去雄对睡莲花瓣开放角度及生理生化特征的影响

为揭示睡莲(基部被子植物)的开花特性,探究雄蕊在睡莲花瓣节律性开放过程中的作用.本研究以蓝鸟睡莲(Nymphaea 'Blue Bird')为实验材料,在去雄(摘除雄蕊)后记录花瓣开放角度和萎蔫时间,并于去雄后第6、24、48及72小时测定花瓣的生理生化指标变化.结果 显示,去雄后睡莲花瓣的开放角度小于对照组,在第48小时与对照组开放角度差异最大,达到49.31°,而去雄后花瓣萎蔫的时间与对照组相同,均出现在第72小时;去雄引起了花瓣多项生理生化指标发生变化,其中,含水量在第24小时与72小时显著低于对照组,比对照组分别低0.7％与0.9％;可溶性糖含量变化显著,在第24小时和48小时比对照组分别高出0.48与0.68 mg/g;脯氨酸(Pro)含量在第72小时显著高于对照组;过氧化物酶(POD)活性从第24小时起比对照组显著升高;而丙二醛(MDA)含量则与对照组无明显差异.以上结果说明,去雄导致了睡莲花瓣开放角度及生理状态发生改变,该发现进一步地揭示了睡莲的开花特性,首次证明了雄蕊对于花瓣节律性开放具有调节作用,为花瓣开放闭合及切花保鲜等领域的研究提供了新的思路.     

Comparison of the microbial communities of alpacas and sheep fed diets with three different ratios of corn stalk to concentrate

The objective of this study was to investigate the characteristics of ruminal microbial communities of alpacas (Lama pacos) and sheep (Ovis aries) fed three diets with varying ratios of roughage (corn stalk) to concentrate, 3:7 (LS), 5:5 (MS) and 7:3 (HS). Six alpacas (one-year-old and weighing 29.5 ± 7.1 kg) and six sheep (one-year-old and weighing 27.9 ± 2.7 kg) were used in this study, in a replicated 3 × 3 Latin square experiment. Total protozoa concentration was determined under the microscope; total fungi and methanogens were assessed using quantitative polymerase chain reaction and expressed as a percentage of total bacterial 16S rRNA gene copies; bacterial communities were investigated by targeted 16S rRNA gene (V3–V4 region) sequencing. The percentage of fungi was significantly higher in alpacas than in sheep under the LS diet, while the concentration of protozoa was significantly lower in alpacas under HS, MS and LS diets. The alpha diversity including Shannon, Chao l and ACE indices of bacterial communities was higher in alpacas than in sheep, under the LS diet. A total of 299 genera belonging to 22 phyla were observed in the forestomach of alpaca and sheep, with Bacteroidetes and Firmicutes dominating both animal species. Phyla Armatimonadetes and Fusobacteria, as well as 64 genera, were detected only in alpacas, whereas phyla Acidobacteria and Nitrospira, as well as 44 genera, were found only in sheep. The abundance of cellulolytic bacteria, including Butyrivibrio and Pseudobutyrivibrio, was higher in alpacas than in sheep under all three diets. These differences in the forestomach microbial communities partly explained why alpacas displayed a higher poor-quality roughage digestibility, and a lower methane production. Results also revealed that the adverse effects of high-concentrate diets (70%) were lesser in alpacas than in sheep.     

