桃(Prunus persica)砧木抗南方根结线虫分子标记开发与利用

王慧敏1,李 勇2,3,吴金龙2,李文清2,曹 珂2,王新卫2,3,王力荣2,3*

1塔里木大学园艺与林学学院,新疆 阿拉尔 843300;2中国农业科学院郑州果树研究所,郑州 450009;3中国农业科学院西部农业研究中心,新疆 昌吉 831100)

摘 要:【目的】南方根结线虫是威胁桃产业绿色发展的地下主要害虫,开发抗性分子标记,对抗性砧木分子育种具有重要意义。【方法】根据前人对桃砧木抗根结线虫的定位结果,在GDR 网站peach genome V2.0查询定位区间的候选基因。在5个抗病、5个感病种质中扩增候选基因,并通过DNAMAN、IGV等软件对候选基因进行序列差异分析,开发抗南方根结线虫KASP分子标记,在抗性种质筑波3号与感性种质哈露红的杂交F2群体中对该分子标记进行验证,并与前人开发的SCAR和35 bp indel抗南方根结线虫分子标记的准确性进行比较。【结果】KASP标记结果将基因型划分为3种,分别为抗性纯合型(A),抗性杂合型(B),感性纯合型(C),A∶B∶C=42∶94∶64,与表型符合率为88.5%;SCAR标记检测结果划分为2种,分别为抗病型(A1)和感病型(C1),A1∶C1=135∶65,与表型符合率为87.0%;35 bp indel分子标记分为3 种类型,分别为抗性纯合型(A2),抗性杂合型(B2),感性纯合型(C2),A2∶B2∶C2=1∶154∶45,与表型符合率为52.0%。【结论】本研究中开发的KASP标记提高了分子标记选择准确率,对抗南方根结线虫分子育种具有重要意义。

关键词:桃;KASP标记;南方根结线虫;抗性

根结线虫是一种重要的植物寄生性线虫,主要危害作物根系[1-2],严重影响农业生产。在桃产业中,根结线虫感染会导致树势衰弱、果实产量和品质降低,甚至死树。南方根结线虫是危害我国桃树的主要线虫种类[3]。对比传统化学防治方法,选用抗性砧木是解决根结线虫危害问题的根本途径。前人研究发现野生种质红根甘肃桃1 号(P.kansuensis)对南方根结线虫完全免疫,山桃(P.davidiana)以及寿星桃1号(P.persica)对南方根结线虫高抗[4]

近年来,分子标记辅助育种在植物中得到广泛应用,显著提高了选择的准确性,缩短了育种周期。李肯等[5]利用indel分子标记检测32份甜瓜基因型,检测结果与表型符合率极高;吴翼等[6]利用分子标记对100株香水椰子的纯度进行检验,发现分子标记结果与表型鉴定完全吻合,可用于鉴定苗期香水椰子的纯度;刘广等[7]利用筛选到的3 个分子标记检测20 份西瓜材料抗枯萎病情况,检测结果与表型基本一致。由于不同研究者利用的遗传群体不同,因此得到的标记与性状连锁距离的远近不同,甚至位于不同的染色体上[8]。在桃上,为获得与桃抗南方根结线虫紧密连锁的标记,刘伟[9]利用分子标记将红根甘肃桃抗南方根结线虫基因定位在LG5(linkage group,LG),紧密连锁M3E15-300 标记;Cao 等[10]、张倩[11]利用多种分子标记如SSR、RGA 等将野生种质红根甘肃桃1 号的抗南方根结线虫基因PkMi定位到2号染色体顶端,位于两个标记NBS29 与NBS3 之间,连锁SSR的标记UDP98-025,随后通过标记加密鉴定到了红根甘肃桃抗南方根结线虫关键基因并加以验证。Duval 等[12]利用[(Pamirskij×Rubira)×(Montclar×Nemared)]的杂交群体,将栽培桃(P.persica)抗性基因定位在2号染色体,但与野生种质红根甘肃桃1 号抗性基因位置不同,位于A20 SNP 和SNP_APP91 标记之间,约92 kb,关键基因尚不明确。

