GENETIC VARIATION AMONG ZEA MAYS GENOTYPES USING START CODON TARGETED MARKER POLYMORPHISM

Maize (Zea mays L.) is considered as one of the most important cereals after wheat and rice for nutritional value and industrial use. Molecular markers have been frequently used by breeders for studying genetic variation and selecting suitable promising genotypes for hybridization programs. The current study was conducted with the aim to determine the genetic variation among 10 synthetic local and exotic maize genotypes (SNH-8605, IPA-5012, Sarah, Buhooth-106, IPA-5011, Biotech Bag, DKC-5783, 3078, 89-May-70, and Pio-3751) using 11 start codon targeted (SCoT) markers. These primers produced a total of 627 fragments across 10 maize genotypes, in which 56 were found to be polymorphic with an average of 5.09 polymorphic fragments per primer, and the number of amplified fragments ranged from 16 (ScoT-63) to 117 (SCoT-44). Among all the studied primers, primer SCoT-44 produced the highest and lowest molecular size amplification with unique bands, i.e., 1670 and 102 bp, respectively. The highest discriminatory value and polymorphic bands were produced by primers SCoT-44 and SCoT-12. Primer SCoT-29 produced the highest value for efficiency and polymorphism. The highest numbers of monomorphic bands were produced by primers SCoT-9, SCoT-30, and SCoT-36. Primer SCoT-12 provided a unique fingerprint for seven maize genotypes. The lowest genetic distance (0.167) was observed between maize genotypes Sarah (local) and IPA-5011 (local), whereas the highest value for genetic distance (0.5066) was obtained between two other genotypes, i.e., DKC-5783 (USA) and 3078 (Russia). The variation in genetic distance among genotypes was correlated to the geographical origins of the genotypes. A UPGMA dendrogram was constructed for 10 genotypes based on SCoT markers. In the phylogenetic tree, the maize genotypes with the most closely related geographical origins were arranged in the same cluster. Present results could serve as a guideline for the selection of promising maize genotypes for future breeding programs to obtain the optimum heterosis in maize.