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Wplyw czyszczen poznych na ksztaltowanie sie cech biomorfologicznych i budowy pietrowej podrostu jodly [na przykladzie powierzchni doswiadczalnej w Brzozowie-Jahonce]

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Jaworski A. , Paluch J.

tom 36

15-30

During 1983-1989 late cleanings were carried out in silver fir up-growth. Cuttings based on a positive selection had the most benefical effect on the biomorphological characteristics of silver fir up-growth. They were most intensive and led to increased increment in diamater of the stem and length of the crown, and also to storeyed structure of the up-growrh. Promotion of the most valuable individuals which in future should form the overstorey of the stand is also an important advantage of this treatment. In comparison with the control treatment the negative selection had a statistically significant effect on the height and diameter increment, change in absolute length of the crown and its height above the ground, as well as the number of its whorls. However, the negative selection led to disappearance of height differentiation in the silver fir biogroups.

Seed vigor, photosynthesis and early growth of saplings of different triploid Betula families

100%

Mu H. , Jiang J. , Li H. , Liu G.

tom 68

Breeding scientists have given extensive attention to triploids in trees because of their importance to forestry. Consequently, creating and breeding triploids of good quality has become one of purposes of tree breeding. We chose two autotetraploids (Betula platyphylla, named Q10 and Q65) as female parents and eight hybrid diploids (B. platyphylla × B. pendula, named F1 – F8) as male parents to obtain progenies through controllable pollination, resulting in triploid progenies. Germination rate and germination energy of triploid seeds of Q65 were significantly higher (P < 0.01) than in triploid seed s of Q10. Triploid families with Q65 as female parent had a large quantity of saplings, whereas triploid families with Q10 as female parent had a small quantity of saplings. Triploid families with Q65 as female parent were generally superior in base diameter and height to base diameter ratio when compared to a diploid family. Q65×F3 was preliminarily recognized as the superior family. These results demonstrate that the female parent has a major influence on triploid progenies, although the male parent also has a small influence. The results provided a reference to build seed orchards of triploid birch trees, choose tetraploids as female parents and forecast triploid families of good quality.