Genetic Analysis and Preliminary Mapping of Two Recessive Resistance Genes to Brown Planthopper, Nilaparvata lugens Stl in Rice

An F2 population derived from the cross of WB01, an introgression line resistant to brown planthopper (BPH) originated from Oryza rufipogon Griff. and a susceptible indica variety 9311, was developed for genetic analysis and gene mapping. The population with 303 F2:3 families was genotyped by 141 simple sequence repeat (SSR) markers and used for gene mapping. Two softwares, Mapmaker/Exp 3.0 and Windows QTL Cartographer V2.0 were applied to detect QTLs. Totally, two QTLs resistant to BPH, named temporarily a...     

Genetic Analysis and Preliminary Mapping of Two Recessive Resistance Genes to Brown Planthopper,Nilaparvata lugens Stl in Rice

An F2 population derived from the cross of WB01, an introgression line resistant to brown planthopper (BPH) originated from Oryza rufipogon Griff. and a susceptible indica variety 9311, was developed for genetic analysis and gene mapping. The population with 303 F2:3 families was genotyped by 141 simple sequence repeat (SSR) markers and used for gene mapping. Two softwares, Mapmaker/Exp 3.0 and Windows QTL Cartographer V2.0 were applied to detect QTLs. Totally, two QTLs resistant to BPH, named temporarily a...     

Identification and Genetic Analysis of Fertility Restoration Ability in Dongxiang Wild Rice （Oryza rufipogon）

Two populations of Dongxiang wild rice (Oryza rufipogon), Shuitaoshu and Dongtangshang, were crossed with five male sterile rice lines with different cytoplasmic backgrounds (B06S, Zhenshan 97A, Xieqingzao A, Zhong 9A, and Yuetai A), and the seed setting rate of the F₁ was used to judge the fertility restoration ability in the Dongxiang wild rice. With P₁, F₁, P₂, and F₂ populations as materials, the Akaike's Information Criterion (AIC) was used to identify the major genes affecting quantitative traits, and when the major genes existed, the genetic effects of the major gene and the polygene and their genetic variance were estimated through segregation analysis. The seed setting rates of the F₁ generation varied from 45.98% to 76.57%, suggesting that the Dongxiang wild rice had the fertility restoration ability. One major gene plus polygene mixed inheritance model was the most fitted genetic model for this trait in all the F₂ populations. The heritability values of the major genes varied from 56.63% to 88.29% and those of the polygenes from 2.74% to 30.97%, and the total heritability values were from 63.17% to 94.01%. The major gene inheritance of the combination Zhong 9A/Dongtangshang was controlled by the additive effect without dominant effect, and the other nine combinations were by the completely dominant inheritance.     

Donors for Resistance to Brown Planthopper Nilaparvata lugens(St?l) from Wild Rice Species

Out of 1 989 wild accessions sown in seed boxes for screening, only 1 003 wild accessions with good germination were screened against brown planthopper(BPH), Nilaparvata lugens(St?l) under greenhouse conditions. The collection comprised of accessions from 11 wild species and African cultivated rice. The germplasm was screened for BPH following standard seed box screening technique in the greenhouse. As many as 159 accessions were identified as resistant during the year 2012 based on one year screening. A selected set of BPH resistant accessions were screened again during 2013. Based on the two years screening, seven accessions of O. nivara(AA), one accession of O. officinalis(CC), seven accessions of O. australiensis(EE), five accessions of O. punctata(BB and BBCC) and nine accessions of O. latifolia(CCDD) were confirmed to be resistant to BPH. So far no BPH resistance genes have been identified and designated from O. nivara and O. punctata, hence these may act as new sources of resistance.     