栽培桃是桃砧木的最重要类型。笔者在本研究中基于Duval 等[12]对栽培桃抗南方根结线虫的定位结果,拟通过定位区间内序列差异比较,锁定候选关键基因,开发抗南方根结线虫的相关分子标记,以期在抗南方根结线虫砧木育种中应用。

1 材料和方法

1.1 试验材料

5 个表型为抗南方根结线虫的品种:列玛格、阿克拉娃、筑波2 号、筑波3 号、寿星桃1 号;5 个表型感性品种:贝蕾、喀什1 号、喀什2 号、哈露红、西伯利亚C[13]。杂交F2代群体为筑波3 号(抗)×哈露红(感)。

线虫材料取自中国农业科学院郑州果树研究所桃园,鉴定为南方根结线虫后接种至番茄苗中进行繁殖备用。

1.2 候选基因的确认

通过Duval 等[12]对栽培桃的定位结果,桃抗根结线虫基因在标记A20SNP与SNP_APP91的92 kb区间内,通过GDR 网站在peach genome V2.0 中对该候选序列进行BLAST 找到对应区域包含的所有候选基因共6 个。利用IGV 可视化和Excel表查看10 份种质的基因组重测序结果,挑选具有规律性序列差异的基因进行下一步验证[14]

1.3 叶片DNA的提取、PCR扩增及测序

采集筑波3 号(抗)×哈露红(感)F2群体(共200株)及10 份种质的叶片,用CTAB 法提取DNA。DNA的质量与浓度用紫外分光光度仪NanoDrop 1000 spectrophotomete(rThemo Scientific)测定,利用无菌水将其稀释至100~200 ng·μL-1后保存至-20 ℃。在10 份种质中对候选基因进行基因组序列扩增(扩增引物见表1),扩增模板为H2O 7 μL,上、下游引物各1 μL,1 μL DNA以及10 μL Mix(南京诺唯赞生物科技股份有限公司,南京)。扩增条件按照Mix 说明书进行。PCR 产物通过凝胶电泳后,参考韦莹华等[15]的方法稍作修改,将产物进行回收、连接载体、挑取单克隆并通过阳性鉴定后将菌液交由生工生物工程(上海)股份有限公司测序、拼接,查看序列差异的软件为DNAMAN。

表1 扩增候选基因所用引物序列信息
Table 1 Primer sequence information used to amplify candidate genes

基因Gene Prupe.2G055500引物名称Primer name 5500-F1 5500-R1引物序列(5'-3')Primer sequence(5'-3')GGTTCTTCCTTGCTTGCATC CTGACTCTACTACCCTCAGC

1.4 KASP标记基因分型

竞争性等位基因特异性PCR(KASP)扩增参考吉爽秋等[16]的方法,所用荧光为六氯荧光素(hexachlorouorescein,HEX)和羧基荧光素(carboxy fluorescein,FAM),引物序列见表2。

表2 KASP 分型所用引物序列信息
Table 2 Primer sequence information used for KASP genotyping

位点名称Loci name Pp02:6601310引物名称Prmer name B2F1 B2F2 B2R引物序列(5'-3')Primer sequences(5'-3')GAAGGTGACCAAGTTCATGCTTCTAATGAATCAGATTTAAACATC GAAGGTCGGAGTCAACGGATTATTTAATGAATCAGATTTAAACATA CTGTATGTTGCATTCTTTTGCGCGGTTG

1.5 2个分子标记的检测

采用前人开发的SCAR分子标记和35 bp indel 分子标记检测200 株实生苗抗南方根结线虫情况[17-18]。利用2个标记分别对200株实生苗进行PCR序列扩增(引物见表3),SCAR 标记检测结果通过凝胶电泳查看,35 bp indel 分子标记检测结果通过聚丙烯酰胺凝胶电泳查看。

