不同品种枇杷果实微量元素分析及综合评价

本研究采用电感耦合等离子体质谱法（ICP-MS）测定23种枇杷果实中9种微量元素含量,并对果实的外观品质指标进行测定,运用主成分分析、聚类分析方法及结合SPSS 19.0统计软件对测定结果进行综合评价。结果表明：（1）不同品种枇杷果实中微量元素含量顺序均为：Mn>Zn>Fe>Cu>Ni>Co>Mo>Se>V。其中Mn、Fe和Zn 3种微量元素是枇杷果实中主要微量元素,主成分分析筛选出4个主因子,枇杷果肉中Mn、Co、Cu和Se是枇杷的特征微量元素,综合得分较高的前3个品种依次是‘新霄’、‘卓南1号’和‘少核大红袍’。（2）根据微量元素含量将枇杷分为3个类型,即高Zn、Fe含量类型,包括‘木鱼种’、‘小毛枇杷’等共计19个品种;高Cu含量类型,包括‘少核大红袍’和‘湖北二六’;高Mn、Co含量类型,包括‘卓南1号’和‘新霄’。（3）对果实中微量元素之间相关性分析发现,元素Mn和Co、Cu之间表现为极显著性相关,相关系数分别为0.852和0.538;此外元素V和Fe、Zn,元素Co和Cu之间表现出显著相关,元素Ni和Se表现为显著相关。同时对微量元素与果实品质之间做相关性分析表明,Fe与果肉中的可溶性固形物呈极显著相关;元素Cu与果实横径表现为极显著相关。综合分析表明,枇杷中富含Fe、Zn、Mn等有益微量元素,且含有特征微量元素Se。‘新霄’是23个品种中营养价值最高的品种。     

稻草还田对设施切花菊品质及连作土壤养分的影响

[目的]针对设施切花菊连作土壤质量严重下降切花菊品质逐年下降的现象,研究探讨暗管排水(埋管最适间距2 m)条件下,稻草还田措施对设施切花菊‘神马’连作土壤理化性质及品质的改善效果。[方法]试验设5个处理:1)无暗管和无秸秆还田(CK);2)有暗管和无秸秆还田(PS0);3)有暗管和800 kg/hm^2秸秆还田(PS800);4)有暗管和1600 kg/hm^2秸秆还田(PS1600);5)有暗管和2400 kg/hm^2秸秆还田(PS2400)。测定温室耕作层土壤(0 15 cm)养分含量、阳离子交换量、全盐含量以及植株主要生理指标。[结果]暗管排水条件下,不同稻草还田量均可显著增加土壤中的有机质含量、有效磷含量及速效钾含量。与CK相比,1600 kg/hm^2稻草还田量处理后土壤碱解氮含量最低,而土壤的阳离子交换量与其他处理相比分别增加了32.7%、23.6%、11.4%、8.23%;除此之外,各稻草还田处理均可有效降低土壤pH值、土壤全盐量及电导率,其中1600 kg/hm^2稻草还田量处理后土壤耕作层电导率最低,为167μS/cm,相比CK下降了31.1%;各稻草还田处理使切花菊的株高、茎粗、舌状花数、花鲜重和生物量等主要生理指标显著提高,切花菊‘神马’的株高、舌状花数、生物量在1600 kg/hm^2稻草还田处理下显著高于其他处理。[结论]1600 kg/hm^2稻草还田量为本试验综合效果最佳的处理,其对设施切花菊‘神马’土壤理化性质改善明显,土壤肥力增加显著,切花菊品质提高最佳。     

The quality of baby spinach as affected by developmental stage as well as postharvest storage conditions

