Abstract:
This study was undertaken In vitro to investigate the inhibitory effects of Chromium (Cr) VI by using K2Cr2O7 on the growth of adventitious roots of potato (Solanum tuberosum L. cv Desiree). Another objective was to determine possible reversal of the detrimental growth effects with suitable combinations of GA3 and IAA. It was observed that the applied Cr VI (100 ppm) alone in MS media inhibited root growth. However, addition of selected combinations of GA3 and IAA in the MS media along with Cr VI improved the root growth. The plants grown on MS medium + 100 ppm K2Cr2O7 resulted in reduction in number of adventitious roots up to 36.26%, number of rootlets (80.64%), diameter (37.27%), fresh and dry weights (72.96 and 84.74%, respectively) in comparison with control (MS medium). MS media containing 100 ppm K2Cr2O7 + 20 ppm GA3 + 16 ppm IAA enhanced the average number of roots from 4.78 to 62.6, number of rootlets from 2.6
to 28.2, diameter from 0.13 mm to 0.68 mm, fresh weight from 34.4 mg to 1234.75 mg and dry weight from 1.8 mg to 80.40 mg compared with cultures grown on MS + 100 ppm Cr (VI). The results thus highlight the fact that the deleterious effects of Cr VI on potato growth In vitro can be reversed with suitable hormonal treatments. Furthermore, this research has possible implications on large scale potato cultivation under heavy metal stress in a broader sense.
