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The Gnaphalieae are a group of sunflowers that have their greatest diversity in South America, Southern Africa, and Australia. The objective of this study was to reconstruct a phylogeny of the South African Gnaphalieae using sequence data from two noncoding chloroplast DNA sequences, the trnL intron and trnL/trnF intergenic spacer. Included in this investigation are the genera of the Gnaphalieae from the African basal groups, members of the subtribes Cassiniinae, Gnaphaliinae, and Relhaniinae, and African representatives from the large Old World genus Helichrysum. Results indicate that two Gnaphaloid genera, Printzia and Callilepis, should be excluded from the Gnaphalieae. In most trees the Relhaniinae s.s. (sensu stricto) and some of the basal taxa comprise a clade that is sister to the remainder of the tribe Gnaphalieae. The Relhaniinae, which are restricted to Africa, are not a monophyletic group as presently circumscribed, nor are the South African members of Helichrysum, the Cassiniinae and Gnaphaliinae. There is general agreement between our molecular analysis and that of morphology, particularly in the terminal branches of the trees.  相似文献   
2.
Abstract Anaphalis is one of the largest genera of the Asian Gnaphalieae (Asteraceae) and is most diversified on the Qinghai‐Tibet Plateau. The chromosome numbers and karyomorphology of six species from seven populations were investigated for the first time for this region. Chromosome numbers have been newly documented for four species: Anaphalis deserti (2n = 56 = 24 median [m]+ 24 submedian [sm]+ 8 acrocentric [st]); Anaphalis plicata (2n = 56 = 26m + 30sm); Anaphalis xylorhiza (2n = 28 = 2 median point [M]+ 14m + 12sm); and Anaphalis rhododactyla (2n = 56 = 32m + 24sm). Two further counts are in agreement with the previously reported numbers, that is, Anaphalis royleana (2n = 28 = 4M + 6m + 18sm) and Anaphalis margaritacea (2n = 28 = 12m + 16sm). A new polyploid cytotype (2n = 56 = 26m + 30sm) was found in the Zougong population of A. margaritacea. Polyploidy is for the first time reported for Anaphalis, with four out of seven counts being tetraploid. Our cytological results suggest that polyploids might have played an important role in the evolution of Anaphalis on the Qinghai‐Tibet Plateau.  相似文献   
3.
Anaphalis is one of the largest genera of the Asian Gnaphalieae (Asteraceae) and is most diversified on the Qinghai-Tibet Plateau. The chromosome numbers and karyomorphology of six species from seven populations were investigated for the first time for this region. Chromosome numbers have been newly documented for four species: Anaphalis deserti (2n = 56 = 24 median [m] + 24 submedian [sm] + 8 acrocentric [st]); Anaphalis plicata (2n = 56 = 26m + 30sm); Anaphalis xylorhiza (2n = 28 = 2 median point [M] + 14m + 12sm); and Anaphalis rhododactyla (2n = 56 = 32m + 24sm). Two further counts are in agreement with the previously reported numbers, that is, Anaphalis royleana (2n = 28 = 4M + 6m + 18sm) and Anaphalis margaritacea (2n = 28 = 12m + 16sm). A new polyploid cytotype (2n = 56 = 26m + 30sm) was found in the Zougong population of A. margaritacea. Polyploidy is for the first time reported for Anaphalis, with four out of seven counts being tetraploid. Our cytological results suggest that polyploids might have played an important role in the evolution of Anaphalis on the Qinghai-Tibet Plateau.  相似文献   
4.
 The tribal affinities of Cratystylis and Haegiela were assessed using three chloroplast DNA sequences, the trnL/F spacer, the trnL intron and the matK coding region. The outgroup was represented by two species of the subfamily Barnadesioideae, whereas one to seven genera (45 species including Cratystylis and Haegiela) of the tribes of the Asteroideae [Anthemideae (6 genera), Astereae (7), Calenduleae (2), Gnaphalieae (7), Heliantheae s.l. (5), Inuleae s.str. (3), Plucheeae (3), Senecioneae (4)] and Cichorioideae, [Arctotideae (1), Cardueae (2), Lactuceae (2), Liabeae (1), Mutisieae (1) and Vernonieae (1)] comprise the ingroup. Phylogenetic analysis indicates that Cratystylis has strong support as a member of the tribe Plucheeae, whereas Haegiela is a member of Gnaphalieae. At some point in their taxonomic history, both genera have been placed in these tribes and there are good morphological and chemical characters that justify these placements. The monotypic Haegiela was once included in Epaltes (Plucheeae) and this study has confirmed the need for the separation of the two genera. The genus Cratystylis appears to be monophyletic. Received August 26, 2002; accepted September 19, 2002 Published online: February 7, 2003  相似文献   
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