کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
2180232 | 1095120 | 2006 | 8 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: On the embryology and mode of reproduction of selected diploid species of Hieracium s.l. (Asteraceae) from Bulgaria On the embryology and mode of reproduction of selected diploid species of Hieracium s.l. (Asteraceae) from Bulgaria](/preview/png/2180232.png)
Three diploid taxa – Hieracium transylvanicum (subgenus Hieracium), Hieracium caespitosum subsp. brevipilum and Hieracium pavichii (subgenus Pilosella) – from five natural Bulgarian populations were investigated embryologically. The peculiarities of the male and female gametophytes, embryo- and endospermogenesis were established in each species. The results suggest that the species propagate sexually as expected from their diploid chromosome number. However, some forms of apomixis have also been observed, e.g. somatic apospory and integumental embryony in H. pavichii. The presence of apomixis in a diploid taxon shows that polyploidy is not an obligatory prerequisite for apomixis and the two phenomena are independent. The embryological plasticity detected in H. pavichii and H. transylvanicum suggests they may have higher opportunities for adaptation and successful reproduction.
Journal: Flora - Morphology, Distribution, Functional Ecology of Plants - Volume 201, Issue 8, 23 November 2006, Pages 668–675