中国种子植物特有属的地理分布格局

生物特有现象的地理格局及其形成机制是生物地理学的重要研究内容.本文通过整合173个地区的中国种子植物特有属编目资料、环境和空间因子数据,运用多元回归和方差分解的方法,探索了中国种子植物特有属丰富度及其占全部种子植物属丰富度的比例(特有属比例)与环境(生境异质性和气候)和空间因子的关系.结果表明:(1)特有属丰富度及特有...     

Pararotylenchus n. gen. (Pararotylenchinae n. subfam., Hoplolaimidae) with Six New Species and Two New Combinations

A new subfamily, Pararotylenchinae, (Hoplolaimidae) is described. It includes a single genus, Pararotylenchus n. gen., six new species, attd two new combinations, Pararotylenchus (syn. Tylenchorhynchus) brevicaudatus (Hopper, 1959) n. comb. and Pararotylenchus (syn. Rotylenchus) pint (Mamiya, 1968) n. comb. Pararotylenchinae is similar to certain other Hoplolaimidae, such as Rotylenchinae, with respect to most characters including the short tail, the position of the phasmids near the anus, and the relatively great distance of the dorsal gland orifice from the base of the stylet knobs. The lip region, as observed with the scanning electron microscope, conforms to the basic pattern for Hoplolaimidae. The labial disc is round with slit-like amphidial openings at the lateral sides of the periphery of the disc. The distinctive anterior-most lip annule is segmented into six sectors. Unlike other Hoplolaimidae, however, the esophageal glands of Pararotylenchinae form a basal bulb similar to that of Tylenchorhynchidae; other characters do not resemble Tylencborhynchidae. Specimens of Pararotylenchus have been recovered only from cool regions at high elevations and Pacific coastal areas in the Western United States, Japan, and Korea.     

New Upper Cambrian Lingulata (Brachiopoda) from the Agyrek mountains (northeastern central Kazakhstan)

Two new genera, Repkinella and Aristotreta, and five new species from the class Lingulata (Brachiopoda) are described from the Upper Cambrian olistolith limestone enclosed in the Upper Ordovician olistostrome from the Agyrek mountains (northeastern Kazakhstan). The family Curticiidae Walcott et Schuchert is referred to the order Lingulida, not order Acrotretida, where it was previously placed.     

Xanthidae MacLeay, 1838 (Decapoda: Brachyura: Xanthoidea) systematics: A multi-gene approach with support from adult and zoeal morphology

Currently, 13 subfamilies are recognised in the brachyuran family Xanthidae: Actaeinae, Antrocarcininae, Chlorodiellinae, Cymoinae, Etisinae, Euxanthinae, Kraussiinae, Liomerinae, Polydectinae, Speocarcininae, Xanthinae, Zalasiinae and Zosiminae. This classification has been based on shared adult features like a transversely ovate carapace, well defined dorsal carapace regions, usually with lateral dentition, stout chelipeds and relatively short ambulatory legs. Such characters are now considered to be convergent. Consequently a number of higher xanthid taxa may be artifical and not monophyletic. A broad sample of 147 xanthid species representing 75 out of 124 genera from all 13 xanthid subfamilies were sampled in a multi-gene analysis. Four markers (three mitochondrial and one nuclear) were used and yielded a tree with ca. 30 xanthid clades. Monophyletic support was demonstrated for the Antrocarcininae (although substantially redefined), Cymoinae, and Polydectinae. Almost every other subfamily was para- or polyphyletic. Furthermore, the two other families of the Xanthoidea, Pseudorhombilidae and Panopeidae, were found nested within the Xanthidae. The molecular results were consistent with phylogenetic relationships implied by a suite of novel and/or neglected “ventral” adult characters including sternal characters, position of genital openings and morphology of the first zoea, instead of “dorsal” characters traditionally used to infer xanthid relationships.     

中国金缕梅科植物属分布区特点的定量研究

利用ArcGIS软件制作以县为单元的中国金缕梅科植物属的空间分布图,并从图中提取每个属的斑块个数、面积及周长,计算斑块的形状指数、最大斑块指数、Simpson均匀度指数和Shannon均匀度指数,定量分析中国金缕梅科植物各属的空间分布区特点,为金缕梅植物资源的保护、开发和利用提供依据.结果 表明:(1)山铜材属、银缕梅...     

