水稻纹枯病抗性基因定位及抗性资源发掘的研究进展

纹枯病是水稻三大主要病害之一。抗纹枯病品种的选育与推广对防治纹枯病具有决定性意义,而纹枯病抗性资源的发掘、抗性遗传、抗性基因定位及外源基因的利用是抗性品种选育的基础。综述了水稻纹枯病抗性基因的定位、纹枯病抗性QTL的潜在应用价值以及纹枯病抗性资源挖掘的最新进展,以期对纹枯病抗性育种提供帮助。     

抗水稻纹枯病遗传研究的改良方法及其验证

 报道了抗水稻纹枯病遗传研究的一种新方法体系，包括采用新的接种方法、评定病级指标和适宜调查时间，采用永久性遗传分析群体设置有重复的田间试验，田间保持中肥水平，以及浅水灌溉不脱水等内容。用F2无性系群体和重组自交系群体，对新方法进行了4年的验证试验，证明新方法有相当好的重演性。     

安徽省部分水稻品种（组合）对纹枯病的苗期抗性评价

为了解安徽省水稻品种（组合）对纹枯病的抗性现状,用5个不同致病力的水稻纹枯病菌,对收集来自该省的87个水稻品种（组合）进行了苗期抗性鉴定。基于参试的水稻品种（组合）的平均病情指数,仅有3个组合表现为抗病,分别是纯王优2号、辐优136和中优9801,占总材料数的3.44%;中抗、中感和感病的品种（组合）分别占总数的21.84%、62.07%和12.64%。基于聚类分析,抗、中抗、中感和感的材料分别占3.44%、20.69%、43.68%和32.18%。相关分析表明,两个分类结果间达极显著相关（r=0.85,P〈0.01）。结果说明安徽省大多数品种（组合）对纹枯病表现为中感或感病级别,抗性总体较差,生产上应加强对纹枯病抗性品种的选育。     

江西省水稻种质资源对纹枯病的抗性评价

利用C30、、E67、GD118、YN7和YN3等5个水稻纹枯病鉴别菌株在苗期对322份江西水稻种质资源对纹枯病抗性进行接种鉴定。结果表明,对5个鉴别菌株均表现高抗或抗病的有兴国寸谷糯、南城麻壳红、湘矮早10号、二禾红、小站红米稻、47601（韩国）和晚油红8个品种,平均病级分别为2.34、1.97、2.46、1.73、2.04、1.89、2.46和2.53,系统观察还发现G珍籼97B、湘恢91269与Rocca 3个品种比对照高感品种Lemont更感病。本文对国内水稻纹枯病鉴别体系中鉴别菌株和鉴别品种的选择进行了讨论。     

PQQ诱导水稻对纹枯病的抗性研究

为筛选出诱导水稻对纹枯病抗性的最佳诱导因子及其诱导最佳条件,在水稻苗期分别喷施不同浓度苯并噻二唑(BTH)、壳寡糖(COS)、吡咯喹啉醌(PQQ)、前胡提取液、益农和翠倍加,开展不同诱导因子及诱导方式对水稻纹枯病抗性影响研究.通过调查发病度,计算病情指数和相对防效,筛选出最佳诱导因子及其诱导条件(浓度、方式、诱导时间)...     

转基因水稻株系的纹枯病抗性分析

对通过基因枪转化获得的41个转水稻碱性几丁质酶和苜蓿β-1,3-葡聚糖酶基因（RC24和β-1,3-Glu）的高世代纯合株系进行纹枯病抗性接菌鉴定,结果表明不同转基因系间抗性存在极显著差异,聚类分析可分为抗、中抗、中感、感病四种类型,但其中92.1%的株系属中抗或中感类型;选择不同抗感类型的代表性株系,测定其几丁质酶活力,结果显示中抗、中感、感病类型转基因株系表达的几丁质酶活力与其纹枯病抗性表现呈现一致性,而抗病类型表达目标基因编码的酶活力低于中抗类型;接菌诱导后,在不同时间或同一植株的不同部位检测,转基因系的几丁质酶活力因其组成性表达而无明显差异,而未转基因的对照品种在诱导后不同时间其几丁质酶活力表达呈“峰”式曲线分布,同一植株不同空间位置的酶活力却无明显差异。     

水稻纹枯病对水稻产量的影响

田间试验研究了不同水稻品种对水稻纹枯病发病程度和产量的影响。结果表明,水稻纹枯病属中等偏重发生,对产量影响大,空育131病情指数最高,为26.15,产量损失最高,为28.29％。     

