杂交水稻稻瘟病抗性鉴定及其与父母本抗性的相关性

对9个水稻不育系与12个恢复系及其配制的53个杂交水稻组合在福建省将乐县黄潭、上杭县茶地的稻瘟病重病区进行了稻瘟病抗性鉴定,结果筛选出22个抗稻瘟病组合.对杂交组合与父母本的稻瘟病抗性进行相关分析,发现杂交组合的叶瘟和穗瘟与母本叶瘟均呈极显著正相关,而与父本叶瘟相关不显著.因此,在杂交水稻抗瘟性育种中,选用抗瘟性好的不育系作亲本配组尤为重要.     

水稻稻瘟病抗性的研究进展

稻瘟病是当前粳稻主产区危害最严重的病害之一,而品种抗病性的利用则被公认为是病害综合防治的根本策略。本文从抗性鉴定方法、抗性资源筛选和发掘、抗性遗传规律及抗病基因定位3个方面,对水稻稻瘟病抗性的研究进展进行了简要综述,以期为水稻抗稻瘟病的育种提供参考。同时对水稻品种稻瘟病抗性研究的现存问题与今后的研究方向进行了讨论。     

稻瘟病抗性基因的鉴定及利用进展

20世纪60年代中期,日本率先开展了水稻品种抗稻瘟病基因分析的研究工作,鉴定了最初的8个抗性位点上的14个基因,并建立了一套抗稻瘟病基因分析用的鉴别体系（JDCs, Japanese differential cultivars）,随后,国际水稻研究所和中国等产稻国也逐渐开展了水稻稻瘟病抗性遗传的系统性研究。截至2007年12月,已至少报道了58个抗稻瘟病位点共67个主效基因。这些基因成簇地分布于除第3染色体外的所有水稻染色体上,其中,66个为显性基因,1个为隐性基因,包括Pi b、Pi ta、Pi z5、Pi zt、Pi 9、Pi d2、Pi 36和Pi 37等8个已被克隆的基因(Pi z5、Pi zt和Pi 9同为Pi z基因位点上的复等位基因)。还讨论了合理利用抗性基因等问题。     

福建省稻瘟病生理小种及品种资源抗性鉴定

通过采集福建省水稻主产区的稻瘟病菌,鉴定并分析了福建省稻瘟病菌生理小种种群情况,将2017—2018年福建省的126份稻瘟病菌株划分为6个群32个生理小种,其中ZA群为优势生理小种,出现频率为41.6%。同时收集南平地区生产上主栽水稻品种,通过苗期抗病性表现,筛选出适合该区域种植的抗病性水稻品种,如隆两优华占、和两优332、隆两优1988、民优667、科优16等品种的抗谱值高达95%以上。     

水稻稻瘟病抗性基因研究进展

概述了稻瘟病抗性基因的经典遗传鉴定、分子标记定位、克隆以及稻瘟病抗性基因与无毒基因的互作等方面的研究进展。     

国际稻瘟病圃种质稻瘟病抗性的鉴定与评价

分别采用苗期喷雾接种和成株期注射、涂抹接种对375份国际稻瘟病圃材料进行稻瘟病抗性人工接种鉴定,发现苗瘟与叶瘟抗性间具有极显著的相关性,而苗瘟、叶瘟与穗颈瘟间相关性不显著,结果筛选出一批抗性较好的材料,可供育种部门在选配亲本时应用。     

水稻稻瘟病抗性基因研究进展

介绍了稻瘟病抗性基因的结构,综述了其定位和克隆的最新研究进展,阐述了在其研究过程中分子标记技术的利用,并提出今后的研究方向。     

水稻新品种田间自然病圃抗稻瘟病性鉴定

利用田间自然病圃,用高感稻瘟病品种做诱发,对44个杂交水稻新组合(品种)的抗稻瘟病性进行了鉴定.结果表明:福优27和福优28对稻瘟病表现高抗,富优6号表现抗病,其它组合(品种)对稻瘟病表现感病或高感病.     

