四株糖单孢菌分离株的分类学研究

从广西地区的土样中,分离到4株细胞壁Ⅳ型,糖型A, 无枝菌酸的假诺卡氏菌科的放线菌菌株,编号分别为191、221、202、和212。根据4株 菌的形态学特征和细胞化学特征,将其归入糖单孢菌属。与该属5个已知种的7个代表株进行 的rDNA的BamHI酶切片段长度类型分析(Ribotyping)的结果表明：191为青绿色糖单孢菌(S.viridis),202为青灰色糖单孢菌(S.caesia),221和212为相同的与青绿色糖单孢菌(S .viridis)的亲缘关系最近的种,但不同于已知的任何一个种。     

紫花凤梨的生物学习性

在南亚热带的广州对荷兰引进的紫花凤梨的生物学习性观察研究。考察了紫花凤梨的分芽发生与叶片生长;花序生长发育与开花;耐性、抗性表现等多个方面的生物学习性,并进行综合评价,并提出掌握和利用其习性的建议。     

几种葡萄品种特性的比较研究

本文以玫瑰香、俄罗斯康可、康可、白香焦、大宝、红富士、波鲁克斯为试材,通过对它们生物学特性的观察、生理测定和品质分析的比较,为选育优质高产多用途的葡萄品种大面积推广应用,提供一定的理论依据。     

增强子RNA研究现状

增强子是真核生物基因表达调控的主要顺式作用元件,能有效促进基因表达。活化的增强子可以转录生成增强子RNA (enhancer RNAs, eRNAs),其合成受到信号系统和信号转录因子的约束。eRNAs与其他转录本(如lncRNAs和mRNAs)相比,其长度更短、稳定性更差、组织特异性更强。此外,eRNAs对增强子与启动子之间的染色质环(looping)的形成和稳定有一定的作用,并能促进靶基因的表达。目前,越来越多的研究发现eRNAs在发育和疾病发生等生物学过程中扮演着重要角色,但是其功能研究一直进展缓慢,调控机制尚不清楚。本文概述了eRNAs的特征、研究方法和功能特性,探讨了eRNAs作为潜在治疗靶标的可能性,以期为eRNAs的后续研究提供参考。     

六出花属DUS测试性状筛选与评价

以39份六出花品种为试材,对51个候选性状进行观测,比对不同测量方式对花相关数量性状的影响,并同时研究了同品种中外花被片与侧外花被片长度的相关性。结果表明:"花序:花序梗长度"和"花:花梗长度"不满足DUS测试性状要求,最后筛选出43个性状作为DUS测试性状。12个数量性状可分别划分为3~7级;不同观测方式对花相关数量性状具有影响,推荐DUS测试时采用随机观测方式;不同批次的同一品种观测结果部分性状上存在差异;多数品种的中外花被片长度与侧外花被片长度之间呈线性正相关;形态性状的聚类分析结果支持将"花:主色"作为分组性状。     

Fluid-Structure Interaction Analysis of Pulsatile Flow within a Layered and Stenotic Aorta

In this paper, the hemodynamic characteristics of blood flow and stress distribution in a layered and stenotic aorta are investigated. By introducing symmetrical and unsymmetrical stenosis, the influence of stenosis morphology and stenotic ratio on the coupled dynamic responses of aorta is clarified. In the analysis, the in-vivo pulsatile waveforms and fully fluid–structure interaction (FSI) between the layered elastic aorta and the blood are considered. The results show that the fluid domain is abnormal in the stenotic aorta, and the whirlpool forms at the obstructed and downstream unobstructed regions. The maximum wall shear stresses appear at the throat of the stenosis. Downstream region appears low and oscillated shear stresses. In addition, along with the increase of the stenotic ratio, the amplitude of the maximum shear stress will be intensively increased and localized, and the sensitivity is also increased. In the aorta with unsymmetrical stenosis, the Von Mises stresses reach the peak value at the side with the surface protuberance, but they are reduced at the side with no protuberance. The sign variation of the layer interface shear stresses near the throat indicates the variation of the shear direction which increases the opportunity of shear damage at the transition plane. Moreover, the shear stress levels at the fluid-solid and intima-media interfaces are higher than that at the media-adventitia interface. The unsymmetrical stenosis causes higher stresses at the side with the surface protuberance than symmetrical one, but lower at the side with no protuberance. These results provide an insight in the influence of the stenosis, as well as its morphology, on the pathogenesis and pathological evolution of some diseases, such as arteriosclerosis and aortic dissection.     

