Improvement of Potato through Parasexual Methods of Breeding

Abstract

An efficient in vitro technique on meristem culture, micro propagation and plant regeneration via callus induction was developed for potato (Solanum tuberosum L.) using three varieties as called Atlanta, Japanese red and Kenne bec. In the present study meristem tips were cultured on Murashige and Skoog (MS) medium, supplemented with different hormonal conditions, i.e. 0.3, 0.4, 0.5 mg/l GA3; 0.1, 0.5, 1 mg/l BAP; 0.3, 0.4, 0.5 mg/l KIN; BAP1+0.3KIN, 1BAP+0.4KIN, 1BAP+0.5KIN, BAP1+0.3GA3 BAP1+0.4GA3, BAP1+ 0.5GA3 as showed differential effect on in vitro propagation of potato. Meristm culture was found to be the best technique for virus elimination among tested potato varieties. Shoot multiplication into MS semisolid basal medium supplemented with different cytokinins, auxins and GA3 either singly or in combination resulted that media formulation with 0.3 mg/l GA3 is best for development of complete plantlets and multiplication from meristem tips. Best response was observed in variety Atlanta. For callus culture and plant regeneration two explants (internodes and leaf segments) were used and 2,4-D (3, 3.5 and 4) NAA(1.5, 2 and 2.5) and NAA+BAP (1+0.5, 0.5+1 and 1+1) levels were applied to MS media for callus induction as well as plantlet regeneration. Ten explants were cultured in each combination. Internode showed better performance in callus induction and plantlet regeneration. The highest percentage (88.88%) of callus was induced with 3mg/l 2,4-D in Atlanta and highest no. of shoot per callus was 3.417 in Atlanta. The success of plant tissue culture for in vitro culture of potato was encouraged by acclimatization of the plantlets in the green house conditions. Regenerated plants were morphologically uniform with normal leaf shape and growth pattern. For callus induction among the three genotypes Atlanta was found to be best. Regeneration of plantlets from internodes derived calli was optimum when they were transferred on MS medium supplemented BAP 3mg/l+1mg/l NAA and was found most effective in production of shoot. In vitro evaluations of salinity (NaCl) effects on three potato varieties (Atlanta, Japanese red and Kenne bec) were investigated with four NaCl level (0,25,50 and 75 mM) by using single node explants. The results revealed that the growth of all genotypes was significantly inhibited by increasing salt treatments under in vitro condition. Salinity stress gradually depressed plant growth and root development with increased NaCl concentration in MS media. The result indicates that Kenne bec performed better in shoot length and root length than Atlanta and Japanese red. Highest salinity level drastically inhibits root growth in all the cultivars tested. The control and 25 mM NaCl containing MS media did not affect the growth traits of in vitro potato plantlets. The control was found superior in growth characterized than rest of the tested NaCl levels. The result is replicable for tropical, subtropical and for winter conditions specially it can be useful for the researchers, teachers of the different Universities and specially for the ministry of agriculture of Bangladesh.