杂交水稻稻瘟病抗性育种体系研究进展

改良稻瘟病抗性是当前杂交水稻育种的主要目标之一。从稻瘟病生理小种的鉴定、水稻材料的接种鉴定、抗源筛选、抗性基因的分子检测及抗瘟性品种的选育等方面介绍了杂交水稻稻瘟病抗性育种研究进展。     

Genetic Transformation of Rice with Pi-d2 Gene Enhances Resistance to Rice Blast Fungus Magnaporthe oryzae

The gene Pi-d2, conferring gene-for-gene resistance to the Chinese blast strain ZB15, was isolated from a rice variety (Digu) by the map-based cloning strategy. Here, we constructed a control plasmid pZH01-pi-d2tp309 (pZH01-tp309) and three different expression constructs, pCB-Pi-d25.3kb (pCB5.3kb), pCB-Pi-d26.3kb (pCB6.3kb) and pZH01-Pi-d22.72kb (pZH01-2.72kb) of Pi-d2, driven by Pi-d2 gene's own promoter or CaMV35S promoter. These constructs were separately introduced into japonica rice varieties Lijiangxintuanhegu, Taipei 309, Nipponbare and Zhonghua 9 through Agrobacterium- mediated transformation. A total of 150 transgenic rice plants were obtained from the regenerated calli selected on hygromycin. PCR, RT-PCR and Southern-blotting assay showed that the gene of interest had been integrated into rice genome and stably inherited. Thirty-five transgenic lines independently derived from T1 progeny were inoculated with the rice blast strain ZB15. Transformants exhibited resistance to rice blast at various levels. The lesions on the transgenic plant leaves were less severe than those on the controls and the resistance level of transgenic plants harboring the gene of interest from three vectors had no difference. The own promoter of Pi-d2, about 2.2 kb or 3.2 kb, had the similar promoter function as CaMV35S. Field evaluation for three successive years supported the results of artificial trial, and some lines with high resistance to rice leaf blast and neck blast were obtained.     

四川省稻瘟病菌群体遗传结构分析

由稻瘟病菌(Magnaporthe oryzae)侵染引起的稻瘟病是全球水稻生产上最严重的病害之一。利用6对SSR荧光标记对采自四川绵阳、营山、雅安、北川和武胜地区的5个稻瘟病菌群体的遗传结构进行分析。结果表明,在124个稻瘟病菌中检测出43个等位基因,平均每个位点的观测等位基因数为7.2,有效等位基因数为3.1,所有位点均显著偏离HardyWeinberg平衡。5个群体的平均观测杂合度(0.374)低于期望杂合度(0.502),暗示群体内存在因近交而导致的杂合子缺失。AMOVA分析显示,绝大多数遗传变异(81.17%)存在于群体内个体间,仅有18.83%的变异来自于群体间的差异。5个地理群体间呈现高水平的遗传分化(遗传分化系数为0.057~0.528)。Mantel检验表明,群体间的遗传距离与地理距离相关未达显著水平,说明稻瘟病菌的遗传变异呈现随机分布的空间模式。群体遗传学数据分析表明5个群体间存在不同程度的基因流(基因流水平为0.472~4.347),基于贝叶斯聚类法的Structure分析也证实了这一结果。     

Molecular Scree ning of Blast Resistance Genes in Rice Germplasms Resistant to Magnaporthe oryzae

Molecular screening of major rice blast resistance genes was determined with molecular markers, which showed close-set linkage to 11 major rice blast resistance genes (Pi-d2, Pi-z, Piz-t, Pi-9, Pi-36, Pi-37, Pi5, Pi-b, Pik-p, Pik-h and Pi-ta²), in a collection of 32 accessions resistant to Magnaporthe oryzae. Out of the 32 accessions, the Pi-d2 and Pi-z appeared to be omnipresent and gave positive express. As the second dominant, Pi-b and Piz-t gene frequencies were 96.9% and 87.5%. And Pik-h and Pik-p gene frequencies were 43.8% and 28.1%, respectively. The molecular marker linkage to Pi-ta² produced positive bands in eleven accessions, while the molecular marker linkage to Pi-36 and Pi-37 in only three and four accessions, respectively. The natural field evaluation analysis showed that 30 of the 32 accessions were resistant, one was moderately resistant and one was susceptible. Infection types were negatively correlated with the genotype scores of Pi-9, Pi5, Pi-b, Pi-ta² and Pik-p, although the correlation coefficients were very little. These results are useful in identification and incorporation of functional resistance genes from these germplasms into elite cultivars through marker-assisted selection for improved blast resistance in China and worldwide.     

