小黄花菜(Hemerocallis minor)的开花特性与繁育系统研究

为明确小黄花菜开花特性和繁育系统对有性繁殖过程的影响,通过对小黄花菜不同储藏条件下的花粉活力变化和柱头可授性的测定、人工授粉试验以及计算花粉-胚珠比(P/O)和杂交指数(OCI),研究小黄花菜开花特性和繁育系统类型。结果表明:1)小黄花菜单花期长达20.5~21.5 h,群体花期60 d左右。2)随着花粉储藏时间的延长,花粉活力呈现降低的趋势;相同储藏时间和温度下,花粉活力在干燥条件下比非干燥条件下高;最佳储藏条件为-80 ℃干燥储藏。3)小黄花菜柱头可授性呈现开花后先上升后下降的趋势,开花3 h后可授性达到最高。4)小黄花菜的繁育系统类型为兼性异交型,部分自交亲和,异交需要传粉者。其P/O值为2 364.13±117.39,OCI值为4。本研究结果为小黄花菜加入萱草育种,培育早花且长花期的萱草新品种提供了研究基础。     

生态资源赋能乡村共富——数字经济的促进作用

为探究数字经济在生态资源赋能乡村共富中的促进作用,基于空间异质性,构建“生态资源-数字经济-乡村共富”的分析框架,利用2010—2020年省级面板数据,采用地理探测器工具进行了实证研究。结果表明:1)生态资源价值对乡村共富具有驱动作用。其中,森林资源、草原资源、自然保护区资源通过生态经济化促进城乡财富转移,而政府保护治理投资和污水再利用则保障乡村分享生态资源价值化红利的可持续性。2)数字经济对乡村共富具有驱动作用。主要来源于数字经济通过赋能农业生产、丰富产业发展模式、重构人力资本积累方式和推动统一大市场建设等途径直接或间接促进要素从城市向乡村流动,缓和发展不平衡不充分的问题。3)生态资源价值和数字经济的交互作用对乡村共富具有显著驱动作用。这主要源于数字经济赋能生态资源的产权界定过程,以及价值核算、开发建设、市场交易和利益分配等产权实施过程,促进生态产品价值实现,使其真正变成生态产业,进而促进乡村共富。因此,从推动乡村数字化发展,构建生态资源监管、开发、交易平台以及促进数字经济赋能生态资源价值实现等三方面提出政策建议。     

甘草水氮效应研究及基于有效成分的水氮方案

为研究不同水氮配比对甘草生长及活性成分含量的影响,并提出基于水、氮因子的甘草有效成分含量的灌水施氮方案,以乌拉尔甘草为研究对象,设4种灌溉定额,4个氮肥水平,采用裂区试验设计,研究水、氮因子及其组合对甘草生长指标及有效成分的效应,并依据活性成分建立回归模型寻优,结合Topsis综合评价法确定最优的灌水施氮方案。结果表明：灌水极显著增加株高、侧枝数、根长、根鲜质量、根干质量、甘草酸、甘草苷及总黄酮含量;施氮显著影响株高、侧枝数、根长、根鲜质量、根干质量、甘草酸及总黄酮含量;水氮交互显著影响株高、根长、根鲜质量、根干质量、甘草酸、甘草苷及总黄酮含量。回归分析可知,当灌溉定额为3 000 m²/hm²,氮肥施量分别为108.86 kg/hm²、134.20 kg/hm²和144.28 kg/hm² 时,对应的甘草酸、甘草苷和总黄酮含量最高,分别为1.270%、0.670% 和7.173%。结合Topsis综合评价法分析,得出甘草活性成分含量最大化的最优灌溉定额为3 000 m²/hm²,氮肥施量为108.86～144.28 kg/hm²。株高、侧枝数及根长与甘草有效成分含量相关性比较高,可作为甘草有效成分筛选的指标。     