Baby spinach is rich in phytochemicals that provide great benefits to consumers’ health. The study aim was to investigate the effect of the growth harvest stage, postharvest storage duration and temperature on quality of baby spinach leaves. A 3?×?5?×?3 factorial experiment was laid out in a randomised complete block design with four replicates per treatment. The treatments were arranged as follows namely: stage I [28 days after sowing (DAS)], stage II (35 DAS)and stage III (42 DAS), and leaves were kept up to 12 d at three different temperatures – 4, 10 and 20°C. The study demonstrated that the overall appearance and odour were both well maintained in the leaves of baby spinach harvested at stage II. The baby spinach harvested 28 DAS led to higher content of iron [1.13?mg?g^?1 dry weight (DW)], magnesium (14.4?mg?g^?1 DW), and zinc (0.17?mg?g^?1 DW). The highest level of total antioxidant activity (0.43?mg?g^?1 DW) and flavonoids (12?mg?g^?1 DW) after 12 d of storage was observed in baby spinach leaves at stage I when stored at 4°C. Therefore, baby spinach leaves harvested 28 DAS and store at 4°C for 6 d improved shelf life and nutraceutical quality. Thus, early harvest of fresh produced baby spinach harvested in order to attain high phytochemical and mineral content when stored at low temperature (4°C) without exceeding 6 days is recommended.     

山药不同处理方式的保存效果

运用涂抹草木灰、石蜡及自然干燥、吹风机干燥等方法对山药茎段切口进行处理,研究不同切口处理方式对山药外观及品质的影响;比较不同浓度壳聚糖与15%柠檬酸组合对切片的保鲜影响,进行山药茎段切口处理方法及切片表面处理方法的筛选。结果表明:室温下涂抹草木灰对鲜切山药茎段的贮藏效果最好;4℃条件下,15%柠檬酸+0.5%壳聚糖处理对山药切片的保鲜效果最好。     

不同饲养密度对地面平养蛋鸡福利状况和生产性能的影响

试验旨在通过研究地面平养模式下不同饲养密度对蛋鸡行为、外观、血液应激指标及生产性能的影响,筛选保证蛋鸡福利状况及生产性能的最大饲养密度,为我国推广地面平养模式蛋鸡福利养殖奠定理论基础。将780只苏禽绿壳蛋鸡按舍内密度分为四组,其中地面平养分为低密度组(6只/m^2)、中密度组(8只/m^2)、高密度组(10只/m^2),笼养组为对照组,每组3个重复。试验期为18~27周龄,蛋鸡行为学数据均采用视频录像收集,在27周龄末进行翅静脉采血和福利外观评价,统计分析24~27周龄生产性能。结果显示:笼养蛋鸡的产蛋率,攻击、刻板等非福利行为均显著高于平养组(P<0.05),脚垫损伤、羽毛评分、应激激素浓度(CORT、ACTH)显著低于平养组(P<0.05)。地面平养各组间,高密度组蛋鸡料蛋比显著高于低、中密度组(P<0.05);低、中密度组蛋鸡行走和休息时间比例均显著高于高密度组(P<0.05);低密度组蛋鸡啄羽行为显著低于高密度组(P<0.05),但与中密度组差异不显著(P>0.05);低、中密度组蛋鸡脚垫损伤、背羽损伤显著低于高密度组(P<0.05);高密度组蛋鸡血清中CORT和ACTH浓度显著低于低、中密度组(P<0.05)。由此可见,平养蛋鸡比笼养蛋鸡行为表现更积极,羽毛覆盖度更好,但应激水平和足部损伤较高、生产性能较低;在试验场地模式下,推荐8只/m2为最佳饲养密度。     

甘肃文县珙桐群落的区系组成结构特征

甘肃文县让水河流域的珙桐群落,是目前该种群自然分布的最北残遗。通过群落学特征分析研究表明：①该区域珙桐群落的植物约有种子植物１６９种,分属于６６科,１２３属;②地理成分复杂多样,温带分布型属约占７０．７％,并在群落各层的区系组成中均占居优势;③在群落中起重要作用的植物富有单型属和少型属,并多为白垩纪及第３纪植物区系的后裔或残遗;④该群落以单叶、中型叶及高位芽植物为基本外貌特征,隶属于北亚热带常绿、落叶阔叶混交林;⑤群落的成层现象明显,以乔木层和草木层较为发达,一般可分为２～３个亚层;⑥由于本区环境因子对该种群生态适应的临界性及自身繁殖和基因交流的障碍机制,珙桐后备种群缺乏,天然更新能力较差,群落的稳定性十分脆弱。     

