采收期对‘红心’番石榴品质和耐贮性的影响

以福建漳州栽培的‘红心’番石榴(Psidium guajava ‘Hongxin’)为材料,探究不同采收期对其果实采后耐贮性和品质的影响。实验分盛花期后95 d (采收期Ⅰ)、105 d (采收期Ⅱ)和115 d (采收期Ⅲ) 3个时段进行采收,采后果实在常温(25±1℃) 和相对湿度85%条件下贮藏,贮藏期间测定番石榴果实商品率、失重率、呼吸强度、相对电导率、色调角、硬度、可溶性固形物、可滴定酸、维生素C和总糖含量变化。结果表明,‘红心’番石榴果实采后软化迅速,颜色由绿转黄较快;随着采后贮藏时间的延长,番石榴果实的商品率、硬度、色调角、可滴定酸、维生素C和总糖的含量降低,而果实失重率、细胞膜相对透性增加;采收期Ⅰ较采收期Ⅱ、Ⅲ的耐贮性强。因此,对于‘红心’番石榴果实,考虑贮运期长,适宜在采收期Ⅰ采收;其他两个采收期可在产地销售。     

1-MCP对室温贮藏下不同成熟度猕猴桃的生理效应

以适期采收(成熟度Ⅰ)和晚采收(成熟度Ⅱ)的'海沃德'猕猴桃果实为材料,研究0.5 μL·L~(-1) 1-甲基环丙烯(1-MCP)处理对室温贮藏(20℃)条件下两种果实的生理生化指标的影响.结果显示:1-甲基环丙烯(1-MCP)处理能有效延缓贮藏期间两种成熟度果实的硬度、可滴定酸含量、维生素C含量的下降,显著降低二者的乙烯释放速率和呼吸强度及其峰值,提高果实的POD、CAT和SOD活性.与成熟度Ⅰ相比,成熟度Ⅱ果实的硬度下降较快,且丙二醛含量和呼吸速率却明显较高,呼吸速率和乙烯释放量高峰时间相对提前.研究表明,在相同的贮藏条件下,晚采收的'海沃德'猕猴桃果实成熟衰老进程明显快于适期采收果实,贮藏效果较差;1-MCP能够明显延长猕猴桃果实的贮藏时间,表现出显著的保鲜效果.     

采收期和贮藏温度对金艳猕猴桃品质的影响

研究了金艳猕猴桃(Actinidia chinensis ×A. eriantha) 4个不同采收期(Ⅰ~Ⅳ)在常温[(23±1)℃]贮藏60 d,以及低温(4℃)贮藏2、4、6月后常温货架14 d内果实品质和果肉色彩的变化。结果表明：采收期Ⅰ和Ⅳ的果实在常温贮藏过程中呼吸高峰出现早、失重快,可滴定酸(TA)、维生素C(Vc)含量和果肉硬度迅速下降;而采收期Ⅱ和Ⅲ的果实呼吸高峰出现晚,保持了较高的TA、Vc含量和果肉硬度。4个采收期猕猴桃果实在常温贮藏期间,果实亮度L*、色度C*和色彩角h显著降低;而在低温贮藏后常温货架期间,果实色彩角h相对于亮度L*和色度C*变化更加明显。研究表明,采收期Ⅱ和Ⅲ为金艳猕猴桃的适宜采收期,色彩角h可以作为适宜的指标反映猕猴桃果实的后熟与衰老,而低温贮藏6个月金艳猕猴桃仍能保持较好的食用品质和色彩。     

1-甲基环丙烯对猕猴桃乙烯产生和贮藏品质的影响

室温和0℃两种贮藏条件下,100 nL*L-1的1-MCP显著抑制“秦美“猕猴桃果实乙烯的释放,延缓乙烯高峰的出现,延缓果实硬度和可滴定酸含量的下降以及可溶性固形物含量的增加.     

