Relation of computerized tomography Hounsfield unit measurements and internal components of fresh chestnuts (Castanea spp.)

Little is known about Chestnut (Castanea spp.) in vivo cultivar characterization and morphology, the effect of mechanical harvesting, peelability, postharvest mold, physiological kernel decay, and quality. Thus, there is a need to develop a nondestructive technique able to assess fresh chestnut internal components, especially disorders. In this study, a medical grade computed tomography (CT) was used to obtain transversal two-dimensional (2D) images from decayed and healthy fresh chestnuts, from the hybrid cultivar ‘Colossal’ and ‘Chinese seedlings’. Attenuation coefficients, referred to as Hounsfield-units (HU) or CT numbers, were acquired from different 2D CT image regions including air, and several chestnut components containing decayed tissue, healthy tissue, various imperfections such as pellicle invagination into healthy kernel, and void spaces. Results offer an in vivo accurate insight of fresh intact chestnuts, and suggest that CT technology is appropriate for inline sorting. HU measurements can be used as a nondestructive predictor of fresh chestnut internal components with a 90.6% overall accuracy rate.     

Effects of gamma and electron beam irradiations on the triacylglycerol profile of fresh and stored Castanea sativa Miller samples

The present chestnut (Castanea sativa Miller) commercialization process, including distribution to novel markets, demands suitable preservation technologies. Irradiation has been considered a promising alternative to chemical fumigation (legally forbidden and harmful for human health and environment) or heat treatments (technological difficulties and low efficiency). Following previous studies on the effects of irradiation in different chemical parameters, the present work aimed to evaluate the effects of electron beam and γ-irradiation on the triacylglycerol profiles of fresh and stored chestnuts. An analysis of variance with type III sums of squares was performed using the general linear model procedure. As a classification technique, a linear discriminant analysis using the stepwise procedure was also applied. Independently of irradiation type, samples irradiated with higher doses showed higher modifications in triacylglycerol profiles. Samples irradiated with 1 and 3 kGy were clearly separated from the remaining groups in the linear discriminant analysis. The results highlight the potential of triacylglycerol profiles as indicators of chestnut irradiation. Irradiation might be recommended as a suitable method for chestnut preservation.     

Nondestructive detection of insect infested chestnuts based on NIR spectroscopy

Insect feeding is a significant postharvest problem for processors of chestnuts (Castanea sativa, Miller). In most cases, damage from insects is ‘hidden’, i.e. not visually detectable on the fruit surface. Consequently, traditional sorting techniques, including manual sorting, are generally inadequate for the detection and removal of chestnuts with hidden damage. For the most part, the only method currently used by processors is a flotation system, in which chestnuts are placed in salt water and those that float are discarded. Flotation is unreliable, and a more effective method for detection of insect damage would benefit industry and consumers alike. In this study, the feasibility of using NIR spectroscopy to detect hidden insect damage is demonstrated. Using a genetic algorithm for feature selection (from 2 to 6 wavelengths) in combination with a linear discriminant analysis routine, classification error rates as low as 16.81% false negative, 0.00% false positive, and 8.41% total error were achieved, with an AUC value of 0.952 and an Wilk's λ of 0.403 (P < 0.001). A Savitzky–Golay first derivative spectral pretreatment with 13 smoothing points was used. The optimal features corresponded to Abs [1582 nm], Abs [1900 nm], and Abs [1964 nm]. These results represent an average of 55.3% improvement over a traditional flotation sorting system.     