Preliminary Study on Resistance of the Rice Stem Borer （Chilo Suppressalis） to Fipronil

By means of topical application, fipronil resistance was surveyed in the rice stem borer, Chilo suppressalis, from 12 diferent areas in east China from 2001 to 2004. The rice stem borers in most regions of Jiangsu and Anhui were still susceptible to fipronil. But in Wuxi, Jiangsu Province and Cixi, Zhejiang Province, their sensitivity became decreased （resistance ratios were 3.1 and 3.6, respectively）, and the medium level of resistance （resistance ratio was 21.2） was found in Cangnan, Zhejiang Province. So, it was still at the early stage for fipronil resistance development in this pest. Synergism experiments showed that piperonyl butoxide（PBO） had a little effect on both susceptible and resistant borers （synergism ratios were 1.1-1.2）. Though triphenyl phosphate （TPP） and diethyl meleate （DEM） had no effect on the susceptible borers, they had significant synergism on fipronil in the resistant population to fipronil （synergism ratios were 1.8 and 1.6, respectively）, indicating esterase and glutathion S-transferase may be involved in the resistance mechanism. Bioassay with currently used insecticides indicated that triazophos （because of high resistance）, trichlorphon and acephate had very low toxicity to resistant borers. But diazinon, pyridaphenthion, decamethrin and avermeatin showed high toxicity and had no cross resistance to fipronil, which could be considered as substitute insecticides in the resistance managment.     

Optimization of Electroporation Parameters for Immature Embryos of indica Rice （ Oryza sativa）

To obtain a suitable condition for electroporation transformation in indica rice, the 10-day-old immature embryos were selected for optimization experiments. The results showed that one pulse at 850 V/cm, 950 μF capacitance, 200 μL electroporation buffer with 70 mmol/L sodium glutamate, 100 μg/mL plasmid, 50 μg/mL carrier DNA, 20 embryos per cuvette, 0°C treatment and CC medium were the best parameters, which not only improved the transformation efficiency to 30.89%, but also ameliorated the embryo survival ratio to 95.92%. To further verify the practicability of this condition, the embryos from another indica rice variety and a rice type II metallothionein-like gene (OsMT2bL) promoter::mgfp5::gusA construct were tested, and specific GUS expression on the embryos was visualized by histochemical staining. The results showed that the GUS expression on the embryos activated by the OsMT2bL promoter was mainly concentrated on the apical point of the plumule whereas the expression driven by CaMV35S promoter was distributed on nearly all areas of the electroporated tissues. These results indicated that the optimized embryo electroporation conditions could be used not only in genetic transformation of indica rice but also in assay of gene regulation on embryos.     

Bacterial Community in Different Populations of Rice Brown Planthopper Nilaparvata lugens （St~l）

The structures of bacterial communities in the brown planthopper （BPH） Nilaparvata lugens （St~l） from different geographic and resistant virulent populations were analyzed by using denatured gradient gel electrophoresis （DGGE）. Results showed that the bacterial communities in BPH nymph from the first to the fifth instars varied with nymphal growth and development. The bacterial communities in the first-instar BPH nymph were similar to those in adults. Nine geographic BPH populations were divided into three groups based on the cluster analysis of DGGE fingerprint. The first group was from the Philippines; the second group was from Thailand and Hainan, Yunnan and Zhejiang provinces of China; and the third group was from Vietnam and Guangxi, Hunan and Jiangxi provinces of China. BPH populations adapted to different resistant rice varieties. The BPH populations from Mudgo （with resistant gene Bphl） and ASD7 （with resistant gene bph2） differed with those of the susceptible rice variety TNI.     

Differential Expression of Whitebacked Planthopper Resistance in the japonicaJindica Doubled Haploid Rice Population under Field Evaluation and Seedbox Screening Test

Whitebacked planthopper (WBPH) -resistance in a japonica / indica doubled haploid (DH) rice population established from a cross between WBPH-resistant japonica Chunjiang 06 and susceptible indica TN1, was comparatively evaluated through a field experiment based on the WBPH immigrant density and standardized seedbox screening test (SSST). All the susceptible DH lines in the field experiment behaved accordingly in SSST. However, 35 of resistant 66 lines (53%) in the field, were categorized to susceptible groups in SSST. Likewise, there were no significant differences in WBPH immigrant densities among 70 DH lines that were highly resistant to susceptible in SSST. The results revealed that SSST could not evaluate properly WBPH resistance in the DH lines. Four QTLs for WBPH-resistance phenotyped by the immigrant density were detected on chromosomes 2, 3, 4, and 11. Of them, the QTL on chromosome 4 was the most effective (LOD 21.8, variance 78%). Five QTLs associated with seedling mortality were mapped on chromosomes 2, 3, 4, 5 and 6. In addition to the QTL (LOD 10.5, variance 68%) on chromosome 4, there was another major QTL (LOD 12.7, variance 71%) located on chromosome 5, which was SSST-specific but might be irrespective of the WBPH resistance traits.     