稻瘟病菌对新型模式植物二穗短柄草的致病性研究

 建立了稻瘟病菌对二穗短柄草的接种体系,观察了稻瘟病菌在二穗短柄草上的发病过程和特点,并与在水稻和大麦上的发病情况进行了比较。在人为接种稻瘟病菌的条件下,二穗短柄草的叶片、叶鞘、茎秆、穗部均可获病。利用稻瘟病菌孢子悬浮液对二穗短柄草进行苗期活体或离体接种,都能引发典型病斑。与大麦相比,二穗短柄草叶片上病斑的出现时间及发展速度更接近水稻。同时,二穗短柄草叶片上的接种和发病条件比水稻更易控制,病斑更具一致性。另外,稻瘟病菌致病突变体在二穗短柄草叶片上致病性变化（降低或丧失）趋势与在水稻上的情况一致。显微观察及组织化学染色表明,稻瘟病菌在二穗短柄草叶片上可有效形成附着胞,侵入叶片表皮细胞,形成典型的侵染菌丝,其过程与水稻近似。因此,二穗短柄草可以作为稻瘟病菌与寄主互作的研究材料,并有望为杂草上梨孢菌的研究提供可能的模式植物以及为农作物的抗病育种提供参考。     

Pathogenicity of Rice Blast Fungus Magnaporthe oryzae on Brachypodium distachyon

Inoculation methods for rice blast fungus Magnaporthe oryzae to Brachypodium distachyon were developed to investigate the infection process and symptom development in comparison with those on rice (Oryza sativa) and barley (Hordeum vulgare).M.oryzae could infect leaves,sheathes,stems and panicles of B.distachyon and cause blast disease.Spraying conidial suspension on either intact seedlings or leaf segments induced typical symptoms on B.distachyon.During the intact seedling inoculation,the symptom developed on B.distachyon leaves closely resembled that on rice;but the lesions on B.distachyon had better uniformity in shapes and sizes than those on rice or barley.In the leaf segments inoculation,only initial and low-developed lesions could be found on rice,while normal symptoms on B.distachyon and barley.Inoculated with low-virulent mutants of M.oryzae,B.distachyon produced low-level symptoms.The symptom level of each mutant on B.distachyon corresponded well to that on rice.In addition,typical infection processes presented on B.distachyon leaves:forming melanized appressoria,penetrating into host epidermis and then forming hyphae in epidermal cells.According to these results,B.distachyon can be used as a candidate for studying fungus-plant interactions and as a probable source of disease resistance.     

Different Hypotheses for Resistance Loss of Rice Varieties to Magnaporthe oryzae

It is widely believed that a rice variety loses its resistance to rice blast after three to five years in commercial production due to the emergence of new Magnaporthe oryzae pathotypes(or physiological races)(Ou,1985).However,we believe that a resistant rice variety loses its resistance to M.oryzae not due to the emergence of new physiological races.We propose that pathogenic physiological races already exist in the natural environment,serving as potential physiological races.It is only because of the lack of appropriate environmental conditions,particularly the lack of a suitable rice host,on which such a race is unable to propagate widely and exists as an inferior race.However,when there is an appropriate rice host,the potential pathogenic physiological race can quickly proliferate to become the dominant physiological race,thus leading to the loss of blast resistance in resistant rice varieties.     

Genetic Variation Dissection of Rice Blast Resistance Using an Indica Population

正Rice blast disease, caused by fungus pathogen Magnaporthe oryzae, is one of the most destructive diseases that impact rice farming. In the worldwide, rice harvests lose 10% to 30% of the total production because of blast infection, which is estimated to be enough for feeding 60 million people     

稻瘟病抗性基因对安徽省稻瘟病菌种群抗性的影响

为分析抗稻瘟病基因对安徽省稻瘟病菌株的抗性水平的影响,采用10个水稻抗稻瘟病单基因品系对安徽不同地区的稻瘟病菌株进行致病力测定,同时对201份水稻品种的抗稻瘟病基因Pi9进行扩增,结合田间抗性表现,分析抗性基因Pi9的利用价值。抗性基因Pi9、Pik、Pizt等对安徽地区的稻瘟病菌株具有较好的抗性,抗性频率分别为66%、60%和54%,其中携带Pi9抗性基因的水稻品种的田间抗性表现也较好,说明Pi9可直接作为分子标记辅助安徽地区水稻品种选育抗原基因。