猕猴桃简易降温和低乙烯贮藏技术及应用

通过对猕猴桃果实成熟主要指标的测定,确定了秦美适宜采收期为１０月３日至１２日,西选１号和海沃德为１０月下旬。这时果实可溶性固形物含量为６．５─９％,硬度１２─１６ｋｇ／ｃｍ２。猕猴桃贮鲜技术在１９９２／９３年度中试（示范）成功的基础上,１９９３／９４年度在６４ｔ果实上的应用又取得了好结果。秦美贮藏１５７天,果实新鲜,完好果和商品果分别为９６．６％和９７．４％。果实在贮藏期间硬度逐渐降低,由采收时１２─１６ｋｇ／ｃｍ２下降到１．６ｋｇ／ｍ２;淀粉在酶的作用下不断转化为可溶性糖,可溶性固形物由采收时６．５─９％增加到１３．７％。简易降温库成本低,可利用自然低温设施,果实在箱袋内加保鲜剂后置该库内有利于延长猕猴桃贮藏保鲜期。     

苹果新品种‘瑞阳’果实主要特性研究

该研究以红色晚熟苹果新品种‘瑞阳’及其母本‘秦冠’、父本‘富士’为试验材料,分析各品种果实发育过程中的生长动态、色泽变化以及采收期对其果实品质的影响,为品种栽培管理和推广应用提供参考。结果表明:(1)在果实生长发育期,‘瑞阳’单果质量的变化与双亲接近,单果质量的日增长高峰出现在花后105d,果实发育前期纵径增长较大,果形指数大,在发育后期果形指数降低,至成熟时果形指数达到0.86,介于父母本‘秦冠’和‘富士’之间。(2)套袋处理使果实着色期的色泽参数a*值和花青苷含量上升,但品种间存在差异,套袋处理对‘瑞阳’的色泽参数a*值和花青苷含量影响不大。(3)随果实采后天数的延长,各采收期‘瑞阳’果实淀粉指数逐渐上升,硬度和可滴定酸逐渐下降,而可溶性固形物含量先上升后下降;‘瑞阳’果实在花后174d采收时,果实的硬度和可滴定酸下降均较少,且果实可溶性固形物含量保持在较高水平,能较好地维持该品种的果实品质。研究发现,‘瑞阳’苹果果实膨大期出现在花后105d前后,果实套袋对其表面色泽和花青苷含量影响不大,在陕西渭北以花后174d前后采收为宜。     

采收成熟度对油桃贮藏品质的影响

以‘秦光2号＇油桃为材料,研究了5个采收成熟度油桃果实在冷藏过程中呼吸速率、硬度、可溶性固形物含量（SSC）、可滴定酸含量（TA）的变化.结果表明：（1）冷藏过程中,完熟果实（第V成熟度）在贮藏15 d后最先到达呼吸高峰,未成熟果实（第Ⅰ、Ⅱ、Ⅲ、Ⅳ成熟度）则成熟度越低呼吸高峰出现的越早,且峰值越高.（2）冷藏过程中,果实硬度和TA逐渐下降,不同成熟度果实硬度变化除第Ⅲ成熟度和第Ⅳ成熟度之间差异不显著外,其余成熟度间均有显著差异（P＜0.05）;不同成熟度果实在贮藏前期TA差异显著,但后期差异不显著;SSC在贮藏过程中表现出先升高后下降趋势.（3）在冷藏条件下,成熟度越低的果实对低温的敏感性越高,越易发生冷害.（4）第Ⅳ成熟度果实（果实底色呈乳白色,SSC 11.4%,硬度7.3 kg·cm^-2）在冷藏期间呼吸高峰出现时间晚,能保持相对较高的果实硬度和可溶性固形物含量,贮藏后货架期好果率高,贮藏效果佳,为最适宜的采收成熟度.     

乙醇对‘木纳格’葡萄采后贮藏期间品质的影响

葡萄采收后分别用不同浓度乙醇处理放在低温下贮藏,测定其品质指标的结果表明：40％的乙醇能有效控制葡萄果实的腐烂,对果实可溶性固形物含量则无影响,还可减缓果实硬度和可滴定酸含量下降,以及抑制细胞膜透性的增加,从而提高果实的贮藏品质。     

