Transfer of resistance to potato leafroll virus, potato virus Y and potato virus X from Solarium brevidens to S. tuberosum through symmetric and designed asymmetric somatic hybridisation

Resistance to potato leafroll virus (PLRV), potato virus Y (PVY^o) and potato virus X (PVX) was studied in symmetric and asymmetric somatic hybrids produced by electrofusion between Solanum brevidens (2n=2×=24) and dihaploid S. tuberosum (2n=2×=24), and also in regenerants (B-hybrids) derived through protoplast culture from a single somatic hybrid (chromosome number 48). All of the somatic hybrids between 5. brevidens and the two dihaploid lines of potato cv. Pito were extremely resistant to PLRV and PVY^oand moderately resistant to PVX, irrespective of their chromosome number and ploidy level (tetraploid or hexaploid). Most (56%) of the asymmetric hybrids of irradiated S. brevidens and the dihaploid line of potato cv. Pentland Crown (PDH40) had high titres of PVY^osimilar to those of PDH40, whereas the rest of the hybrids had PVY^otitres less than a tenth of those in PDH40. Three B-hybrids had a highly reduced chromosome number (27, 30 and 34), but were however as resistant to PLRV, PVY^oand PVX as 5. brevidens. Two asymmetric hybrids and one B-hybrid were extremely resistant to PLRV but susceptible to both PVY and PVX. The results suggested that resistance to PLRV in 5. brevidens is controlled by a gene or genes different from those controlling resistance to PVY and PVX, and the gene(s) for resistance to PVY and PVX are linked in S. brevidens.     

获取复配农药最佳增效配方的一种简易方法

借鉴共毒因子法评价农药复配联合作用的思想,将参与复配的单剂引起25％死亡率的剂量定为零水平,利用二次回归通用旋转组合设计安排实验研究氯氰菊酯和喹硫磷复配对斜纹夜蛾（Spodoptera litura）2龄幼虫的增效作用,得出杀虫剂使用量与斜纹夜蛾幼虫死亡率机率值之间的关系,从共毒系数（CTC）的计算公式推导出共毒系数与杀虫混剂中两单剂使用浓度N1、N2之间的数学关系,CTC＝100／N1／α N2/b（α、b分别为氯氰菊酯和喹硫磷的LC50）,进而确定最优化问题的目标函数j=N1/α＋N2／b,利用国际统计分析软件SAS的NLP过程求最大共毒系数和最优配方,所得结论与共毒系数法一致。     

线虫全基因组RNAi筛选确定CAB-1为特异性调节致密核心囊泡分泌的因子

内分泌细胞和神经细胞通过释放激素和神经肽类物质来响应外界刺激,而这些物质的分泌,都是通过致密核心囊泡(dense core vesicle,DCV)来实现的.但是,现阶段关于DCV的生成、转运、释放的机制很大程度上是不清楚的.在本研究中,我们将线虫的排便行为和肠道分泌联系起来,并以此表型进行全基因组RNAi筛选,寻找调节DCV的新基因.我们成功筛选到了一些在肠道调节DCV生成或释放的基因.其中,CAB-1被确认为特异性调节DCV分泌的重要因子.在肠道中,cab-1突变会降低肠道DCV内容物的分泌,而在神经系统中,CAB-1的缺失也会导致DCV的标识物堆积在突触前,而突触囊泡(synaptic vesicle,SV)不受影响.     

萱草叶片响应低温胁迫的转录组分析

低温胁迫是萱草（Hemerocallis fulva）生长过程中经常会遭遇的一种非生物胁迫。比较了萱草叶片在低温处理（10、5、0 ℃）下转录组与对照（15 ℃）数据的差异,共筛选出差异表达基因2 457个,其中上调基因1 253个,下调基因1 204个。差异表达基因主要富集在细胞过程、代谢过程和催化活性等49个GO过程,代谢途径、次生代谢产物的生物合成、植物激素信号转导等42条KEGG代谢途径中。其中参与植物激素信号转导通路的差异表达基因发生了不同程度的变化,GH3.10基因上调至对照组的13.624倍,IAA1基因下调0.120倍;参与可溶性糖合成通路的差异基因发生了0.076~28.114倍不同程度的变化。随后对3个低温处理组共有的29个差异表达基因进行热图和网络调控分析,基于基因在网络调控中的位置,对ABCF5、OFPs和SWEETs等基因在冷应答的作用进行了分析。本研究结果为进一步挖掘萱草低温响应的关键基因及耐寒萱草种质开发、分子育种提供了一定的理论支撑。     

东海浮游等足类和涟虫类的调查

根据1997~2000年东海(23°30′~33°00′N,118°30′~128°00′E)海域4个季节海洋调查资料,对东海浮游等足类和涟虫类种类的组成、数量变化及地理分布等特征作了探讨。结果表明,调查海域出现浮游等足类2种,其中圆柱水虱(Cirolanasp.)在东海等足类数量中具有绝对优势(占总丰度的98%),中国急游水虱(Tachaea chinensis)是稀有种。等足类主要在夏季出现,并分布在东海近海。浮游涟虫类主要分布在台湾海峡和东海南部海域。浮游涟虫类有4种,细长涟虫(Iphinoe tenera)和萨氏异涟虫(Heterocumasarsi)在3个季节出现,丰度和出现率较高,是东海涟虫类的常见种;无尾涟虫(Leueonsp.)在2个季节出现,丰度和出现率与前2个种相似,是次常见种。卵圆涟虫(Bodotria ovalis)仅出现在秋季,数量和出现率极低,是稀有种。细长涟虫、萨氏异涟虫和无尾涟虫都是暖水种。相比之下,无尾涟虫有更广泛的适温能力。卵圆涟虫在盐度较低的长江口出现,是一个近岸种。     