Tagging of Brown Planthopper Resistance Genes in F2s of IR50 × Ptb33 of Rice by Using Bulked Segregant Analysis

Brown planthopper(Nilaparvata lugens St?l) is one of the most damaging pests causing hopper burn in rice,and thereby reducing the productivity and also the quality of the product.The effective management strategy to control this pest is the identification and transfer of desirable genes to local rice cultivars.The most important approach for developing resistant cultivars is the identification of markers,which can help in marker-assisted selection of more durable resistant genotype.The susceptible parent IR50 and the resistant parent Ptb33,and their F2 populations were used in bulked segregant analysis for identification of resistant genes with random amplified polymorphic DNA marker(RAPD) primers.The primers OPC7 and OPAG14 showed both dominant and susceptible specific banding pattern so called co-dominant markers.Moreover,OPC7697 and OPAG14680 showed resistant specific bands and thus being in coupling phase,whereas OPC7846 and OPAG14650 showed susceptible specific genotypic bands in bulked segregant analysis.Therefore,the coupling phase markers,OPC7697 and OPAG14680,are considered to be more useful in marker-assisted selection of rice genotypes in crop improvement.     

Analysis of QTLs for Flag Leaf Shape and Its Response to Elevated CO2 in Rice （Oryza sativa）

To understand the responses of flag leaf shape in rice to elevated CO2 environment and their genetic characteristics,quantitative trait loci(QTLs)for flag leaf shape in rice were mapped onto the molecular marker linkage map of chromosome segment substitution lines(CSSLs)derived from a cross between a japonica variety Asominori and an indica variety IR24 under free air carbon dioxide enrichment(FACE,200μmol/mol above current levels)and current CO2 concentration(Ambient,about 370μmol/mol).Three flag-leaf traits,flag-leaf length(LL),width(LW)and the ratio of LL to LW (RLW),were estimated for each CSSL and their parental varieties.The differences in LL,LW and RLW between parents and in LL and LW within IR24 between FACE and Ambient were significant at 1%level.The continuous distributions and transgressive segregations of LL,LW and RLW were also observed in CSSL population,showing that the three traits were quantitatively inherited under both FACE and Ambient.A total of 16 QTLs for the three traits were detected on chromosomes 1,2,3,4,6,8 and 11 with LOD(Log10-likelihood ratio)scores ranging from 3.0 to 6.7.Among them,four QTLs (qLL-6*,qLL-8*,qLW-4*,and qRLW-6*)were commonly detected under both FACE and Ambient.Therefore,based on the different responses to elevated CO2 in comparison with current CO2 level,it can be suggested that the expressions of several QTLs associated with flag-leaf shape in rice could be induced by the high CO2 level.     

Evaluation of Rice Germplasm for Resistance to the Small Brown Planthopper(Laodelphax striatellus)and Analysis of Resistance Mechanism

One hundred and thirty-eight rice accessions were screened for resistance to the small brown planthopper(SBPH)resistance to SBPH were detected,accounting for 18.1%of the total accessions,which included 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 the resistance mechanism.The resistant check Rathu Heenati(RHT),highly resistant varieties Mudgo and Kasalath,and resistant variety 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 Milyang 23 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,whereas 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 materials for the resistance breeding.     

