THE STUDY OF VARIABILITY OF VEGETATIVE AND REPRODUCTIVE ORGANS AND SOWING QUALITIES OF AMERICAN LARCH SEEDS UNDER THE CONDITIONS OF INTRODUCTION

Abstract

Introduction. Definition of germinating capacity and viability of seeds is of significant importance for introduction. There are no references to American larch (Larix laricina L.) in the standards for definition the sowing qualities of seeds and for determination the degree of quality for the seeds of coniferous species (12 kinds of larches are included). The goal of the research is to study the variability of morphological characters of cones, needles and seeds of American larch (Larix laricina L.) as well as to carry out the analysis for sowing qualities of seeds of American larch, growing under  the  conditions of introduction. Objects and methods of research. American larch was introduced in the Main Botanical Garden (Moscow) in 1956.  Fifty nine trees were grown from the seeds brought from the USA and Canada. Germinating capacity, viability, and degree of quality of seeds were determined in accordance with the international standards. The samples of cones and needles for the research purposes were collected in the sunny side of the bottom of tree crowns. Results. There is a substantial similarity between American and European larches on the dynamics of seed germination. This makes it possible to use the recommendations of the standards for European larch to define the germinating capacity of the seeds of American larch. Germinative energy and germinating capacity of the seeds of American larch were 8 and 15,8 % accordingly. Using the requirements of the standards for determination the degree of quality of seeds of European larch, the seeds of American larch may be designated as the seeds of 2 degree of quality. The share of viable and germless seeds of American larch under the conditions of introduction is very close to the figures for European larch. To estimate the seed qualities of American larch, it is possible to use the parameters recommended GOST 14161-86 (Government Standard) for the seeds of European larch. Conclusion. Under the conditions of introduction, low germinating capacity of seeds is determined. It is explained with the particularity, typical for Larix Mill at large and Americal larch in particular. It is recommended to use GOSTs (Government Standards) elaborated for European larch.