青海高原小麦千粒重与生理形态的相关性

小麦千粒重与平均净同化率和光合势呈极显著正相关（ｒ＝０．４１５＾＊,ｒ＝０．５０７＾＊）,与平均灌浆速度,充实指数和穗下茎维管刺数量呈级显著正相关（ｒ＝０．６０４＾＊＊,ｒ＝０．８２９＾＊＊,ｒ＝０．６３５＾＊＊）。籽粒最大体积与平均净化同化率呈极显著正相关（ｒ＝０．８６８＾＊＊）,与穗下茎维管束数量呈显著正相关（ｒ＝０．５２３＾＊）。充实指数与平均灌浆速度呈极显著正相关（ｒ＝０．８５２＾＊＊）。     

基于改进YOLO v4的玉米种子外观品质检测方法

针对玉米种子在外观品质检测中需要快速识别与定位的需求,提出了一种基于改进YOLO v4的目标检测模型,同时结合四通道(RGB+NIR)多光谱图像,对玉米种子外观品质进行了识别与分类。为了减少改进后模型的参数量,本文将主干特征提取网络替换为轻量级网络MobileNet V1。为了进一步提升模型的性能,通过试验研究了空间金字塔池化(Spatial pyramid pooling, SPP)结构在不同位置上对模型性能的影响,最终选取改进YOLO v4-MobileNet V1模型对玉米种子外观品质进行检测。试验结果表明,模型的综合评价指标平均F1值和mAP达到93.09%和98.02%,平均每检测1幅图像耗时1.85 s,平均每检测1粒玉米种子耗时0.088 s,模型参数量压缩为原始模型的20%。四通道多光谱图像的光谱波段可扩展到可见光范围之外,并能够提取出更具有代表性的特征信息,并且改进后的模型具有鲁棒性强、实时性好、轻量化的优点,为实现种子的高通量质量检测和优选分级提供了参考。     

郑州黄河风景名胜区文化景观认知与保护研究

郑州黄河风景名胜区经历长期的发展演变,形成具有中原特色的黄河文化,但目前对于其景观资源的认知模式仍以资源导向型为主,忽略了人与自然持续演进过程中产生的文化价值。因此,基于文化景观的视角,通过研究郑州黄河风景区文化价值层积的演变特征,剖析其文化景观物质表象与精神内涵的构成要素,解读其文化景观价值,并提出相应的保护与发展策略,以实现文化景观的可持续发展。     

Relationships among the chalkiness,kernel size and endosperm cell morphology of rice kernels at different spikelet positions within a panicle

The occurrence of chalky kernels in rice is causally related to kernel size and endosperm morphology. This study aimed to investigate the occurrence of chalky kernels by analyzing kernel size, and the number and area of endosperm cells. Spikelets were sampled from upper and middle primary branches and lower secondary branches in a panicle, and divided into four categories: upper, middle, and lower perfect (PF) kernels and lower milky-white (MW) kernels. On the lower secondary branches, there was a higher percentage of chalky kernels, with smaller kernel lengths, widths and thicknesses, than the kernels on the upper and middle primary branches. MW kernels were smaller in size than PF kernels even on the same lower secondary branches. Regardless of grain appearance quality traits, the total areas of endosperm cross sections in lower kernels were significantly smaller than in upper kernels owing to the decreased cell area, and there was a significant negative correlation between the number of cells and average cell area. When the numbers and the areas of cells were analyzed using angular 30° intervals from the line connecting the center point and the dorsal vascular bundle, the MW kernels had significantly less cells than PF kernels near the ventral side at 120–180°. Thus, the decrease in the number of cells near the ventral side was a main causal factor in the decrease in MW kernel widths compared with PF kernel widths, and this suggested that cell division in MW kernels was inhibited at the early grain-filling stage.