猕猴桃不同季节的嫁接法比较试验

在湖北的试验表明,猕猴桃春季嫁接以切接法较好,夏秋季嫁接则以单芽枝腹接法较好;嫁接后采用遮阳网遮荫可以显著提高嫁接成活率,但对出圃率无明显影响。     

饲喂频率对南方鲇的摄食率、生长和饲料转化效率的影响

决定鱼类摄食量的内因是鱼体对能量的处理及转化能力,外因是食物的可获得性1。       

Pollen morphology and seed surface features of the genus Dactylicapnos Wall.

Pollen grains and seed surface features of the four species in the genus Dactylicapnos Wall. (Papaveraceae) from China were studied under light mi cros cope (LM) and scanning electron microscope (SEM). Pollen grains are usually subs pheroidal in shape, an     

风电项目对潜在生态廊道的影响——基于MSPA-MCR模型

风电作为构建新型电力系统的主体,能够有效助力电力系统脱碳,是实现“双碳”目标的主力军。但风电规模化建设与生态环境保护之间的矛盾日益突出,风电项目对生态环境,尤其是对区域生态廊道及生态安全格局的影响急需厘清。以福建平潭陆上风电项目所在区域为研究单元,运用形态学空间格局分析法和最小累积阻力模型、重力模型等判别重要生态源地及潜在生态廊道,评估风电项目对潜在生态廊道连通性、重要性和结构性等影响。研究表明：(1)研究区生态源地主要位于生态价值高的森林公园及风景名胜区内。受风电项目影响,源地呈现破碎化趋势,核心区占景观要素百分比由79.53%下降至76.64%。(2)风电项目导致生态廊道畅通性降低,生态廊道的走向及长度发生显著变化,大大增加了生物迁徙的空间阻力。(3)风电项目弱化了生态源地之间关联性。核心廊道和次级廊道均减少了6条,且重要性强的生态廊道完全避开风电项目所在位置。风电项目建设之后生态网络流通性变差,网络更为单一、整体生态效能降低。本研究不仅从生态环境敏感脆弱区域的生态安全角度给风电项目建成区周边生态修复提供科学参考,也为未来风电项目选址及环境质量评估提供了重要的方法支撑。     

斑点叉尾鮰源普通变形杆菌的分离、鉴定及药敏特性

【目的】对患病斑点叉尾鮰进行病原菌分离、鉴定及药敏实验,为斑点叉尾鮰肠道坏死病的防控提供参考。【方法】从患病斑点叉尾鮰病灶、肝、脾和肾分离纯化病原菌,经理化特性测定及16S rRNA基因序列分析对其进行鉴定,开展人工感染试验,并利用纸片扩散法进行药敏特性分析。【结果】分离菌株k1为本次引发斑点叉尾鮰病害的致病菌,其对斑点叉尾鮰的LD50为2.82×10~5 CFU/g。菌株k1理化特性与普通变形杆菌Proteus vulgaris基本一致,16S rRNA基因序列与普通变形杆菌相似性最高,综合判定分离菌株为普通变形杆菌。分离菌株k1对环丙沙星、头孢唑林及头孢拉定等12种抗生素高度敏感,对苯唑西林、阿莫西林及痢特灵等7种抗生素耐药。【结论】分离菌株k1是斑点叉尾鮰病原菌,养殖时可选用庆大霉素及氟苯尼考等药物进行防控。     

丛枝菌根真菌伴生细菌的研究进展

在丛枝菌根真菌（Arbuscular mycorrhizal fungi,AMF）的孢子、菌丝的表面或内部栖息着细菌,称之为AMF伴生细菌。AMF伴生细菌种类多样、分布广泛,生态位点包括孢子壁的表面或内部、细胞质、菌丝、孢子果等。其可能的生物学意义包括影响AMF孢子萌发、菌丝生长、菌根形成等过程。由于伴生细菌与AMF联系紧密,其对AMF和土壤微生物生态学具有重要的意义。国际上在该领域的研究已有30多年的历史,就其研究进展进行综述。     

灰胸竹鸡的生物学特性及经济价值

本文从形态特征、生活习性、繁殖和血液生理生化特点等方面介绍了灰胸竹鸡生物学特性和经济价值,对灰胸竹鸡的人工驯养与繁殖,以及保护性开发具有重要意义。     

autoinfer1.0: a computer program to infer biogeographical events automatically

autoinfer is a computer program for biogeographical inference based on nested clade analysis. To reduce the obscurity caused by manual inference, we defined geographically concordant clades and intermediate geographical areas between two clades. The program will perform most of the inferences automatically with a minimum of input from the user. We believe that autoinfer will save much time for the user compared with using the inference key by hand and, furthermore, will reduce the errors of inference resulting from different criteria in deduction.     

