【作者】 段灿星；

【导师】 翟虎渠； 万建民；

【作者基本信息】 中国农业科学院 ， 作物遗传育种学， 2008， 博士

【摘要】 水稻灰飞虱(Laodelphax striatellus Fallén),属同翅目(Homoptera),飞虱科(Delphacide),是水稻生产上的一种重要害虫,广泛分布于我国各地。灰飞虱除直接刺吸水稻汁液造成为害外,还传播水稻条纹叶枯病和黑条矮缩病等重要病毒病。近年来,灰飞虱种群发生数量呈逐年锐增态势,并于2004年暴发成灾。伴随着灰飞虱大发生,水稻条纹叶枯病也在我国暴发与流行,给水稻生产造成了严重的损失。长期以来,对灰飞虱的防治主要依靠施用化学农药,导致灰飞虱种群抗药性不断增强,天敌杀伤严重,环境污染加剧,兼之灰飞虱具有迁飞特性,防治效果并不十分理想。利用品种抗性被认为是防治灰飞虱最为经济有效的方法之一,选育高抗灰飞虱新品种,既能有效防止灰飞虱直接取食为害,也可以阻断灰飞虱传播病毒病。本研究在参照标准苗期筛选法的基础上,对该方法进行了适当改进,建立了适用于水稻抗灰飞虱苗期集团鉴定的技术。利用改进的苗期集团筛选法,对138份来自江苏、浙江、云南等地水稻种质进行了抗灰飞虱鉴定与评价,并对其中部分种质进行了抗性特性研究;同时分析了抗虫品种DV85、高抗品种Kasalath和Mudgo对灰飞虱抗性的数量性状基因座。有关研究结果如下:1.利用改进的苗期集团鉴定法从138份水稻种质中筛选出对灰飞虱具有不同程度抗性的材料25份,占总鉴定材料的18.1%,其中高抗种质2份,抗性种质9份,中抗材料14份,粳稻品种明显比籼稻品种感虫。对部分材料进行的排驱性、抗生性试验及相关分析表明,Rathu Heenat(iRHT)、Mudgo、Kasalath和IR36对灰飞虱具有强的排驱性和抗生性,其抗性水平与这两种抗虫机制密切相关;道人桥、羊毛谷的抗生性强,但排驱性弱,其主要抗虫类型为抗生性;Dular、ASD7和Milyang 23对灰飞虱具有较强的排驱性和抗生性,表明排驱性和抗生性是这3个品种的重要抗性类型;DV85具有较强的排驱性,但抗生性较弱,窄叶青8号和鬼衣谷具有中等水平的抗生性和排驱性,推测这3个材料具有较好的耐害特性。中抗材料9311的抗性水平由中等排驱性和抗生性控制,V20A的抗性主要表现为排驱性,明恢63和扬粳9538的排驱性与抗生性均较弱,暗示其抗性机制主要是耐害性。上述具有强抗生性或排驱性的材料是理想的抗灰飞虱资源。2.籼稻品种DV85对灰飞虱表现明显的苗期抗性,运用改进的苗期集团筛选法,结合排驱性及抗生性测验,鉴定了由81个株系组成的Kinmaze ( japonica) / DV85 ( indica)重组自交系(recombinant inbred lines, RIL)群体的亲本及各株系对灰飞虱的抗性表现。利用Windows QTL Cartographer 2.5进行抗灰飞虱数量性状基因座检测和遗传效应分析。通过苗期集团筛选法,在第11染色体上检测到2个抗性QTLs,即Qsbph11a、Qsbph11b,其LOD值分别为2.51和4.38,贡献率分别为16.7%和27.8%,结合表型值,Qsbph11b应为主效QTL。通过排驱性测验,共检测到3个抗性QTLs,分别位于第3、4、11染色体上,LOD值分别为2.88、2.41和2.39,贡献率为9.17～14.9%,可解释37.5%的总表型变异。此外,在第3、11染色体上分别检测到1个抗生性相关QTL,其LOD值分别为2.79和2.33,贡献率分别为12.4%和13.5%。通过上述3种方法,均在11染色体上的XNpb202～C1172标记区间检测到1个抗性QTL,且其抗性效应均来自DV85,说明该抗性位点能够稳定表达。上述抗性QTL及其相应的连锁标记,可望在聚合多个抗性基因的分子标记辅助选择育种中加以应用。3.水稻品种Kasalath高抗灰飞虱,对灰飞虱表现出强的排驱性和抗生性。为了进一步解析该品种的抗性机理,利用Nipponbare/ Kasalath//Nipponbare回交重组自交系群体进行水稻抗灰飞虱数量性状基因座分析。通过Windows QTL Cartographer 2.5进行复合区间作图发现,在苗期集团接虫试验中,于第3、11染色体上共检测到3个抗灰飞虱QTL位点Qsbph3b、Qsbph11d、Qsbph11e,其LOD值分别为3.14、2.95和4.12,贡献率为13.8%、12.6%和23.5%。从其加性效应看出,增强抗性的基因效应分别来自于Kasalath、Nipponbare和Kasalath。通过排驱性测验,检测到3个对灰飞虱具有排驱性的QTLs(Qsbph3c、Qsbph8和Qsbph11f),分别位于第3、8、11染色体上,各QTL的LOD值分别为3.19、2.58和3.36,贡献率为10.3 %～13.6 %,可解释群体表型总变异的36.4 %。抗生性研究表明,在第2、11染色体上各存在1个抗性QTL位点Qsbph2、Qsbph11g,LOD值分别为3.23和3.52,贡献率为13.8%和14.7%,加性效应显示这2个数量性状基因座对灰飞虱的抗性均来自抗虫亲本Kasalath。通过三种不同的表型鉴定方法分别检测到的Qsbph11e、Qsbph11f和Qsbph11g,均位于第11染色体上标记S2260～G257之间,表明该位点对Kasalath的抗性表现起着重要作用。与这些数量性状基因座连锁的分子标记,可望应用于培育对灰飞虱具有持久抗性水稻新品种的育种实践中。4.Mudgo是一个高抗稻飞虱的籼稻品种,对灰飞虱具有强的排驱性和抗生性抗性。本研究利用Mudgo/武育粳3号F2群体,构建了含有177个单株的F2群体的遗传连锁图谱。该连锁图包含104个SSR标记和3个Indel标记,覆盖整个水稻基因组1409.9 cM ,每两个标记之间的平均距离为13.2 cM。采用改进的苗期集团筛选法对177个F2:3家系进行了抗性鉴定,通过Windows QTL Cartographer 2.5进行复合区间作图分析,在第2、3、12染色体上各检测到1个抗灰飞虱QTL位点Qsbph2b、Qsbph3d和Qsbph12a,分别位于标记RM5791～RM29、RM3199～RM5442和I12-17～RM333 1之间,单个LOD值分别为3.25、3.11和6.82,贡献率为15.6%～35.3%,可解释68.7%的总表型变异。其中Qsbph12a与标记RM3331和I12-17紧密连锁。加性效应表明,各QTL增强抗性的等位基因效应均来自于Mudgo。结合表型鉴定的结果,Qsbph12a应为抗灰飞虱主效QTL,与该位点紧密连锁的标记可用于进行抗灰飞虱快速选择辅助育种。更多还原

【Abstract】 The small brown planthopper (SBPH), Laodelphax striatellus Fallén (Homoptera: Delphacide), is an economically important pest in rice (Oryza sativa L.) and distributes widely in China. It not only causes direct damage by sucking plant sap but also transmits several viral diseases such as rice stripe virus (RSV) and rice black-streaked dwarf virus (RBSDV), which often cause major yield losses. In recent years, the damage caused by SBPH feeding and the diseases transmitted by this planthopper has been increasing in China and the outbreak occurred in 2004, which caused serious rice yield reduction.Protection against SBPH pest