表3 分子标记所用引物序列信息
Table 3 Primer sequence information used in molecular markers

分子标记类型Molecular marker type SCAR标记SCAR marker 35 bp indel分子标记35 bp indel marker引物名称Primer name 834B-F 834B-R 5D3-F 5D0-R引物序列(5'-3')Primer sequence(5'-3')GCAGTCAAAAATTTCAAACC TCCGATTCGAGCCCACTACA GTTGTCTTGCCCCACTTCTGC GAGGAGTGGCTCATCGAGTTTC

1.6 F2群体表型的调查

参考吴波鸿[19]的方法稍作修改,收集番茄根上繁殖的南方根结线虫虫卵,在28 ℃培养箱孵化5 d后收集南方根结线虫二龄幼虫(J2)制成线虫悬浮液于50 mL 离心管中,随后在显微镜下确认该悬浮液浓度为50 头J2·100 μL-1。对20 株桃苗进行南方根结线虫的接种,每盆接种3 mL。接种后定期对温室的桃苗进行管理,3 个月后调查表型,观察桃苗有无根结。

1.7 3个单一标记在杂交群体中的选择符合率

抗性符合率=标记为抗性的F2群体中表型为无根结的个数/标记检测为无根结的群体总数;感性符合率=标记为感性的F2群体中表型为有根结的个数/标记检测为有根结的群体总数。

2 结果与分析

2.1 候选基因的确认及序列差异分析

根据Duval等[12]对栽培桃抗南方根结线虫的定位结果,找到了6 个候选基因即Prupe.2G055500Prupe.2G055600Prupe.2G055700Prupe.2G055800Prupe.2G055900Prupe.2G056000。利用重测序数据查看候选基因的序列差异情况,发现基因Prupe.2G055500 在抗感品种中存在规律性变异位点。为进一步验证,笔者在5个抗性和5个感性品种中对该基因进行扩增、测序,经软件DNAMAN 比对后发现基因Prupe.2G055500 在抗、感品种中确实存在规律性变异,其内含子上存在一个2 bp的ins变异(Pp02:6 601 310 bp,G→GAT),抗性品种存在AT插入,感性品种无(图1);另外,以v2.0.a1 版本为参考基因组,通过IGV 软件查看10 份桃种质材料的重测序数据,并进行序列的比对、分析,发现了同样的结果(图2),表明该插入具有高度准确性。

图1 抗感品种在Prupe.2G055500 中序列差异
Fig.1 Sequence difference of susceptible varieties in Prupe.2G055500

从上到下依次为列玛格、阿克拉娃、筑波2 号、筑波3 号、寿星桃1 号、喀什1 号、贝蕾、喀什2 号、哈露红、西伯利亚C 和Prupe.2G055500 的基因组序列。
From top to bottom, they are Nemaguard, Okinawa,Tsukuba 2,Tsukuba3, Shouxingtao 1, Kashi 1, Bailey, Kashi 2, Harrow Blood, Siberian C and Genome sequence of Prupe.2G055500.

图2 抗感品种IGV 比对结果
Fig.2 Comparison results of IGV resistant varieties

a.抗性品种;b.感性品种。
a.Resistant varieties;b.Susceptible varieties.

2.2 KASP分子标记的开发与检测

结合上述对候选基因序列的比对结果,笔者在该位点开发了一个用于基因分型的KASP 分子标记。利用该标记对5 份抗性种质和5 份感性种质进行目标位点基因型检测,发现抗性种质列玛格同时检测到FAM 和HEX 荧光信号,信号点为红色,基因型为AT/--;抗性种质阿克拉娃、筑波2 号、筑波3 号和红寿星信号点为绿色,聚合在y 轴附近,基因型为AT/AT;感性种质喀什1 号、贝蕾、喀什2 号、哈露红和西伯利亚C 的信号为蓝色,聚合在x 轴附近,基因型为--/--。

