Ethylene Gas for Sprout Control in Processing Potato Storages

Ethylene was tested as a sprout inhibitor on potatoes intended for processing over the 2006-2007 and the 2007-2008 storage seasons. Russet Burbank, Shepody, Innovator, FL-1867, and FL-1833 were loaded into the University of Maine potato research facility in October of 2006. Ethylene gas was metered into the storage until a concentration of 0.1 ppm was reached and then held for one week. At weekly intervals, the ethylene concentration was increased to 0.3 ppm, 0.6 ppm, 12 ppm, 5.0 ppm and 102 ppm. Subsequently, the concentration was maintained at 10.0 ppm for the duration of the storage season. Control potatoes received chlorpropham （CIPC） for sprout control. The trial was repeated in the 2007-2008 storage season. The Agtron readings were performed on the processed potatoes at the end of the storage season. There was no difference in the US color grade between the CIPC-treated and ethylene-treated tubers within any tested variety in either storage season. Sprout inhibition of the ethylene-treated potatoes was acceptable for normal storage length of the potato varieties tested. Ethylene may have promise as an alternate to CIPC for sprout control in potato storages.     

香蕉果实发育成熟过程中多酚物质的变化规律

以3个香蕉品种‘巴西蕉’‘粉蕉’‘皇帝蕉’为供试材料，利用福林酚法测定其整个生育及成熟期果皮、果肉的多酚含量，探索不同香蕉品种在发育成熟过程中的多酚含量变化规律，及其与果实发育成熟的关系。结果显示，在香蕉果实整个生育期，多酚物质含量果皮均大于果肉。多酚物质在香蕉果皮、果肉生长发育期迅速积累，到采收期下降，采后果皮多酚物质含量随着成熟度的增加而增加，而果肉多酚物质基本维持不变。用外源乙烯和1-MCP处理后发现，与对照果实相比，乙烯促进其多酚物质的积累，而1-MCP抑制其积累。     

丙烯海松酸聚氧乙烯酯聚醚多元醇的合成研究

研究了丙烯海松酸与不同摩尔数的环氧乙烷所进行的开环均聚和共聚反应。探讨了不同因素对反应速度及环氧乙烷聚合度对产物性能的影响，分析了产物的红外光谱及热重曲线。结果表明，该聚醚多元醇可作为一种新型多元醇应用于聚氨酯涂料中。     

二氯乙烷对管道的腐蚀分析及处理方法

在采用材质为１Ｃｒ１８Ｎｉ９Ｔｉ的系统接收二氯乙烷过程中，管道多处发生腐蚀泄漏。通过对系统进行探伤检测及宏观检查，发现储罐及各条管道的焊口处存在裂纹。分析了二氯乙烷对不锈钢的腐蚀机理，指出造成该系统腐蚀的主要原因是由于二氯乙烷物料产生的Ｃｌ＾－对奥氏体不锈钢产生了应力腐蚀。针对各种腐蚀部位的具体情况制定了处理方法。     

苜蓿花叶病毒和白三叶草花叶病毒复合侵染对本氏烟中5种激素含量的影响

为探明苜蓿花叶病毒(alfalfa mosaic virus, AMV)和白三叶草花叶病毒(white clover mosaic virus, WCMV)复合侵染的协生作用致病机理,以复合接种AMV+WCMV的本氏烟为处理,分别以单独接种AMV、WCMV、磷酸盐缓冲溶液(pH 7.0, PBS)的本氏烟为对照,采用DAS-ELISA (double-antibody sandwich enzyme-linked immunosorbent assay)方法检测了接种病毒72 h的本氏烟(Nicotiana benthamiana)叶片中的病毒含量及72～720 h内水杨酸(salicylic acid, SA)、茉莉酸(jasmonic acid, JA)、独脚金内酯(strigolactones, SLs)、油菜素内酯(brassinolide, BR)、乙烯(ethylene, ETH) 含量的变化。结果表明：AMV和WCMV 接种比例为3∶1的植株720 h时的发病症状比单独接种一种病毒(AMV或WCMV)明显,主要症状表现为轻花叶、斑驳花叶、重花叶、明脉、皱缩。检测接种72 h时叶片病毒浓度发现,接种比例3∶1的植株中AMV的浓度比单独接种AMV以及AMV和WCMV接种比例为1 ? 1和1 ? 3的处理高,而WCMV的浓度略低于其单独接种WCMV处理,高于AMV和WCMV接种比例为1 ? 1和1 ? 3的处理;接种AMV和WCMV混合液后复合侵染的本氏烟叶片中SA、JA、SLs、BR、ETH含量在一定时间内与单独接种AMV、WCMV及对照之间差异显著(P < 0.05),其中,AMV和WCMV接种比例为3∶1的混合液可在一定时间段内提高本氏烟叶片中SA (216～504 h)、SLs (216～432 h)、BR (216～504 h)、ETH (288～720 h)含量,降低JA (216～504 h)含量,其SA、SLs、BR、ETH含量分别比单独接种AMV、WCMV和健康植株(CK)提高了36.27%以上,JA含量降低了59.09%多。     