has depended mostly on insecticides in the past years, which has led to enhanced resistance of SBPH to chemicals, natural enemy death and environmental pollution and then caused the pest resurgence. Host resistance has been recognized as one of the most economic and effective measures in controlling SBPH. The varieties, highly resistant to SBPH can control this planthopper effectively as well as RSV due to prevention of transmission of virus.Based on the trait of SBPH, a seedling screening technique suitable for SBPH has been established by way of proper modification of standard seedbox screening test. 138 rice accessions, collected from Jiangsu, Zhejiang and Yunnan Province were screened for resistance to SBPH by seedbox screening test with modification. Mechanism of resistance to SBPH in some varieties was analyzed. Then, QTLs for SBPH resistance in‘DV85’,‘Kasalath’and‘Mudgo’was detected. The results were as follows:1.Out of the one hundred and thirty-eight rice accessions, twenty-five entries with different level of resistance to SBPH were detected, accounting for 18.1% of the total accessions, including 2 highly resistant, 9 resistant and 14 moderately resistant varieties. Compared with indica rice, japonica rice was more susceptible to SBPH. Antixenosis test, antibiosis test and correlation analysis were performed to elucidate resistance mechanism. The highly resistant varieties such as Rathu Heenat(iRHT), Mudgo and Kasalath and resistant IR36 expressed strong antixenosis and antibiosis against SBPH, indicating the close relationship between resistance level and these two resistance mechanisms in the four rice varieties. Antibiosis was the dominant resistance pattern in the resistant varieties Daorenqiao and Yangmaogu due to their high antibiosis but low antixenosis. Dular, ASD7 and Milyang23 had relatively strong antixenosis and antibiosis, indicating the two resistance mechanisms were significant in these three varieties. The resistant DV85 expressed relatively high level of antixenosis but low antibiosis, while Zhaiyeqing 8 and Guiyigu conferred only moderate antibiosis and antixenosis to SBPH, suggesting tolerance in these three varieties. Antibiosis and antixenosis governed the resistance to SBPH in the moderately resistant accession 9311. Antixenosis was the main resistance type in V20A. Tolerance was considered to be an important resistance mechanism in Minghui 63 and Yangjing 9538 due to their poor antibiosis and antixenosis resistance. The above accessions with strong antibiosis or antixenosis were the ideal candidate for resistance breeding.2.The indica rice‘DV85’showed resistance to SBPH at the seedling stage. A mapping population consisting of 81 recombinant inbred lines (RILs), derived from a cross between a japonica cultivar Kinmaze and an indica rice DV85, was used to detect quantitative trait loci (QTLs) for the resistance to SBPH. Modified seedling screening test (MSST), along with antixenosis test and antibiosis test were applied to evaluate the resistance response of the two parents and 81 RILs to SBPH and composite interval mapping (CIM) was used for QTL analysis. When the resistance was measured by MSST method, two QTLs conferring resistance to SBPH were mapped on chromosome 11, namely Qsbph11a and Qsbph11b, with log of odds (LOD) scores 2.51 and 4.38, respectively. The two QTLs explained 16.7% and 27.8% of the phenotypic variance in this population, respectively. A total of three QTLs controlling