Assessment of Microsatellite Markers for Varieties Identification: A Case of Six Varieties of Maize Hybrids Sold in Tanzania

Background: Varieties identification is essential for protecting seeds sold to farmers from counterfeiting. Currently, the grow-out test (GOT) is used for varieties identification. This test is constrained by its long assessment, environmental dependency and subjective nature. Alternative test/tests are needed. This study aimed to determine the utility of microsatellite markers as a complement to GOT in varieties identification. Methods: In this study, six varieties of commercial maize hybrids released in Tanzania, herein coded as H1, H2, H3, H5, H6 and H9, were selected as candidates. For morphological evaluation, a field experiment was laid out in a complete randomized block design, followed by the collection of phenotypic data. The qualitative data were analyzed by one-way ANOVA in SPSS v.20 software, while qualitative data were summarized in a frequency distribution table. On the other hand, by conventional polymerase chain reaction (PCR), seven microsatellite markers were used to fingerprint the varieties. The PCR results were manually scored and transferred to GenAIEX v.6.5 and DARwin v.6. software for genetic distance and clustering analysis, respectively. Result: Quantitative data showed significant variation in all the tested varieties at p less than 0.05, whereas 15 qualitative traits out of 21 showed phenotypic variations among the tested varieties. Furthermore, two microsatellite markers, namely phi080 and umc1071, out of the seven markers used in this study, proved useful in the fast and timely identification of two varieties (H1 and H2) out of six varieties. Nei’s genetic distance ranged from zero to four; the highest measure of genetic distance was observed in H1, followed by H2 and the least measure was observed in both of the four varieties. Neighbor Joining clustered the varieties into three different populations that distinguished each of H1 and H2 from the rest of the four varieties. This study shows that microsatellite markers are a promising complement to GOT in varietal identification.