Association of plant development to organic matter and fungal presence in soils of horticultural crops

Soil microbial communities are a crucial link between soil nutrient availability and plant productivity. They particularly depend on soil organic matter (SOM) content, which is considered one of the main components of soil fertility. But agricultural intensification and the increase in the use of fertilisers of mineral origin in recent decades (to the detriment of the incorporation of organic materials in agricultural soils) have resulted in a continuous loss of agricultural soil quality and fertility, which is considered one of the greatest challenges to addressing global food security. Therefore, a better understanding of the mechanisms driving soil improvement via soil microbiota could result in a sustainable improvement in crop yields. Soils were sampled in 40 intensively managed greenhouses in southeast Spain to understand how SOM influences soil fungal community and how both these factors influence plant development. The values of three out of four growth‐related variables (plant height, aerial dry weight and leaf area, but not root dry weight) in both tomato and cucumber plants showed a positive relation with SOM content and soil fungal diversity. This study concludes that SOM is key for the maintenance of soil fertility in intensive horticulture and that it is linked to the composition and diversity of soil fungal community. Both SOM and soil fungal communities should be considered as essential factors in achieving high soil fertility, and ultimately, to ensure an optimum crop development.     

Cretaceous climate variations indicated by palynoflora in South China

We compiled the Cretaceous sporopollen fossil data from 19 locations of six provinces in South China, reviewed the affinities of spore and pollen genera by examining and assessing these fossils with published data, and associated them with the sporomorph eco-groups (SEG) model and vegetation type. Seven palynofloral assemblages (PA1–PA7) were identified. PA1 (Berriasian–Valanginian) and PA2 (Hauterivian–Barremian) mainly include Cheirolepidiaceae (～60–80%), Cycadophytes (～10%), and Lygodiaceae (～10%), indicating warm and dry climate; PA3 (Aptian) and PA4 (Albian) represent warm, semi-arid to semi-humid climate with vegetation composed of Araucariaceae (～10%), Cheirolepidiaceae (～40–60%), Cycadophytes (～10%), and Lygodiaceae (～10%); PA5 (Cenomanian–Turonian) and PA6 (Coniacian–Santonian) imply a hot, semi-humid to humid climate with the vegetation taxa of Lygodiaceae (～20–40%), Cheirolepidiaceae (～20–50%), Ephedraceae (～5–8%), and Araucariaceae (～10%); and PA7 (Campanian–Maastrichtian) indicates a relatively cool and dry climate evidenced by the vegetation composition of Cheirolepidiaceae (～30–40%), Pteridaceae (～10%), Ephedraceae (～5–8%), and Ulmaceae (～30–40%). Our SEG analysis reveals three climatic evolution phases: the Berriasian–Barremian warm-dry phase, the Aptian–Santonian warm-wet phase, and the Campanian–Maastrichtian cool-dry phase. The climatic variation pattern is compatible with that indicated by fossil stomatal pCO₂ values and the pCO₂ simulation of GEOCARB II and III models, providing independent climatic proxies of the region and contributing to better understanding of the global Cretaceous climatic changes.     

Why one species in New Zealand,Pugetia delicatissima (Kallymeniaceae,Rhodophyta), should become two new genera,Judithia gen. nov. and Wendya gen. nov.

Blade-forming red algae occur worldwide and, prior to DNA sequencing, had been notoriously difficult to identify and classify, especially when lacking critical reproductive features. This, coupled in New Zealand with many longstanding assumptions that taxa were identical to non-New Zealand species or genera, resulted in many misapplied names. Pugetia delicatissima R.E. Norris, an endemic New Zealand blade-forming species of the family Kallymeniaceae, is actually comprised of one existing and one new species belonging to two distinct genera, as established by our phylogenetic analyses of DNA sequences from the rbcL gene. Analyses of combined rbcL and LSU genes showed that neither is closely related to the generitype of Pugetia, the northern-eastern Pacific, P. fragilissima Kylin. We propose the names Judithia and Wendya for these two newly revealed genera. In addition to diagnostic rbcL and LSU sequences, Judithia is morphologically and anatomically characterized by rounded to oblong blades that do not taper basally at the stipe, loosely aggregated surface cortical cells and cystocarps lacking both a pericarp and an ostiole, all features observed in the holotype of P. delicatissima. Wendya, in contrast, is characterized by blades that taper both apically and basally, compactly arranged surface cortical cells and cystocarps that have both a pericarp and a distinct ostiole. The two genera also are distinguished from one other, as well as from Pugetia by features of pre- and post-fertilization development, including the number of subsidiary cells produced on carpogonial and auxiliary branch systems, whether subsidiary cells in the carpogonial branch system fuse with the supporting cell or not, and the site of origin of gonimoblast cells. Although small in area, New Zealand hosts ten of the 27 currently recognized genera in the Kallymeniaceae and is the southern-hemisphere region of greatest generic diversification in this family.