不同产地‘金圆’猕猴桃低温贮藏下的生理指标及贮藏性变化

以中华猕猴桃(Actinidia chinensis Planch.)黄肉新品种‘金圆’果实为材料,通过低温贮藏实验(1℃±0.5℃,相对湿度90%~95%),系统研究武汉和六盘水所产‘金圆’果实的生理指标及贮藏性。结果显示,两地‘金圆’果实硬度和色彩角(h值)随贮藏时间延长而逐渐下降,硬度在前20 d下降幅度大。果实可溶性固形物(SSC)含量和干物质在贮藏期间变化规律基本一致,六盘水产果实的SSC和干物质含量高于武汉。武汉产果实VC、可溶性总糖、可滴定酸含量仅在80 d时高于六盘水,其他时间均低于六盘水。两地果实的固酸比和糖酸比变化一致,六盘水产果实固酸比(SSC/TA)和糖酸比(SS/TA)在80 d时均达到峰值,而武汉产果实只有糖酸比达到峰值。随贮藏时间延长,两地果实的失重率均缓慢上升,160 d时武汉和六盘水果实的失重率分别为2.82%和2.55%;在贮藏前60 d两地果实腐烂率较低,之后上升较快,160 d时六盘水产果实腐烂率是武汉的1.77倍。本研究结果表明六盘水产‘金圆’果实的风味品质优于武汉,而武汉产果实贮藏性更好些。     

黑莓品种'Boysen'鲜果贮藏特性的研究

对黑莓(Rubus spp. )品种'Boysen'不同成熟度(七成熟、八成熟和九成熟)的鲜果在常温(25 ℃)和低温(4 ℃)条件下的贮藏特性进行了研究,对贮藏时间以及贮藏前后果实的感官指标(色泽、香味和霉烂指数)、形态指标(质量和平均果径)及品质指标(可溶性固形物含量、可滴定酸含量、总花色苷含量以及固酸比)进行了比较.结果表明,不同成熟度和贮藏温度对黑莓鲜果的贮藏时间有明显影响,常温条件下九成熟、八成熟和七成熟果实的贮藏时间分别为3、4和5 d,低温条件下则分别为7、9和14 d;果实霉烂指数则随成熟度的提高及贮藏时间的延长不断提高,成熟度或贮藏温度越低(大于0 ℃),霉烂指数越小,果实的贮藏时间就越长;七成熟和八成熟的果实贮藏后色泽加深、香味变浓,而九成熟果实贮藏前后色泽和香味变化不大.采摘时不同成熟度的果实形态指标和品质指标具有一定的差异,其中,果实成熟度越大,果实质量、平均果径、可溶性固形物含量、固酸比及总花色苷含量越高,可滴定酸含量越低.低温及常温下贮藏后果实质量及平均果径、可溶性固形物含量和可滴定酸含量均不同程度减少,而固酸比和总花色苷含量均不同程度提高,但在低温贮藏条件下各项指标的变化幅度明显小于常温.总体上,在低温条件下,八成熟果实的霉烂指数低,贮藏时间较长,贮藏后的果实质量和平均果径变化幅度小,可溶性固形物含量、可滴定酸含量和总花色苷含量以及固酸比逐渐接近九成熟果实,果实品质提高.因而,在实际生产中宜采收八成熟果实并在4 ℃条件下贮藏和运输,能较好地保持黑莓鲜果的品质.     

岷江上游高山森林溪流木质残体碳、氮和磷贮量特征

森林溪流木质残体是森林生态系统与水域之间物质循环和能量流动的主要联结之一,其碳、氮和磷贮量不仅可影响森林与溪流生态系统的结构和功能,而且与下游水体环境密切相关。因此,于2013年8月雨季以岷江上游典型高山森林为研究对象,调查了12条森林溪流木质残体的碳、氮和磷贮量分配特征,并汇算了研究区域内碳、氮和磷在溪流中单位面积的总贮量。结果表明,高山森林溪流木质残体碳、氮和磷的溪流单位面积总贮量分别为312.1 g/m2、809.5 mg/m2和110.9 mg/m2;在溪流中,木质残体碳、氮和磷贮量以径级为1—2.5 cm和2.5—5 cm的木质残体分布居多,分别共占碳、氮和磷总贮量的86.71%、87.20%和84.55%;木质残体碳、氮和磷贮量以Ⅴ腐烂级分配最多,分别共占碳、氮和磷总贮量的65.86%、67.86%和60.31%;尽管溪流各项特征与碳、氮和磷元素贮量的相关性不显著,但基本达到中度相关关系。这些结果为认识森林生态系统中以木质残体为载体的碳、氮和磷输出潜力提供了基础数据。     

Biochemical and ultrastructural features of human fibroblasts cultured from a new variant of type 3 lipid storage myopathy

A new variant of multisystemic lipid storage myopathy (type 3) has been identified. Human cultured fibroblasts present a major triacylglycerol storage whereas other neutral lipids and phospholipids are in the normal range. When feeding the cells in the presence of radiolabelled oleic acid we observed an accumulation of radiolabelled triacylglycerols demonstrating the endogenous biosynthesis of the stored triacylglycerols. After a 72-hr chase period, no degradation of radiolabelled triacylglycerols was observed. Histochemical examination of multisystemic lipid storage myopathy skin fibroblasts showed a massive accumulation of neutral lipids (stained by the fluorescent probe Nile Red) in cells grown in medium supplemented with 10% fetal calf serum. These cytoplasmic vacuoles were not obviously membrane-surrounded as shown by electron microscopy.     