水稻纹枯病的发生原因及防控技术

近十几年来,清流县水稻纹枯病逐年发生日趋严重,此病害发病初期常被忽略,后期严重影响粮食产量。对清流县纹枯病发生、危害因素进行分析,并介绍有效的防控措施。     

水稻稻瘟病抗性育种研究进展

稻瘟病是水稻三大病害之一.综述了稻瘟病菌的致病机理、病菌的变异性和抗稻瘟病基因的定位、克隆的研究进展,以及抗稻瘟病育种的主要方法,并就目前稻瘟病育种中存在的问题和相应的对策进行了分析探讨,以为加速抗稻瘟病育种工作进程,提高工作成效提供依据.     

盘锦水稻纹枯病发展趋势及防控技术

通过对盘锦稻区水稻纹枯病的发展趋势调查,明确了影响水稻纹枯病发生的相关因子及该病害对水稻产量的影响。结合盘锦地区的水稻生产情况提出了培育壮苗、加强田间管理、结合气候因子、药剂防治等对纹枯病的可持续防控技术。     

Advances in Mapping Loci Conferring Resistance to Rice Sheath Blight and Mining Rhizoctonia solani Resistant Resources

Sheath blight (SB) caused by Rhizoctonia solani is one of the three major diseases of rice, and now has become the most severe disease causing rice yield loss in China. Breeding and use of varieties resistant to SB is crucial in controlling the disease, but the advances achieved have been limited due to the lack of highly SB-resistant rice germplasm. Genetic analysis revealed that the SB resistance in rice was a typical quantitative trait controlled by multi-genes. Although many QTLs conferring resistance t...     

Establishment of Agrobacterium tumefaciens-Mediated Transformation System for Rice Sheath Blight Pathogen Rhizoctonia solani AG-1IA

To construct the T-DNA insertional mutagenesis transformation system for rice sheath blight pathogen Rhizoctonia solani AG-1 IA,the virulent isolate GD118 of this pathogen was selected as an initial isolate for transformation.The conditions for transformation of isolate GD118 were optimized in five aspects,i.e.pre-induction time,co-culture time,acetosyringone(AS) concentration at the co-culture phase,co-culture temperature and pH value of induction solid medium(ISM) at the co-culture phase.Finally,a system ...     

Efficacy of Bacillus subtilis MBI 600 Against Sheath Blight Caused by Rhizoctonia solani and on Growth and Yield of Rice

Rice sheath blight disease(ShB),caused by Rhizoctonia solani,gives rise to significant grain yield losses.The present study evaluated the efficacy of Integral?,the commercial liquid formulation of Bacillus subtilis strain MBI 600,against rice ShB and for plant growth promotion.In greenhouse studies,four log concentrations of Integral(from 2.2×106 to 2.2×109 cfu/mL) were used as seed treatment(ST).After 25 d,seedlings were dipped(SD) into Integral prior to transplanting.At 30 d after transplanting(DAT),leaf sheaths were inoculated with immature sclerotia of the pathogen.At 45 DAT,a foliar spray(FS) with Integral was applied to some treatments.The fungicide control was 50% carbendazim at 1.0 g/L,and a nontreated control was also included.Overall,there were 10 treatments,each with five replications.ShB severity was rated at 52 DAT,and seedling height and number of tillers per plant were rated at 60 DAT.In 2009,two field trials evaluated Integral at 2.2×108 and 2.2×109 cfu/mL.Integral was applied as ST,and seedlings were produced in a nursery bed.After 32 d,seedlings were treated with Integral as SD and transplanted into 10 m2 blocks.Foliar sprays were given at 45 and 60 DAT.There were seven treatments,each with eight replications arranged as a factorial randomized complete block design.At 20 DAT,the plots were broadcast inoculated with R.solani produced on rice grains.Seedling height before transplanting,ShB severity at 90 DAT,and grain yield at harvest were recorded.Integral at 2.2×109 cfu/mL provided significant increase of seedling heights over other treatments under greenhouse conditions.The Integral treatments of ST + SD + FS at 2.2×109 cfu/mL significantly suppressed ShB over other treatments.In field studies,Integral provided significant increase of seedling height in nursery,and number of tillers per plant,compared with the control.ShB severity was significantly suppressed with higher concentrations of Integral compared to lower concentrations.Grain yield were the highest at an Integral concentration of 2.2×109 cfu/mL.Overall,Integral significantly reduced ShB severity,enhanced seedling growth,number of tillers per plant and grain yield as ST + SD + FS at the concentration of 2.2×109 cfu/mL under the conditions evaluated.     

