Genetic Analysis and Molecular Mapping of Two SMV-Resistance Traits in Soybean:Adult-Plant Resistance and Resistance to Seed Coat Mottling

Soybean mosaic virus(SMV) could lead to adult-plant system diseases,and cause mottling of soybean seeds.Genetic analysis and molecular mapping were conducted using an F2 population and derived F3 families from two crosses of Dongnong 3C624(susceptible) × Dongnong 8143(resistant) and Dongnong 3C628(susceptible) × Tie 6915(resistant).Simple sequence repeat(SSR) markers with bulked segregation analysis(BSA) were used to conduct genetic mapping of the resistance to SMV1 in the segregating populations.The results indicated that resistance to SMV1 in adultplants and the resistance to seed coat mottling in Dongnong 8143 and Tie 6915 was separately controlled by one single dominant gene.The two dominant genes were identified to be linked on the MLG F by Mendel's genetics and SSR genetic mapping.The order and distance of markers DPRSMV1 and DSRSMV1 were Sat_229-6.9 cM-DSRSMV1-4.6 cM-Sat_317-3.6 cM-DPRSMV1-5.2 cM-Satt335.The order and distance of markers TPRSMV1 and TSRSMV1 was Satt160-16.1 cM-TPRSMV1-7.3 cM-Satt516-2.0 cM-TSRSMV1-4.5 cM-Sat_133.This research provides the useful information for breeders to select the two types of SMV resistance simultaneously in soybean breeding through molecular marker-assisted selection(MAS).     

Fine Mapping and Candidate Gene Analysis of Resistance Gene RSC3Q to Soybean mosaic virus in Qihuang 1

Soybean mosaic virus （SMV） disease is one of the most destructive viral diseases in soybean （Glycine max （L.） Merr.）. SMV strain SC3 is the major prevalent strain in huang-huai and Yangtze valleys, China. The soybean cultivar Qihuang 1 is of a rich resistance spectrum and has a wide range of application in breeding programs in China. In this study, F1, F2 and F2：3 from Qihuang 1×nannong 1138-2 were used to study inheritance and linkage mapping of the SC3 resistance gene in Qihuang 1. The secondary F2 population and near isogenic lines （nILs） derived from residual heterozygous lines （RhLs） of Qihuang 1×nannong 1138-2 were separatively used in the ifne mapping and candidate gene analysis of the resistance gene. Results indicated that a single dominant gene （designated RSC3Q） controls resistance, which was located on chromosome 13. Two genomic-simple sequence repeat （SSR） markers BARCSOYSSR_13_1114 and BARCSOYSSR_13_1136 were found lfanking the two sides of the RSC3Q. The interval between the two markers was 651 kb. Quantitative real-time PCR analysis of the candidate genes showed that ifve genes （Glyma13g25730, 25750, 25950, 25970 and 26000） were likely involved in soybean SMV resistance. These results would have utility in cloning of RSC3Q resistance candidate gene and marker-assisted selection （MaS） in resistance breeding to SMV.     

Identiifcation and Molecular Mapping of the RsDmR Locus Conferring Resistance to Downy Mildew at Seedling Stage in Radish （Raphanus sativus L.）

Downy mildew （DM）, caused by the fungus Peronospora parasitica, is a destructive disease of radish （Raphanus sativus L.） worldwide. Host resistance has been considered as an attractive and environmentally friendly approach to control the disease. However, the genetic mechanisms of resistance in radish to the pathogen remain unknown. To determine the inheritance of resistance to DM, F1, F2 and BC1F1 populations derived from reciprocal crosses between a resistant line NAU-dhp08 and a susceptible line NAU-qtbjq-06 were evaluated for their responses to DM at seedling stage. All F1 hybrid plants showed high resistance to DM and maternal effect was not detected. The segregation for resistant to susceptible individuals statistically iftted a 3：1 ratio in two F2 populations （F2（SR） and F2（RS））, and 1：1 ratio in two BC1F1 populations, indicating that resistance to DM at seedling stage in radish was controlled by a single dominant locus designated as RsDmR. A total of 1 972 primer pairs （1 036 SRAP, 628 RAPD, 126 RGA, 110 EST-SSR and 72 ISSR） were screened, and 36 were polymorphic between the resistant and susceptible bulks, and consequently used for genotyping individuals in the F2 population. Three markers （Em9/ga24370, NAUISSR826700 and Me7/em10400） linked to the RsDmR locus within a 10.0 cM distance were identiifed using bulked segregant analysis （BSA）. The SRAP marker Em9/ga24370 was the most tightly linked one with a distance of 2.3 cM to RsDmR. These markers tightly linked to the RsDmR locus would facilitate marker-assisted selection and resistance gene pyramiding in radish breeding programs.     

