混合盐胁迫对马蔺幼苗根系构型及生长量的影响

为探讨不同种类盐胁迫对马蔺幼苗生长状况的影响,采用室内培养的方法,研究总质量浓度为0.3%的NaCl、NaHCO₃单盐溶液及其不同配比的混合盐溶液胁迫对马蔺(Iris lactea var. chinensis)幼苗生长量、地上部干鲜重比值、地下部干鲜重比值以及根系构型的影响。结果表明,随着胁迫时间的延长,0.3%NaCl溶液对叶数和株高增长量的影响最小,其次为3种混合盐溶液,各处理在第14天时株高增幅达到最大。经0.3%NaHCO₃处理后的幼苗地上部干鲜重的比值为空白对照的2.17倍,地下部干鲜重则为空白对照的56.61%,随着混合溶液中NaHCO₃浓度的上升,地上部干鲜重比值表现出上升的趋势,地下部干鲜重比值则表现出下降的趋势。经35天处理后,0.3%NaHCO₃胁迫的马蔺幼苗根系总长、根系表面积较对照均显著下降,降幅分别为39.73%、26.08%,而各处理间的根系体积却无显著差异。研究结果显示,0.3%NaHCO₃溶液对马蔺幼苗的胁迫作用最强,2种单盐对根系的胁迫作用强于混合盐胁迫,而0.3%NaCl溶液对生长量的胁迫作用最弱。     

浅析奖励机制在科研成果产出中的导向作用 ——以北京市农林科学院为例

科研成果产出反映了科技创新能力的强弱,成果产出离不开杰出的科研人才和团队.为了提升科技创新能力,有效激发科研人员的主动性和积极性,不断提升科研成果质量,国家、地方、科研单位和高校都制定并出台了相应的科研成果奖励办法.文章以北京市农林科学院为例,对该院科技创新成果奖励的执行情况进行分析,以期总结出科技创新奖励对成果产出的导向作用.     

Characterizing a novel predator–prey relationship between native Diplonychus esakii (Heteroptera: Belostomatidae) and invasive Gambusia affinis (Teleostei: Poeciliidae) in central China

International Aquatic Research - A considerable body of the literature considers the potential impact of exotic predators on native prey organisms, while comparatively, few studies have asked...     

不同苦荞品种花和籽粒空间分布特征及差异分析

以8个苦荞品种为试验材料,研究不同苦荞品种花和籽粒在植株不同部位的分布特征及差异。结果表明,不同苦荞品种花和籽粒总数存在显著差异,其中川荞2号总花数、总籽粒数最高,分别为3 046.6和1 367.8,而川荞1号最少,分别为1 017.6和487.2,品种间总花数和总籽粒数变异系数分别为34.8%、29.0%。不同苦荞品种花和籽粒空间分布呈现相同趋势,均主要分布于分枝上,分别占整株的76.3%和74.2%以上,且均显著高于主茎,分别高68.7%~87.0%和65.2%~84.5%。生产上可通过调控分枝的有效籽粒数来提高苦荞产量。     

2019—2021年我国部分地区PRRSV ORF5基因遗传变异分析

为了解2019—2022年我国南方地区猪繁殖与呼吸障碍综合征病毒（PRRSV）ORF5基因遗传变异情况,自广东、广西、湖南、江西4个省份的种猪场和育肥场,采集疑似PRRSV感染样品进行RT-PCR检测,并对部分阳性样品进行病毒分离培养和ORF5基因测序。结果显示：PRRSV总检出率为26.12%,其中育肥场场检出率（86.36%）高于种猪场（52.00%）;共成功分离到97株病毒并对其进行了ORF5测序分析,发现Sublineage 1.8占比最高（51.55%）,其次为Lineage 5(15.46%),Sublineage 1.5、Lineage 8、Lineage 3占比依次为13.40%、10.31%和9.28%;类NADC34毒株在2021年有3个省份（广东、广西和湖南）被首次检出,且当年检出率达13.40%。GP5蛋白分析结果显示,分离株中第13和151位氨基酸以及中和表位变异较多。对其中1株毒株进行重组分析发现,该毒株以类NADC30毒株为主要亲本,其多处基因组与JXA1和IA2014毒株发生了重组。结果表明：我国南方地区PRRSV流行较为普遍,尤其是在育肥猪群中;流行毒...     

