Identification of F1 hybrid progenies in mango based on Fluorescent SSR markers

Abstract

Background Artificial cross breeding (hand pollination) is an important method for breeding new mango cultivars. It is easy to produce false hybrids during hybridization, which makes it difficult to distinguish the authenticity of hybrid offspring. Therefore, it is necessary to identify the authenticity of hybrids. Results Mango ‘Jinhuang’ and ‘Renong No.1’ and 65 individual plants of their F1 hybrids were used as experimental materials, eight SSR primer pairs with polymorphism in parents were used to identify the F1 hybrids by capillary electrophoresis. The results showed that a total of 62 true hybrids were identified from 65 hybrid progenies, and the true hybrid rate was 95.38%. According to the segregation type of co-dominant SSR markers in F1 generation, the segregation ratio of different alleles at the same locus of eight markers was performed by x2 test. Results showed that eight SSR loci were consistent with Mendel’s segregation law. The results of cluster analysis showed that the parents and 62 true hybrids could be classified into two categories at 0.58: the first category contained 27 offspring, clustered with ‘Jinhuang’ and showed a maternal genetic tendency. The second category contained 35 offspring, clustered with ‘Renong No.1’ and showed a partial paternal genetic tendency. DNA fingerprint of hybrids from ‘Jinhuang’ × ‘Renong No.1’ cross were constructed using eight SSR primers for variety protection. Conclusion We used eight SSR fluorescent markers to test the authenticity of hybrids derived from crossing combinations of ‘Jinhuang’ and ‘Renong No.1’. A total of 62 true hybrids were identified from 65 hybrid progenies, which would lay a foundation for the follow-up mango cross breeding and molecular marker assisted breeding. In addition, the development of hybrid fingerprints could facilitate variety protection.