Genetic diversity among different physiological traits of Sorghum bicolor cultivars of subtropical origin.

The genetic diversity of Saudi locally growing sorghum (Sorghum bicolor) cultivars has not been thoroughly characterized. To understand the genomic patterns of diversification in Saudi sorghum cultivars (N = 7), random amplified polymorphic DNA (RAPD) was used as a rapid, inexpensive method for providing information regarding genomic variability below the species level. Six commercially available primers were initially used to select a single primer based on availability, universality, and its use with standard polymerase chain reaction (PCR) conditions. PCR-amplified molecular markers were reproducibly detected in Saudi cultivars. The single primer 2 produced clear bands and revealed variability among the cultivars. Seven tested cultivars were categorized into 2 major groups, indicating 2 genomogroups for the Saudi-cultivars. Five cultivars (S2, S3, S4, S5, and S6) showed identical banding patterns and were grouped in the same clade, although their panicles varied in size, shape, and color. Two cultivars (S1 and S7) showed different banding patterns. In this study, a single primer (P2) was used to demonstrate the effectiveness of genotype detection among sorghum cultivars. This is the first report describing genetic variation among S. bicolor cultivars in Saudi Arabia. The commercial primer (P2) and PCR reaction mixture used in this study are readily available and can be used in sorghum improvement programs.