苯甲酸在松材线虫病中的作用

在室内条件下,初步研究苯甲酸对松树和松材线虫病的作用.用不同浓度的苯甲酸溶液分别处理松枝,显示低浓度苯甲酸溶液能显著延长松枝的存活期,高浓度苯甲酸溶液处理的松枝针叶出现褐变现象,但对松枝的存活期没有影响,其症状与松材线虫病不同.分别用1.0 mmol·L-1的苯甲酸溶液和自来水培养接种松材线虫的松枝,在用苯甲酸溶液处理的接种松枝中,虽然松材线虫仍能大量增殖,但与用自来水培养的接种松枝相比,其蒸腾强度显著增强,失水萎蔫程度显著降低,存活期显著延长,这说明苯甲酸在松材线虫病树中可能起着抑制与病害相关的致病菌或提高松树抗病能力的作用.     

甘肃省非物质文化遗产旅游开发SWOT分析

随着中国有越来越多的非物质文化遗产进入联合国非物质文化遗产名录,非物质文化遗产的保护日益受到社会各界的关注,以旅游开发来促进非物质文化遗产的保护和传承成为旅游界的一项新课题。甘肃拥有丰厚的非物质文化遗产,文中在全面介绍甘肃省非物质文化遗产赋存状况的基础上,运用SWOT分析法,详细分析了甘肃非物质文化遗产旅游开发的优势、...     

Factors Affecting Sensory Quality of Cooked japonica Rice

The sensory quality of cooked rice is an important factor in determining its market price, as well as consumer acceptance and breeding efforts aimed at improvement of rice grain quality. In this study,the sensory quality and physicochemical properties of three japonica rice varieties harvested in two different growing locations(Xiangshui and Hangzhou of China) were compared to determine the most important factors affecting the sensory quality. All the three varieties had higher scores for overall sensory quality in Xiangshui than in Hangzhou, indicating that the growing location is a key factor in determining the sensory quality of cooked japonica rice. In addition to growing location, variety(genotype) also had an important effect. Longdao 18 scored the highest for overall sensory quality in the two locations, whereas Longdao 30 had the lowest score in Xiangshui, and both Longdao 20 and Longdao 30 had the lowest scores in Hangzhou. Many physicochemical properties, such as apparent amylose content, protein content, thermal properties and free amino acid contents, showed significant differences between the two locations. Correlation analysis showed that apparent amylose content and protein content had contrasting effects on all the sensory attributes. The overall sensory quality was negatively correlated with protein content(r =-0.89, P 0.01) and positively correlated with gel hardness(r = 0.91, P 0.01),indicating that the protein content and hardness are important physicochemical properties for predicting the sensory quality of japonica rice. These findings will provide guidance for selection from the diverse genotypes available to develop new varieties with the desired eating and cooking quality.     

Minimally invasive evaluation of the anaesthetic efficacy of MS‐222 for ornamental discus fish using skin mucus biomarkers

Skin mucus has been demonstrated to provide stress biomarkers for evaluating the physiological status, providing new convenient and non‐invasive methods to detect stress response in fish. Here, we investigated the anaesthetic efficacy of tricaine methanesulphonate (MS‐222; 75–115 mg/L) for discus Symphysodon aequifasciata (34.27 ± 4.46 g; 8.10 ± 0.59 cm) using skin mucus stress biomarkers. The induction time, recovery time and respiratory frequency were also determined. According to the criteria for anaesthesia and recovery, discus fish to reach stage A3 (deep anaesthesia) within 3 min and to reach stage R4 (full recovery of normal behaviour) within 5 min were observed at 95–105 mg/L MS‐222. Respiratory frequency increased first and then decreased during MS‐222 exposure and increased after recovery. At 10 min after deep anaesthesia, a lower mucus glucose was only observed at 115 mg/L MS‐222. No change in mucus cortisol and increased lactate were observed in all treatments. Increased mucus protein was observed at 75, 85 and 95 mg/L MS‐222. At 10 min after recovery, increased mucus glucose and decreased mucus protein were observed at 85, 95 and 115 mg/L MS‐222, but increased mucus cortisol only at 115 mg/L and lactate only at 75 and 105 mg/L MS‐222. At 24 hr after recovery, mucus glucose returned to the initial level only at 75, 95 and 105 mg/L MS‐222, while cortisol at 75 and 85 mg/L and protein and lactate at 75 mg/L respectively. Overall, the effective dose of MS‐222 for discus fish has been suggested to be 95–105 mg/L.