Resistance to the Whitefly Aleurotrachelus socialis（Hemiptera：Aleyrodidae） and SSR Marker Identification in Advanced Populations of the Hybrid Manihot esculenta subsp.Manihot flabellifolia

Genes resistant to Aleurotrachelus socialis were transferred to the F 1 from the interspecific hybrid wild species of Manihot flabellifolia to M.esculenta and two advanced generations of backcrosses（BC 1 and BC 2）.We characterized the resistance of A.socialis transferred to BC 2 parents（CW67-160,CW67-130,CW67-44）,MTAI-8（BC 1）,resistant（CMB9B-73） and susceptible（CMB9B-104） genotypes from contrasting pools,and resistant（MEcu-72） and susceptible（CMC-40） genotypes.Whitefly demography and biology were evaluated.SSR molecular markers associated with a phenotypic response of plant resistance were detected in segregating populations（BC 2）.Results showed that although female survival time was similar on all hosts,the lowest averages of longevity,fecundity and oviposition rate were observed in the resistant control MEcu- 72,only being significantly similar to the parent CW67-130.When the BC 1 and BC 2 populations were compared,it was found that A.socialis fecundity was eight times lower on CMB9B-73 progeny than on CW67-130,expressing the highest levels of resistance to the whitefly.Ten genotypes of CMB9A and CMB9B family had the best segregation.A total of 486 microsatellite primers were evaluated using bulked segregant analysis（BSA）,11 showed polymorphism between the contrasting pools and only one showed significant differences between resistant and susceptible individuals.In conclusion,fecundity was the parameter that impacted most on the intrinsic rate of A.socialis population growth.     

Inheritance Analysis and Identification of SSR Markers Linked to Late Blight Resistant Gene in Tomato

Late blight caused by Phytophthora infestans is the most serious disease of tomato production in China. Studies on the genetics of resistance and identification of molecular markers are very useful for breeding late blight resistant varieties. The objective of this paper was to study the inheritance of late blight resistance and identify simple sequence repeat （SSR） markers associated with resistance allele in tomato （Lycopersicon esculentum Mill）. The results came from an F2 progeny of 241 plants derived from a cross between 5~ inbred line that is susceptible to late blight and a resistant accession CLN2037E. The late blight responses of F2 plants were tested by artificially inoculation of detached-leaflets in plate and natural infection assayed under greenhouse conditions. Both methods showed that the resistance is dominant and inherited as monogenic trait. Genetic mapping and linkage analysis showed that the late blight resistance gene Ph-ROL was located on chromosome 9 with a genetic distance of 5.7 cM to the SSR marker TOM236.     

Development of SRAP Markers Linked to a Gene for Stem Nematode Resistance in Sweetpotato, Ipomoea batatas (L.) Lam.

Sequence-related amplification polymorphism (SRAP) markers closely linked to stem nematode resistance gene were developed in sweetpotato, Ipomoea batatas (L.) Lam. Using bulked segregant analysis (BSA), 200 SRAP primer combinations were screened with the resistant and susceptible bulked DNA from the 196 progenies of an F1 single-cross population of resistant parent Xu 781×susceptible parent Xushu 18, 77 of them showed polymorphic bands between resistant and susceptible DNA. Primer combinations detecting polymorphism between the two bulks were used to screen both parents and 10 individuals from each of the bulks. The results showed that primer combination A9B4 produced 3 specific bands in the resistant plants but not in the susceptible plants, suggesting that the markers, named Nsp1, Nsp2 and Nsp3, respectively, linked to a gene for stem nematode resistance. Primer combination A3B6 also produced a SRAP marker named Nsp4 linking to the resistance gene. Amplified analysis of the 196 F1 individuals indicated that the genetic distance between these markers and the resistance gene was 4.7, 4.7, 6.3, and 9.6 cM, respectively.     

