In vitro Screening and Molecular Genetic Markers Associated with Salt Tolerance in Potato

Aims: The main aim of this study was to screen potato germplasms for salt tolerance and to find out the suitable molecular markers associated with salt tolerance in potato lines.

Experimental Design: The present experiment was laid out in Completely Randomized Design (CRD) and replicated thrice.

Experimental Site: The experiment was conducted at the plant molecular laboratory, Department of Biotechnology, Bangabandhu Sheikh Mujibur Rahman Agricultural University, Salna, Gazipur and Tissue culture laboratory of Bangladesh Agricultural Research Institute, Gazipur, Bangladesh.

Methodology: In vitro screening of eight potato lines viz. CIP 101, CIP 102, CIP 111, CIP 112, CIP 117, CIP 124, CIP 134, CIP 139 along with two popular potato varieties namely Asterix and Diamant were used to screen for salt tolerance at different levels of NaCl concentration (0, 2, 4, 6 and 9 dS/m). MS20 medium was used as a culture media with different concentration of NaCl where single node cuttings (SNC) from the collected plant materials were transferred accordingly. Minute observations on shoot length, root length, leaf area, shoot dry weight, and root dry weight were documented periodically.

A polymerase chain reaction (PCR) based approach, namely random amplified polymorphic DNA (RAPD) analysis was applied to the selected lines and varieties of potato in order to assess the degree of salt tolerance.

Results: Perusal of the tables revealed a significant variation among the potato lines and varieties. Shoot length, root length, leaf area, shoot dry weight, and root dry weight was decreased with the increase of salt concentration in the used medium. Banding pattern of RAPD confirmed a distinct polymorphism between salt tolerant, moderately salt tolerant and salt sensitive lines. The clustering pattern of the potato genotypes in this study suggests that, the salt tolerance and salt sensitivity of some potato lines are due to the genotypic variation and possibly not for the epigenetic adaptation under salt stress condition.

Comparing the mean value of growth parameters using ANOVA and from RAPD marker analysis, total ten potato genotypes can be classified as follows: the salt tolerant (CIP 102, CIP 112 and CIP 139), the moderately salt tolerant (CIP 111, CIP 124, CIP 134, Asterix and Diamant) and the salt sensitive lines (CIP 101, CIP 117).

Conclusion: The salt tolerant potato lines (CIP 102, CIP 112 and CIP 139) of the present experiment can be used for future breeding programs to develop salt tolerant potato variety.