为检验KASP 分子标记的适用性和有效性,利用抗性材料筑波3 号和感性材料哈露红的F2代200株个体进行验证。利用KASP 标记对每份单株进行目标位点基因型检测,结果显示该群体有3 种基因型,把荧光信号为绿色的显性纯合类基因型记为A,荧光信号为红色的显性杂合类基因型记为B;荧光信号为蓝色的隐性纯合类基因型记为C(图3)。200株实生苗的基因分型结果如下:A 类的材料有42份,占总群体的21.0%;B 类的材料有94 份,占总群体的47.0%;C 类的材料有64 份,占总群体的32.0%。抗性纯合(A)∶抗性杂合(B)∶感性(C)=42∶94∶64,接近1∶2∶1。经卡方检验可知χ2=5.56,p值>0.05,结果表明内含子的插入与根结线虫抗性显著相关,说明该分子标记符合孟德尔分离定律,且抗南方根结线虫基因为显性遗传,与前人研究结果较一致[20]

图3 部分KASP 基因分型结果
Fig.3 Partial KASP genotyping results

绿色荧光代表AT/AT;红色荧光代表AT/--;蓝色荧光代表--/--。
Green fluorescence stands for AT/AT;Red fluorescence stands for AT/--;Blue fluorescence stands--/--.

2.3 SCAR、35 bp indel分子标记检测结果

利用前人已开发的SCAR标记[17]、红根甘肃桃35 bp indel[18]分子标记对F2群体200 株实生苗进行基因分型。通过琼脂糖凝胶电泳查看SCAR 标记结果,将结果划分为A1、C1两类。其中A1为抗南方根结线虫,C1为感南方根结线虫。部分SCAR标记结果如图4 所示,扩增出A1 类条带的材料有135 份,占总群体的67.5%;扩增出C1 类条带的材料有65 份,占总群体的32.5%。即SCAR 分子标记检测结果为抗南方根结线虫的植株有135 株,对南方根结线虫感性的植株有65 株,经卡方检验可知χ2=6.00,p 值<0.05,不符合分离定律。

图4 部分SCAR 标记检测结果
Fig.4 Partial SCAR marker detection results

通过聚丙烯酰胺凝胶电泳35 bp indel分子标记扩增出了3种类型的条带,分别记为A2、B2、C2。部分标记检测结果如图5 所示,以抗性材料红根甘肃桃1号为对照,在该位点有1条带记为A2类,在该位点有对应2 条带记为B2 类,在该位点无条带则记为C2 类。结果显示,扩增出A2 类型条带的材料有1份,占总群体的0.5%;扩增出B2 类型条带的材料有154 份,占总群体的77.0%;扩增出C2 类型条带的材料有45 份,占总群体的22.5%,A2∶B2∶C2=1∶154∶45。标记结果表明200 株实生苗中抗根结线虫的有155 株,感性的有45 株,抗∶感≈3∶1,卡方检验显示χ2=0.67,p 值>0.05,该位点的缺失与根结线虫的抗性有显著相关性。在聚丙烯酰胺凝胶电泳结果中显示超过2/3 的植株在该处均有2 条带,说明该群体在此处的基因型大多为杂合。

图5 部分35 bp indel 分子标记结果
Fig.5 Partial 35 bp indel marker results

以左一红根甘肃桃1 号为对照。
With Honggen Gansutao 1 as the control.

