发掘奠定基础,本文采用螟虫自然种群接虫方法,连续2年对10个甘蔗新品种进行了苗期螟害分析与抗螟虫性评价。结果表明,不同甘蔗新品种对螟虫抗性存在显著差异,桂糖29号、桂糖31号等较抗虫,福农39号、德蔗03-83和云蔗05-49等较感虫。部分甘蔗品种抗性会随螟虫选择压力不同而变化,云蔗03-194、云蔗05-51、云蔗06-407等在螟虫虫口密度高时表现为感虫,而在虫口密度低时表现为抗虫。     

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。     

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.     

基于田间表型和Bru1基因检测分析甘蔗褐锈病抗性遗传

由黑顶柄锈菌(Puccinia melanocephala)引起的甘蔗褐锈病具有产孢量大、流行性强的特点, 可导致甘蔗产量和蔗糖分的严重损失, 了解抗病性遗传有助于抗锈病育种中的亲本选择和组合配制, 而有效的抗性鉴定技术则是分离个体选择所必需的。本研究以甘蔗分离群体为材料, 利用表型与抗褐锈病主效基因Bru1检测相结合, 研究甘蔗褐锈病抗性遗传倾向并评价Bru1基因检测与表型抗性的关联性。结果显示, 发病盛期, 感病个体中, Bru1基因未检出率为96.7%, 但未感病个体中, Bru1基因的检出率仅为66.0%, 且高抗组合CP84-1198×云蔗89-7群体中的未感病个体, 该基因检出率为0, 尽管也发现有2个组合的未感病个体中, 该基因的检出率为100%。说明由Bru1基因控制的抗性可根据该基因的检测结果判断其抗/感病性, 同时, 甘蔗基因池中还存在其他未知的控制抗病性状的主效基因。值得强调的是, 父母本的抗病性均影响杂交后代的抗病性, 但以抗病亲本为父本的组合, 其分离群体的感病个体明显减少, 说明父本对杂交后代的褐锈病抗性影响可能更大。     

甘蔗苗期抗旱性鉴定评价研究

以12个甘蔗品种试验材料,通过桶栽试验,在苗期进行反复干旱胁迫处理,测定甘蔗幼苗存活率和叶片叶绿素含量、可溶性糖含量、丙二醛含量、超氧化物歧化酶活性等生理指标.运用抗旱系数法和隶属函数值法,对苗期甘蔗各生理指标性状进行了反复干旱胁迫下的抗性评价和鉴定,为甘蔗抗旱品种的选择提供可借鉴的方法,同时为其抗旱育种和蔗区抗旱品种...     

云南蔗区首次发现由屈恩柄锈菌引起的甘蔗黄锈病

为明确在国家甘蔗体系云南示范点甘蔗新品种上发生的锈病病原菌种类。采用田间症状观察,结合病原菌形态特征观察及分子生物学方法对20份锈病样品进行病原菌鉴定。鉴定结果表明：来源于云南勐海‘‘海引1号’’的4份甘蔗锈病样品属甘蔗黄锈病,病原菌为屈恩柄锈菌,其核苷酸序列与GenBank中登录的屈恩柄锈菌相应核苷酸序列（GenBank登录号：GU058021和GQ283004—GQ283009）同源性在99.9%以上,并在系统发育树中聚为一簇;来源于云南保山、临沧、勐海其他甘蔗新品种（系）的16份甘蔗锈病样品属甘蔗褐锈病,病原菌为黑顶柄锈菌,它们的核苷酸序列与GenBank中登录的黑顶柄锈菌相应核苷酸序列（GenBank登录号：EU164548,GU058001和JX036025）同源性在99.8%以上,在系统发育树中处于同一分枝。本研究首次在云南蔗区发现由屈恩柄锈菌引起的甘蔗黄锈病。