Mutational witches’ brooms (WB) spontaneously arise in the tree crown. There are no male cones in Pinus sibirica WB and pollination always occurs with normal pollen. We studied 2-year-old seed progeny obtained from open-pollinated cones of WB and normal crown (NC) pines. There were significant morphological differences in two pairs of WB and NC families, while the third family pair studied showed barely pronounced differences. Segregation analysis of WB seed progeny based on needle length (growth trait) and total bud number (branching trait) revealed that about half of seedlings had a normal phenotype, while mutants were from 15.6 to 35.7 %. The rest seedlings could not be unambiguously identified, because they have not yet fully demonstrated the phenotype. Looking normal seedlings from WB families differed not only from mutants but also from NC progeny. Therefore, the mutation had some effect on both mutant seedlings and seedlings with a normal phenotype. Moreover, the denser was maternal WB the more differences were observed between WB and NC progeny.

中文翻译：

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巫婆扫帚突变对西伯利亚松幼苗生长的影响

变异女巫的扫帚（WB）自发地出现在树冠上。西伯利亚松没有雄性锥白粉病和授粉通常发生在普通花粉中。我们研究了从WB和普通树冠（NC）松的开放授粉锥中获得的2岁种子后代。在两对WB和NC家族中存在明显的形态学差异，而所研究的第三对WB家族则几乎没有显着差异。基于针长（生长性状）和总芽数（分支性状）的WB种子后代的分离分析表明，大约一半的幼苗具有正常的表型，而突变体的突变率为15.6％至35.7％。其余幼苗无法明确鉴定，因为它们尚未充分显示表型。从WB家族看正常的幼苗不仅与突变体不同，而且与NC后代也不同。因此，该突变对突变苗和具有正常表型的苗均具有一定作用。