Molecular Mapping of a Gene for Resistance to Stripe Rust in Wheat Variety PIW138

Stripe rust, caused by Puccinia striiformis f. sp. tritici （Pst）, is one of the most damaging diseases of common wheat （Triticum aestivum L.）. Wheat variety PIW138 introduced from Pakistan is resistant to the currently prevailing Pst race CYR32 in China. In this study, the bulked segregant analysis （BSA） method and simple sequence repeat （SSR） markers were used to map the stripe rust resistance gene in PIW138. The resistant and susceptible DNA bulks were prepared from the segregating F2 population of the cross between Thatcher, a susceptible variety as the female parent, and PIW138 as the male parent. The segregation of resistant and susceptible F2 plants inoculated with CYR32 indicated that single dominant gene determined the reactions of PIW138 line and temporarily designated as YrP138. Total 200 SSR primers were screened, and 4 SSR markers, Xwmc52, Xbarc61, Xgwm268, and Xgwm153, on chromosome 1B were found to be polymorphic between the resistant and the susceptible DNA bulks as well as their parents. Genetic linkage was tested on the segregating F2 population with 259 plants, including 196 resistant and 63 susceptible plants. All 4 SSR markers were linked to the stripe rust resistance gene in PIW138. The genetic distances of Xwmc52, Xbarc61, Xgwm268, and Xgwm153 to the resistance gene were 29.8, 6.2, 6.8, and 8.2 cM, respectively.     

Quantitative Trait Loci for Resistance Against Fusarium Wilt Based on Three Cotton F2 Populations

Fusarium wilt （FW） is one of the most common cotton diseases in the world. Identification of QTLs conferring resistance to FW is key for the incorporation of resistance genes into elite cultivars. Two intraspecific （cross between Gossypium hirsuturn L.） and one interspecific （cross between Gossypium hirsutum L. and Gossypium bardence L.） F2 populations were constructed by using a highly resistant cultivar and crossing it to a susceptible cultivar with 154, 79, and 148 offsprings, respectively. Simple sequence repeats （SSR） were used to screen genomic regions closely linked to FW resistance. The results showed that five QTLs associated with FW resistance were detected in two intraspecific populations using a composite interval mapping method under four different conditions. Four of these loci located on Chr. 2/Chr. 17 neighboring markers JESPR304 or CIR305 which explained 13.1 to 45.9% of the phenotypic effect. Furthermore, JESPR304 and CIR305 were previously testified and found to be tightly linked. It is possible that these four QTLs detected under different conditions were the same resistance QTL/gene. We consider that there is the possibility of a major FW resistant gene in intraspecific populations. In the interspecific mapping populations two QTLs were detected on Chr. 9 and Chr. 12/26 which explained great phenotypic variance of 49.4 and 45.7%. As the location of QTLs for FW resistance among the intraspecific and the interspecfic populations were totally different, it is suggested that there may be different resistance mechanisms between G. bardence L. and G. hursutum L. Thus, the present research provides an opportunity to understand the genetic control of resistance to FW in Gossypium hirsutum and Gossypium bardence and to conduct MAS in breeding programs to develop FW resistant cultivars.     

Marker-assisted pyramiding of soybean resistance genes R_(SC4),R_(SC8),and R_(SC14Q) to soybean mosaic virus

Soybean mosaic virus(SMV)is one of the major viral pathogens affecting soybean crops worldwide.Three SMV resistance genes,R_(SC4),R_(SC8),and R_(SC14Q),have been identified and mapped on soybean chromosomes 14,2,and 13 from Dabaima,Kefeng 1,and Qihuang 1 cultivars,respectively.Soybean cultivar Nannong 1138-2 is widely grown in the Yangtze River Valley of China.In this study,crosses were made between Qihuang 1×Kefeng 1 and Dabaima×Nannong 1138-2.Ten simple sequence repeat(SSR)markers linked to three resistance loci(R_(SC4),R_(SC8),and R_(SC14Q))were used to assist pyramided breeding.Pyramided families containing three resistance loci(R_(SC4),R_(SC8),and R_(SC14Q))were evaluated by inoculating them with 21 SMV strains from China.Results indicated that the 10 markers can be used effectively to assist the selection of resistant individuals containing R_(SC4),R_(SC8),and R_(SC14Q).A total of 53 F_6 plants were confirmed to contain three homozygous alleles conferring resistance to SMV.Five F_7 homozygous pyramided families exhibited resistance to 21 strains of SMV and showed desirable agronomic traits using dual selection.The strategy of pyramiding resistance gene derived from different varieties has practical breeding value in providing broad-spectrum resistance against the existing strains of SMV in China.     