antixenosis against SBPH were detected on chromosomes 3, 4 and 11, respectively, accounting for 37.5% of the total phenotypic variance. Two QTLs expressing antibiosis to SBPH were mapped on chromosomes 3 and 11, respectively, explaining 25.9% of the total phenotypic variance. The identified QTL located between markers XNpb202 and C1172 on chromosome 11 was detected repeatedly by three different screening methods and therefore may be important to confer the resistance to SBPH. Once confirmed in other mapping populations, these QTLs should be useful in breeding for resistance to SBPH by marker-assisted selection of different resistance genes in rice varieties.3.An indica variety,‘Kasalath’is highly resistant to SBPH, which expresses strong antixenosis and antibiosis against SBPH. A mapping population of 98 BC1F9 lines (Backcross inbred lines: BILs), derived from a backcross of Nipponbare (japonica) / Kasalath (indica) // Nipponbare by the single-seed descent methods, was applied to detect quantitative trait loci (QTLs) for resistance to SBPH. In the modified seedbox screening test, three QTLs for SBPH resistance were mapped on chromosomes 3 and 11, namely Qsbph3c, Qsbph8 and Qsbph11f, with LOD scores 3.14, 2.95 and 4.12, explaining 13.8%, 12.6% and 23.5% of the phenotypic variance in this population, respectively. As indicated by the additive effect, resistance alleles at Qsbph3c, Qsbph8 and Qsbph11f derived from Kasalath, Nipponbare and Kasalath, respectively. In the antixenosis, a total of three QTLs(Qsbph3c, Qsbph8 and Qsbph11f)conferring antixenosis against SBPH were detected on chromosome 3, 8 and 11, with LOD scores 3.19, 2.58 and 3.36, respectively, accounting for 36.4% of the total phenotypic variance. In addition, two QTLs, Qsbph2 and Qsbph11g, which came from Kasalath, expressing antibiosis to SBPH were detected on chromosomes 2 and 11, with LOD scores 3.23 and 3.52, respectively. Individual QTL accounted for 13.8% and 14.7% of the phenotypic variance. Qsbph11e, Qsbph11f and Qsbph11g were located in the region between S2260 and G257 on chromosome 11, indicating the locus is significant in conferring resistance in Kasalath. The molecular markers linked to these QTLs should be useful in breeding of varieties with horizontal resistance to SBPH.4.The indica rice‘Mudgo’expressed high resistance to SBPH, with strong antixenosis and antibiosis against SBPH. A genetic linkage map constructed from a F2 population, derived from a cross of‘Mudgo’and‘Wuyujing 3’was used for mapping QTLs associated with resistance to SBPH. The linkage map comprised of 104 SSR and 3 Indel markers and covered 1409.9 cM of the rice genome with an average marker interval of 13.2 cM. One hundred and seventy-seven F2:3 families were identified for resistance to SBPH by way of seedbox screening test with modification. A total of three QTLs such as Qsbph2b, Qsbph3d and Qsbph12a conferring resistance to SBPH were detected on chromosome 3, 8 and 11, locating in the region of RM5791～RM29, RM3199～RM5442 and I12-17～RM3331, with LOD scores 3.19, 2.58 and 3.36, respectively, accounting for 68.7 % of the total phenotypic variance observed in this population. As showed by the additive effect, resistance alleles at Qsbph2b, Qsbph3d and Qsbph12a came from Mudgo. The locus Qsbph12a, with 35.3% of variance explained, was linked tightly to the makers RM3331 and I12-17, which were useful in breeding for resistance to SBPH by rapid marker-assisted selection.更多还原