Effect of growth regulators on the morphological traits of three potato cultivars in vitro

Abstract

The experiments were conducted to study the effect of sub cultures (3 sub-cultures) of in vitro propagated plants of three cultivars of potato (Arnova, Riviera and Provento) and their interaction with Indole Acetic acid  (IAA) at 0.0 , 1.0 mg L-1 and Benzyl Adenine ( BA) at 0.0, 0.5, 1.0 and 2.0 mg L-1 concentrations on morphological traits of vegetative (plant height, number of shoots, leaves , nodes and length of shoots) and roots (number of roots and their lengths) system. The cultures were incubated under temperature of 25 ± 2°C and illumination for 16 h day-1. The plants were transferred to the greenhouse and data were taken on the number of minitubers, their diameter and weight after 90 days. The results showed the effectiveness of IAA at 1 mg L-1 increasing in plant height (16.06 and 14.83 cm for Rivera and Provento cultivars, respectively), and in number of leaves and nodes (18.08 leaf plant-1 for Rivera and 16.92  nod plant -1 for Provento), and the number of roots and their length. (11.25 root plant-1 and 11.25 cm for Rivera and Arnova cultivar, respectively). The results also showed the effectiveness of the combination of IAA (1 mg L-1 ) + BA (0.5 mg L-1 )  increasing the number and length of shoots  (6.50 shoot plant-1 and 4.83 cm for Provento and Rivera cultivar). A decrease in the number of roots was also observed with increasing concentrations of BA which added to the medium with or without of IAA. Results also recorded the highest average of diameter and weight of minitubers was 8.63 cm and 3.64 g for the mother plants of the Riviera and Provento cultivars, respectively, while the mother plants and in vitro  propagated plants of three cultivars did not differ in the average number of minitubers.