Growth regulators on potato meristem culture

Abstract

Fourteen culture media were tested for differentiation and growth of potato (Solanum tuberosum L. cv. Baronesa) meristems with one to three primordial leaflets (2-4 mm long). Seven of these media were variations from Murashige & Skoog (MS) basic medium with the addition of 100 mg/l of myo-inositol, 30 g/l of sucrose and 10 g/l of agar (MS). The other seven media were variations from White basic medium with the addition of 20 g/l of sucrose and 10 g/l of agar (WB). Both MS and WB were supplemented with the various concentrations of growth regulators, such as two auxins – alphanaphthaleneacetic acid (ANA) and 2,4-dichlorofenoxiacetic acid (2,4-D) - and two cytokinins - 6-furfurilaminopurine (KIN) and 6.benzilaminopurine (BAP). The culture media were adjusted to pH 5.6, after autoclaved at 105ºC for 10 min. The meristems were explanted onto flasks with 25 ml of the medium, which were then kept in a growth chamber with a temperature of 22 ± 2ºC. Continuous light with an intensity of 600 lux provided by cool, white fluorescent tubes was utilized. The first signs of differentiation occurred about 30 days after placement of the meristem on the media. Small outgrowths were evident on the surface of a developed callus tissue or directly on the explants. These outgrowths elongated and rooted abundantly when transferred to MS. The seedlings were transplanted to 200 - ml pots containing a sterilizer mixture of sand and soil (1:1 ratio). MS were best than WB to root outgrowths, plant vigor and development. The best treatment was MS-6 (0,01 mg/l of 2,4-D and 0,04 mg/l of BAP) followed by MS-5 (0.02 mg/l of ANA and 0,04 mg/l of BAP). For MS-5 rooting was delayed.