纹枯病菌对不同水稻品种叶片中抗病性相关酶活性的影响

对优质抗纹枯病水稻品种ZH5、较抗纹枯病品种特青、感纹枯病品种Lemont及恢复系泸恢17、多系1号和GB8等水稻材料进行纹枯病菌接种,测定了水稻叶片中与抗病性相关的超氧化物歧化酶 (SOD)、过氧化物酶 (POD) 的活性和丙二醛 (MDA) 的含量。不论纹枯病菌接种与否,ZH5和特青叶片中SOD活性均明显高于Lemont;纹枯病菌接种后,抗性品种ZH5和特青叶片中POD活性升高,感病品种Lemont 叶片中POD活性降低;不论是抗病还是感病的水稻材料,纹枯病菌接种后叶片中MDA含量均有所增加,但ZH5叶片中MDA含量明显低于其他参试材料。     

Morphological and Genetical Variability among Rhizoctonia solani Isolates Causing Sheath Blight Disease of Rice

Eighteen isolates of Rhizoctonia solani collected from infected rice plants in four different locations of Bangladesh were studied by using morphological characters and molecular markers. Anastomosis study with a reference isolate confirmed that all the isolates belonged to R. solani. Significant variation was observed in sclerotial size, shape and distribution. Un-weighted pair group method with arithmetic mean dendrogram constructed based on the Gower's general similarity coefficient showed that these isolates were grouped into four clusters at the 0.68 similarity coefficent according to morphological characters. Cluster I was a major cluster consisting of 13 isolates, while clusters Ⅱ to Ⅳ consisted of 1 or 2 isolates. Analyses by variable number of tandem repeat and amplified fragment length polymorphism markers showed that the isolates were grouped into five and three clusters at a similarity coefficient of 0.64 and 0.69, respectively. Although most of the variability was found between isolates from different regions as expected, significant variation was observed within the isolates collected from similar agro-ecological regions. Our results suggest the presence of different races of R. solani within the same local geographic regions.     

水稻抗纹枯病育种成效的初步评价

以广东省和江苏省里下河农科所新近育成的部分籼稻品种（系）、扬州大学农学院的研究组以不同抗源杂交后代向抗感两个极端选育的9份籼稻品系以及另一组合向抗病方向选育的5份籼稻品系为材料,设置抗感病对照,进行田间纹枯病菌接种试验。结果表明品种间对纹枯病的抗性存在极显著差异;聚类分析将参试材料按抗性水平高低聚为6类：高度感病、感病、中等感病、中等抗病、抗病和更高水平抗病。广东品种在6种类型中均有分布,但属于抗和更抗类型的品种只有3个。扬州大学农学院对抗×抗杂交向抗感两个极端选育的品系在病级的中间类型中几乎没有分布;而向抗病方向选育的品系则仅分布于中抗至抗病的范围内,且属于抗的品种数占此类品种的60%。江苏省里下河农科所近些年育成的几个品种则只分布于后4类之中,且最高水平抗性的3个品种中,其品种占2/3。表明水稻对纹枯病的抗性是可遗传的性状,对抗性的选择有效。     

Resistance Evaluation to Sheath Blight in Transgenic Rice Lines

Resistance of forty-one homozygous rice lines transformed with chitinase gene (RC24) and β-1,3 -glucanse gene (β-1,3-Glu) to sheath blight was analyzed by inoculation. Among different lines, the resistance had significant differences according to the result by cluster analysis. The lines could be categorized into resistant, moderately resistant, moderately susceptible and susceptible types, while 92.1% of which belonging to moderately resistant or moderately susceptible type. For different resistant or susceptible lines, the resistance to rice sheath blight was remarkable correlated with the chitinase activity of transgenic lines except resistant type lines, in which enzyme activity coded by target gene was lower than moderately resistant type. The chitinase activity of transgenic lines tested at different time after inoculation or different organs of the same plant was uniform, which suggested that the expression of chitinase gene was constitutive in nature. Check varieties‘ chitinase activity would change at different time after inoculation and reach a peak at sometime, but it had no difference at various parts of the same plant.