中国巨松鼠Ratufa bicolor(Sciuridae:Ratufinae)头骨形态的地理学变异

巨松鼠(Ratufa bicolor)是东洋界的特有类群.中国仅有一种,分布于海南、广西西南部、云南南部、西南部、西部和西北部,关于其亚种的分化结论过去主要依据其皮毛的颜色特征.本研究共测取75个巨松鼠头骨,每号头骨标本测取23个变量,运用统计分析软件SPSS 11.0对巨松鼠的可测量变量进行主成分分析、判别分析及聚类分析,以探讨巨松鼠各亚种地位的有效性及其头骨形态的地理学变异.研究结果显示阿萨姆亚种R.b.gigantea和海南亚种R.b.hainana均为有效亚种,前者分布自广西西南部向西经云南南部、西南部、西部达西北部,后者分布于海南.同时,本研究结果不支持滇南亚种R.b.stigmosa作为一个有效的亚种.

北京东灵山暖温带典型植被类型物种构成及物种多样性对氮素转化过程的影响

通过调查东灵山地区7个典型植被类型的物种多样性，并测定各林型中植物叶片养分特征，凋落物品质，土壤理化特性，豆科植物的生物固氮作用以及土壤有机质的净N矿化与硝化作用，研究了不同林型及其物种多样性对氮素转化过程的可能影响。结果表明： 1) 各林型乔灌草三层13个物种多样性指数之间都不同程度存在差异，且都表现基本一致的大小顺序，各样地乔灌草三层3个丰富度指数和5个多样性指数之间大都表现草本层>灌木层>乔木层的大小顺序。 2) 林型对植物叶片养分特征、叶片凋落物品质指标、土壤的大多数理化特性都有显著影响，其中，落叶阔叶林与针叶林之间的差异最为明显，优势种不同的针叶林之间也不同程度地存在差异。各林型物种多样性对植物叶片养分特征，凋落物品质和土壤理化特性也都不同程度存在显著影响，且乔灌草三层的物种多样性的影响不同。我们的结果支持物种多样性对生态系统过程存在显著影响的观点。 3) 胡枝子(Lespedeza bicolor)％FNDA值较低，在0～53.3％之间，与国外学者对某些木本豆科固氮植物的研究结果接近，但低于三叶草、野豌豆等草本豆科固氮植物。胡枝子生物固氮具有明显的季节差异，不同样地生境对胡枝子％FNDA值也存在显著影响，大都都表现铁塔辽东栎样地>重力点样地>站下灌丛样地>垭口样地的趋势。除胡枝子之外的其他豆科植物的％FNDA都高于胡枝子，且存在种间差异，以三籽两型豆(Amphicarpaea capillipes)最高(100％)，歪头菜(Vicia unijuga)最低(平均66.4％)，这些结果与国外相关研究接近。不同林型之间和同一林型不同样地之间也影响豆科植物的％FNDA。东灵山地区有相当数量的植物种具有和固氮植物相近的δ15N值和全N含量，具有潜在的生物固氮能力。6个林型中所有豆科植物的％FNDA平均值主要受乔木层和草本层物种多样性的影响，乔木层和草本层物种多样性提高，豆科植物的％FNDA将随之显著降低。 4) 气温、土壤温度和降水量显著影响各林型净氮硝化速率的季节动态，都表现为温度升高，降水量增加，净氮硝化速率也随之增大。 5) 在不同取样时间，不同林型在土壤NH4+、N03-含量，矿化、硝化速率以及年度总净矿化、硝化量之间均不同程度存在显著差异，其中，以辽东栎落叶阔叶林与针叶林之间，常绿针叶林与落叶针叶林之间，纯林与混交林之间的差异最为明显。 6) 土壤初始N0_3含量与年度总净硝化量，年度总净矿化量及其占TKN的百分比呈显著正相关关系;植物叶片全N浓度与净氮矿化、硝化作用呈显著负相关：植物叶片凋落物的品质指标与净氮矿化、硝化作用没有显著相关。 7) 胡枝子固氮作用(％FNDA值)越强，土壤有机氮的净硝化量就越大，胡枝子在从大气中获取大量N，的同时，很可能会增加氮素的淋溶损失量。胡枝子固氮作用(％FNDA值)与净氮矿化量不存在显著相关关系。 8) 只有乔木层和草本层部分种多样性指数对净氮矿化、硝化量存在显著影响。乔木层均匀度提高，土壤净氮碳化量将随之增大;而草本层物种多样性提高，均匀度提高，净氮矿化、硝化作用将随之降低，草本层植物对土壤氮素矿化作用具有显著抑制作用。 9) 落叶阔叶林与针叶林的供氮能力和维持无机氮素的能力之间存在比较明显的差异，而不同针叶林的矿化／硝化作用也有所差别。其中，辽东栎落叶阔叶林的供氮能力和维持氮素能力均高于针叶林和山杏灌丛;油松林的供氮能力与防止氮素损失的能力显然要强于落叶松林和山杏灌丛。 10) 尽管箭叶锦鸡儿灌丛植物叶片与凋落物中全N、全P浓度在大多数取样点上都低于硕桦(高于草甸)，但表层土中全N浓度高于硕桦和草甸，且其土壤有机质的供氮能力以及维持氮素能力都高于硕桦林和草甸，表明，锦鸡儿灌丛为侵入草甸和硕桦入侵提供了良好的养分条件，在该演替序列的发展过程中起了一定的推动作用。

Phylogeny and zoogeography of the cyprinid genus Epalzeorhynchos Bleeker (Cyprinidae : Ostariophysi)