谷胱甘肽硫转移酶(GST)的固定化及酶学特性研究

对谷胱甘肽硫转移酶的固定化、游离酶和固定化酶的酶学特性进行了研究,通过试验,确定谷胱甘肽硫转移酶的最佳固定化条件为先用2％壳聚糖吸附酶,然后再加戊二醛交联,交联用戊二醛浓度为1．2％,交联时间6h;游离酶的最适温度为45—55℃,最适pH值为6．5-7．0：固定化酶的最适温度为45-50℃,最适pH值为7．0;游离酶和固定化酶的最适酶促反应时间为30min。     

粤东地区的国家保护植物

经调查粤东地区有中国珍稀濒危保护植物 2 7种 (含栽培种 ) ,分属于 2 4科 2 6属 ,占广东境内分布的中国珍稀濒危保护植物的 4 5 .8% ,占全国分布的 6 .9%。其中蕨类植物 1种 ,裸子植物 6种 ,被子植物 2 0种 ;确定为濒危植物的有 5种 ,稀有的 4种 ,渐危的 18种 ;被列为一级重点保护的 1种 ,二级重点保护的 7种 ,三级重点保护的 19种。有国家重点保护野生植物2 2种 (含栽培种 ) ,分属于 2 0科 2 0属 ,占全国重点保护野生植物的 8.3%。其中蕨类植物 5种 ,裸子植物 6种 ,被子植物 11种 ;被列为一级重点保护的 6种 ,二级重点保护的 16种。其国家保护植物资源具有种类丰富、古老性强、中国特有现象突出等特点。对其名录特点和利用价值也进行了分析     

花卉育种技术研究进展(综述)

本文综述近年来国内外花卉育种技术及成果。常规育种仍是花卉育种的主要方法,但日益成熟的生物技术为花卉育种提供了新的途径,尤其是基因工程在改良花卉的色、香、形及延缓衰老等方面将发挥重要作用。     

Spatial Characteristics and Change for Tree Species along the North East China Transect (NECT)

Spatial characteristics of sixteen tree species were analyzed by theinformation from 287 permanent plots in 1986 and 1994 on North East ChinaTransect (NECT). Some species expanded and some retracted theirdistribution extents. Betula costata andPhellodendron amurense spread most fast toward west andeast, respectively. All tolerant tree species extended their frontiers and allintolerant tree species retracted their frontiers except Betulaplatyphylla. The distribution area decreased for all species exceptBetula costata, Juglans mandshurica,Ulmus spp. and Fraxinusrhynchophylla.The patch sizes of Pinus koraiensis, Populusdavidiana, Phellodendron amurense,Juglans mandshurica, Fraxinusmandshurica, Betula dahurica,Picea spp., Abies nephrolepis andLarixolgensis decreased, however, the patch sizes of Quercusmongolica, Betula costata, Acermono, Tilia spp., Ulmusspp., Betula platyphylla and Fraxinusrhynchophylla increased. The frequency pattern of Populusdavidiana, Betula platyphylla,Fraxinus rhynchophylla and Betuladahurica changed significantly(p< 0.05). The dominance pattern ofPopulus davidiana, Tilia spp.,Juglans mandshurica, Betulaplatyphylla, Betula dahurica andAbiesnephrolepis changed significantly(p < 0.05). The spatial correlation betweenspecies changed, such as the spatial correlation between Larixolgensis and Betula platyphylla, Acermono and Ulmus spp. increased. The possiblecause of these changes might be climate change, disturbances and habitat loss.