杜果乙烯抑制剂的筛选及其采后保鲜效果研究

比较研究不同浓度乙烯抑制剂AOA(aminooxyacetie acid)、AIB(α-amino-isobutyric acid)、AVG (Aminoethoxyvinyl glycine hydrochloride)、ATA(3-amino-1,2,4-triazole)、1-MCP(1-methylcyclopropene)、精胺、亚精胺对采后杧果(Mangifera indica L)乙烯释放的抑制效果,以期筛出最佳乙烯抑制剂并探究其对杧果的贮藏保鲜效果.结果表明:不同浓度乙烯抑制剂处理杧果,均可降低杧果果实乙烯释放量,其中1 mmol/L精胺、10 mmol/L亚精胺和50 mmol/LATA可有效延缓硬度、可滴定酸(Titratable acid,TA)下降,维持较高VC(Vitamin C)和TSS(Total soluble solids)含量.综合分析,精胺、亚精胺、ATA处理可有效延缓采后杧果果实软化,为采后杧果贮藏保鲜提供技术支持.     

香蕉果实乙烯释放量GC的测定方法及其不同处理下的变化趋势

采用毛细管柱气相色谱法测定香蕉果实采后成熟期的乙烯释放量,以外标法峰面积定量,以保留时间定性,乙烯测定结果相对标准偏差(RSD)为1.85％,检出限为0.062 μL/L.该气相色谱法测定香蕉乙烯释放量和生成速率具有快捷高效、灵敏度高、重复性好、结果理想等优点.香蕉果实采后不同成熟处理条件下的乙烯释放量跟踪测量中,不同成熟度的香蕉乙烯释放量变化趋势明显,外源乙烯诱导时乙烯释放量提前达到峰值,1-MCP处理下的乙烯释放量只维持在很低水平.     

采后处理对青梅果实的生理和品质的影响

测定了青梅采后室温贮藏下生理和品质的变化 ,研究了采后处理对梅果室温和冷藏后转入常温的贮藏效果。结果表明 ,采后果肉急速软化 ,可滴定酸迅速下降。各处理对青梅果实的保鲜效果以乙烯吸收剂处理效果最好 ,其次是GA3处理。CaCl2 处理浓度以 2 %为宜 ,热空气处理的时间不能超过 2d     

核桃果实成熟过程中呼吸速率与内源激素的变化

对核桃颗粒成熟过程中呼吸速率，乙烯释放量和内源激素ＩＡＡ（吲哚乙酸）、ＡＢＡ（脱落酸）、ＧＡ３（赤霉素）、ＺＲ（玉米素核苷）、Ｚ（玉米素）含量的变化进行了测定，结果表明，除种仁中Ｚ含量较上，青皮中其它激素水平均高于种仁。随着颗粒的成熟，ＩＡＡ、ＧＡ３、Ｚ、ＺＲ含量及乙烯释放量均呈下降趋势；而青皮中ＡＢＡ含量则逐渐增加。果实成熟后青皮中ＧＡ３和种仁中Ｚ含量明显增长，颗粒乙烯释放量明显增高，而采后果实     

Responses of the First Internodes of Hong Mang Mai Wheat to Ethylene,Gibberellins and Potassium

Abstract

Seedlings of Hong Mang Mai wheat ( Triticum aestivum L.) emerge from much deeper in the soil than do other cultivars by elongating their first internode. We examined the roles of ethylene, gibberellins (GA) and potassium in the elongation of the first internode in wheat cultivars. Although ethylene stimulated the elongation of the first internode of Hong Mang Mai in the dark, the ethylene evolution and the expression level of ethylene-receptor-like gene of this cultivar were not greater than those of other cultivars.