水稻种质资源抗灰飞虱评价及抗性机制分析

通过改进的苗期集团筛选法,对138份水稻种质进行了抗灰飞虱鉴定与评价。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 Heenati(RHT)、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,其主要抗虫机制表现为抗生性;Dular、ASD7和密阳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的排驱性和抗生性均较弱,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。     

不同植物上灰飞虱适合度的研究

 通过室内笼罩饲养法观察了水稻、玉米、高粱、稗草等57种植物上灰飞虱Laodelphax striatellus（Fallén）的生长发育繁殖情况。不同供试植物上灰飞虱羽化率、若虫历期、初羽化成虫体质量、成虫寿命和产卵量等参数均存在不同程度的差异。结合主成分分析和种群趋势指数分析,发现57种供试植物中,适宜灰飞虱生存的寄主植物有稗草等5种,这些植物上灰飞虱羽化率介于59.4%~86.9%,种群趋势指数在27.8以上;较适宜灰飞虱生存的寄主植物有黑麦草等9种,灰飞虱羽化率在27.0%~64.5%,种群趋势指数多在10以上;较不适宜灰飞虱生存的寄主植物有牛筋草等5种,羽化率介于130%~35.6%,种群趋势指数为1~10;不适宜灰飞虱生存的植物有无芒雀麦等13种,羽化率在10%以下,种群趋势指数在1以下;玉米等25种植物上灰飞虱若虫不能羽化为成虫。其中,黑麦草、棒头草、菵草、白顶早熟禾、野燕麦和荠菜等为新证实的寄主植物。     

灰飞虱从冷冻病叶获得水稻黑条矮缩病毒方法的研究初报

  研究出一种利用灰飞虱从冷冻病叶中获得水稻黑条矮缩病毒（rice black streaked dwarf virus, RBSDV）的方法。以-70℃条件下冷冻保存的RBSDV罹病植株叶片对灰飞虱饲毒,随后接种感病水稻品种,结果发现灰飞虱可从冷冻病叶上获得RBSDV,并传播RBSDV,且获毒能力和传毒能力与新鲜病叶没有差异。这表明从冷冻病叶上获得RBSDV的灰飞虱可以应用于品种抗性鉴定,此法可望加快RBSDV抗病品种的选育进程。     

籼型杂交水稻抗褐飞虱育种研究

 对80份籼型杂交水稻恢复系的抗褐飞虱特性鉴定表明,30份材料对褐飞虱抗性达中抗以上水平,其中12份材料的持抗性优于ASD7。将这12份材料的抗级为0～3级、持抗期≥7 d的优质抗性材料归为一级抗性材料。经杂种优势的测定、外观米质评价、白叶枯病和稻瘟病抗性鉴定,筛选出对两病一虫达中抗水平,与协青早A的杂种产量比对照汕优10号增产12.9%的杂交水稻新恢复系埃红/台1059;以及高抗褐飞虱、高抗稻瘟病、中抗白叶枯病且外观米质极好的恢复系LS2/密阳46。     

广东普通野生稻种质资源对白背飞虱的抗性鉴定

1987～1990年对1537份广东普通野生稻(Oryza sativa L.f.spontanea Roschev.)进行了筛选鉴定。供试虫源采自本院稻田,经扩大繁殖备用。供试样本由广东省农科院水稻研究所野生稻组提供。抗性对照品种为IR13475-7-3-2,以广陆矮4号为敏感对照品种。采用套袋防止异交的方法采集种子;用苗期群体接虫进行初筛;筛出50份抗性材料,剔除敏感植株后移植,分蘖期分丛笼罩接入高龄若虫作生存率测定,作为重复鉴定;评出9份相对生存率40%左右的材料,从中选取生存率最低的单株进行繁殖,再作害虫群体增长、泌露面积测定。初筛不设重复,其余测定为三次重复。     