化肥减量配施增效剂对土壤理化性质及菜心产量、品质的影响

【目的】探讨化肥减量配施增效剂对广东省惠州地区蔬菜地土壤理化性质及菜心产量、品质的影 响,为蔬菜地化肥减量提供理论依据和技术支持。【方法】以华南地区代表性的蔬菜作物菜心为研究对象,采 用田间小区试验,设置当地施肥（T1,CK）、当地施肥 + 增效剂（T2）、减肥 20%（T3）、减肥 20%+ 增效剂 （T4）4 个处理,比较不同处理下土壤的理化性质、微生物量、酸性磷酸酶活性以及菜心产量、品质等指标。【结 果】与 T1（CK）相比,T3 处理菜地土壤毛管持水量、田间持水量、非毛管孔隙度和总孔隙度分别提高 13.3%、 43.1%、29.4% 和 9.2%,T4 处理菜地土壤非毛管孔隙度和总孔隙度分别提高 42.1% 和 13.0%;与 T1（CK）相比, T3 处理菜地土壤 pH 值提高 15.9%,其他土壤肥力指标均无显著变化,T4 处理菜地土壤 pH 值提高 13.4%、碱解 氮和速效钾含量分别显著提高 33.3% 和 15.8%;与 T1（CK）相比,T3 处理菜地土壤微生物量碳、氮和酸性磷酸 酶活性分别提高 35.6%、43.1% 和 15.5%,T4 处理土壤微生物量碳、氮、磷和酸性磷酸酶活性分别提高 78.1%、 111.2%、49.1% 和 24.3%; 与 T1（CK）相比,T3 处理菜心氮、磷、钾养分吸收量分别提高 22.1%、11.3%、 17.9%,T4 处理菜心氮、磷、钾养分吸收量分别显著提高 33.0%、28.5% 和 30.0%;与 T1（CK）相比,T3 处理 菜心产量提高 19.4%、硝酸盐含量下降 13.6%、Vc 含量提高 2.2%,T4 处理菜心产量显著增加 28.1%、硝酸盐含 量下降 12.1%、Vc 含量提高 4.2%。【结论】化肥减量配施增效剂可以提升土壤肥力、提高土壤的微生物量和酸 性磷酸酶活性、提高菜心的产量和改善品质。     

Influence of two-stage harvesting on the properties of cold-pressed rapeseed (Brassica napus L.) oils

Rapeseed (Brassica napus L.) harvesting method is critical since it significantly determines the seed yield, oil quality, and industrial efficiency. This study investigated the influences of harvesting methods on the quality of cold-pressed rapeseed oil of two varieties. Oil color, peroxide value (POV), tocopherol content, fatty acid composition, and polarity of total polyphenols (PTP) contents of two rapeseed varieties in Huanggang and Xiangyang were compared through artificially simulated combined harvesting and two-stage harvesting. Results showed significant differences in the quality of rapeseed oil between the two harvesting methods. The red value (R-value), POV, total tocopherol contents, linoleic and linolenic acid content, and PTP content of the pressed rapeseed oil prepared by the combined harvesting method were about 27.6, 5.7, 15.8, 2.0, 0.5, and 28.6% lower than those of the oil produced from the two-stage harvesting method, respectively. Xiangyang and Huayouza62 performed better in the two regions and two varieties, respectively. To sum up, the rapeseed oil obtained 41–44 days after final flowering of combined harvesting, 35 days after final flowering, and six days of post-ripening of the two-stage harvesting had the best quality.     

Effect of group size and regrouping on physiological stress and behavior of dairy calves

Mixing or regrouping of calves from different pens is a common animal management practice on the farm, which frequently occurs after weaning and has a negative effect on calve welfare.  Social integration before regrouping may relieve stresses, but more evidences are needed to verify this hypothesis.  The present study aimed to investigate acute physiological and behavioral variations of individually- or group-housed calves after being introduced into a mixed group.  A total of 132 postnatal calves were randomly divided into groups of 1, 3, 6 and 12 animals (S, G3, G6, and G12; 6 replicates in each group) until 59 days of age.  At 60 days of age, every two replicates from different groups (S, G3, G6 and G12) were introduced in a larger pen which containing 44 of the aboved experimental calves.  Before and after regrouping, physiological parameters of stress, including heart rate (HR), saliva cortisol (S-CORT), saliva secretory immunoglobulin A (SIgA), interleukin-2 (IL-2), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α) levels, and behavioral responses were recorded.  After regrouping, HR and S-CORT increased immediately (P<0.05), and higher (P<0.05) levels of such molecules were found in S calves compared to those in group-housed calves.  Levels of SIgA and IL-2 were decreased (P<0.05), and the lowest (P<0.05) IL-2 values were found in S calves compared to those in group-housed calves.  In addition, the introduced calves displayed a distinct behavior, including altered active and rest time, which was associated with negative emotions triggered by the novel surroundings.  Allogrooming, play, exploration behaviors and lying time were increased significantly (P<0.05) in group-housed calves than those in S calves.  Conversely, self-grooming, aggressive behaviors, standing and walking time were increased (P<0.05) in S calves than those in group-housed calves.  These findings suggest that individually-housed calves may be more susceptible to stressors arising from regrouping than group-housed calves, which consequently negatively affected behavioral and neuroendocrine responses.  Furthermore, moving calves with previous social experience may help mitigate regrouping stress.     

