Articles by Martti Ryynänen

The curly-grained trait of Betula pendula Roth is inheritable, but it is persumably not question of only one Mendelian gene since, for instance, there are a number of different types of curly-birch. The progeny obtained from controlled crossing between two curly-birch individuals do not all posses the curly-grained trait.

Plantlets were produced from adult curly-birch (Betula pendula var. carelica). Murashige and Skoog’s medium was used as the culture medium. Growth was initiated on a medium containing 1 mg/l BAP. Bud formation was induced using a medium containing 10 mg/l BAP and 0.2 mg/l NAA. Development of shoots was achieved on a medium containing ½ x Murashige and Skoog’s macrominerals and sucrose, 1/1 x Murashige and Skoog’s microminerals and vitamins, and 0.5 mg/l BAP and 0.5 mg/l IAA. The medium used for inducing root formation was the same as above, but without any growth regulators. The results indicate that adult deciduous trees can be best propagated through tissue culture when the least differentiated cells, i.e. the initial cells of the promeristem, are used as the startin material. The axillary buds provide easily available study material which can be prepared with little difficulty and are continuously renewed.

The PDF includes a summary in Finnish.

• Ryynänen, E-mail: lr@mm.unknown
• Ryynänen, E-mail: mr@mm.unknown

Soft X-ray radiation (Grenz rays) has been used in the X-ray radiography of seeds. It is based on the principle that the different parts of the seed absorb X-rays to a slightly varying extent. Empty seeds and empty regions in the seeds appears as dark areas on the film. X-ray radiography without staining and X-ray contrast radiography were compared to study the stored seeds of Scots pine (Pinus sylvestris L.). The results were compared with the results of germination in a Jacobsen germinator according to ISTA norms.

Normal X-ray radiography gave too good estimates of germinative capacity of the seeds, and was shown to suit only when it is used to study fully ripe seeds which have recently been collected in an undamaged condition. The results of X-ray contrast radiography when barium chloride was used as the stain, however, followed closely the germination results.

The PDF includes a summary in Finnish.

• Ryynänen, E-mail: mr@mm.unknown