燕山板栗和太行山板栗品质差异的研究

从外观品质、营养品质和风味品质对燕山板栗和太行山板栗品质的差异进行研究。结果表明,燕山地区和太行山地区的板栗品质间存在显著差异,主要表现在燕山组的板栗单果重、还原糖、矿质元素Zn,Cr含量明显低于太行山组,而燕山组栗果中的蛋白质、矿质元素P,Cu含量明显高于太行山组。     

燕山地区板栗果实香气成分的GC-MS分析

以燕山地区特有板栗品种“大板红”、“冀栗1号”和“燕山早丰”果实为试材,采用固相微萃取技术结合气相色谱-质谱联用技术进行果实香气成分的测定分析。结果表明,“大板红”、“冀栗1号”和“燕山早丰”3个品种中共检测到62种香气成分,分别为33种、38种和34种,化合物的成分以醛类、醇类、酮类为主;3个品种中共有的香气成分有10种;不同品种间香气物质种类及相对含量不同。“大板红”中检测出其他两个品种中均未检测出的乙酸丁酯、乙酸己酯,故乙酸丁酯和乙酸己酯可能是其特有香气物质。研究结果有助于深入了解板栗的特征香气成分及组成,亦为不同板栗品种的香气物质指纹图谱研究提供理论指导。     

不同烤梨品种加工适宜性评价

对31个烤梨及其鲜梨品种的13项品质指标进行测定,分析其品质指标变化,并对各项品质指标进行相关性分析,通过主成分分析筛选核心指标,采用频数分布对核心指标进行分级,运用层次分析法确定品质评价指标权重以及评分标准,最后采用K类中心聚类分析和判别建立烤梨品质判别函数。结果表明,不同烤梨及其鲜梨各品种间品质指标离散程度有差异;相关性分析得出除果肉L*值外,其他指标间存在不同程度的相关性;通过主成分分析筛选出8项指标为烤梨品质评价核心指标;综合考虑8项指标对烤梨品质的影响程度并进行分级,通过层次分析法确定8项指标的权重系数,由此建立烤梨评分标准;确定烤梨品质判别函数。不同烤梨品种品质可用8项指标进行综合评价,其中以雪青烤梨品质为优,鸭梨、雪花梨、佛见喜等13个品种烤梨品质为良,均可作为烤梨的优选品种。     

燕山板栗种质资源AFLP遗传多样性分析

为研究燕山板栗的遗传多样性,用扩增片段长度多态性(amplified fragment length polymorphism,AFLP)技术对44份板栗种质的遗传多样性及遗传距离进行分析,其中36份原产燕山地区的种质中有18份为野生种质和18份为栽培品种,另外8份为原产山东的品种.共检测了384个AFLP位点,有217个是多态性位点,占56.5%,这表明了所检测的板栗材料中存在着明显的遗传多样性.用NT.SYS软件对44份板栗种质进行聚类分析.所有材料聚成4个类群,其中燕山地区原产的板栗材料被聚为3个类群,山东起源的被聚类为1个独立的类群.在所分析的44份材料中,遗传距离在0.0292和0.2214之间.燕山板栗和外来板栗存在着明显的差异,本研究结果与本实验室用RAPD技术分析的结果是一致的.结果对这些板栗材料在育种中的应用具有重要指导意义.     

Effects of controlled atmospheres and low temperature on storability of chestnuts manually and mechanically harvested

The aim of this study was to determine the effect of controlled atmospheres on quality of manually and mechanically harvested chestnuts (Castanea sativa Miller cv. Marrone Fiorentino), treated with “water curing” and stored for two months. Parameters such as color, weight, firmness, acetaldehyde and ethanol concentration, soluble solids content and sensory quality were analyzed. Mechanical harvesting increased the incidence of cracks and bruises inflicted on the chestnuts, as well as removal of the tuft. As regards storability, controlled atmospheres helped maintain chestnut quality, preserving typical organoleptic characteristics and reducing the incidence of rots where damage caused by cracks and removal of the tuft were most frequent from use of a mechanical harvester.     

