富平县梅家坪镇车家村果园节水灌溉工程设计思路与效益

介绍了车家村果园节水灌溉工程的设计方案,特色及效益,并对工程在设计,施工和管理上存在的不足之处进行了总结。     

不同虫态茶银尺蠖过冷却点和结冰点的测定

为探究茶银尺蠖Scopula subpunctaria越冬虫态及其抗寒能力,利用过冷却点测定仪测定各虫态茶银尺蠖的过冷却点和结冰点。结果表明茶银尺蠖卵的过冷却点和结冰点最低,分别为-23.21℃和-22.52℃,均显著低于其他虫态,5龄幼虫的过冷却点最高,为-5.86℃,预蛹的结冰点最高,为-1.79℃。随着幼虫龄期增加,过冷却点和结冰点逐渐升高。同虫态不同个体过冷却点和结冰点的变异均符合正态分布。雄蛹的过冷却点和结冰点分别为-11.07℃和-4.57℃,均显著低于雌蛹的-7.82℃和-2.10℃。雄成虫的过冷却点和结冰点分别-13.39℃和-7.82℃,显著低于雌成虫的-9.60℃和-3.69℃。在蛹和成虫阶段,茶银尺蠖雄性个体的抗寒能力要强于雌性个体的抗寒能力。     

‘六月早’蜜柚叶绿体基因组及其特征分析

‘六月早’蜜柚(Citrus maxima ‘Liuyuezao’)为国内重要的柚品种琯溪蜜柚早熟芽变品种。以‘六月早’蜜柚为材料,利用二代测序进行全基因组重测序,从中组装获取叶绿体基因组并对其进行注释。结果表明:组装获得的‘六月早’蜜柚的叶绿体基因组全长160 186 bp,四分体结构由大单拷贝区(large single copy, LSC)、小单拷贝区(small single copy, SSC)和反向重复区(inverted repeat, IR)组成,3个分区的长度分别为87 939、18 395、26 926 bp。注释得到133个基因,其中包含89个编码基因,37个tRNA和8个rRNA。共识别到31个短串联重复序列,101个SSR位点。将已公开发表的29个芸香科叶绿体基因组使用最大似然法进行系统发育关系的构建,结果表明,‘六月早’蜜柚与甜橙(C. sinensis)、柠檬(C. limon)和C. platymamma的亲缘关系较近。     

动物黑色素细胞及其相关性状形成机制的研究进展

黑色素细胞是合成黑色素的细胞，由其前体细胞黑色素母细胞分化而来，胚胎期黑色素母细胞的形成有两次，一次是具有黑色素细胞特性的神经嵴细胞沿背外侧迁移而形成，另一次是由沿腹侧迁移的神经嵴细胞亚细胞雪旺氏细胞前体（Schwann cell precursors，SCPs）受到某种信号诱导后形成，这是皮肤中黑色素细胞形成的主要方式。黑色素细胞的形成与动物毛发颜色及其他重要经济性状密切相关，其形成的增多或减少，异位形成或异位侵袭均可能导致相应的疾病，但脊椎动物中具有典型黑色素细胞异位形成特征的乌骨鸡却繁衍至今，而且是重要的食用和药用经济动物。探索黑色素细胞的形成及其对相关性状的影响不但能为动物经济性状育种提供相关理论基础，也可为相关疾病的治疗提供理论依据。作者从黑色素细胞的来源及其形成过程中参与的信号因子来探讨其形成机制，并对黑色素细胞相关性状的形成机制尤其是乌质性状进行综述。     

柚芽变株系类胡萝卜素代谢差异基因的转录组学分析

为了研究‘琯溪蜜柚’果实红肉突变株系类胡萝卜素代谢和芽变的分子机制,本研究以‘琯溪蜜柚’及其芽变一代品种‘红肉蜜柚’和芽变二代品种‘三红蜜柚’果实为材料,使用RNA-seq技术研究3个品种3个发育时期果肉类胡萝卜素的代谢。经生物信息学分析,共筛选出参与类胡萝卜素生物合成显著差异表达的10个基因,分别为八氢番茄红素合成酶基因（PSY）、六氢番茄红素脱氢酶基因（ZDS）、类胡萝卜素异构酶基因（CRTISO1、CRTISO2）、紫黄质脱环氧酶基因（NPQ1）、9-顺式-环氧类胡萝卜素双加氧酶基因（NCED3、NCED5）、脱落醛氧化酶基因（AAO3）、ABA 8’-羟化酶基因（CYP707A1）、类胡萝卜素裂解双加氧酶基因（CCD4）。共表达分析揭示了7个家族转录因子的表达模式与类胡萝卜素合成基因高度相关,分别为MADS、bZIP、bHLH、MYB、AP2/ERF、NAC和WRKY。通过实时荧光定量PCR（qRT-PCR）验证了部分基因的表达模式,结果与RNA-seq结果高度一致。此外,经对‘红肉蜜柚’果肉转色期的初生和次生代谢通路DEGs富集分析,发现类胡萝卜素的积累过程中,细胞壁、脂质、类黄酮代谢差异基因大量富集。研究结果揭示,‘琯溪蜜柚’果实红肉突变品种‘红肉蜜柚’和‘三红蜜柚’果实类胡萝卜素的形成和积累,是由类胡萝卜素的代谢相关酶基因差异表达和转录因子调控引起的;在果肉红色芽变的同时,伴随着与汁胞粒化相关的基因突变。这对进一步开展柚子果实类胡萝卜素的形成与积累、汁胞粒化研究,为解析柚果实不同颜色突变、汁胞粒化的机制有重要参考价值。     