贮藏方式对切花菊贮后品质的影响

研究了干、湿贮藏方式及其贮藏期对三种不同发育程度切花菊贮后品质的影响。两种湿藏能促进切花发育,贮藏6周后切花花径分别增大了2.54cm(清水)和3.29cm(S+AgNO_3),但不能延长贮藏期;干藏能延长贮藏期,可贮期达4～6周,提高切花催开后品质。     

Effects of wall linings on moisture ingress into traditional grain storage pits

Increasing climate variability, resulting in frequent years of poor rainfall, has recently subjected the traditional subsistence farmers in the Central Clay Plain of the Sudan to longer periods of food shortage. However, excess production in years of good rainfall could bridge the gap of years with poor rainfall if the grain is properly stored. Resource-poor farmers have tried several linings to improve the traditional underground pit (”matmura”) they use for storage of sorghum. In the experimental study described here, pits with two types of lining: (i) a mixture of mud, cow dung and straw and (ii) sorghum chaff, were compared with unlined pits. Six closed pits were used, two for each type, and temperature and moisture content were monitored. It was found that the temperature increased in all pits and at all positions within the pits, with few differences between the linings. Moisture levels also increased everywhere but the sources of moisture were at the sides and bottoms of the pits. The chaff-lined pits were superior to the others because they showed smaller increases in moisture content at all positions and thus maintained a better quality of sorghum. Joint traditional assessments with local farmers after the pits were opened supported these findings. Received: 15 March 2000 / Revised: 4 January 2001 / Accepted: 10 January 2001     

Presence of a single abundant storage hexamerin in both larvae and adults of the grasshopper, Schistocerca americana

We identified a single hexameric storage protein in the grasshopper, Schistocerca americana, and monitored its abundance through the last larval instar and up until reproductive competence in adults of both sexes. This storage hexamerin, termed Schistocerca americana Persistent Storage Protein (saPSP) was the most abundant soluble protein in both larvae and adults. In both sexes, saPSP abundance started out low at the onset of the last larval instar and accumulated during feeding, peaking just prior to molting. Adults of both sexes contained significant amounts of saPSP after eclosion. In adult males, saPSP content dropped continuously after eclosion and was lowest once individuals reached reproductive maturity. In contrast, adult females depleted saPSP reserves during the first days of adulthood, but subsequently accumulated significant saPSP stores. In adult females, saPSP stores peaked just prior to the completion of egg provisioning. Given the overall patterns of abundance, saPSP has functions in both larvae and adults. In addition, the observed pattern of storage hexamerin accumulation differs from patterns of accumulation in the other known grasshoppers, Locusta migratoria and Romalea microptera, suggesting that significant functional diversity has evolved in storage hexamerins among the grasshoppers.     

豫西黄土丘陵区不同林龄栎类和侧柏人工林碳、氮储量

利用空间代替时间样地调查法,分析了豫西黄土丘陵区栎类和侧柏人工林生态系统碳、氮储量的分布格局,以及不同土层碳储量和氮储量随林龄的动态变化.结果表明:随着树龄的增加,两类人工林乔木层和枯落物层碳储量均增加,土壤碳储量和氮储量主要在表层(0~20 cm)汇聚,且各土层碳储量和氮储量随着林龄增加表现为减少-增加-减少的趋势.各林龄栎类人工林土壤表层碳、氮储量分别为20.31~50.07和1.68~2.12 t·hm^-2;不同林龄侧柏人工林土壤表层碳、氮储量分别为23.99~48.76和1.59~2.34 t·hm^-2;各林龄栎类和侧柏人工林生态系统的碳储量分别为52.04~275.82和62.18~279.81 t·hm^-2;侧柏人工林碳汇能力略高于栎类人工林.土壤C/N随着造林年限的增加呈增加趋势.     

