Effect of SO sub 2 on Generative Organs of Woody Plants.

摘要

The authors have made observations at three factories in Leningrad with specific conditions of air contamination. The authors used ethylene, ethyl ether, sulphur dioxide and sometimes chlorine. The common elm, the common bird cherry, and the common June berry did not bear fruit, although they flowered; the white birch and the silver birch, the white-cornel, and the balsam poplar bore fruit and seeds but shed them before they had ripened. Out of the 50 flowers produced by the white cornel, 18 bore fruit, and they all fell without ripening. The Tartar honeysuckle showed a considerable shedding of ovaries. In all the plants observed there was a clear increase in the relative number of prematurely falling ovaries on the side which was turned towards the source from which the gases were emitted. One theory proposed that the cause of these phenomena due to the action of sulphur dioxide on the angiospermae was the destruction of the activity of the assimilation leaf apparatus of the plants, which led to delay of flowering and insufficient accumulation, of reserve materials for forming the fruits. Another theory proposed, with regard to the fir plantations, that the smokey gases act directly on flowering and fruit bearing and indirectly cause weakening of the assimilation apparatus and destruction of the supply of the tissues. Regular fruit bearing cannot be expected from fir plantations which are damaged by smoke. A qualitative reduction of seed material does not ensure reproduction of the plantation based on the natural regeneration. 17 refs.