仙人掌科果类植物的品种及生产(综述)

仙人掌科的主要果类植物有５属１８个品种。本文重点介绍以红龙果为代表的柱形仙人掌果的繁殖、栽培与加工利用。     

棉花腺苷酸核糖基化作用因子1(arf1)的结构特征、替换剪接和遗传表达分析

用已建立的新型染色体步移技术同尾酶反向PCR和快速分离目的基因cDNA 5′未知序列方法从陆地棉品种Y18中分离到腺苷酸核糖基化作用因子1(arf1)的全长cDNA、DNA和启动子序列。结果表明,该基因全长4360bp,具有6个内含子和7个外显子,在第一个内含子处存在替换剪接现象,使该基因在棉花中分别形成1026、1103和1544bp的3种mRNA。该基因编码181个氨基酸,转录起始位点上游具有转录起始子、TATA盒、CAAT盒、GC盒、多个正向重复序列和反向重复序列,在转录起始位点下游具有富含AT序列和回文结构等启动子特征序列。Southern杂交结果表明：该基因在棉花基因组中有两个拷贝。Northern杂交结果表明：该基因在棉花的蕾、花、纤维和铃壳等生殖器官中呈优势表达。     

棉花优异纤维品质性状的双列杂交分析

利用5个具有不同纤维品质性状的品种(系)配制完全双列杂交组合20个,通过亲本和F1的2年随机区组试验,结果为除纤维整齐度受环境等因素影响较大,其余性状主要受遗传因素控制;在与环境的互作中,纤维强度和长度的互作效应小,麦克隆值的加性和母体效应及伸长率的显性效应与环境的互作较大,均达到了显著水平;遗传主效中,所有的研究性状不存在母体效应,以加性为主;强度与长度加性遗传率高,分别占77．6％和73．2％;麦克隆值的加性效应占45．2％,显性效应所占的比例在纤维性状中最高,为11．5％。纤维品质性状的群体平均优势仅麦克隆值的较高(3．2％),达到了显著水平,其余性状的优势仅为-0．4％-0．7％。纤维品质性状的遗传结果与杂种优势一致。在杂种优势利用时,可以通过双亲平均值的高低来预测F1的纤维品质表现。纤维强度、长度和细度的加性遗传率高,这些性状均可以早代选择。     

桂西北典型喀斯特区生态服务价值的环境响应及其空间尺度特征

Study on ecosystem service values (ESVs) is the bridge of understanding ecosystem and economic decision-making. To investigate the response of ESVs to ambient environment and their spatial scales is an urgent work in the process of ecological restoration and sustainable development in southwest China. Based on the previous research results, the remote images, and weather data of 31 years (1975-2005), the response of ESVs to ambient environment and their spatial scales in a typical karst area of northwest Guangxi, China were evaluated with the method of empirical mode decomposition (EMD) in this paper. The results showed that ESVs had obvious variations with changes in elevation, rocky types and soil types, and had corresponding characteristics of spatial scales. The ESVs in middle and low elevation areas were higher, but they decreased due to human activities such as deforestation. The ESVs in peak-cluster depression areas were lower, and they would increase as influenced by policies such as returning farmland to forestland. The ESVs were influenced by rocky types, showing lower values but an increasing trend in the typical karst regions while higher values but a decreasing trend in non-karst regions. The average ESVs in the west part of the study region, which is not only the main nature reserve for rare wildlife species in Guangxi, but also one of the best preserved natural vegetation regions in China, were more than 15,000 RMB Yuan ha-1,. Comparatively, the ESVs were less than 10,000 Yuan ha-1 in the middle part of the region attributed to low vegetation coverage, serious peak-cluster depression and karst rocky desertification. After about 20 years, that is from 1985 to 2005, the ecosystem conditions had been improved and the ESVs had increased in the middle and eastern part of this study region. On the contrary, in most western part, which was dominated by subtropical evergreen broad-leaved forest, they had been worsened, and the balance values of ESVs were negative. As for the relationships of ESVs with rocky types and soil types, lime soil and red soil were the two main soil types that contributed to ESVs (The total contribution was above 60%, and it is 63.77%,64.37%,64.56%,64.91% respectively in the four years of 1985, 1990, 2000 and 2005.). The variance contribution of intrinsic mode function (IMF) and trend (R) showed that there were obvious special sales for ESVs in this study area, and the main spatial scales were about 2.7 km, 5.5 km, and 11.6 km. The variance contribution ratio was 12.29%, 11.26%, 11.49% respectively, and the trend (R) was high (17.74%). In conclusion, this study indicated that ecosystem conditions in the typical karst area were improved owing to the application of rocky desertification control policies, such as ecological migration and returning farmland to forestland. Besides, the main spatial scales of ESVs in the study area were the interactions of terrain, physiognomy, land use / land cover and human activities.     