In Hong Mang Mai, gibberellin A₃ (GA₃) substantially stimulated the elongation of the first internode in the dark. Maximum elongation of the first internode was obtained by GA₃ at the concentrations of 2.89 × 10^–6 to 2.89 × 10^–7 M. This cultivar responded markedly to gibberellins A₁ and A₃ by elongating the first internode in the dark. A mixture of gibberellins A₄ and A₇ (GA₄₊₇) was not effective in inducing the elongation. Haruhikari, a cultivar having no GA -insensitive-reducing-height (Rht) genes, substantially responded to GA₃, but other cultivars did not. The differences in the sensitivity to GA could account, at least in part, for the varietal differences in the elongation of the first internode in wheat. Takune-komugi, a cultivar whose first internode elongates in response to ethylene, did not respond to GA₃. Thus, there are different mechanisms for the GA- and ethylene-stimulated elongation of the first internode in wheat.

Also, it was suggested that potassium uptake from the soil might function together with endogenous GA in inducing the elongation of the first internode in Hong Mang Mai wheat.     

硅窗袋处理对肥城桃果实的呼吸速率及乙烯释放速率的影响

采用硅窗袋贮藏“肥城桃”明显地抑制果实的呼吸速率和乙烯释放速率，推迟呼吸高峰。硅窗袋加入乙烯吸收剂处理可增强贮藏效果，在低温下贮藏25d后去掉硅窗袋转至14℃下存放5d，果实能正常后熟，并具有9d的货架期。     

乙烯利对银杏叶黄酮和内酯含量的影响

喷施乙烯利对银杏叶黄酮和内酯类物质的含量有明显影响，且随乙烯利浓度的增加而增加，不同的乙烯利浓度对银杏叶光合速率、PAL活性、相对生长量也有显著的影响。     

巴西橡胶树产排胶机理的研究进展

天然橡胶是一种重要的战略性资源,巴西橡胶树(Hevea brasiliensis Mull.Arg.)是天然橡胶的主要来源。由于巴西橡胶树是高大乔木,传统育种周期特别长,基因组测序还未完成,橡胶转基因技术尚未成熟,导致橡胶突变体不易获得,这些问题较大限制了橡胶的基础研究。尽管如此,橡胶产排胶研究近年来还是取得了一定进展。本文回顾模式植物拟南芥茉莉酸和乙烯信号途径研究的最新进展,并对其进行归纳总结,概括橡胶产排胶机制研究的进展,分析当前面临的理论和技术瓶颈,并对今后研究前景做了展望。     

Anaerobic metabolism during short and long term storage of kiwifruit

Kiwifruit were stored in 0.25% O₂ (ULO), 1% O₂ (LO) and 2% O₂ + 5% CO₂ (CA) and the controls were kept in air. The fruit were held at 0 °C for 34 and 94 d of storage and, after these times, were transferred to 20 °C in air for 14 d of shelf life. During the short term storage (34 d), a significant increase in anaerobic metabolites, above all ethanol, was observed in ULO, LO, and CA fruit (166, 131, 120 μL/L). After the shift to shelf life, a large and unexpected increase in PDC (pyruvate decarboxylase), ADH (alcohol dehydrogenase in the direction of ethanol oxidation), LDH (lactate dehydrogenase), and GPT (glutamate-pyruvate transaminase) was observed, resulting in ethanol depletion (ULO) or no further increase, and an increase in acetaldehyde which, in turn, could have hastened fruit ripening. Even the control fruit showed an increase in ethanol during storage and an increase in enzyme activity during shelf life, especially in ADH, but to a lesser extent without an increase in acetaldehyde. During the long term storage, anaerobic metabolites (ethanol and acetaldehyde) still increased and GPT activity rose significantly in the ULO and CA samples. A burst of enzyme activity was also observed during the second shelf life in the CA and LO samples, but not in the control, while in ULO fruit the activity rose continuously. GPT activity showed the highest peaks in CA and ULO fruit. An ethylene burst was observed in ULO and CA fruit during the second shelf life (about 25 μL/kg-h) but not during the first shelf life. The potential role of these enzymes in kiwifruit stress response during storage and shelf life is discussed.