A MOLECULAR CHARACTERIZATION OF SIX GARLIC CULTIVARS FROM PAKISTAN BY USING ISSR METHOD

Abstract

In this current investigation, a DNA fingerprinting analysis was conducted to explore the genetic variation among six distinct garlic cultivars originating from Pakistan. This was achieved using six ISSR markers. The genetic material was extracted from the leaves of all cultivars and subsequently subjected to individual amplification with each ISSR primer in a PCR thermocycler. The resulting amplification products ranged in size from 340 to 860 base pairs. A total of 97 bands were generated using five primers, with each primer producing between 16 to 20 bands. On average, there were three bands per cultivar. All cultivars exhibited results with five out of the six primers. However, the (CA)8 primer did not yield any discernible banding pattern. Notably, the "White" cultivar displayed no bands with the ISSR primer (GACA)4, while the "Silver Skin" cultivar exhibited no bands with the ISSR primer (GTG)5. This study employed di-nucleotide (CA)8, tri-nucleotide [(GTG)5, (CAA)4], and tetra-nucleotide [(GACA)4, (GATA)4, (GGAT)4] repeats to achieve these findings. n this investigation, a total of 38 loci were identified, with 33 of them displaying polymorphism. A notable 89% polymorphism rate was observed among the six garlic cultivars that were subjected to amplification using five different primers. The Shannon diversity indices calculated for these primers revealed the highest value of 2.173 in the (GGAT)4 primer, signifying complete polymorphism among the garlic cultivars. Conversely, the (GTG)5 primer showed the lowest index of 1.598, attributable to the absence of bands in one garlic cultivar, specifically the "Silver Skin" variant. The ISSR markers proved to be highly effective in discerning genetic distinctions among the garlic cultivars, demonstrating the technology's significance in cultivar identification and the study of their genetic diversity.