水稻品种ZH5及其杂交后代纹枯病抗性和农艺性状研究

以对纹枯病（Rhizoctonia solaniKühn）有良好抗性的水稻品种ZH5为母本,与对纹枯病抗性较差的泸恢17、多系1号和GR83个恢复系进行杂交,获得杂交F1、F2代,于2005—2006年在杭州田间对亲本和杂交后代进行了纹枯病抗性人工接种鉴定及植株生物学性状考查。结果表明,杂交F1代植株对纹枯病的抗性水平介于双亲之间,大多数农艺性状表现出超亲优势或介于双亲之间;同一杂交组合F2代群体内纹枯病抗性分离较大;不同杂交组合间群体内抗、感纹枯病植株分布差异较大。植株对纹枯病的抗性与株型性状相关不显著,主要决定于品种自身的抗性遗传背景。     

5个水稻品种对水稻纹枯病菌鉴别能力的比较

采用苗期接种法和大田成株期接种法,对5个具有不同纹枯病抗性的水稻品种Lemont、武育粳3号、Jasmine85、C418和YSBR1进行纹枯病抗性评价。苗期接种结果表明,30个来源不同的纹枯病菌接种5个品种后,5个品种苗期表现出明显的抗感差异,30个菌株之间致病力差异亦明显,且品种与菌株之间互作显著。根据聚类分析结果,从30个菌株中筛选出5个致病力不同的菌株(分别为GD118、C30、E67、YN7和YN3)进行水稻品种成株期抗性鉴定,发现水稻品种成株期的抗感差异亦显著。     

水稻理想株型的性状研究

在前文“初探超级稻育种与理想株型”中,已就理想株型的理论,发展阶段以及与超级稻育种的关系做了探讨,本文将在此基础上对水稻理想株型的有关性状研究分别加以阐述。一、株高植株高度是衡量水稻对N肥反应灵敏性的一个重要指标,而且植株的抗倒性也主要由株高所决定的（Yoshita,S．1972,Jenming,P．R．等．1979）。至于与植株的光合作用和生长发育紧密相关的群体内通风透光状况更是受着植株高度制约的（黄耀祥等,1983）。缩短茎秆是株型育种初期即矮化育种的核心内容,早期认为矮秆的主要作用是增强耐肥抗倒。适于密植和提高经济…     

两份新株型水稻品系的农艺性状与遗传特性分析

[目的]理想株型水稻能提高光合作用效率、经济产量和抗病能力.通过探究两份新株型水稻种质的农艺性状变异和遗传特性,为水稻高产抗病育种提供优异理想株型种质资源.[方法]以两个重组自交系中发现的两份自然重组的新株型种质08yi和RIL60以及由同一自交系选育出来的常规种质08yc和RILc为材料,进行不同生长时期的株型构成因...     

水稻抗感纹枯病品种Ospgip1基因的表达特征

 从水稻基因组DNA中扩增出1 184 bp的Ospgip1基因片段。该片段包含930 bp的完整开放阅读框,终止密码子为TAA,无内含子。RT PCR结果表明,Ospgip1基因在水稻抗、感纹枯病品种中均能表达,但不同生育期、不同部位表达量有差异。实时PCR结果显示,抗病品种YSBR1和中感品种Jasmine 85中Ospgip1的表达量要明显高于感病品种Lemont;稻苗黄化处理后,无论是抗病品种还是感病品种的Ospgip1表达量均显著提高;纹枯病菌侵染使得抗病品种Ospgip1表达量大大增加,而对感病品种影响不大。     

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。     

水稻抗二化螟特性鉴定技术的评价研究

采用离体叶片、离体茎秆、离体剥开茎秆及活体成株4种室内抗虫性鉴定方法,对相同水稻材料进行抗二化螟特性鉴定,同时对这些水稻室内抗二化螟鉴定技术进行了综合评价。结果表明,这些方法的抗性鉴定结果高度吻合,离体叶片鉴定方法是目前最快速、有效的抗二化螟鉴定方法。并通过离体叶片和活体成株鉴定方法对转Vip3A基因水稻材料进行鉴定,再次验证了离体叶片鉴定方法的有效性。此外,初步发现对于同为鳞翅目水稻害虫稻纵卷叶螟,用离体叶片鉴定方法也可进行有效鉴定。     

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。     

水稻多抗性品种的选育研究

病虫害是造成稻米减产和不稳产的主要原因之一，国内外水稻育种家都十分重视品种对病虫的抗性，并育成了一批单抗或多抗品种在生产上应用。我们在评价水稻种质对白叶枯病抗性的基础上，进行水稻多抗性品种的选育研究，现将结果报道如下。     