胰α-淀粉酶基因5''端调控序列与鱼类食性的关系

为了研究不同鱼类胰α-淀粉酶基因5'端调控序列转录因子差异与鱼类食性分化之间的关系。通过PCR克隆测序和查询NCBI数据库,获得32种鱼类胰α淀粉酶基因5'端824 bp序列,并对鱼类胰α淀粉酶基因5'端序列进行转录因子和系统发育分析。按不同的营养类型将鱼类分为杂食性、植食性和肉食性,通过百分比相似性分析不同食性鱼类的胰α淀粉酶基因转录因子的组成差异以及转录因子与鱼类食性的关系。结果显示:不同食性鱼类的胰α-淀粉酶基因5'端序列存在转录因子种类差异,植食性-肉食性鱼类差异主要体现在E47、C/EBPalpha、NF-Y和Pax-2,植食性-杂食性差异主要体现在deltaEF1、MyoD、NF-Y、AREB6和Pax-2,杂食性-肉食性差异主要体现在GATA-1、SRY、MyoD、HFH-8、AREB6、Pax-2、STAT5A和AP-1。系统发育结果与传统形态分类学大体相符,相同食性的鱼类并没有聚为一类。鱼类胰α-淀粉酶基因5'端调控序列中与食性分化相关的转录因子有E47、C/EBPalpha、NF-Y、Pax-2、deltaEF1、MyoD、AREB6、GATA-1、SRY、HFH-8、STAT5A和AP-1;胰α-淀粉酶基因5'端序列的转录因子与鱼类食性分化具有一定的关系。     

工业级棉短绒清理回收工艺的改进

为降低棉短绒中的杂质含量，提高棉短绒的质量及收率，对棉短绒清理回收的生产工艺进行了改进，创新连续化多级除杂装备和短绒精细化分离工艺。棉籽清理除杂工艺中，增加了圆筛、棒条机，并且调整了风力清籽机组配置；短绒分离工艺中，增加了五联筛和新型棒条机。改进后的工艺能够提升对毛棉籽的除杂效果，彻底清理剥绒得到的棉短绒中的碎棉仁、棉壳及棉秆等杂质。此外，该工艺还能回收棉短绒下脚料，满足大型生产线的生产要求。     

河北省棉田绿盲蝽绿色防控技术体系构建

为了构建科学合理、可操作性强的河北省棉田绿盲蝽绿色防控技术体系，于2011－2015年在河北省沧州植棉区开展了棉田绿盲蝽绿色防控技术研究，包括色板诱杀、性信息素、频振式杀虫灯和高效生物农药应用等，并逐步构建了针对棉田绿盲蝽的绿色防控技术体系。根据相关研究发现，该绿色防控技术对棉田绿盲蝽有较好的防治效果，与常规防治区相比，减药控害成果显著。     

Dynamics of apoptosis-related gene expression during follicular development in yak

The potential reproduction power of domestic animals is limited by a complicated follicular atresia process. P53, caspase-9 (Casp9), Bax, Bcl-2 and Fas play a crucial role in the ovarian mitochondrion-dependent apoptosis and death receptor pathway. In accordance with this study, the expression levels of Casp9, Bax, Bcl-2 and Fas were analysed in ovaries and oviducts of yak by immunohistochemistry (IHC). P53 and the above in ovarian granulosa cells (GCs) from atretic (3–6 mm) to healthy follicles (6–8 mm) and in oviducts were examined from the luteal phase to the follicular phase during the oestrous circle by Western blot (WB) and real-time PCR (RT-PCR). Results demonstrated that typical classic apoptotic factors Casp9, Bax, Bcl-2 and Fas were expressed in the cytoplasm and zonal pellucida of oocytes, primordial follicles, primary follicles, ovarian surface epithelium, ovarian GCs, granular lutein cells, surface epithelia in oviduct uterotubal junction and oviduct ampulla during the luteal phase. RT-PCR and WB revealed that P53 and Fas significantly increased in GCs of atretic follicles. P53 and Casp9 increased in oviduct epithelium during the luteal phase, but Fas was unchanged. A contrary tendency was noted in Bcl-2 and Bax expression. Overall, P53 and Fas play an essential role in inducing GC apoptosis, and Bax, Bcl-2, Casp9 and P53 are involved in oviduct epithelial regeneration in yak.     