The effects of gap size and age on natural regeneration of Picea mongolica in the semi-arid region of Northern China

The aim of this work was to study the effects of gap size and age on natural regeneration of endangered tree species Picea mongolica W. D. Xu, which is only found in the semi-arid region of Northern China. For this purpose, six random transect belts of varying size were established in Baiyinaobao Natural Reserve. The number, height and age of P. mongolica saplings were inventoried. Results show that the total number of saplings per hectare and corresponding number and relative share of saplings in height class I (0.1–0.99 m) decreased along with increasing gap size, opposite to height class III (6–9 m). In height class II (1–5.99 m) the number of saplings per hectare and their relative share increased first slightly and then decreased with the increase of gap size. The number of saplings and their relative share in each height class changed similarly with the increase in the distance to the edge of the mature stand (p < 0.05). Gap age also significantly affect the number of saplings per hectare or their height distribution except in height class II. The distance to the mature stand edge played a very important role in the success of natural regeneration for species P. mongolica.     

QuEChERS-GC/MS检测氯丹的含量

介绍了一种快速低耗、简便可靠的方法测定土壤中氯丹的含量。利用QuEChERS法,以丙酮/正己烷为提取液,超声萃取后,经PSA净化后的样本上清液,用GC-MS-SIM定量检测,回收率在81%~102%之间。用该方法测得农药厂周围土壤样本中氯丹的含量在0.079mg/kg~2 927.95 mg/kg之间。     

Impacts of changing climate on the productivity of Norway spruce dominant stands with a mixture of Scots pine and birch in relation to water availability in southern and northern Finland

A process-based ecosystem model was used to assess the impacts of changing climate on net photosynthesis and total stem wood growth in relation to water availability in two unmanaged Norway spruce (Picea abies) dominant stands with a mixture of Scots pine (Pinus sylvestris) and birch (Betula sp.). The mixed stands were grown over a 100-year rotation (2000-99) in southern and northern Finland with initial species shares of 50, 25 and 25% for Norway spruce, Scots pine and birch, respectively. In addition, pure Norway spruce, Scots pine and birch stands were used as a comparison to identify whether species' response is different in mixed and pure stands. Soil type and moisture conditions (moderate drought) were expected to be the same at the beginning of the simulations irrespective of site location. Regardless of tree species, both annual net canopy photosynthesis (P(nc)) and total stem wood growth (V(s)) were, on average, lower on the southern site under the changing climate compared with the current climate (difference increasing toward the end of the rotation); the opposite was the case for the northern site. Regarding the stand water budget, evapotranspiration (E(T)) was higher under the changing climate regardless of site location. Transpiration and evaporation from the canopy affected water depletion the most. Norway spruce and birch accounted for most of the water depletion in mixed stands on both sites regardless of climatic condition. The annual soil water deficit (W(d)) was higher on the southern site under the changing climate. On the northern site, the situation was the opposite. According to our results, the growth of pure Norway spruce stands in southern Finland could be even lower than the growth of Norway spruce in mixed stands under the changing climate. The opposite was found for pure Scots pine and birch stands due to lower water depletion. This indicates that in the future the management should be properly adapted to climate change in order to sustain the productivity of mixed stands dominated by Norway spruce.     

新疆加工辣椒根腐病病原鉴定

以制干辣椒根腐病病样为分离对象,采用形态学和分子生物学方法对致病菌进行鉴定。结果表明:共采集根腐病样211个,从中分离获得161个分离物,其中镰刀菌Fusarium spp.121个,占总分离物的75.16%;其它菌40个,占24.84%,说明镰刀菌是新疆加工辣椒的主要致病菌。经致病性测定后,采用形态学观察结合18SrDNA-ITS、EF-1α和β?tubulin 3个序列分析,将80株有致病性的镰刀菌鉴定为尖孢镰刀菌(F.oxysporum)和茄病镰刀菌(F.solani),其中尖孢镰刀菌57株,占镰刀菌分离物的47.11%;茄病镰刀菌23株,占19.01%。