中日水稻品种杂交后代的株型性状与产量和品质的关系

以东北地区最具代表性的水稻品种辽粳5号(直立穗型)与日本著名的优质米品种秋田小町(弯曲穗型)杂交后采用单粒传法构建的F9重组自交系群体(以下简称RIL群体)为试材,研究中日水稻品种杂交后代株型性状的变化规律及其与稻米产量和品质的关系,结果表明,来自中日水稻杂交的RIL群体的株型性状、产量和米质性状均发生了分离和重组。株高、倒3、4节长和剑叶基角与产量呈显著正相关。植株越高、颈穗弯曲程度越大、倒3叶越窄长的株系,稻米的加工品质和外观品质越好。食味值与绝大多数株型性状的相关性未达显著水平,仅与倒3片叶的宽、二次枝梗数、着粒密度呈极显著负相关。产量与米质的相关分析表明,产量越高,整精米率就越高,但食味越差。中日水稻品种杂交后代的株型性状与产量和米质性状密切相关。尽管产量与食味很难统一,但RIL群体中仍然有极小部分产量高食味也好的株系,它们的主要株型特征是具有较长的穗长和较长的倒1节间长。     

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.     

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 pans of the same plant.     

中抗纹枯病组合汕优63抗性利用的研究

通过对汕优６３的纹枯病抗性和田间自然发病消长动态的观察，分析研究了其发病程度与产量损失的相关性；并从汕优６３抗性利用的试验示范中，总结出利用其自身的中等抗性控制纹枯病的危害，可减少施药次数，节约成本，是一经济而有效的途径．     

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。     

对水稻纹枯病抗源的初步研究

 对引自美国的水稻纹枯病抗源进行了2 年的田间接种试验和1 年的田间性状考察。结果显示, 抗源与感病对照以及抗源间, 在抗性水平上存在极显著的差异, 且品种与年份间的互作不显著, 抗性与株型性状及生育期的相关也不显著, 表明抗性是一个真实存在的遗传性状。多数抗源在中美两地的抗性表现大体一致, 且多数引进抗源为半矮秆品种(系) 或推广品种, 具有较好的农艺性状和经济性状, 较易为育种家所利用。     

Identification of New Resistance Loci Against Sheath Blight Disease in Rice Through Genome-Wide Association Study

Sheath blight (SB) caused by the soil borne pathogen Rhizoctonia solani is one of the most serious global rice diseases. Breeding resistant cultivar is the most economical and effective strategy to control the disease. However, no rice varieties are completely resistant to SB, and only a few reliable quantitative trait loci (QTLs) linked with SB resistance have been identified to date. In this study, we conducted a genome-wide association study (GWAS) of SB resistance using 299 varieties from the rice diversity panel 1 (RDP1) that were genotyped using 44 000 high-density single nucleotide polymorphism (SNP) markers. Through artificial inoculation, we found that only 36.5% of the tested varieties displayed resistance or moderate resistance to SB. In particular, the aromatic and aus sub-populations displayed higher SB resistance than the tropical japonica (TRJ), indica and temperate japonica sub-populations. Seven varieties showed similar resistance levels to the resistant control YSBR1. GWAS identified at least 11 SNP loci significantly associated with SB resistance in the three independent trials, leading to the identification of two reliable QTLs, qSB-3 and qSB-6, on chromosomes 3 and 6. Using favorable alleles or haplotypes of significantly associated SNP loci, we estimated that both QTLs had obvious effects on reducing SB disease severity and can be used for enhancing SB resistance, especially in improving SB resistance of TRJ sub-population rice varieties. These results provided important information and genetic materials for developing SB resistant varieties through breeding.     

Improvement of Rice Resistance to Sheath Blight by Pyramiding QTLs Conditioning Disease Resistance and Tiller Angle

Rice resistance to sheath blight （SB） is controlled by polygenes or quantitative trait loci （QTLs） and affected by plant morphological traits, qSB-9^TQ and TAG1^TQ, which control SB resistance and tiller angle （TA）, respectively, were employed to test whether the combination of the two genes will further improve rice SB resistance and reduce yield loss rather than only one of them or neither. Using two pairs of near isogenic lines （NILs）, TAC1^TQ was confirmed to contribute to SB resistance. However, its effect was less considerable than that of qSB-9^TQ. Subsequently, the two genes were introduced into two commercial rice varieties to develop a series of NILs. The NILs carrying both TAG1^TQ and qSB-9^TQ showed more resistance than the NILs containing only one of them. Comparing the grain yield per plant （GYP） under the three different SB disease conditions, namely slight, moderate and severe conditions, NILs carrying both genes apparently lost lower GYP than the NILs without the two genes and the NILs carrying only TAC1^TQ. Under slight disease condition, no significant differences were found on morphology, development and GYP associated traits except for TA between the NILs carrying both genes and either of them, indicating that the two genes have no inferior effect on rice agronomic traits. Results indicated that mAC1^TQ and qSB-9^TQ have high breeding potential, and pyramiding SB resistance QTL and morphological trait QTL is a potential approach in improving rice SB resistance.     

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。