大豆品种接种SMV叶片POD同工酶的研究

研究采用成株感 SMV1号、 3号株系大豆品种合丰 2 5、丰收 12 ,抗 SMV1号而感 SMV3号株系品种东农 81- 4 3、铁 6 915(东农 ) ,抗 SMV1号、 3号株系品种东农 93- 0 4 6、东农 92 - 0 70 ,在隔离网室内采用盆载试验 ,于对生真叶期采用人工汁液摩擦法分别接种 SMV1号、3号株系 ,以未接种健株为对照 ,在大豆鼓粒初期测定分析叶片 POD同工酶。结果表明 ,抗感品种未接种健株叶片 POD同工酶谱带没有明显差异 ,POD活性品种间略有差别 ,但 POD活性与抗性没有相关。分别接种 SMV二个株系后 ,各品种 POD同工酶谱带数目不变 ,一些酶带活性发生变化。合丰 2 5、丰收 12接种 SMV后 ,叶片 POD同工酶活性增强 ,且接种 3号株系增加得大。说明 SMV毒性越强 ,植株感病越严重 ,POD活性变化越大。因此 ,叶片 POD活性的增强是植株感病的生化症状。东农 81- 4 3、铁 6 915接种 SMV1号株系后 ,叶片 POD同工酶和活性没有明显变化 ,接种 SMV3号株系后 ,叶片 POD同工酶活性增强。说明同一品种对二个株系的抗性不同 ,POD的变化也不同。东农 93- 0 4 6和东农 92 - 0 70接种二个株系后 ,POD同工酶没有明显变化 ,接种 SMV3号株系后 ,POD活性略降低     

Inheritance of Resistance to SMV3 and Identification of RAPD Marker Linked to the Resistant Gene in Soybean

One SMV resistant soybean line (95-5383) was crossed with four susceptible soybean varieties/line ( HB1, Tiefeng21, Amsoy, Williams) and one resistant introduced line PI486355. Their F1 and F2individuals were identified for SMV resistance by inoculation with SMV3. The results showed that in the four crosses of resistant × susceptible, F1 were susceptible and the ratio of F2 populations was 1 resistant : 3susceptible (mosaic and necrosis), indicating that 95-5383 carries one recessive gene that confer resistance to SMV3. There is segregation of susceptibility in F2 progenies from the cross of 95-5383 × PI486355, indicating that the SMV3 resistant gene in 95-5383 is located at different locus from PI486355. By bulked segregating analysis (BSA) in F2 populations of 95-5383 × HB1, one codominant RAPD marker OPN11980/1070 closely linked to SMV3 resistance gene amplified with RAPD primer OPN11 was identified. The DNA fragment OPN11980 was amplified in resistant parent 95-5383 and resistant bulk, and OPN111070 was amplified in susceptible parent HB1 and susceptible bulk. OPN11980/1070 was amplified in F1. Identification of the markers in F2 plants showed that the codominant marker OPN11980/1070 is closely linked to the SMV resistance locus in95-5383, with genetic distance of 2.1cM.     

