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.

DNA barcoding of arid wild plants using rbcL gene sequences.

DNA barcoding is currently gaining popularity due to its simplicity and high accuracy as compared to the complexity and subjective biases associated with morphology-based identification of taxa. The standard chloroplast DNA barcode for land plants recommended by the Consortium for the Barcode of Life (CBOL) plant working group needs to be evaluated for a wide range of plant species. We therefore tested the potential of the rbcL marker for the identification of wild plants belonging to diverse families of arid regions. Maximum likelihood tree analysis was performed to evaluate the discriminatory power of the rbcL gene. Our findings showed that using rbcL gene sequences enabled identification of the majority of the samples (92%) to genus level and only 17% to species level.