2.4 3个分子标记的选择效率分析

对F2群体接种南方根结线虫,3 个月后调查该群体对南方根结线虫的抗性情况。结果如表4 所示,无根结与有根结之比为2.77∶1,经卡方检验可知χ2=0.24,p 值>0.05,该群体符合孟德尔遗传定律。基于F2群体对南方根结线虫抗性的表型调查结果,评价3个标记的选择效率。从表5中可以看出,具有KASP 标记的A 类抗性基因型材料有42 份,其中表型鉴定为抗性的材料有41 份,抗性选择符合率为97.6%;具有KASP标记的B类抗性基因型材料有94份,表型鉴定为抗性的材料有89 份,抗性选择符合率为94.7%;具有KASP标记的C类感性基因型材料有64 份,表型鉴定为感性的材料有47 份,感性选择符合率为73.4%,总符合率达到88.5%。具有SCAR标记的A1 类抗性带型的材料有135 份,其中表型鉴定结果为抗性的材料有128 份,抗性选择符合率为94.8%;具有SCAR 标记的C1 类感性带型的材料有65份,表型鉴定为感性的材料有46份,感性选择符合率为70.8%,总符合率也达到87.0%。具有35 bp indel分子标记为A2类抗性带型的材料有1份,无表型鉴定为抗性的材料,抗性表型选择符合率为0;具有35 bp indel分子标记为B2 类的抗性带型材料有154份,表型鉴定为抗性的材料有103份,抗性选择符合率为66.9%;具有35 bp indel 分子标记为C2 类的抗性带型的材料有45份,表型鉴定为感性的材料只有1 份,感性选择符合率为2.2%,总符合率为52.0%。总之,3 个抗南方根结线虫分子标记中,KASP 分子标记检测的正确率最高;SCAR 标记次之,但同样正确率较高;35 bp indel分子标记的正确率最低。

表4 栽培桃杂交后代抗南方根结线虫分离比调查
Table 4 Investigation on the separation ratio of cultivated peach hybrid offspring against southern root-knot nematodes

亲本组合Parental combination筑波3号×哈露红Tsukuba 3×Harrow blood总株数Total number of plants 200无根结株数Number of rootless plants 147有根结株数Number of rooted plants 53分离比(无∶有)Separation ratio(without∶have)2.77∶1

表5 分子标记检测与表型比对结果
Table 5 Results of molecular marker detection and phenotype comparison

分子标记类型Molecular marker type等位类型Allele type F2群体株数Number of F2 population plants 42 94 64 135 65 1 154 45抗性表现Resistance performance抗性株数Number of resistance 41 89 17 128 19 0 103 44感性株数Number of perception KASP标记KASP marker 1 5总计Total 88.5 SCAR标记SCAR marker 35 bp indel分子标记35 bp indel marker A B C A1 87.0 C1 A2 B2 C2 47 7 46 1 51 1符合率Coincidence rate/%各自Respective 97.6 94.7 73.4 94.8 70.8 0.0 66.9 2.2 52.0

3 讨 论

目前已报道的、能完全用于商业化生产的抗根结线虫基因很有限,野生秘鲁番茄中的Mi基因运用最广泛[21]。在育种改良过程中,研究者利用不同分子标记检测了供试番茄中的Mi基因,发现检测结果差异明显,有的检测方法如CAPS 检测Mi 基因的时候存在明显假阳性,而另一种标记方法即SCAR 标记检测相比之下更稳定、便捷[22-25]。在李属植物中,MaRmiaRmja 为已知的抗线虫基因。目前桃的抗性基因Rmia 能完全抑制根结线虫繁殖和根结线虫虫瘿的形成,对南方根结线虫、大豆根结线虫都具有抗性[26-27]。Duval等[28]利用分子标记评估该基因对尚未检测过的埃塞俄比亚根结线虫(M.ethiopica)的抗性,发现基因分型结果与表型完全匹配,说明该基因能完全控制M.ethiopica,同时更新了基因MaRmiaRmja对线虫的抗性谱系,发现Ma基因对线虫具有广谱抗性。笔者在本研究中所用SCAR 标记位于LG2 抗性基因座附近,35 bp indel 分子标记位于红根甘肃桃1 号抗南方根结线虫基因启动子区,KASP 标记位于2 号染色体候选基因Pru‐pr.2G055500 的内含子上。利用不同分子标记检测栽培桃F2群体对南方根结线虫的抗性,发现35 bp indel 分子标记检测结果与另外两个标记结果的准确率相比差异显著,这说明野生种质红根甘肃桃1号与栽培桃的抗性基因不同;SCAR标记与KASP标记准确率较接近,原因可能是所用的遗传群体与样本数量不同。为加快育种进程,利用抗性基因开发分子标记可提高材料中抗性基因筛选的效率,为选育具有综合抗病的新品种奠定基础。范惠冬等[29]利用抗性基因分子标记分析105 份番茄种质资源中7个病害相关的8 个抗性基因的分布情况,为抗性基因的聚合育种提供了参考。笔者通过分析定位区间内的变异,仅在候选基因上找到一处与抗感性显著相关的2 bp indel变异位点,随后开发分子标记并在群体中进行验证准确率为89.0%,较已报道的标记准确率高。但由于标记准确率未达到100%,推测该变异位点为连锁标记,可能并非功能性变异,笔者下一步将对候选区间内结构变异、转座子变异等不同变异类型进行检测,并在群体中开展准确率和功能验证,发掘南方根结线虫抗性关键基因。

