An Efficient and Rapid Method of DNA Extraction For Molecular Marker Studies in Cotton (Gossypium hirsutum L.)

The plant tissues with rigid cell wall need to be ground in liquid nitrogen for disruption of cells. Further, they are transferred to an extraction buffer containing detergents as well as reducing and chelating agents to disrupt the membranes. However, it can cause serious degradation of the genomic DNA. Moreover, the oil and phenolic compounds in cotton seeds degrade the quality and quantity of extracted DNA. The quality and purity of DNA is essential for the success of the molecular studies. Hence, it was considered worthwhile to evaluate various methods of DNA isolation in terms of DNA yield and amplification. In these studies, three methods (Mini Prep, CTAB and G-Bioscience DNA isolation Kit) were used to isolate DNA from five transgenics (Bt.) cotton hybrids. The results revealed that the highest quantity of DNA was extracted with the Kit method, followed by CTAB and Mini prep method respectively. Though the DNA isolated with Mini Prep method was quantitatively less but it was comparable with Kit and CTAB methods with respect to quality. Hence, Mini Prep method can be utilized effectively for screening of genotypes for genetic purity assessment by PCR based markers.