Purity Identification Of Processing Tomato Hybrids Based On SSR Molecular Marker

Tomato is one of the important species of Solanaceae,which is loved by consumers because of its high nutritional value.In order to meet the needs of production,breeders breed many new varieties every year for application in production.Processed tomato is a kind of cultivated tomato,which is one of the main cash crops in Xinjiang.The varieties used in production are mainly hybrid varieties.The purity of seeds directly affects the yield and quality of agricultural production.The purity identification of F1 hybrids is an important link in the quality control of processed tomato seeds.SSR is becoming the preferred molecular marker for crop breeding and the most practical marker for genome mapping,variety identification and marker-assisted selection due to its characteristics of genetic codominance,high repeatability and multi-allelic variation.This study used SSR molecular marker technology to establish an indoor identification technique for the purity of processed tomato hybrid seeds,and identified the purity of 10 processed tomato hybrid seeds.The main findings are as follows:1.The effects of different parts of radicle,cotyledon and true leaf on DNA quality were studied.The extraction results showed that the extraction concentration of true leaves was the highest(1539.1ng/μL),and that of radicle was the lowest(241.4ng/μL).However,the radicle DNA concentration is sufficient for SSR-PCR amplification reaction,and the growth time of radicle is shorter than that of cotyledon and true leaves.2.Five pairs of SSR molecular marker core primers were selected from 100 pairs of primers to construct the fingerprints of 9 processing tomato parent varieties.5 pairs of SSR core primers are Vg SSR＿250082、Vg SSR＿251194、Vg SSR＿256519、Vg SSR＿260605、Vg SSR＿248672,PIC value range is0.44～0.57,average PIC value is 0.50,all of which are medium-high polymorphism information primers,which can completely distinguish 9 processing tomato varieties.3.Five pairs of SSR primers selected were used to identify the purity of 10 processing tomato hybrids,and field planting identification was also conducted,the molecular marker identification purity of’38×133 ’ is 91.25%,and the field identification purity is 90.63%;the molecular marker identification purity of ’70×154 ’ is 70.89%,and the field identification purity is 72.00%;the molecular marker identification purity of ’144×70 ’ is 70.00%,and the field identification purity is 70.70%.The purity error between the field identification results and the molecular marker results of three hybrids was 0.62%～1.11%,less than2%,which was within the allowable error range,indicating that the primers used could identify the three hybrid combinations.The purity error between field identification results and molecular marker identification results of the other seven hybrids was 34.01%～84.28%.The purity error was too large,and the molecular identification results were generally lower than field identification results.