大豆对SMV株系SC10的抗性遗传及抗病基因的定位研究

【目的】明确大豆对SMV株系SC10的抗性遗传方式以及不同抗源所携带的抗病基因间的等位关系,并对科丰1号所携带的抗SC10基因进行标记定位。【方法】利用抗中国南方大豆产区流行株系SC10的科丰1号、晋大74、大白麻、汾豆56、中作229、徐豆1号、邳县茶豆、Kwanggyo、跃进4号配制部分抗抗杂交组合并与感病品种南农1138-2和8101配制抗感组合,在接种SC10的条件下,调查各组合后代的抗感反应;并利用科丰1号×南农1138-2的F2群体和分离群体分组分析法（BSA）及SSR标记对抗病基因进行标记定位。【结果】科丰1号、晋大74、大白麻、汾豆56、中作229和徐豆1号与感病品种杂交的F1表现抗病,F2呈3抗﹕1感分离比例,F2:3家系呈1抗﹕2分离﹕1感病的分离比率;晋大74×汾豆56、徐豆1号×邳县茶豆的F1表现抗病、F2未发现感病株。科丰1号×Kwanggyo、汾豆56、中作229,晋大74×中作229、Kwanggyo,大白麻×汾豆56、科丰1号和跃进4号×Kwanggyo的F1表现抗病,F2呈15抗﹕1感的分离比例,F2:3家系符合7抗﹕4分离（15抗﹕1感）﹕4分离（3抗﹕1感）﹕1感的分离比例;D1b连锁群上的SSR标记Satt558、Sat_254、Satt634、Gm020580、Gm020584、Gm020562和Gm020546与抗病基因RSC10连锁,遗传距离分别为6.1、2.0、0.9、0.8、2.0、4.6和9.2 cM。【结论】科丰1号、晋大74、大白麻、徐豆1号、汾豆56、中作229各有一个显性基因控制对SC10株系的抗性;晋大74与汾豆56,徐豆1号与邳县茶豆的抗病基因是等位的或紧密连锁的;科丰1号与Kwanggyo、汾豆56、中作229携带的抗SC10株系的基因处于不同位点,晋大74与中作229、Kwanggyo携带的抗SC10株系的基因处于不同位点,大白麻与汾豆56、科丰1号携带的抗SC10株系的基因处于不同位点,跃进4号与Kwanggyo携带的抗SC10株系的基因处于不同位点;科丰1号对SC10株系的抗病基因RSC10位于D1b连锁群。     

Identification, Genetic Analysis and Mapping of Resistance to Phytophthora sojae of Pm28 in Soybean

Phytophthora sojae Kanfman and Gerdemann (P.sojae) is one of the most prevalent pathogens and causes Phytophthora root rot,which limits soybean production worldwide.Development of resistant cultivars is a cost-effective approach to controlling this disease.In this study,127 soybean germplasm were evaluated for their responses to Phytophthora sojae strain Pm28 using the hypocotyl inoculation technique,and 49 were found resistant to the strain.The hypocotyl of P1,P2,F1,and F2:3 of two crosses of Ludou 4 (resistant)×Youchu 4 (susceptible) and Cangdou 5 (resistant)×Williams (susceptible) were inoculated with Pm28,and were used to analyze the inheritance of resistance.The population derived from the cross of Ludou 4×Youchu 4 was used to map the resistance gene (designated as Rps9) to a linkage group.932 pairs of SSR primers were used to detect polymorphism,and seven SSR markers were mapped near the resistance gene.The results showed that the resistance to Pm28 in Ludou 4 and Cangdou 5 was controlled by a single dominant gene Rps9,which was located on the molecular linkage group N between the SSR markers Satt631 (7.5 cM) and Sat_186 (4.3 cM).     

小麦品系西农1163-4抗叶锈病基因的遗传分析和分子作图

【目的】小麦品系西农1163-4高抗小麦叶锈、条锈和白粉病,综合农艺性状良好。明确该小麦品系中所含的抗叶锈病基因及遗传特点,找到与其紧密连锁的分子标记,有利于抗病基因利用和培育抗病新品种。【方法】将西农1163-4与感病品种Thatcher杂交,获得F1、F2代群体,利用中国叶锈菌优势小种THTT进行苗期抗性鉴定和抗性遗传分析;采用SSR技术对西农1163-4所携带的抗叶锈基因进行分子标记研究,共筛选了1 273对SSR引物。【结果】小麦品系西农1163-4对多个叶锈菌小种具有良好的抗病性,对THTT的抗性是由1个显性基因控制,该基因暂命名为LrXi。获得了与LrXi紧密连锁的3个微卫星分子标记Xbarc8、Xgwm582、Xwmc269和1个STS标记(ω-secali/Glu-B3),将LrXi定位于小麦1BL染色体上。距离最近的2个微卫星位点是Xgwm582、Xbarc8,与抗叶锈基因间的遗传距离分别为2.3 cM和3.2 cM。【结论】LrXi位于1BL染色体,抗叶锈表现不同于所有已知抗叶锈病基因,该基因的发现将有利于丰富中国抗叶锈病基因资源,为培育持久抗病品种奠定基础。     

