| Cucumber (Cucumis sativus L.; 2n = 2x = 14) is one of the ten most widely grown vegetable crops worldwide and plays important role for meeting human greenstuff need. The total grown area and yield of cucumber in our country have been ranking first in the world, while unit area yield and export amount are lower than many countries. The relative lack of various cucumber varieties with high quality, especially those fit to grow in dependencies, is a key reason for this phenomenon. Molecular assisted selection (MAS), which can shorten the breeding cycles and increase breeding efficiency, has been approved to be much better for quantitative traits than directly phenotypic selection. It is a pressing need for breeders our country to quicken the study of cucumber molecular markers and QTL mapping which is precondition for breeding with MAS.A molecular linkage map was constructed using F2 progenies with one line S94 (North China type) and the other line S06 (European greenhouse type) as parents. The SRAP, RAPD, ISSR and all derived anchor markers (SSR and SCAR), including development by us, were employed to screen for polymorphisms. Equal to cucumber chromosome pairs, this map contain seven linkage maps. The parameters of this map are the below: total maker number, 210; total mean interval, 5.2cM; the range of mean interval for per linkage group, 4.7-6.4cM. All these parameters reached and even exceeded the level of previously constructed cucumber molecular map.The comparison and integration between maps can share the information and help to learn the genetic backgrounds of quantitative traits in a broader view, and increase much individual value. In this study, totally 36 anchor markers were located on the map by using all derived SSR and SCAR markers including development by us. On the basis of these anchor markers, by communication with Staub lab, Wisconsin University USA, we realized the primary correspondence between our linkage groups with those in the map constructed by Fazio et al who ever worked in Staub lab. In detail, now five of seven linkage groups in our map have found their homologies in their map. This work walked a key step for the deeply integration between maps.Considering the requirements and trend of cucumber breeding in our country, the study mapped QTL for totally 14 fruit and plant structure traits such as fruit length, fruit stalk length, fruit thrichome density, lateral braches, inter-node length in greenhouse condition. Of all the traits, this study first conducted QTL analysis for fruit trichome density, fruit stalk length and fruit rigidity. At LOD≥3.0,toally 98 QTL were detected for 14 traits, most of which having stable and major QTL found out. There had 43 major QTL (R2≥10%) and 24 stable ones (detectable at least in two environments) of all the QTL, the per cent ratios were 43.9% and 24.5% respectively.Otherwise, three QTL hot spots had been found on No.1, 2, 3 and 4 linkage groups. In these regions there are major and stable QTL of some traits, such as the QTL ftd2.1, which can explain 30% of the observed variance (R2) of fruit trichome density on average in three environments. On the No. 1 linkage group there is also a region containing QTL for most traits, of which both the R2 values of lateral branch QTL and lateral average length QTL are more than 30% on average. These regions are the ideal targets for the future QTL cloning.Compared with the results of previous study, our study not only detected the same or similar QTL, but found out many new QTL. The QTL got in this study not only offered new information for understanding quantitative traits of cucumber, but also provided a potential starting point for marker assisted selection of cucumber in our country.
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