A total of 62 variable osteological and external characters was found among the five currently recognized species of Epalzeorhynchos. When the genera Crossocheilus and Paracrossocheilus are combined as the outgroup, only 30 of these characters can be polarized. This includes six autapomorphies. The remaining 24 polarized characters form a data matrix which yields a single, 26-step tree with a Consistency Index (CI) of 1 and a Retention Index (RI) of 1, The analysis was also performed on a combined dataset in which the 32 unpolarized characters (characters for which the combined outgroup was dimorphic) were added and coded as missing data (i.e., "?"), Analyzing this data matrix with all multistate characters ordered generates the same single most-parsimonious tree with a length of 63 steps, a CI of 0.98 and a RI of 0.97, When either Crossocheilus or Paracrossocheilus is used as the sole outgroup, the same single most-parsimonious tree is produced although the numbers of informative characters and some of the polarities differ. Evidence is presented to support the following hypotheses: (1) E, kalopterus + E, frenatus + E. bicolor + E. munensis form a monophyletic group; (2) E. frenatus + E, bicolor + E, munensis form a monophyletic group with E, kalopterus as its sister group; this speciation event is congruent with the predictions of vicariant speciation mode I; and (3) E. bicolor and E. munensis are sister groups, again congruent with vicariant speciation mode I, Evidence presented here also supports the zoogeographical hypothesis that the faunas of the Indochinese region and the Greater Sundas are more closely related to each other than either of them is to the lower Salween basin fauna and that the lower Mekong, Chao Phraya, and Mac Khlong basin faunas are more closely related to each other than any of them is to the Greater Sundas, In addition, the monophyly of Epalzeorhynchos is also preliminarily discussed by including either Paracrossocheilus or Crossocheilus in the ingroup. It is demonstrated that E. bicornis clusters with Paracrossocheilus when Paracrossocheilus is included in the ingroup. It seems likely that the taxonomic position of E. bicornis will be resolved as more fishes of the Crossocheilus group are included in future studies.

重离子辐照对干旱胁迫下甜高粱幼苗的影响

<正>不同剂量(0Gy,40Gy,80Gy)碳离子辐照甜高粱(Sorghum bicolor(L)Moench)干种子后,水培7天时测定发芽率。在温度25℃/18℃,光照12h/12h条件下培养15d后,

甜高粱重离子诱变改良研究进展

<正>甜高粱(Sorghum bicolor(L.)Moench)属C4植物,具有很高的光合效率,是世界上生物量最高的作物,故有"高能作物"之称。另外,甜高粱具有抗旱、耐涝、耐贫瘠、

碳离子辐照诱变产生的甜高粱M2代幼苗对高温胁迫的响应

甜高粱(Sorghum bicolor(L)Moench)"凯勒"种子经不同剂量(0、10Gy、30Gy、50Gy、80Gy)80MeV/u碳离子注入后,其M2代幼苗对40℃高温胁迫作出了不同的响应:株高、叶绿素含量变化不大,相对低剂量(10Gy、30Gy)碳离子处理使M2代幼苗生物量高于对照CK(0Gy)和高剂量(50Gy、80Gy)处理,同时从丙二醛(Malondialdehyde,MDA)和可溶性糖含量的变化来看,30Gy碳离子辐射处理组MDA和可溶性糖含量降低,提高了M2代幼苗的高温抗性。

Flower color chimera and abnormal leaf mutants induced by C-12(6+) heavy ions in Salvia splendens Ker-Gawl.

The effect of C-12(6+) heavy ions bombardment on mutagenesis in Salvia splendens Ker-Gawl. was studied. Dose-response studies indicated that there was a peak of malformation frequency of S. splendens at 200 Gy. Abnormal leaf mutants of the bileaf, trileaf and tetraleaf conglutination were selected. Meanwhile, a bicolor flower chimera with dark red and fresh red flower was isolated in M1 generation of S. splendens. Random amplified polymorphic DNA (RAPD) analysis demonstrated that DNA variations existed among the wild-type, fresh and dark red flower shoots of the chimera. The dark red flower shoots of the chimera were conserved and cultivated at a large-scale through micropropagation. MS supplemented with 2.0 mg/L BA and 0.3 mg/L NAA was the optimal medium in which the maximum proliferation ratio (5.2-fold) and rooting rate (88%) were achieved after 6 weeks. Our findings provide an important method to improve the ornamental quality of S. splendens.

甜高粱在青海高原种植的初步研究；Preliminary study on sweet sorghum growing on Qinghai Plateau

为探讨甜高粱(Sorghum bicolor)在青海作为饲料作物种植的可能性,在青海高原上做了初步试验,结果显示:密度对茎秆高度、茎粗、产量有显著影响,对生育期、单株质量影响不显著,株行距为0.40 m×0.20m时,产量最高;浇水次数对甜高粱的生育期、茎秆高度、茎粗、单株质量、产量没有显著影响,表明甜高粱对水分依赖不高,具有很强的耐旱和抗旱性;地膜对甜高粱有极显著影响,使其生育期提前,茎秆高度增高,单株质量增加、产量提高;糖分含量在开花-收获期为15.93%~16.67%,比不盖地膜增加了29.19%~47.98%;大田示范密度0.50 m×0.20 m,开花-收获期666.7 m2产量达4 890.8 kg,投入产出比为1∶1.78,效益显著。研究表明,在青海高原东部农业区盖地膜种植饲用甜高粱,用作饲料是完全可行的。