Complex agriculture during the second millennium <Emphasis Type="SmallCaps">bc</Emphasis>: isotope composition of carbon studies (δ<Superscript>13</Superscript>C) in archaeological plants of the settlement Cerro del Castillo de Alange (SW Iberian Peninsula,Spain)

The isotope composition of fruits and seeds of Hordeum vulgare L. (barley), Triticum aestivum/durum (wheat) and Vicia faba var. minor (faba bean) from three chronological phases between 2200 and 1321 cal bc of the settlement Cerro del Castillo de Alange (SW Iberian Peninsula) have been studied. The δ¹³C values for cereals were between ?24.40 and ?20.39‰ (V-PDB), with a mean of ?22.01‰, the discrimination (Δ) being 15.96‰. The legumes registered similar values, between ?26.25 and ?20.49‰ (mean = ?22.59‰), with a differential for the period of 16.51‰. In both cases, a change was noted from the first phase, where water availability is clearly a limiting factor for plant development. In subsequent phases the growing conditions appear be wetter. By comparison, we measured samples of Quercus ilex-coccifera (oak) charcoal, which shows similar values throughout the series. This suggests that there was no significant climate shift to moister conditions that could explain the above results, but rather they were the consequence of a change in crop management. In addition, we measured samples of a current rainfed Triticum sp. (year 2014), which averaged Δ¹³C 15.56‰. The changes between the three phases could indicate the development of mixed models of exploitation that combine strategies based on the use of rainfed and potentially irrigated areas during the 2nd millennium bc. The implementation of such a cropping technique, taking advantage of the river banks, could be a response to the processes of climatic degradation that begin in the Middle Holocene. The situation of the Cerro del Castillo reservoir between the rivers of the Guadiana and Matachel rivers is consistent with the development of this type of practice indicated by the isotopic and archaeobotanical data.     

马铃薯花芽分化与内源激素动态变化的关系

以马铃薯2个开花品种YS205和HZ88以及未开花品种YS304为材料,采用石蜡切片法观察花芽分化的解剖学特征,并用酶联免疫吸附法(ELISA)测定开花与未开花品种不同时期叶内4种内源激素——生长素(IAA)、赤霉素(GA3)、玉米核苷素(ZR)、脱落酸(ABA)含量的动态变化,探讨成花过程中叶片内源激素含量和比值的变化与成花的关系,为马铃薯花期调控、栽培和杂交育种提供理论依据。结果显示:(1)马铃薯花芽内部发育与外部形态之间有相对稳定的时序性对应关系,从花芽分化初期生长锥逐渐向上凸起,到雌雄蕊原基形成,完成整个花芽分化仅用了1周左右的时间,此阶段YS205和HZ88的花芽分化过程无明显差异,而YS304未成花。(2)随着花器官的不断发育,HZ88子房形成2室,每室多个胚珠,而YS205的子房在发育过程中发生了变异,形成完整的3室;YS205和HZ88都先后经历了授粉受精过程,HZ88具有一定的自交结实率,YS205无坐果率。(3)马铃薯3个品种的IAA、GA3、ZR和ABA含量在花芽分化前期均较低,且无明显差异性;随后,3个品种的IAA和GA3含量均呈先升后降的单峰变化曲线,但YS304上升和下降的速度较2个开花品种快,而且YS205和HZ88的ZR和ABA含量则始终高于YS304。(4)开花品种YS205和HZ88的ABA/IAA、ABA/GA3、ZR/IAA、ZR/GA3比值均高于未开花品种YS304,且随生育期变化趋势不同。研究表明,较低水平的IAA、GA3和高水平的ABA、ZR均有利于促进马铃薯花芽分化,反之则抑制花原基形态的建成。