ЭлБиб

H E A L T H Y P L A N T S A N D M IC R O P R O P A G A T IO N

MORPHOGENESISANDMICROPROPAGATIONOFTHECURLYBIRCH

I.I.Kontsevaya, A.A.Yatsyna

ForestInstitute ofthe NationalAcademy o fSciences o fBelarus, Gomel

The effect of the explant type and age, macrosalt components and

growth regulators on morphogenesis and micropropagation of the curly birch

in vitro

was studied. Immature embryos, cotyledons, nodule segments with

one bud and segments of laminae of 5-year-old plants were a starting material.

In the current study a modified Murashige and Scoog medium, WPM and

N6 were used. The media contained varying concentrations of BAP (0.5-

10.0 mg/L), 2ip (5.0 to 20.0 mg/L) and NAA (0.1 to 10.0 mg/L) were used to

induce morphogene-sis. The explants were cultured at 25°C under 16 h

photoperiod o f cool white fluorescent light with illuminance of 2-4 klx. Every

3-4 weeks the buds and shoots arose from the explants were transferred to

fresh media to: 1) expedite the growth of the shoots, and 2) stimulate shoot

formation.

It was revealed that the use o f cotyledons and immature embryos was

the most suit-able because it was easy to get sterile culture throughout the

year. However, one should use segments of lam inae o f ephedic plants to

conserve a particular genotype. It was determ ined that callus and multiple

shoot formation on the explants studied proceeded concurrently in spite o f

the fa c t that cotyledons displayed a higher level of shoot formation activity.

As a re-sult o f direct regeneration and through intermediate callusogenesis

buds and shoots were formed on segments o f lam inae. In some of them

rhizogenesis was observed. Macrosalt corn-position had no pronounced

influence on the results obtained. The explants cultured on media containing

BAP (1 to 2 m g /L ) produced organogenic callus. They also produced buds

from m e ris tem a tic tissues. The processes were asynchronous. The

reproduction quotient averaged 10 to 15. The buds and shoots transferred to

the hormone-free medium developed very vigor-ously. Even within two weeks

the explants cultured on this medium produced roots and shoots 2 cm in

length w ith 6-8 leaves.

432

Научная электронная библиотека ЦНСХБ