在本研究中,群体的表型调查结果符合分离定律,但一定程度上也受环境影响。一方面,南方根结线虫的生长和侵染受土壤温度和湿度影响,适合J2侵染的温度为15 ℃~30 ℃[30-32]。研究发现,温度超过35 ℃或低于5 ℃都会抑制南方根结线虫的生长,最适宜根结线虫生活的土壤湿度为6%,土壤过于干燥或湿润均不利于南方根结线虫的活动[32-33]。另一方面,植物对线虫有一定的趋避性,感病植株在接触线虫时可能会躲避线虫的进攻。Duval等[28]研究发现,易感苗在线虫侵染时偶尔会躲避线虫的进攻而产生假抗性个体,为保证评估表型的准确率,需对植株进行持续性接种根结线虫以降低错评植株的风险。因此,笔者在本试验中改良了抗性鉴定指标,以根结有无替代根结率作为评价指标,显著提高了表型鉴定的准确率。另外,也可通过延长线虫侵染时间和多次接种根结线虫提高表型数据的准确性和稳定性。

4 结 论

基于前人对栽培桃抗南方根结线虫基因的定位结果,开发了一个KASP分子标记,并在杂交F2代群体中进行验证,发现与前人开发的抗南方根结线虫分子标记比较,笔者在本研究中开发的KASP 标记准确率最高。该标记的开发提高了抗性品种的选择效率,为加快分子育种进程提供了资源。

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Development and utilization of molecular markers for resistance of peach(Prunus persica)rootstocks to southern root-knot nematodes

WANG Huimin1,LIYong2,3,WU Jinlong2,LIWenqing2,CAO Ke2,WANG Xinwei2,3,WANG Lirong2,3*

(1School of Horticulture and Forestry, Tarim University, Alar 843300, Xinjiang, China;2Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences,Zhengzhou 450009,Henan,China;3Institute of Western Agricultural,Chinese Academy of Agricultur‐al Sciences,Changji 831100,Xinjiang,China)

