Extraction of good quality genomic DNA is mandatory for carrying out crop improvement programme using molecular approaches. Isolation of good quality and quantity of plant genomic DNA is the key challenge due to often contamination with large amount of polysaccharides, polyphenols and secondary metabolites. In our present study, we performed DNA isolation from five native cherry tomato genotype inclusive and exclusive of liquid nitrogen using modified Doyle & Doyle method and CTAB method. Quality of the isolated DNA was determined by horizontal agarose gel electrophoresis using 1% (CTAB) and 0.8% (Doyle & Doyle) agarose in 1X TE buffer at constant voltage of 80V. Purity of extracted DNA was determined by A260/A280 ratio and observed that CTAB with liquid nitrogen (1.62-1.70 and 472-955 ng/µl) and Doyle & Doyle method without liquid nitrogen (1.80-1.95 and 632-1200 ng/µl) yielded PCR amenable DNA. However, Doyle & Doyle method without liquid nitrogen yield the best quality and quantit

cherry tomato, CTAB, Doyle & Doyle method, DNA isolation, liquid nitrogen, standardization.

From the present study, standardization of DNA isolation with high quality genomic DNA amenable for PCR and enzymatic studies was executed from the four different methods. Among the methods used Doyle and Doyle W/liquid nitrogen prove to be inexpensive, simple in operation, produces good amount of high quality DNA for molecular studies. However, CTAB method supplied with liquid nitrogen produces comparable yield and quality of DNA to that of Doyle and Doyle W/liquid nitrogen method. Under critical observation of concentration and contamination by proteins or polyphenols in the isolated DNA, Doyle and Doyle W/ liquid nitrogen produces high purity genomic DNA with good yield amenable for several molecular PCR studies. Therefore, this method meets the objective of the study hence, it can be employed for isolating DNA in ill-equipped laboratories remotely present in corners of the country.

Chanu, N.B., Sarma, P., Deo, C., Hazarika, B.N., Singh, A.K. and Md Ramjan (2021). Standardization of DNA Extraction protocols in underexploited Cherry Tomato (Solanum lycopersicum L. var. cerasiforme) Genotypes of North East India. Biological Forum – A