量化修剪与喷施苹果面膜对果园经济效益的影响

为减少果园用工费,提高果园经济效益,在渭北旱塬以常规修剪苹果园为对照,监测量化修剪对疏花疏果用工费、果实品质和果园经济效益等的影响;在陕北丘陵沟壑区以苹果套袋（纸袋）为对照,监测喷施苹果面膜（腐殖酸型苹果免套袋膜剂）替代果实套袋对果园用工费、果实品质和果园经济效益等的影响。结果表明,量化修剪在冬季修剪时较常规修剪多支付用工费4500元/hm²,疏花可减少11250元/hm²,疏果可减少2250元/hm²;量化修剪的苹果单果重大,品质高,产值提高13.73%;经济效益提高34860元/hm²。喷施苹果面膜较果实套袋和去袋可减少用工费22850元/hm²,材料费减少8250元/hm²;喷施苹果面膜提高了苹果的外观商品价值和贮藏运输性能,产值提高50.01%;果园经济效益提高192900元/hm²。量化修剪和喷施苹果面膜降低了果园用工费,提高了果园经济效益,果园管理过程中应积极开展量化修剪和喷施苹果面膜。     

Preparation of a dicyandiamide-contained novel insulation paper and an experiment on the thermal aging characteristics of relevant oil-paper insulations

In order to study the influence of dicyandiamide added into the insulation paper on the oil-paper insulation during the aging process.The insulation paper containing dicyandiamide and the insulation paper without any stabilizer are prepared. They are immersed in transformer oil separately and placed in the aging chamber with predefined temperature of 130℃ for 31 days to perform thermal aging experiment of oil-paper insulation. The specimens are periodically sampled and some parameters are measured like the degree of polymerization(DP), the breakdown voltage, the nitrogen content, the acidity of insulation oil, and UV-Vis spectrum. The results show that the insulation paper added with dicyandiamide has a distinct anti-aging and anti-breakdown effect and the DP is 58% higher than that of blank sample at the later stage of aging. In the aging process, decline of the nitrogen content of insulation paper is not serious. The oil-paper sample containing dicyandiamide has a far lower value of acidity than that of blank sample, besides the oil color is deeper. Dicyandiamide in the insulation paper improves not only the anti-aging and anti-breakdown properties, but also the performance of oil in the aging process.     

三角帆蚌细胞周期蛋白基因筛选及其表达分析

细胞周期蛋白(cyclin)对细胞生长繁殖起到关键的调节作用。该研究采用高通量测序技术,构建了三角帆蚌(Hyriopsis cumingii)转录组文库,进行了cyclins基因筛选与生物信息分析,通过qRT-PCR技术,探讨其在不同组织(闭壳肌、内脏团、外套膜、斧足、心脏、血液、鳃、性腺)与性别中的表达特征。转录组测序共得到257 457条unigene(N50为1 796 bp),注释率为86.7%;通过分析,cyclin A、cyclin D2、cyclin E被筛选出,且cyclin A、cyclin D2与cyclin E蛋白的氨基酸序列均与美洲牡蛎(Crassostrea virginica)、太平洋牡蛎(Crassostrea gigas)具有较高相似性。实时荧光定量分析结果表明,cyclin A、cyclin D2、cyclin E在三角帆蚌各组织中均有表达,且存在显著的组织差异:cyclin A、cyclin E基因在性腺中表达量显著高于其他组织(P<0.05),在斧足中表达量最低;cyclin D2基因在鳃中表达量最高(P<0.05),在血液中表达量最低。在同一组织的不同性别之间:cyclin A基因在性腺、闭壳肌、心脏、血液中表达存在显著性别差异(P<0.05);cyclin D2在外套膜、心脏、性腺中的表达具有显著(P<0.05)的性别差异;cyclin E在性腺、斧足、鳃、心脏中的表达具有显著(P<0.05)的性别差异;cyclin A、cyclin E基因在雌性心脏和性腺中表达量显著(P<0.05)高于雄性,而cyclin D2反之(P<0.05),cyclin D2基因在雌性外套膜表达量显著高于雄性(P<0.05),暗示cyclin A、cyclin E与性腺发育关系密切,cyclin D2可能与鳃损伤修复有关。本研究初步探究了三角帆蚌cyclin A、cyclin D2、cyclin E基因的功能,为建立三角帆蚌细胞系提供了分子基础。