试论江西种子植物区系热带性属的分布式样

初步分析了江西种子植物区系热带性属的地理分布式样及其区系特征，将本省热带性种子植物４６５属划归为６种地理分布式样和７种间断分布式样。本区系地理成分复杂，以泛热带和热带亚洲分布型属占优势，并与世界各个热带植物区系有着广泛的联系。本区系间断分布类型多样，残遗植物类群丰富，稀危种类颇多，这都与地史变迁、大陆漂移和人类活动等影响密切相关。本区系由南亚热带至中亚热带向北亚热带逐渐过渡，成为许多热带性属的分布北界。

我国担子菌类热带种新知(英文)

近来在川、滇採 到和鉴定了担子菌的三个新种：金囊体刺管牛肝菌Ｔｕｂｏｓａｅｔａ ａｕｒｅｏｃｙｓｔｉｓ Ｍ．Ｚａｎｇ（牛肝菌科 Ｂｏｌｅｔａｃｅａｅ）、石栎假脐菇 Ｔｕｂａｒｉａ ｌｉｔｈｏｃａｒｐｉｃｏｌａ Ｍ． Ｚａｎｇ（锈伞科 Ｃｒｅｐｉｄｏｔａｃｅａｅ）和竹生墨伞 Ｃｏｐｒｉｎｕｓ ｂａｍｂｕｓｉｃｏｌａ Ｍ． Ｚａｎｇ（伞菌科 Ａｇａｒｉｃａｃｅａｅ）。刺管牛肝菌属 Ｔｕｂｏｓａｅｔａ为典型热带属，为我国新记录。

果蔗主要品种的特征特性研究初报

对 1 6个果蔗品种的特征特性进行了初步研究 ,结果表明 :大部分果蔗品种是甘蔗属热带种 (SaccharumofficinarumL .) ,其株形直立 ,蔗茎粗大 ,体细胞染色体数为 2n=80 ,叶片酯酶同工酶的变异不大 ;少部分果蔗品种是杂交选育的品种。不同果蔗品种的出苗率、分蘖率、产量及品质有较大的差异。夏植“黑皮果蔗”的有效茎数及产量与下种量之间没有明显相关性。

Relationship between Physical and Chemical Soil Attributes and Plant Species Diversity in Tropical Mountain Ecosystems from Brazil

Although the high diversity of plant species in the rupestrian fields has been primarily attributed to the existence of a set of distinct habitats, few studies support this assertion. The present study aimed to further investigate the relationship between physical and chemical attributes of soils with the diversity of plant species in this unique ecosystem. The rupestrian field is a unique vegetation formation that covers some of the southeastern Brazilian mountains in the transition of the Atlantic rain forest and the Cerrado(savanna). Different habitats occur according to soil characteristics(e.g., presence of rocks, sand, fertility, hydrology, etc.). These attributes ultimately influence the vegetation that is highly adapted to the harsh edaphic and climatic mountain conditions. Five distinct habitats were studied by us: rocky outcrops, peat bogs, sandy bogs, quartz gravel fields, and "cerrado"(savanna). A floristic survey indicated that four families are found at greater frequency: Poaceae, Asteraceae, Cyperaceae, and Leguminosae. The greatest diversity of plant species was found in the rocky outcrops habitat, followed by cerrado, peat bog, quartz gravel grassland, and sandy bogs, respectively. The main difference in the floristic composition among these habitats was related to the dominant species. Trachypogon spicatus(Poaceae) was the most dominant species in the rocky outcrops, Axonopus siccus(Poaceae) in the peat bogs, Lagenocarpus rigidus(Cyperaceae) in the sandy bogs, Schizachyrium tenerum(Poaceae) in the cerrado, while Vellozia sp. 8(Velloziaceae) dominated the vegetation in the quartz gravel grassland. This study demonstrated that physical and chemical soil properties strongly related the diversity of plant species occurring in the different habitats of rupestrian fields.

