DIGITALNA ARHIVA ŠUMARSKOG LISTA
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ŠUMARSKI LIST 9-10/1971 str. 34 <-- 34 --> PDF |
By comparing ratios of the polien grains dimensions, i. e. their indices, it is visible that B/A and B/D indices are identical in all tree forms of Fir (Tab. 5), while other ratios differ. Thus, the B/C index is greatest in the pollen from yellow inflorescences., the B/E in two-coloured, the C/D in violet, and the D/E in two-coloured inflorescences. Through measuring the lenths of the violet, yellow and intermediate (two-coloured) inflorescences (Tabs. 6 and 7) we came to the conclusion that the male inflorescences with the violet pigmentation were longest, from which it follows that the length of inflorescences was in correlation with the size of pollen. Namely, by all appearances, the violet inflorescences produce larger pollen grains. 2. By evaluating the results of the performed investigations we came to the conclusion that of all environmental factors influencing the germination process of Fir pollen, greatest influence was exerted by the temperature. As regards the effect of light on the pollen germination — despite that we had established no direct influence of light onthe process of germination — this ought to be studied again in detail (Tab. 10). At a temperature of 15° C (at night) — 25° C (during the day), the Fir pollen germinated best from the 3rd to the 6th days, the process of germination was terminated on the 8th or 9th days (Graph 1, and Tab. 8). Bollen from the violet and yellow inflorescences exhibited an almost identical germinability, except that the pollen from the violet inflorescences germinated better during the lrst, 3rd, 4th and 5th days, while from the yellow inflorescences during the lrst, 7th, 8th and 9th days. Pollen from the intermediate inflorescences were lagging considerably behind the first two (Tab. 8, and Graph 1). The reaction of particular individuals to the process of germination is very uneven. Thus, the germination percent of pollen from the Perister locality varied from 23 to 82%, in trees from the Vrteška locality from 47 to 83%, and in trees from Brajčino from 60 to 67%. Which means that the geographical origin of a tree exercised an influence on the process of germination of Fir pollen. The Fir pollen can preserve its germinability in a very simple manner for a period of 24 months (about 750 days) if kept in an exsiccator over CaCh -f- H2SO4 (2%) in an ordinary houshold refrigerator at temperature of ca. 4° C (Graph. 2). Pollen stored in this manner exhibited a germinability of 42% in violet inflorescences, 29% in yellow, and 36% in two-coloured ones. When studying the formation of pollen tubes in pollens from different trees it was noticed that they appeared 3—4 hours after sowing, and in some individuals also after 2—3 days. In like manner it was established that pollen tubes were longer in pollens from violet inflorescences, and shortest in pollens from wellow inflorescences (Tabs. 11 and 12) . A = Length of pollen grain, B = Length of pollen body, C = Width of pollen body, D = Width of air bubble, E = Length of air bubble. |