苹果良好农业操作规范的研究与建立

良好农业操作规范是实行农产品生产全程质量控制的有效手段,在全世界得到广泛应用。笔者引进世界上最为先进、实用的良好农业操作规范体系EUREPGAP,在消化、吸收的基础上,研究建立了适合中国国情的苹果良好农业操作规范,包括“可追溯性”、“记录保存和内部自查”、“品种和砧木”、“园址选择与管理”、“土壤管理”、“肥料施用”、“灌溉”、“植物保护”、“采收”、“采后处理”、“废物、污染物的管理、回收和再利用”、“员工的健康、安全和福利”和“环境问题”等13章和52个记录表格,并引用了13项国家标准、4项农业行业标准和3项法律法规     

从土壤气候视角解析农业文化遗产地的自然禀赋——以宽城传统板栗栽培系统为例

宽城传统板栗栽培系统是中国重要农业文化遗产,宽城板栗栽培历史悠久,品质优良。为从土壤气候角度解析宽城板栗栽培系统的自然禀赋和不足,利用宽城县基本气象站和自动气象站的观测资料以及专项进行的土壤取样分析数据全面分析了宽城板栗栽培的土壤和气候条件,综合评价了宽城板栗栽培的气候适宜性及其空间分布。结果表明：宽城板栗林土壤酸碱度适宜,有机质丰富,N、K含量和Fe、Mn、Mg等微量元素含量较高,宽城光热资源完全满足板栗生长成熟需要,果实生长期水分供应充足,果实成熟期气温日较差大,板栗主要栽培区域综合气候条件优于板栗栽培适宜指标。总之,宽城板栗栽培系统拥有较好的土壤气候环境,具备栽培高产优质板栗的条件和潜力,春季降水偏少是宽城板栗高产的一个限制因素,适当的春季灌溉可较大幅度地促进板栗高产优质潜力的发挥。     

Microstructural characterisation of commercial kiwifruit cultivars using X-ray micro computed tomography

The skin is the physical barrier between the fruit and the environment in which it develops. Environmental conditions during fruit development have a large influence on fruit quality, both at the time of harvest and during subsequent storage. It is hypothesised that some features of the skin and sub-epidermal tissues could provide information about the past growing conditions to which the fruit was exposed and therefore be of predictive value for storage quality. In this study, five commercial kiwifruit cultivars (‘Hayward’, ‘Hort16A’, ‘G3’, ‘G9’ and ‘G14’) were studied, and ‘Hayward’ fruit were manipulated during growth with different cultural practices. After harvest at horticultural maturity, X-ray micro computed tomography (μCT) was used to investigate features of the skin and the immediate parenchyma tissue. Despite orchard management practices (crop load and girdling) being observed to effect macro fruit quality parameters (mass, firmness, SSC, and DM), differences in microstructure (e.g. porosity) caused by these practices were not observed. However, porosity and pore size were found to be highly variable between cultivars. The thickness of dense sub-epidermal tissue could be readily measured and the 3-D distribution of raphide bundles was visible as high density particles distributed within the parenchyma. Overall, μCT was found to be a powerful technique to explore fruit epidermal and sub-epidermal structures in three dimensions at a micro level. However, the length of time required for data capture and analysis and the large number of samples required to overcome natural variation within horticultural products need to be considered. Future work may define the impact of differences in porosity or sub-epidermal anatomy on kiwifruit physiology (e.g. firmness change or sensitivity to low oxygen storage atmospheres). With this information, μCT could be used as a screening tool during plant breeding, or to determine the response to agronomic treatments, without conducting lengthy storage trials.     

13个鲜食甜、糯玉米品种(系)在黑龙江省比较研究试验

本试验以黑龙江省北菜南运鲜食玉米品种筛选为目标,对13个不同鲜食甜、糯玉米品种、品系的生育期、经济性状、抗病性、产量、感观品质等各项指标进行比较分析。结果表明糯玉米米糯91、甜糯玉米米糯910与对照京科糯2000相比综合表现具有明显优势,可作为本地区的首选栽培品种。     