Morphology and molecular phylogeny of Paragorgia rubra sp.nov.(Cnidaria:Octocorallia),a new bubblegum coral species from a seamount in the tropical Western Pacific

A new species of bubblegum coral, Paragorgia rubra sp. nov., discovered from a seamount at a water depth of 373 m near the Yap Trench is studied using morphological and molecular approaches. Paragorgia rubra sp. nov. is the fourth species of the genus found in the tropical Western Pacific. The new gorgonian is red-colored, uniplanar, and measures approximately 530 mm high and 440 mm wide, with autozooids distributed only on one side of the colony. Paragorgia rubra sp. nov. is most similar to P. kaupeka Sainchez, 2005, but differs distinctly in the polyp ovals with large and compound protuberances （vs. small and simple conical protuberances） and the medullar spindles possessing simple conical protuberances （vs. compound protuberances）. Moreover, P. rubra sp. nov. differs from P. kaupeka in the smaller length/ width ratio of surface radiates （1.53 vs. 1.75 ）. The genetic distance of the mtMutS gene between P. rubra sp. nov. and P. kaupeka is 0.66%, while the intraspecific distances within Paragorgia Milne-Edwards ＆ Haime, 1857 except the species P. regalis complex are no more than 0.5%, further supporting the establishment of the new species. Furthermore, the ITS2 secondary structure ofP. rubra sp. nov. is also different from those of congeners. Phylogenetic analyses indicate Paragorgia rubra sp. nov. and P. kaupeka form a clade, which branched early within Paragorgia and diversified approximately 15 Mya.

Three tropical seagrasses as potential bio-indicators to trace metals in Xincun Bay,Hainan Island,South China

Concentrations of the trace metals Cu, Cd, Pb, and Zn were measured in seawater, rhizosphere sediments, interstitial water, and the tissues of three tropical species of seagrasses （Thalassia hemprichii, Enhalus acoroides and Cymodocea rotundata） from Xincun Bay of Hainan Island, South China. We analyzed different environmental compartments and the highest concentrations of Pb and Zn were found in the interstitial and seawater. The concentrations of Cd and Zn were significantly higher in blades compared with roots or rhizomes in 7＂. hemprichii and E. acoroides, respectively. A metal pollution index （MPI） demonstrated that sediment, interstitial water, and seagrasses in the sites located nearest anthropogenic sources of pollution had the most abundant metal concentrations. There was obvious seasonal variation of these metals in the three seagrasses with higher concentrations of Cu, Pb and Zn in January and Cd in July. Furthermore, the relationships between metal concentrations in seagrasses and environmental compartments were positively correlated significantly. The bioconcentration factors （BCF） demonstrated that Cd from the tissues of the three seagrasses might be absorbed from the sediment by the roots. However, for C. rotundata, Zn is likely to be derived from the seawater through its blades. Therefore, the blades of T. hemprichii, E. acoroides and C. rotundata are potential bio-indicators to Cd content in sediment, and additionally Zn content （C. rotundata only） in seawater.

Trace metal anomalies in bleached Porites coral at Meiji Reef, tropical South China Sea

Coral bleaching has generally been recognized as the main reason for tropical coral reef degradation, but there are few long-term records of coral bleaching events. In this study, trace metals including chromium(Cr), copper(Cu), molybdenum(Mo), manganese(Mn), lead(Pb), tin(Sn), titanium(Ti), vanadium(V), and yttrium(Y), were analyzed in two Porites corals collected from Meiji Reef in the tropical South China Sea(SCS) to assess differences in trace metal concentrations in bleached compared with unbleached coral growth bands. Ti, V, Cr, and Mo generally showed irregular fluctuations in both corals. Bleached layers contained high concentrations of Mn, Cu, Sn, and Pb. Unbleached layers showed moderately high concentrations of Mn and Cu only. The different distribution of trace metals in Porites may be attributable to different selectivity on the basis of vital utility or toxicity. Ti, V, Cr, and Mo are discriminated against by both coral polyps and zooxanthellae, but Mn, Cu, Sn, and Pb are accumulated by zooxanthellae and only Mn and Cu are accumulated by polyps as essential elements. The marked increase in Cu, Mn, Pb, and Sn are associated with bleaching processes, including mucus secretion, tissue retraction, and zooxanthellae expulsion and occlusion. Variation in these trace elements within the coral skeleton can be used as potential tracers of short-lived bleaching events.

Surface Reactivity in Tropical Highly Weathered Soils and Implications for Rational Soil Management

Highly weathered soils are distributed in the humid and wet-dry tropics, as well as in the humid subtropics. As a result of strong weathering, these soils are characterized by low activity clays, which develop variable surface charge and related specific properties. Surface reactions regarding base exchange and soil acidification, heavy metal sorption and mobility, and phosphorus sorption and availability of the tropical highly weathered soils are reviewed in this paper.Factors controlling surface reactivity towards cations and anions, including ion exchange and specific adsorption processes, are discussed with consideration on practical implications for rational management of these soils. Organic matter content and pH value are major basic factors that should be controlled through appropriate agricultural practices, in order to optimise favorable effects of colloid surface properties on soil fertility and environmental quality.