Isolation and Characterization of Mustard (Sinapis alba L.) Seed Storage Proteins

A total storage protein fraction was prepared from mustard (Sinapis alba L.) seeds via isolated protein bodies and characterized by sedimentation, immunological, and electrophoretic techniques. Mustard seed storage protein consists of three fractions (1) a “legumin-like” 13-S complex composed of two pairs of disulfide-linked polypeptides (16.5 + 28.5 kDa and 19.5 + 34 kDa, respectively) and two single polypeptides (18 kDa and 26 kDa), (2) a “vicilin-like” 9-S complex composed of two glycoproteins (64 kDa and 77 kDa), and (3) two small polypeptides (10 kDa and 11 kDa) which probably represent the 1.7-S complex found in other Cruciferae. In contrast to related species, no glycosylated polypeptide was found in the 13-S complex. Immunological relationships were found between the paired polypeptides of the 13-S complex but not between polypeptides of the 13-S complex and polypeptides of the 9-S complex. Pulse-chase labeling and in vitro translation of polysomal RNA from young embryos demonstrated that the polypeptides of the 13-S complex originate from high molecular mass precursors, except for the 18 kDa polypeptide which appears to be synthesized in its final size. The amino-acid composition of the major polypeptides of the mustard storage protein is given.     

Hypoxic storage of erythrocytes slows down storage lesions and prolongs shelf-life

Conventional storage conditions of erythrocytes cause storage lesions. We propose that hypoxic storage conditions, involving removal of oxygen and replacement with helium, the changes in stored erythrocytes under hypoxic condition were observed and assessed. Erythrocytes were divided into two equal parts, then stored in conventional and hypoxic conditions, separately. Blood gas analysis, hemorheology, and hemolysis were performed once a week. Energy metabolism and membrane damage were monitored by enzyme-linked immunosorbent assay. Phosphatidylserine exposure was measured by flow cytometry. P₅₀ was measured and the oxygen dissociation curve (ODC) plotted accordingly. Erythrocyte morphology was observed microscopically. In the 9th week of storage, the hemolysis of the hypoxia group was 0.7%; lower (p < .05) than that of the control group and still below the threshold of quality requirements. The dissolved oxygen and pO₂ were only 1/4 of that in the control group (p < .01); the adenosine triphosphate, glucose, and lactic acid levels were decreased (p < .05), while the 2,3-diphosphoglycerate levels were increased relative to that in the control group (p < .01). There were no statistically significant differences in membrane damage, deformability, and aggregation between the two groups. In addition, the ODC of the two groups was shifted to the left but this difference was not statistically different. Basically similar to the effect of completely anaerobic conditions. Erythrocytes stored under hypoxic conditions could maintain a relatively stable state with a significant decrease in hemolysis, reduction of storage lesions, and an increase in shelf-life.     

Non-destructive evaluation of in vitro-stored plants: A comparison of visual and image analysis

Summary In vitro plants, in slow-growth storage require routine evaluation for assessment of viability and need for repropagation. Determination of plantlet health by visual assessment is subjective and varies by genus due to variations in growth pattern and plant structure. Developing a standardized plant evaluation system would improve the efficiency of in vitro storage. This study was initiated to develop digital image analysis techniques for plantlets during slow-growth cold storage and to compare that system with visual examinations. Pear (Pyrus communis L) cultivars were chosen for this initial trial because they have an open structure and clear internode position for image composition. Pear shoots stored at 4°C in tissue culture bags were evaluated monthly by standard visual examination and by digital image analysis. Digital images were evaluated for red, green, blue, modified normalized differences of vegetation index (MNDVI), green/red ratio (G/R), intensity, hue, and saturation at the first two nodes of each, plantlet. At 6 mo., the visual ratings had declined steadily for P. communis ‘Luscious’ and ‘Bartlett—Swiss’, while ‘Belle Lucrative’ and ‘Louse Bonne de Jersey’ ratings did not show significant declines until 9 mo. Correlations between visual ratings and G/R and MNDVI values were significant (r ²>=0.5) for all cultivars. Regression analysis indicated that the MNDVI and G/R ratios changed significantly over the 15-mo. rating period for most cultivars. Intensity, hue and saturation values were not consistently significant and did not correlate with visual ratings. These results will assist in the development of digital imaging as an alternative technique for evaluation of stored in vitro plantlets.