Seed genetic purity testing of F1 Benincasa hispida var. chieh-qua hybrids using SSR molecular marker analysis

To ensure that farmers can access high-quality seeds, it is essential to find a simple, rapid and accurate method to assess seed purity. In recent years, heterosis in chieh-qua has been widely applied to production. Using the whole genome sequence of chieh-qua, we designed simple sequence repeat (SSR) primers specific for chieh-qua. The parental lines of nine hybrids were screened using 200 SSR primers, seven of which exhibited polymorphisms. The bands were clear, stable and reproducible. We found dominant and co-dominant bands between the parents of the nine hybrids. The seven pairs of SSR primers were successfully used to assess genetic purity of the nine chieh-qua hybrids. The SSR molecular marker purity assessment results were consistent with the results obtained from a field grow-out test (GOT). However, the use of SSR markers provided a more accurate, reliable and faster method for seed purity testing than the GOT. We propose using SSR molecular marker technology to assess the genetic purity of chieh-qua hybrid seeds. With this method, the seed quality can be determined faster, which may help to accelerate the chieh-qua breeding process.