林木氮素吸收偏好性及其形成机制研究进展

森林土壤中可被林木吸收利用的氮（N）素主要以铵态氮（NH₄+-N）和硝态氮（NO₃--N）的形态存在。受全球气候变暖、氮沉降和人类活动等因素的影响，NH₄+和NO₃-的分布存在很大的时间波动性和空间异质性，且NH₄+-N和NO₃--N亏缺已成为限制林地生产力的主要因素。在森林土壤N亏缺和N异质分布的逆境中，在林木长期进化过程中形成了对不同形态N素的吸收偏好，且这种吸收偏好会随生长环境条件而发生改变。特别是对于NH₄+和NO₃-这2种主要形态的偏好选择性已被证明是决定林木生产力、竞争、共存和生态演替的重要因素之一。对不同树种在N异质分布环境下的N吸收偏好和形成机制的研究，是揭示林木N素营养遗传特性和提高林地N素利用效率的关键。文中从森林土壤中N的主要形态及其分布特征、林木对不同形态N素的吸收偏好和形成机制、林木N吸收偏好的影响因素3个方面进行总结阐述，并对未来研究方向进行展望，以期为我国人工林培育中不同树种的造林配置和合理N素施肥技术提供理论依据和参考。     

Effect of Foliar GA3 and ABA Applications on Reactive Oxygen Metabolism in Black Currants (Ribes nigrum L.) During Bud Para-dormancy and Secondary Bud Burst

The secondary bud burst can cause around 10％-20％ yield losses in black currants, an economically important crop in parts of Europe, Asia and North America. The metabolism of reactive oxygen species (ROS) has been linked to bud dormancy and its early release (secondary bud burst) in several fruit crops. But the relationship between ROS metabolism and the secondary bud burst is still not well understood in black currants. In the present study, two black currant cultivars (Adelinia and Heifeng) with opposing tendency of exhibiting the secondary bud burst were sprayed with abscisic acid (ABA) and gibberellic acid (GA3) to either inhibit or induce the secondary bud burst. The results showed that ABA inhibited the secondary bud burst by reducing the contents of ROS (H2O2, O2-?) in buds; decreasing the activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT); and increasing the contents of oxidized glutathione (GSSG) and ascorbic acid (AsA). GA3 effectively induced the secondary bud burst by increasing ROS contents; increasing the activities of several antioxidant enzymes, such as SOD, POD, CAT, glutathione reductase (GR), ascorbate peroxidase (APX) and the contents of reduced glutathione (GSH); and decreasing the contents of AsA. The experimental results showed that GA3 treatment increased the content of ROS, accelerated the metabolism of reactive oxygen species, and promoted the second burst of black currants. However, ROS metabolism was at a low level under ABA treatment, and the buds remained dormant. These results suggested that ROS metabolism might play an important role in the two black currants of the secondary bud burst.     

Hybridization between Crassostrea hongkongensis and Crassostrea ariakensis at Different Salinities

To evaluate the survival and growth performance of hybrid larvae and juveniles, we conducted hybridization experiments between Crassostrea hongkongensis and Crassostrea ariakensis at three salinities (15, 23, and 30 ppt). Hybrid fertilization occurred in one direction (C. hongkongensis ♀ and C. ariakensis ♂), and the fertilization rates did not differ significantly among the three trial salinities. Molecular genetics analysis revealed that hybrid progenies were true hybrids. Hybrid juveniles survived better than C. hongkongensis juveniles at a salinity of 30 ppt. Hybrid larvae and juveniles showed intermediate growth between C. hongkongensis and C. ariakensis progenies. The growth of hybrid juveniles was significantly greater than that of C. hongkongensis juveniles at a salinity of 30 ppt. Overall, C. hongkongensis has a high economic value but favorable hatchery and farm of this species is restricted to lower salinity sites. Because the hybrids were shown to have greater growth and survival characteristics at high salinity, hybrids may be a more desirable candidate to be cultured in those areas of China with higher salinities, such as the Bohai Sea of China where the salinity is usually 30 ppt.     

湿地松幼苗根系微生物数量变化规律的研究

采用平板稀释法研究了湿地松幼苗1 a中微生物根系数量的变化规律,为合理的生物防治时期提供科学依据。结果表明:湿地松苗圃土壤中存在着大量的微生物。湿地松幼苗根系的生长和发展可以大大促进其周围微生物的生长,受湿地松根系生长和环境变化等因素的影响,在松苗移栽后的几个月内,根际细菌和真菌的种群数量迅速增加,细菌比真菌的种群增长速度要快。利用生物防治细菌进行苗木猝倒病防治的最佳时期应该是在芽苗移栽后1个月以内。