山茶花切花采后生理特性研究

试验对山茶花切花采后生理特性进行了研究,结果显示,已开的山茶花在20℃、空气相对湿度60％的环境条件下,插入去离子水中2d后就萎蔫;未开的花蕾在相同环境下花期能持久一些,但始终不能开放;已开放的山茶花在空气相对湿度近似100％的环境条件下,瓶插寿命可达到4d,最终花瓣还是脱落;花瓣脱落起因于水势、水分传导等原因;所有供试材料在收获后的最初时间所释放的乙烯量都比较低,在山茶花花瓣脱落之前乙烯释放量有—急剧上升的过程,花瓣所呈现的褐色区域与花朵释放的乙烯量呈正相关;用去离子水或0.2 mmol/L的硫代硫酸银溶液处理,可降低乙烯诱导山茶花脱落的速度.但对于花瓣褐色坏死斑点的抑制效果不明显.     

Availability of Micro-Tom mutant library combined with TILLING in molecular breeding of tomato fruit shelf-life

Novel mutant alleles of an ethylene receptor Solanum lycopersicum ETHYLENE RESPONSE1 (SlETR1) gene, Sletr1-1 and Sletr1-2, were isolated from the Micro-Tom mutant library by TILLING in our previous study. They displayed different levels of impaired fruit ripening phenotype, suggesting that these alleles could be a valuable breeding material for improving shelf life of tomato fruit. To conduct practical use of the Sletr1 alleles in tomato breeding, genetic complementation analysis by transformation of genes carrying each allele is required. In this study, we generated and characterized transgenic lines over-expressing Sletr1-1 and Sletr1-2. All transgenic lines displayed ethylene insensitive phenotype and ripening inhibition, indicating that Sletr1-1 and Sletr1-2 associate with the ethylene insensitive phenotype. The level of ethylene sensitivity in the seedling was different between Sletr1-1 and Sletr1-2 transgenic lines, whereas no apparent difference was observed in fruit ripening phenotype. These results suggested that it is difficult to fine-tune the extent of ripening by transgenic approach even if the weaker allele (Sletr1-2) was used. Our present and previous studies indicate that the Micro-Tom mutant library combined with TILLING could be an efficient tool for exploring genetic variations of important agronomic traits in tomato breeding.     

Effects of various stress treatments on growth and ethylene evolution in seedlings and sprouts of betula pendula Roth and B. pubescens Ehrh.

Experiments were conducted to determine growth and ethylene evolution in seedlings and coppiced plants of Betula pendula Roth and B. pubescens Ehrh. when subjected to stresses relevant to the maintenance of natural forests, and especially in fuelwood plantations, i.e. cutting of the stem, thinning, bending, flooding and various combinations of these. Most of the experiments were carried out in the laboratory using 1‐year‐old seedlings or 1‐month‐old sprouts. Height and diameter growth, biomass production, morphology and ethylene evolution were studied for 1–2 months. Material for comparison was obtained from young sprouts on the stumps of fully developed trees growing under natural conditions and natural seedlings of a comparable age. Exposure of seedlings and coppiced plants to stress factors usually altered growth and increased ethylene evolution. Cutting of the stem and thinning had similar effects in that they stimulated transient ethylene evolution by both roots and stems. Bending retarded the height growth to some extent, while increasing the ethylene content especially on the lower side of the horizontal stem. Flooding arrested height growth and increased ethylene evolution in the roots. The two species reacted basically in similar ways, but B. pendula produced more ethylene. though at a slower rate, and also showed a more pronounced retardation of growth. The sprouts had a higher ethylene content than the seedlings and also increased their ethylene evolution more rapidly. The changes in ethylene evolution and growth are discussed from the point of view of the resilience of the plants and as an indication of stress factors in experimental plots.