大粒优质三倍体葡萄新品种“红标无核”的选育

“红标无核”是以“2倍体郑州早红”和“4倍体巨峰”杂交育成的三倍体葡萄新品种。1986年杂交，经初选、品种比较试验、区域试验及生产试栽，表现极早熟、果粒大、无核、品种优、紫黑色、抗病、丰产稳产等优良性状，适宜露地和设施栽培，除鲜食外，可加工制罐，适宜栽培范围广，社会经济效益极为显著。2003年通过河北省林木良种审定。     

基于最小外接圆直径的苹果分级研究

苹果大小是苹果品质分级的重要因素之一,为实现苹果的大小分级,针对苹果外形近似球的特点,专门设计了一套基于图像处理的苹果大小分选系统。研究采用30个果径为65~95 mm的苹果,模拟苹果在输送翻转装置上的多种随机姿态,对每个试验样本进行9个不同角度的拍摄,将拍摄的所有图像传送给计算机进行二值化、去噪去斑及边缘处理等预处理,提取苹果果径面图像。根据图像边缘确定苹果的质心,寻求质心与边缘的最远距离则为苹果图像的最小外接圆半径;寻求9个图像中苹果的像素面积与其最小外接圆面积最接近的图像,计算出苹果样本果径面的最小外接圆直径。将苹果的实际大小与系统测量大小进行比较,试验表明,研究分选的正确率为96.67%,为苹果大小自动分选提供参考。     

紫色甘薯新品种引进鉴定及利用

为筛选适宜龙岩市种植的紫色甘薯新品种,采取一年多点完全随机区组试验设计,以“金山57”为对照,2014年夏季引进6个紫色甘薯新品种进行品种比较试验,从农艺性状、经济性状、鲜产、干产、淀粉产量、品质和花青素含量等方面进行筛选鉴定。结果表明：6个紫色甘薯新品种中,2个品种表现较好。其中,‘龙津薯1号’鲜薯产量最高,为39.11t/hm2,薯干产量9.22 t/hm2,淀粉产量5.53 t/hm2,干物率23.57%,淀粉率14.15%,食味评分80.0分,花青素含量17.66mg/100g。‘福薯24号’鲜薯产量其次,为36.30 t/hm2,薯干产量10.82 t/hm2,比对照增产3.32%,淀粉产量7.11 t/hm2,比对照增产6.77%。干物率29.81%,淀粉率19.57%,食味评分84.7分,花青素含量11.95mg/100g。‘龙津薯1号’鲜薯产量高,干物率和花青素含量指标适宜,可以推荐作为紫色地瓜干加工品种在龙岩市推广种植。‘福薯24号’鲜薯产量较高,食味品质好,干物率和淀粉产量高,可以推荐作为鲜食型和紫色淀粉加工型品种在龙岩市推广。‘广紫薯8号’将进一步观测。‘福宁紫3号’、‘宁紫薯1号’和‘徐紫薯2号’等品种均不适宜在龙岩市推广种植。     

改良微气调沙藏法贮藏板栗的研究

在传统沙藏法基础上,运用介质散热装置和PE薄膜覆罩研制出改良微气调沙藏法,并对板栗贮藏介质温度、呼吸强度、气体成分、品质变化及贮藏效果进行试验。结果表明,利用介质散热装置与0.04mmPE覆膜处理作用的改良微气调沙藏法,有效地改善了板栗贮藏环境,能使其保持适宜的温度、湿度、O2与CO2浓度比例,其贮藏品质得到改善,经120天常温贮藏,商品果率达93.4%。     

