The Situation in the Biological Sciences (1948)
Modifying Flax
I. A. Minkevich

I believe that our experiments with oil flax may be of some interest. Back in 1939 a dwarf variety of a single-stalk and single-boll upland flax was gathered in Uzbekistan. Its height was 13-15 centimetres. After a change of external conditions (sowing at Krasnodar, in a zone of sufficient humidity, provision of an increased feeding area and application of basic fertilizers) in 1940-1942 a multi-stalk and multi-boll oil flax was obtained. But the most important point is that we have succeeded in perpetuating the alterations thus achieved. The oil content of the seed of the initial variety, the dwarf single-boll flax, was 42.7%, for absolutely dry seeds. After its transfer to and training in the North Caucasus (under new conditions) the oil content of this form reached 45.8%. And, as our investigations have shown, this was due not only to a reduction of the husk of the seeds, but mainly to a reshuffling and change of the components of the seed itself. A change has also occurred in the quality and quantity of the fibre. Experiments with this new form at the Odessa Institute of Selection and Genetics, at the Leninakan State Plant-Breeding Station and in other places in 1947 have shown that the oil-content character is preserved.

Another experiment (with flax) was carried out at the Don Oil Crop Experiment and Breeding Station. In 1939-1941 original seeds of the fibre flax 806/3 bred by the Flax Institute (Torzhok) were sown at the Station. Parallel to this all the subsequent generations of this variety, as reproduced by the Don Station, were sown. All the requirements of field experiment were strictly observed in the sowing. An examination of the crops and their qualities has elicited the following facts: The original seed received from the Flax institute contained 39.3% of oil (in absolutely dry seeds); the seeds planted at the Station in the first year yielded 3.7 c. of seeds and 16.2 c. of stem per hectare. In the second year the crop per hectare was 4.3 c. of seeds and 11.7 c. of stem; the oil content was 40.1% Analysis of the plants grown in the third year showed a yield of 4.4 c. of seeds and 7.4 c. of stem, and an oil content of 40.4%. To appreciate these results we must bear in mind that fibre flax is distinguished from the oil flax and intermediate varieties cultivated in the South by a low yield of seeds, a much higher yield of stem and a low oil content. From these facts it is to be seen that when grown under southern conditions the fibre flax shows a tendency towards a gradual increase in the yield of seeds, a lowering in the yield of stem and a higher oil content in the seeds--in other  words, it reveals a shifting, even if slow, of characters from those of fibre flax in the direction of intermediate varieties.

The process of oil formation in flax begins from the moment of flowering and continues until full maturation. The rate at which oil accumulates in the seeds under definite favourable conditions (meteorological and agrotechnical) is subject to definite laws. The factors which ensure a high crop, as a rule, also create the favourable conditions for the accumulation of oil in the seeds.

The results of our work with flax show that alterations in development can be transmitted to succeeding generations. Of course, this transmission is accomplished only as the result of repeated influences brought to hear in the course of several generations.

The facts I have cited show the correctness of the Michurin trend in biology, which proceeds from materialist positions. It means that changes in the conditions of life, in the conditions of the external environment, as a rule, inevitably lead to the breakdown of the old type of a plant organism and the creation of new forms corresponding to the new conditions of life. The Michurin trend in biology maintains that the new properties of living organisms, acquired under the influence of changes in the conditions of the environment, can be hereditary. This arms the practical worker with scientific methods for changing and perfecting plants so as to serve man's requirements, so as to breed highly-productive varieties. To deny that hereditary properties of plants undergo qualitative alterations under the influence of changes in environmental conditions, to deny that living organisms can transmit properties and qualities which arise in the living body under the influence of the conditions of life, is to take a metaphysical attitude to the matter; it means abandoning the materialist, dialectical position. One result of denying that the conditions of life of plants influence the heredity of living organisms is that selection loses touch with agrotechny, which is harmful.

We thus see that there is no break, no disconnection between organism and environment, between the genotype and the phenotype, between hereditary variation and modification. This means that we have every opportunity to take a hand in changing the nature of plants by making use of the external conditions of their existence. This is the point of departure of I. V. Michurin's and Academician T. D. Lysenko's teachings. It is the only correct point of departure and its succinct expression is to be found in Darwin's definition of a species. By using the influence of external factors and creating suitable conditions of development, it is possible, by means of selection, to breed new, more perfect varieties of plants.

This premise is borne out by the facts of practical breeding and by the history of the development of cultivated plants. By making use of the external conditions and directing them in such a way as to best bring out the properties and organs for the sake of which the given plant is cultivated, we can gradually alter and improve the plant along the lines we need, perpetuating the useful alterations by selection. The sunflower may serve as an example of an exceptionally rapid process of form development under the influence of the above-mentioned factors. It is relatively recently, as we know, that the sunflower became a cultivated plant; yet in this short space of time there has evolved a complete species of cultivated sunflower with numerous ecotypes.

The degree to which various forms and strains of oil plants react to external conditions varies. Forms and varieties with sharp fluctuations of economical and biological properties depending on environmental factors cannot be expected to range over a large area. They can only be cultivated in a limited number of regions where the soil and climatic conditions are conducive to the development of the positive properties.

The factual material concerning oil plants shows that vegetative hybridization opens up new ways of directing the form-building process and should in future he widely used in breeding new varieties of oil plants. To make sure of success in this matter, it is necessary, as in the case of sexual hybridization to create training conditions conducive to the development of the properties and characteristics which it is desired to obtain and to fix in the progeny. It has been established, on the basis of the Institute's work in recent years, that a highly promising method for obtaining new initial material for sunflower breeding is the free intervarietal cross-pollination of varieties distinguished by high yield, high oil content, resistance to broom rape and other positive properties, but of different origin and cultivated in the course of several generations under different conditions and in various places. The materials and facts accumulated by the Institute in recent years attest that the larger tasks in regard to the production of oilseeds can no longer be tackled by the old methods. At the same time the new methods must be devised in conformity with the advanced Soviet teaching in biology, which opens up boundless vistas in this sphere. (Applause.)


Durrant began similar research a few years after this work was published in English translation.