Application of simple sequence repeats (SSRs) markers to study the resistance of locally adapted maize hybrids to damaging maize streak virus disease

Simple sequence repeat markers were used to study S6 recombinant inbred lines originating from a single cross between two inbred lines OSU 23i and EM12-210, for resistance to maize streak virus disease. A total of 115 recombinant inbred lines belonging to three families previously selected using conventional methods were screened using 52 SSR markers contained between Bin 1.04 and 1.05 of maize chromosome 1. Of these, only three markers were chosen on the basis of their polymorphism content for use in the study. This paper discusses the results of combined selection with both artificial inoculation and the three selected SSR markers. The use of artificial inoculation detected 78 resistant lines and 36 susceptible lines. On the other hand, the SSR markers detected 40 resistant lines, and 74 susceptible lines. But a combination of both the artificial inoculation and SSR marker selection reduced the number of resistant lines to 29 and increased the number of susceptible lines to 85. With these findings it was concluded that, a conventional maize breeder requires the use of molecular markers in order to improve selection intensity and maximize genetic gain.