棉铃虫取食转Bt棉后蛹的抗寒力测定

在棉铃虫HelicoverpaarmigeraH櫣bner人工饲料中分别添加转Bt基因棉叶粉和常规棉叶粉饲喂幼虫,经滞育诱导后,发现2个处理间棉铃虫蛹的滞育率相似,2个处理间滞育蛹的自由水和结合水含量没有差异;但取食含Bt棉叶粉人工饲料的棉铃虫滞育蛹的过冷却点和结冰点显著高于对照组,蛹重及与抗寒性有关的脂肪和糖原含量均显著低于对照组。     

Plants and insects in early old-field succession: comparison of an English site and an American site

The plant and insect communities of early, secondary succession beginning with bare ground in an Old World site (southern Britain) and a New World site (Iowa, U.S.A.) shared a number of characteristics. Both sites showed similar temporal patterns of plant species cover and species richness, although overall richness was greater at the Old World site. Annuals dominated at both sites during the first year of succession and were largely replaced by perennials in the second year. Monocotyledons were more abundant at the Old World site, especially in the second year. The two sites differed markedly in the contribution of native and introduced plant species, with the Old World site dominated by natives and the New World site by alien plant species. Insect herbivore load was greater at the Old World site, when expressed in terms of structural complexity of the vegetation, suggesting that there may be major differences in the influence of herbivores on the direction and rate of succession at the two sites.     

斑腿泛树蛙早期胚胎发育的研究

报道斑腿泛树蛙(Polypedates megacephalus Hallowell)的早期胚胎发育过程。根据胚胎发育过程中的形态变化规律将胚胎发育过程分为25个时期,在室温(26±1)℃的条件下,胚胎发育历时128.58h。描述了各时期的形态特征,并讨论了发育中的一些现象     

改良早期预警评分对转院转运工作影响的临床研究

目的 研究改良早期预警（MEWS）评分对转院转运工作的影响.方法 在转院转运工作中应用MEWS评分系统对患者进行病情评估,对比其应用前（对照组）、应用后（研究组）转院患者转运途中病情恶化的发生率、患者或家属满意度及医生、护士对实施MEWS评分转运管理模式前（对照组）、后（研究组）满意度的变化.结果 转院患者转运途中病情恶化发生率由应用前（对照组）的10.63%降至应用后（研究组）的3.74%,应用前、后比较差异有显著统计学意义（P＜0.01）;患方满意度则由96%提高至99%,医护人员对实施MEWS评分转运管理模式前、后的满意度由应用前的83.3%提高至应用后的95%,应用前、后比较均有显著性意义（P＜0.05）.结论 MEWS评分能对转院患者的病情进行比较客观、准确的评估,提高了医务人员的质量和医疗干预意识,从而有效降低转院患者转运途中的病情恶化发生率和提高院前医患双方的满意度,是转院转运工作中简便、快捷、客观、实用的病情评估方法和模式,值得推广应用.     

Rate of forcing and the forecastability of critical transitions

Critical transitions are qualitative changes of state that occur when a stochastic dynamical system is forced through a critical point. Many critical transitions are preceded by characteristic fluctuations that may serve as model‐independent early warning signals, implying that these events may be predictable in applications ranging from physics to biology. In nonbiological systems, the strength of such early warning signals has been shown partly to be determined by the speed at which the transition occurs. It is currently unknown whether biological systems, which are inherently high dimensional and typically display low signal‐to‐noise ratios, also exhibit this property, which would have important implications for how ecosystems are managed, particularly where the forces exerted on a system are anthropogenic. We examine whether the rate of forcing can alter the strength of early warning signals in (1) a model exhibiting a fold bifurcation where a state shift is driven by the harvesting of individuals, and (2) a model exhibiting a transcritical bifurcation where a state shift is driven by increased grazing pressure. These models predict that the rate of forcing can alter the detectability of early warning signals regardless of the underlying bifurcation the system exhibits, but that this result may be more pronounced in fold bifurcations. These findings have important implications for the management of biological populations, particularly harvested systems such as fisheries, and suggest that knowing the class of bifurcations a system will manifest may help discriminate between true‐positive and false‐positive signals.     

三种花生幼胚蛋白质提取方法比较研究

植物组织(或细胞)的蛋白质提取效率与效果直接影响蛋白质双向凝胶电泳等实验的结果。为探索建立适用于花生幼胚蛋白质(双向凝胶电泳用)提取的最佳条件,尝试了磷酸缓冲液直接提取法、改良的荔枝胚胎蛋白提取法和Trizol(附加)提取法等3种提取方法,根据蛋白提取得率、试剂成本、双向电泳图谱的质量(蛋白质斑点的丰度、分布特点)进行初步评价。结果表明,磷酸缓冲液直接提取法简单但总体效果较差,改良的荔枝胚胎蛋白提取法综合评价最好,与双向凝胶电泳条件更兼容。