Abstract: 【Objective】Meloidogyne incognita is an underground pest threatening the development of peach industry.It is of great significance to develop molecular markers for the resistance to the pest for breeding new rootstocks.【Methods】According to the mapping results of peach rootstocks published by the predecessors, the candidate genes in the mapping interval were queried in GDR website Peach Genome V2.0.The candidate genes were amplified by PCR in five resistant germplasm Nemaguard, Okinawa,Tsukuba 2,Tsukuba 3 and Shouxingtao 1,and five susceptible germplasm Bailey,Kashi 1,Kashi 2, Harrow Blood and Siberian C.The target fragments of PCR products were purified, ligated and sequenced by agarose gel electrophoresis.The hybrid F2 population of disease-resistant germplasm Tsukuba 3 and susceptible germplasm Harrow Blood was inoculated with M.incognita,and the phenotypes of the population were investigated three months later to verify the accuracy of the KASP marker, and compared with the accuracy of molecular markers developed by the predecessors for the resistance to Meloidogyne incognita in SCAR and 35 bp indel.【Results】Six candidate genes were found through previous studies, namely Prupe.2G055500, Prupe.2G055600, Prupe.2G055700, Prupe.2G055800,Prupe.2G055900 and Prupe.2G056000.Through sequence comparison, it was found that there were regular variations in the resistant and susceptible varieties of the gene Prupe.2G055500,and there was a 2 bp indel variation(Pp02:6 601 310 bp,G→GAT)in its intron,and at insertion existed in the resistant varieties, but not in the susceptible varieties.In addition, using IGV software, with v2.0.a1 version as the reference genome,the same results were found in 10 resequencing data of peach germplasm materials.A molecular marker for genotyping was developed by using the above mutation sites.Five resistant germplasm and five susceptible germplasm were detected by this marker.The results showed that FAM and HEX fluorescence signals were simultaneously detected in the resistant germplasm Nemaguard,and the signal point was red,and the genotype was AT/--;The signal points of resistant germplasm Okinawa Tsukuba2 Tsukuba3 Shouxingtao 1 are green, aggregated near the Y axis, and the genotype is AT/AT; The signals of sensitive germplasm Bailey Kashi 1 Kashi2 Harrow Blood Siberian C are blue, aggregated near the X axis, and the genotype is--/--.The detection results of KASP marker in F2 population divided the genotypes into three types, green fluorescence was homozygous for resistance (A), red fluorescence was heterozygous for resistance (B), blue fluorescence was homozygous for sensibility(C), and A∶B∶C = 42∶94∶64 was close to 1∶2∶1, which was consistent with separation of mendelian law.The detection results of SCAR markers in F2 population were also divided into two types.The materials with target bands were resistant(A1),and the materials without target bands were sensitive(C1),and A1∶C1 = 135∶65,which did not conform to separation phenomenon.Three bands can be amplified by 35 bp indel marker in F2 population.Taking Hong Gen Gan Su Tao 1 as control, one band in the same position is classified as A2, two corresponding bands in the same position are classified as B2,and no band in the same position is classified as C2,and A2∶B2∶C2=1∶154∶45,which is not in conformity with separation phenomenon.The phenotypic survey of F2 population showed that the ratio of rootless nodules to rootless nodules was 147:53.Based on the phenotypic investigation results of F2 population resistance to Meloidogyne incognita, the selection efficiency of three markers was evaluated.The results showed that the selection coincidence rate of KASP for resistant materials was 95.6%, that of susceptible materials was 73.4%, and the total coincidence rate was 88.5%.The selection coincidence rate of SCAR marked as resistant material is 94.8%, that of scar marked as sensitive material is 70.8%,and the total coincidence rate is 87.0%.The selection coincidence rate of 35 bp indel marked as resistant materials was 66.5%, and the total coincidence rate was 52.0%.Among the three molecular markers for resistance to Meloidogyne incognita,the correct rate of KASP molecular marker was the highest,followed by SCAR marker, and the correct rate of 35 bp indel marker was the lowest.【Conclusion】Based on the mapping results of resistance genes of cultivated peaches to Meloidogyne incognita, this study developed a KASP molecular marker, which was verified in the F2 population.It was found that the KASP molecular marker developed in this study had the highest accuracy compared with the molecular marker developed by predecessors.The development of this marker improves the selection efficiency of resistant varieties and provides resources for accelerating molecular breeding.

Key words: Peach;KASP marker;Meloidogyne incognita;Resistance

中图分类号:S662.1

文献标志码:A

文章编号:1009-9980(2024)07-1429-09

DOI: 10.13925/j.cnki.gsxb.20240145

收稿日期:2024-03-27

接受日期:2024-04-30

基金项目:国际合作重点研发项目(2023YFE0105400);中国农科院院青创项目(Y2022QC23);河南省优秀青年基金(232300421042);中国农业科学院科技创新工程(西部中心林果团队)

作者简介:王慧敏,女,在读硕士研究生,研究方向为桃种质资源与遗传育种。E-mail:1651728884@qq.com

*通信作者 Author for correspondence.Tel:0371-55906989,E-mail:wanglirong@caas.cn