Table of Contents

18 January 2010, Volume 48 Issue 1
Cover illustration: Representative most parsimonious tree obtained after addition of 13 Early Cretaceous fossil taxa to a backbone tree of living angiosperms based primarily on molecular data. See DOYLE and ENDRESS, pp. 1–35 in this issue.
    Research Articles
  • James A. DOYLE* Peter K. ENDRESS**
    J Syst Evol. 2010, 48(1): 1-35.
    Over the past 25 years, discoveries of Early Cretaceous fossil flowers, often associated with pollen and sometimes with vegetative parts, have revolutionized our understanding of the morphology and diversity of early angiosperms. However, few of these fossils have been integrated into the increasingly robust phylogeny of living angiosperms based primarily on molecular data. To remedy this situation, we have used a morphological data set for living basal angiosperms (including basal eudicots and monocots) to assess the most parsimonious positions of early angiosperm fossils on cladograms of Recent plants, using constraint trees that represent the current range of hypotheses on higher-level relationships, and concentrating on Magnoliidae (the clade including Magnoliales, Laurales, Canellales, and Piperales) and eudicots. In magnoliids, our results confirm proposed relationships of Archaeanthus (latest Albian?) to Magnoliaceae, Endressinia (late Aptian) to Magnoliales (the clade comprising Degeneria, Galbulimima, Eupomatia, and Annonaceae), and Walkeripollis pollen tetrads (late Barremian?) to Winteraceae, but they indicate that Mauldinia (early Cenomanian) was sister to both Lauraceae and Hernandiaceae rather than to Lauraceae alone. Among middle Albian to early Cenomanian eudicots, we confirm relationships of Nelumbites to Nelumbo, platanoid inflorescences and Sapindopsis to Platanaceae, and Spanomera to Buxaceae. With the possible exception of Archaeanthus, these fossils are apparently not crown group members of living families but rather stem relatives of one or more families.
  • Yan LIU, Hai-Fei YAN, Tong CAO, Xue-Jun GE
    J Syst Evol. 2010, 48(1): 36-46.
    DNA barcoding is a molecular tool that uses a standardized DNA region to identify species. Our preliminary study reported here is the first attempt to specifically focus on universality and attributes of candidate barcodes across a wide systematic range of mosses. We tested eight previously proposed plant barcoding regions (atpF-atpH, ITS2, matK, psbK-psbI, rbcL, rpoB, rpoC1, trnH-psbA) and two popular phylogenetic markers (rps4 and trnL-trnF of cpDNA) in 49 moss species and 9 liverwort species, representing half of the orders in moss lineages. The ITS2, rbcL, rpoC1, rps4, trnH-psbA and trnL-trnF regions showed good universality, and therefore the efficacy of these loci as DNA barcodes was further evaluated in 36 mosses and 2 liverworts, each of which included two to three individuals per taxa. The five loci, viz. rbcL, rpoC1, rps4, trnH-psbA and trnL-trnF, were easy to amplify and sequence and showed significant interspecific genetic variability, making them potentially useful DNA barcodes for mosses. The best performing single loci were the rbcL and rpoC1 coding regions. Several loci showed equivalent performance and combinations of them did not greatly increase their discrimination capacity. In addition, phylogenies generated from each of the separate regions and multi-locus combinations by using best-fit and Kimura 2-parameter models were compared, but no significant difference was found.
  • Qin QIAO, Chang-Qin ZHANG, Richard Ian MILNE
    J Syst Evol. 2010, 48(1): 47-57.
    The levels and partitioning of genetic diversity and inbreeding depression were investigated in Tupistra pingbianensis, a narrow endemic of South-east Yunnan, China, characterized by a naturally fragmented distribution due to extreme specialization on a rare habitat type. Here genetic diversity and patterns of genetic variation within and among 11 populations were analyzed using AFLP markers with 97 individuals across its whole geographical range. High levels of genetic variation were revealed both at the species level (P99 = 96.012%; Ht = 0.302) and at the population level (P99 = 51.41%; Hs = 0.224). Strong genetic differentiation among populations was also detected (FST = 0.2961; ⍬= 0.281), which corresponded to results reported for typical animal-pollinated, mixed selfing and outcrossing plant species. This result was consistent with mating patterns detected by our pollination experiments. The indirect estimate of gene flow based on ⍬ was low (Nm = 0.64). Special habitat and its life history traits may play an important role in shaping the genetic diversity and the genetic structure of this species. A pollination experiment also fail to detect significant inbreeding depression upon F1 fruit set, seed weight and germinate rate fitness-traits. Since naturally rare species T. pingbianensis is not seriously genetically impoverished and likely to have adapted to tolerating a high level of inbreeding early in its history, we propose this species need only periodic monitoring to ensure their continued persistence but not intervention to remain viable.
  • Ying MENG,Hang SUN, Yong-Ping YANG, Ze-Long NIE
    J Syst Evol. 2010, 48(1): 58-64.
    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=24m+24sm+8st), A. plicata (2n=56=26m+30sm), A. xylorhiza (2n=28=2M+14m+12sm),and A. rhododactyla (2n=56=32m+24sm). Two further counts are in agreement with the previously reported numbers, i.e., Anaphalis royleana (2n=28=4M+6m+18sm) and A. 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 may have played an important role in the evolution of Anaphalis on the Qinghai-Tibet Plateau.
  • Yan-Ling LI, Zhi-Jun GONG, Chun-Chao WANG, Ji SHEN
    J Syst Evol. 2010, 48(1): 65-72.
    One new species, four newly recorded genera, and two newly recorded species of diatoms are described from China. They are Sellaphora fuxianensis sp. nov. Li, Sellaphora Mereschkowsky, Karayevia Round & Bukhtiyarova,Placoneis Mereschkowsky, FallaciaStickle & Mann, Placoneis prespanensis Levkov, Krstic & Nakov, andFallacia lucinensis (Hustedt) D. G. Mann. All taxa were collected from Lake Fuxian in Yunnan Province, China. These species were observed with LM and SEM, and their taxonomic characters are discussed.