Molecular Marker Analysis Of Seed Genetic Purity And Cultivar Identification In Cauliflower

Cauliflower(Brasica oleracea var.botrytis L.),one of the most popular vegetable crops,has high nutrition value and large production area,play an important role in the vegetable industry of China.It is a typical cross-pollinated crop exhibited prominent heterosis of quality,yield and disease resistance in F₁ hybrid progeny.Cauliflower F₁ hybrid seeds have been wildly used in the production.If the seed genetic purity was very low,it could have bad effect on the production.Therefore,it is necessary that quality control assessment of cauliflower hybrid seed is carried out before seed being released in the market.In this study,cauliflower hybrid 'yin'guan' and its parents were studied for identification with three PCR based molecular markers,RAPD,ISSR and SSR.Two RAPD primers(NAURP23 and NAURP56),two ISSR primers(NAUISR43 and NAUISR75) and two SSR primers(NAUSSR2 and NAUSSR14),produced male and female parent-specific markers simultaneously in the hybrid,were found to be useful in determining the hybrid seed genetic purity.The results indicated that three of 210 'yin'guan' hybrid individuals appeared to be false hybrids(Nos.4,178,184).Three putative false hybrids confirmed with all six primers,exhibited similar band patterns to be female parent,suggesting that they could be derived from selfing of the female parent.It was high accordance with the result from field grow-out trails.Therefore,the genetic purity of hybrid 'yin'guan' seed lots was 98.57%.The present study showed that all three molecular marker systems were useful tools for testing the cauliflower hybrid seed genetic purity,and using the combination of RAPD,ISSR and SSR markers were more reliable and efficient than using the three markers in isolation.In this study,three molecular marker systems RAPD,ISSR and SRAP,were employed to identify cultivar and the relationship of 29 cauliflower cultivars and one broccoli cultivar and one cabbage cultivar,and construct the fingerprint of these cultivars,respectively.The result showed that 32 cultivars existed higher polymorphism.32 cultivars studied were identified with two primers.Cluster analysis and relatively genetic similarity coefficient indicated that the relationships of cabbage with cauliflower and broccoli and cauliflower were larger.The genetic relationship of these cauliflower cultivars was tightly associated with its origin and its characters.The study showed RAPD,ISSR and SRAP marker were useful of identify cauliflower cultivars and analysis genetic diversity,and this could be useful for the new cultivar breeding and the new cultivar protection.