黄河调水调沙对黄河口海域双酚A的影响

于2011年6—7月黄河调水调沙前、中期、后对黄河口海域双酚A(BPA)污染情况进行调查,研究了调水调沙对黄河口海域双酚A的影响。结果表明:黄河口13个站位表层海水和沉积物中均有双酚A检出,以调水调沙前测得的海水和沉积物中双酚A含量评估黄河口附近双酚A的污染程度。海水中双酚A浓度范围为13.6—64.0 ng/L,平均浓度为26.2 ng/L;沉积物中双酚A的浓度为0.559—2.73μg/kg干重,平均浓度为1.19μg/kg,是海水中平均含量的48倍。黄河河口区域海水中双酚A浓度受调水调沙影响而呈现较大变化,调水调沙后双酚A浓度明显增加,调水调沙前、后呈显著性差异(P0.01),说明陆源输入是黄河口区域中双酚A的主要污染来源。离入海口近的站位沉积物中双酚A浓度受调水调沙影响较大,呈显著性差异(P0.01),调水调沙后含量显著降低。黄河口海域已经遭受双酚A污染,存在生态安全问题。     

Potential effects of interaction between CO2 and temperature on forest landscape response to global warming

Projected temperature increases under global warming could benefit southern tree species by providing them the optimal growing temperature and could be detrimental to northern species by exposing them to the supra optimal growing temperatures. This benefit-detriment trade-off could increase the competitive advantage of southern species in the northern species range and cause the increase or even dominance of southern species in the northern domain. However, the optimum temperature for photosynthesis of C3 plants may increase due to CO₂ enrichment. An increase in the optimum temperature could greatly reduce the benefit-detriment effect. In this study, we coupled a forest ecosystem process model (PnET-II) and a forest GAP model (LINKAGES) with a spatially dynamic forest landscape model (LANDIS-II) to study how an optimum temperature increase could affect forest landscape response due to global warming. We simulated 360 years of forest landscape change in the Boundary Water Canoe Area (BWCA) in northern Minnesota, which is transitional between boreal and temperate forest. Our results showed that, under the control scenario of continuing the historic 1984–1993 mean climate (mainly temperature, precipitation and CO₂), the BWCA will become a spruce-fir dominated boreal forest. However, under the scenario of predicted climatic change [the 2000–2099 climates are predicted by Canadian Climate Center (CCC), followed by 200 years of continuing the predicted 2090–2099 mean climate], the BWCA will become a pine-dominated mixed forest. If the optimum temperature increases gradually with [CO₂] (the increase in optimum temperature is assumed to change gradually from 0 °C in year 2000 to 5 °C in year 2099 when [CO₂] reaches 711 ppm and stabilizes at 5 °C after year 2099), the BWCA would remain a fir-dominated boreal forest in areas with relatively high water-holding capacity, but not in areas with relatively low water-holding capacity. Our results suggest that the [CO₂] induced increases in optimum temperature could substantially reduce forest landscape change caused by global warming. However, not all tree species would be able to successfully adapt to future warming as predicted by CCC, regardless of optimum temperature acclimations.     

基于上转换纳米材料的免疫检测技术应用

免疫分析法具有简便、快速、准确等特点，广泛应用于医学、食品、环境等领域检测，将免疫分析方法与纳米材料相结合可以提高免疫分析的性能。与传统纳米材料相比，上转换纳米颗粒（upconversion nanoparticles，UCNPs）具有光稳定性好、发光寿命长和狭窄及可调整的发射带等优秀的光学性质，与免疫分析相结合可显著降低背景噪声，提高分析灵敏度。本文简要介绍了UCNPs的发光机制，对UCNPs的合成和表面修饰方法进行了总结，并详细论述荧光共振能量转移、内滤效应、磁分离技术、上转化连接免疫吸附技术和上转换免疫层析技术五种基于UCNPs的免疫检测技术，最后对该技术所面临的挑战和前景进行总结和展望，以期为UCNPs免疫检测技术的发展提供理论指导。     

Novistrombidium sinicum n. sp. and Novistrombidium orientale n. sp. (Protozoa: Ciliophora): Two New Oligotrich Ciliates from a Mangrove Wetland, South China

ABSTRACT. The morphology and infraciliature of two new marine oligotrich ciliates, Novistrombidium sinicum n. sp. and Novistrombidium orientale n. sp., isolated from a mangrove wetland near Guangzhou, southern China, were studied from live and protargol-stained specimens. Novistrombidium sinicum is different from its congeners by the combination of the following characters: three posteriorly directed thigmotactic membranelles, one ellipsoidal macronucleus, the extrusomes equidistantly arranged, and the ventral kinety commencing below the right end of the girdle kinety. The small-sized N. orientale can be separated from its congeners by two posteriorly directed thigmotactic membranelles, one ellipsoidal macronucleus, the extrusomes equidistantly arranged, and the ventral kinety commencing below the right end of the girdle kinety.     

在大肠杆菌中表达酮酸脱羧酶产异戊醇

酮酸脱羧酶作为异戊醇生物合成的关键酶,不存在于大肠杆菌中。以乳酸乳球菌的基因组DNA为模板,经过PCR扩增得到酮酸脱羧酶基因kivD(rbs),插入到大肠杆菌高效表达载体pET-28a(+)上形成pET-kivD(rbs),重组质粒热击转化进大肠杆菌BL21(DE3)中,其成功表达了酮酸脱羧酶。对发酵产物进行分析,检测到了微量的目标产物—异戊醇。