多毛番茄‘LA2329’对B型烟粉虱抗性的QTL分析

QTL Analysis of Resistance to Type B Bemisia tabaci in Solanum habrochaites LA2329

多毛番茄‘LA2329’对烟粉虱具有很高的抗性。利用‘LA2329’与普通番茄‘9706’得到的BCl群体构建了一张包含180个分子标记，总长度为1166．6cM的番茄分子连锁图谱。采用离体鉴定的方法对BC，群体进行抗烟粉虱鉴定，鉴定指标为叶片烟粉虱成虫附着量、叶片烟粉虱卵量，叶片正、背面Ⅵ型腺毛密度。共定位到33个与4个指标相关的QTL。其中叶片烟粉虱成虫附着量和卵量显著正相关，二者定位到8个相同的QTL，其中2个主效QTL定位在2号染色体，分别介于标记InDel_FT45～SSR57之间和SSR57～InDel_FT49之间，解释的表型变异率分别为33．2％和39．8％。叶片背面Ⅵ型腺毛密度相关的QTL在6号染色体具有集群分布的现象，其中4个显著性QTL定位在C2～．At3g11210C2．Atlg24360标记之间，解释的总变异率为56％。叶片正面Ⅵ型腺毛密度相关的4个QTL和叶片烟粉虱成虫附着量及卵量相关的4个QTL定位在2号和12号染色体的相同位点，增效基因来源相反。以上结果说明叶片烟粉虱成虫附着量和卵量指标具有相同的抗性鉴定效果，可以认为是同一个鉴定指标；此外，番茄中Ⅵ型腺毛密度不是影响叶片烟粉虱成虫附着量和卵量的性状。

The wild species of tomato, Solanum habrochaites LA2329 has high levels of resistance to whitefly （Bemisia tabaci） and is thus an important resource for breeding of insect resistance. A linkage map that covered 1 166,6 cM of the tomato genome and includecl 180 markers was generated based on the BC1 population of generated from tomato cultivar 9706 crossed with Solanum habrochaites LA2329. Parents, Fl and BCI population were bioassayed with whiteflies using an in vitro method. Four phenotypic traits including number of adult whiteflies per leaflet, number of eggs per leaflet and densities of type VI trichomes on adaxial and abaxial surfaces were evaluated. A total of 33 QTLs associated with the four phenotypic traits were found in the BC1 population. The adult whitefly numbers had a significant positive relationship with oviposition numbers in the BC1 population. Eight QTLs associated with adult whitefly numbers and ovipitision numbers were located in the same locus. Of the 8 QTLs, 2 major QTLs were located in the interval defined by the markers InDel_FT45 - SSR57 and SSR57 - InDel FT49 on chromosome 2 and explained 33.2% and 39.8% of phenotypic variation, respectively. A QTL cluster that associated with density of type VI trichomes on abaxial surfaces was mapped on chromosome 6. Four major QTLs affecting density of VI trichomes in abaxial surfaces were located in the interval defined by C2_At3g11210 - C2_Atlg24360 and explained 56% of phenotypic variation. Four QTLs associated with density of type VI trichomes on adaxial surfaces were mapped to the same locus as 4 of QTLs associated with adult whitefly numbers and oviposition numbers, but their additive effects were opposite. The results showed that adult whitefly numbers and ovipitision numbers were measures of similar phenotypic traits for resistance to whiteflies. In addition, density of type VI trichomes on tomato was not the major trait of tomato to whitefly resistance.