小麦品系西农1163-4抗叶锈病基因的遗传分析和分子作图#br#

【目的】小麦品系西农1163-4高抗小麦叶锈、条锈和白粉病,综合农艺性状良好。明确该小麦品系中所含的抗叶锈病基因及遗传特点,找到与其紧密连锁的分子标记,有利于抗病基因利用和培育抗病新品种。【方法】将西农1163-4与感病品种Thatcher杂交,获得F1、F2代群体,利用中国叶锈菌优势小种THTT进行苗期抗性鉴定和抗性遗传分析;采用SSR技术对西农1163-4所携带的抗叶锈基因进行分子标记研究,共筛选了1 273对SSR引物。【结果】小麦品系西农1163-4对多个叶锈菌小种具有良好的抗病性,对THTT的抗性是由1个显性基因控制,该基因暂命名为LrXi。获得了与LrXi紧密连锁的3个微卫星分子标记Xbarc8、Xgwm582、Xwmc269和1个STS标记(ω-secali/Glu-B3),将LrXi定位于小麦1BL染色体上。距离最近的2个微卫星位点是Xgwm582、Xbarc8,与抗叶锈基因间的遗传距离分别为2.3 cM和3.2 cM。【结论】LrXi位于1BL染色体,抗叶锈表现不同于所有已知抗叶锈病基因,该基因的发现将有利于丰富中国抗叶锈病基因资源,为培育持久抗病品种奠定基础。     

Molecular mapping of leaf rust resistance genes in the wheat line Yu 356-9

The Chinese wheat line Yu 356-9 exhibits a high level of resistance to leaf rust. In order to decipher the genetic base of resistance in Yu 356-9, gene postulation, inheritance analyses, and chromosome linkage mapping were carried out. Gene postulation completed using 15 leaf rust pathotypes and 36 isogenic lines indicated that Yu 356-9 was resistant to all pathotypes tested. F1 and F2 plants from the cross Yu 356-9(resistant)/Zhengzhou 5389(susceptible) were tested with leaf rust pathotype "FHNQ" in the greenhouse. Results indicated a 3:1 segregation ratio, indicative of the presence of a single dominant leaf rust resistance gene in Yu 356-9 which was temporarily designated as Lr Yu. Bulk segregant analysis and molecular marker assays were used to map Lr Yu. Five simple sequence repeat(SSR) markers on chromosome 2BS were found closely linked to Lr Yu. Among these markers, Xwmc770 is the most closely linked, with a genetic distance of 5.7 c M.     

北方春大豆品系大豆花叶病的鉴定与抗原筛选

为了详细了解我国近几年来育成的北方春大豆品系对花叶病毒病的抗性表现,本研究通过分析2003～2007年的国家北方春大豆品种区域试验和生产试验病毒病2个流行株系(SMV1和SMV3)抗性鉴定数据,筛选兼抗SMV1号和SMV3号株系的抗原有19份,专抗SMV1号株系的抗原55份,专抗SMV3号株系的抗原20份,并发现辽宁省的新品系对2个株系的抗性表现都是最好的,尤其是表现抗病级别(R)的品系较多;而黑龙江省对2个株系的抗性表现都是最差的,尤其是对3号株系,大部分表现感病。建议黑龙江省今后要重视花叶病毒与抗性育种,可以考虑从辽宁和吉林两省引入抗原,进行品种选育和抗性改良。     

小麦白粉病抗病新基因PmHNK的遗传分析和分子标记定位

 【目的】周98165对河南省当前流行白粉菌生理小种具有较好的抗性,并且综合农艺性状优良。明确其抗白粉病基因及遗传特性,筛选与其紧密连锁的分子标记,为抗白粉病育种提供抗源和理论支撑。【方法】将周 98165与中国春杂交、自交、测交,对双亲及其杂交后代进行苗期鉴定,用小麦白粉病菌08B1进行遗传分析,利用SSR、EST-SSR技术对双亲及抗感池进行筛选和电泳分析,并结合中国春缺四体材料进行染色体定位。【结果】周98165对3个白粉菌高毒力小种抗性良好,其抗病性受1对显性核基因控制,将该基因暂命名为PmHNK。筛选了与PmHNK 连锁的5个微卫星标记,在遗传图谱上的顺序为Xbarc77、Xgwm547、Xwmc326、Xgwm299、PmHNK、Xgwm108,Xgwm299和Xgwm108分别为PmHNK两侧距离最近的标记,图距分别为4.2 cM、5.6 cM,最远标记Xbarc77与PmHNK图距为10.6 cM,并将PmHNK 定位于3BL。【结论】抗病鉴定、遗传分析结合分子标记分析结果表明,PmHNK是一个白粉病抗病新基因。