Effects of Pre-Stratification Storage Conditions on Black Walnut Seed Post-Stratification Germination Capacity

The objective of this work was to quantify changes in the germination capacity of Juglans nigra seeds following storage and then artificial stratification. Seeds were stored at 5 and –20 °C under 5% and 14% internal moisture content (IMC) for 0, 8, 10, and 12 months under conditions with oxygen or under vacuum. Germination percentage (GP) was affected by storage temperature, IMC, and storage period. Seeds stored with 5% IMC succeeded in germinating regardless of the temperature. Seeds stored with 14% IMC did not germinate (–20 °C) or germinated during storage (5 °C). The GP was reduced with the time of storage in seeds at –20 °C and 5% IMC and this effect was avoided in storage under vacuum. In conclusion, the germination capacity of black walnut seeds did not change for up to 12 months at low above-zero temperature and low IMC (5 °C, 5% IMC), being the most cost-effective alternative for long-term storage of black walnut seeds in commercial nurseries. Vacuum storage avoided the decrease of around 50% in average germination capacity of seeds stored for a year at –20 °C.     

施用有机肥对凯特杏果实品质和产量的影响

以12年生的凯特杏为试材,连续3年进行了施有机肥处理对其果实品质和产量的影响试验,结果表明,在凯特杏果园施肥管理中应注重有机肥施入,即每667 m~2施2 800kg有机肥,可保证果实生长发育,增加果园产量和品质。     

泥炭覆土搅拌时间对覆土结构及双孢蘑菇产量和质量的影响

为优化双孢蘑菇(Agaricus bisporus)覆土技术,以泥炭为覆土材料,研究泥炭覆土搅拌时间对覆土物理结构以及对双孢蘑菇产量和质量的影响。结果证实,随搅拌时间的延长,泥炭覆土充气孔隙度降低,容重增加。充气孔隙度与双孢蘑菇产量高度正相关,但是与双孢蘑菇子实体大小及商品菇率高度负相关;覆土容重与双孢蘑菇产量高度负相关,但是与双孢蘑菇子实体大小及商品菇率高度正相关。搅拌时间较短的覆土(5~20 min),双孢蘑菇总产量较高,且每潮菇产量更均匀,更有利于工厂化生产。搅拌时间较长的覆土(40~120 min),双孢蘑菇子实体较大,但是会降低双孢蘑菇的总产量以及影响每潮菇产量的均匀性。本试验条件下泥炭覆土最适搅拌时间为10 min,双孢蘑菇3潮菇总产量34.5 kg/m~2,商品菇产量27 kg/m~2。研究初步揭示覆土物理结构对双孢蘑菇产量及质量的影响,为优化覆土技术及筛选优质覆土材料提供参考。     

桃硬度与果实部分性状的相关性研究

以16个桃品种为试材,研究不同品种桃果实硬度与其果实性状之间的关系。结果表明,桃果实的果肉硬度与Vc含量呈极显著相关性,相关系数为0.72;桃果实果皮硬度与Vc含量呈显著相关性,相关系数为0.52;桃果实果肉硬度与可溶性果胶含量呈显著相关性,相关系数为0.58;不同品种桃果实的Vc含量与可溶性果胶含量呈显著相关性,相关系数为0.58。     

Strawberry Shelf Life,Composition, and Enzymes Activity in Response to Edible Chitosan Coatings

A series of active biodegradable coatings based on chitosan, gelatin, starch, and sorbitol with or without monoterpenes (geraniol and thymol) were prepared and applied on fresh strawberry fruit as postharvest treatments. The coated fruits were inoculated with fungal spores of Botrytis cinerea and stored for 7 days at 4 °C. Decay incidence, weight loss, anthocyanins, total soluble solids (TSS), total soluble phenolics (TSP), polygalacturonase (PGase), pectin-lyase (PLase), antioxidant activity, guaiacol peroxidase (G-POD), polyphenol oxidase (PPO), and catalase (CAT) were elucidated in the fruits of experimental sets and they were compared with that of controls. The coatings showed a significant effect on the development of quality variables, with the additional effect of geraniol and thymol as a function of the polysaccharide matrix. The coatings inhibited decay incidence, reduced weight loss, delayed changes in the contents of anthocyanin, TSS, and total soluble phenolics; inhibited the increase in G-POD and PPO activities; and retarded the reduction in CAT activity. Compared to the controls, all of the coatings had positive effects on the inhibition of cell wall degrading enzymes (PGase and PLase) and among all the tested coatings, T5, chitosan (1%) + starch (1%) + sorbitol (0.5%) + tween (0.05%) + thymol (0.02%) was the best. This formulation showed also the highest antimicrobial activity and the greatest effect on other physiochemical parameters and it can be suggested to use it as a useful coating agent for extending the shelf-life and maintaining quality of strawberry fruit.     

观赏型金豆新品系‘桔豆’的选育与栽培技术要点

‘桔豆’由实生单株选育而成。该品系具有果色鲜艳、花量大、坐果率高、树姿美观等优良观赏特性，且挂果期长，挂果时间可从10月中旬至次年的3-4月，作为观赏果树有着良好的应用前景。     

10种杀细菌剂对火龙果细菌性茎腐病菌的毒力测定

采用抑菌圈法，对10种杀细菌剂在火龙果茎腐病病原上进行了毒力测定。结果表明：72%农用硫酸链霉素可溶粉剂、53.8%氢氧化铜水分散颗粒剂（杜邦TM）、45%代森铵水剂、47%春雷?王铜可湿性粉剂、50%福美双可湿性粉剂和3%中生菌素可湿性粉剂对火龙果茎腐病病原均有一定抑制效果。其中，45%代森铵水剂和50%福美双可湿性粉剂防治效果较好，抑制率分别达到78.88%和71.42%，其直线回归方程分别为y=2.380 2.477x，y=2.896 1.146x，EC50分别为0.4929，0.0240。72%农用硫酸链霉素可溶粉剂效果次之，抑制率达到66.67%，直线回归方程为y=1.020 1.040x，EC50值为2.5686。这3种药剂可作为火龙果茎腐病田间药效试验的首选药剂。     

火龙果镰刀菌果腐病病原菌鉴定及生物学特性研究

采用形态学特征观察、rDNA-ITS序列、EF-1α序列比对和系统发育树分析的方法对引起火龙果镰刀菌果腐病病原菌进行鉴定,并初步研究其生物学特性。结果表明:引起火龙果镰刀菌果腐病是单隔镰刀菌(Fusarium dimerum Penzig in Saccardo),这是该菌引起火龙果果腐病在国内的首次报道。该菌菌丝生长的适宜温度25~35℃,最适温度30℃,适宜产孢温度25~35℃,最适产孢温度30~35℃,致死温度75℃(10 min);适宜pH5~9,最适pH7,最适产孢pH4;连续光照、D-果糖为碳源、牛肉膏和蛋白胨为氮源时最有利于该菌菌丝生长;完全黑暗、D-半乳糖为碳源、尿素为氮源时最有利于该菌产孢。综合分析认为,该菌耐高温,光照充足、弱酸和富含有机营养的环境有利于该菌的生长和繁殖。     

黑木耳简单快速组织分离新法

利用酒精、镊子对黑木耳耳片进行组织分离,方法方便、快捷,分离成功率100%。