低温对燕山板栗枝条生理的影响研究

为了探讨低温处理对燕山板栗枝条生理的影响,以燕山板栗‘燕龙’品种一年生健壮枝条为材料,采取不同低温处理,测定其电导率、丙二醛(MDA)含量、多酚氧化酶(PPO)活性生理指标以及嫁接成活率。板栗枝条电解质渗出率、伤害率均随处理温度的降低而增加;在-20℃之前,MDA含量随温度的降低而增加,在-20℃,MDA含量达到最高,而在-25℃时MDA含量又降低到极低水平;PPO活性在0~20℃之间随温度的降低而逐渐降低,在-20℃之后PPO活性又升高;成活率随处理温度降低而降低,在0℃下的枝条嫁接成活率最高(60%)在-20℃以下处理的嫁接成活率为0%。-20℃是‘燕龙’板栗枝条所受到低温极限;MDA含量、PPO活性在其承受的低温极限处出现拐点。初步认定在不同低温处理下,可以用MDA含量和PPO活性出现拐点的温度预示测定植物或材料可以承受的极限低温。     

基于区块链技术的特色农产品质量供应链设计研究：以“门头沟京白梨”为例

针对不良经济活动导致特色农产品品牌严重受损、传统农产品质量追溯技术数据易被篡改等问题，研究设计基于区块链的质量供应链技术，有效发挥追溯技术在保障特色农产品质量供应链中的作用。本研究以“门头沟京白梨”为例，系统阐述北京市门头沟区‘京白梨’产业现状及特色农产品质量供应链存在的问题，分析区块链应用于特色农产品追溯的技术可行性。基于区块链技术分布式存储、去中心化和不可篡改性等特点，设计了“门头沟京白梨”质量安全可追溯体系的总体构架，基于区块链的技术架构，阐述了在种植、仓储、流通、消费和监管等环节质量信息全程记录和追溯管理的实现途径，以期为构建基于区块链的特色农产品质量安全追溯技术与实践提供支持。建立的特色农产品质量供应链体系，将会使特色农产品品牌和质量得到更加有效的保护、监督和管理。     

甘薯苗期根系农艺性状与内源激素的动态变化研究

为了解甘薯苗期根系生长发育与内源激素之间的关系,通过水培的方法分析了根系农艺性状与内源激素的动态变化,结果表明：在栽后25天内,‘烟薯25’的根长指标一直保持最高,色素提取型甘薯品种Aya和‘济黑1’的平均根鲜重最高,但其平均单株根干重却最低。淀粉型甘薯品种（‘徐薯18’、‘济徐23’）根系在栽后10天就已块根分化完成,并开始了干物质的积累,早于鲜食型甘薯品种（‘济薯22’、‘烟薯25’）和色素提取型甘薯（Aya、‘济黑1’）的根系分化过程。对不同节位根系的内源激素分析发现,尽管6个品种的不同时期、不同节位上根系的内源激素含量变化存在品种间差异,但3个节上根系生长促进类激素(IAA、ZR、GAs)含量在栽后15天左右达到高峰,倒三节根系中的ABA含量低谷也出现在栽后15天左右。对甘薯苗期不同节位根系农艺性状与内源激素间的相关性分析发现,从栽后5天至栽后25天,倒一节根系体积的增大主要与生长类内源激素的平衡紧密相关,生长较为缓慢,而薯苗的倒二节和倒三节根系在栽后20天左右进入了生长的旺盛期,干物质积累迅速。倒一节至倒三节根系分化的时间分别为栽后20天、栽后15天和栽后10天左右,从薯苗基部向上,各节位根系分化时间有逐渐提前的趋势。总之,甘薯苗期不同节位根系的生长、分化特点以及内源激素调控存在时间和空间的差异。     

白肋烟新品种‘鄂烟215’的选育及特性

‘鄂烟215’由‘MSBurley21’为母本、‘Virginia509’为父本杂交选育而成,2015年4月通过全国烟草品种审定委员会审定。该品种田间长势强,遗传性状稳定,属非转基因烟草。综合经济性状与对照‘鄂烟1号’相当;烟叶外观质量好,主要化学成分含量适宜且协调性好,物理特性好,感官评吸质量中等 ,与对照属同一质量档次;抗TMV,抗至中抗黑胫病,中感至感根结线虫病,感至高感赤星病。该品种品质优良,抗病性好,丰产性较好,可作为白肋烟生产的储备品种。