水稻抗性蛋白OsRRK1抗褐飞虱机理分析

目的 OsRRK1（Rop-interacting receptor-like kinase 1）蛋白是水稻中第一个被研究的类胞质受体激酶RLCKⅥ家族蛋白。在调控水稻叶片的卷曲和对褐飞虱的防御中都起着重要作用,但是其调控机理尚不清楚。本研究试图进一步探究OsRRK1基因抗褐飞虱的机理。方法 利用酵母双杂交的方法分析OsRRK1蛋白与OsLecRK（lectin-like receptor kinase）、OsLecRK1、OsLecRK2、OsLecRK3的互作关系,OsLecRK是抗褐飞虱基因BPH15区间的候选基因,是水稻先天免疫系统中一个重要成员,既参与水稻先天免疫反应,包括对褐飞虱、白叶枯病和稻瘟病的抗性,又参与水稻的发育过程。OsLecRK1、OsLecRK2、OsLecRK3的基因簇组成抗褐飞虱基因BPH3,含BPH3基因的水稻具有广谱、持久的抗虫性。同时利用DNAMAN软件分析OsLecRK蛋白与OsLecRK1、OsLecRK2、OsLecRK3的同源性。结果 DNAMAN的分析结果显示OsLecRK与OsLecRK1、OsLecRK2、OsLecRK3的同源性都很高,蛋白一致性在50%以上;酵母双杂交结果显示OsRRK1与OsLecRK、OsLecRK2和OsLecRK3互作。结论 OsRRK1通过与抗褐飞虱基因BPH15和BPH3候选基因的相互作用参与水稻抗褐飞虱过程。     

Mechanism Analysis of Rice Resistance Protein OsRRK1 Against the Brown Planthopper

【Objective】 OsRRK1 (Rop-interacting receptor-like kinase 1) protein in rice is the first RLCK VI family protein in rice that has been studied. It plays an important role in regulating the curling of rice leaves and the defense against brown planthoppers. However, the mechanism of its regulation of resistance to the brown planthopper remains unclear. We attempt to further explore the mechanism of OsRRK1 gene resistance to the brown planthoppers. 【Method】The interaction between OsRRK1 protein and OsLecRK (lectin-like receptor kinase), OsLecRK1, OsLecRK2 and OsLecRK3 was analyzed by yeast two-hybrid method. OsLecRK is a candidate gene for BPH15 range of anti-brown planthopper, and is an important member of rice innate immune system. OsLecRK is involved in not only rice innate immune response, including resistance to brown planthoppers, white leaf blight and rice blast, but also the development of rice. The gene clusters of OsLecRK1, OsLecRK2 and OsLecRK3 constitute the anti-brown planthopper gene BPH3. Rice containing the BPH3 gene has a broad spectrum and lasting insect resistance. Meanwhile, DNAMAN software was used to analyze the homology of OsLecRK with OsLecRK1, OsLecRK2 and OsLecRK3. 【Result】The analysis results of DNAMAN showed that OsLecRK has high homology with OsLecRK1, OsLecRK2 and OsLecRK3, and the proteins shared more than 50% identity. The results of yeast two-hybrid analysis showed that OsRRK1 interacted with OsLecRK, OsLecRK2 and OsLecRK3.【Conclusion】OsRRK1 participates in the process of resistance to the brown planthoppers through interacting with BPH15 and BPH3 candidate genes.     

浅析褐飞虱对吡蚜酮的抗药性及其对策

褐飞虱是一种水稻生产上危害较严重的害虫。吡蚜酮作为防治稻飞虱的首选长效药剂,使用频繁。为此,笔者结合平湖当地近年来相关田间试验和防治实践,分析了褐飞虱对吡蚜酮较快产生抗药性的原因,并从抗性治理角度提出加强抗性监测、调整防治策略、筛选新药剂、合理轮换和混用,以及推进病虫统防统治等对策建议。     

水稻品种RP1976-18-6-4-2对褐飞虱和稻瘿蚊的抗性评价及其遗传分析

对水稻品种RP1976-18-6-4-2进行褐飞虱和稻瘿蚊的抗性评价及其遗传分析。结果表明,该品种抗褐飞虱生物型Ⅱ、孟加拉型及稻瘿蚊中国Ⅱ型和中国Ⅳ型,它对褐飞虱生物型Ⅱ和孟加拉型的抗性由1对显性基因和1对隐性基因控制;对稻瘿蚊中国Ⅱ型和中国Ⅳ型的抗性由1对显性基因控制。