Effects of heat treatments and germination on trypsin inhibitor activity and polyphenols in jack bean (Canavalia ensiformis L. DC)

The application of dry heat to seeds and meal was not effective in inactivating the TI and reducing the polyphenol content. Soaking for 24 h followed by cooking for 20 min, was equally effective in destroying the TI activity. Germination of jack bean seeds for 40 h decreased the levels of TI and polyphenols by 31% and 35%, respectively.     

草本缓冲带优化配置对氮磷的去除效果

利用自行设计的小型试验装置模拟缓冲带,选择东北地区草木犀、白三叶、马唐、夏枯草4种常见植物,通过人工配水模拟农田径流水,采用草种不同栽种方式及草皮与其他生物处理方式相结合的方法,开展缓冲带对污染物的净化效果试验研究。结果表明,在渗流中,草种不同栽种方式和草皮与其他生物处理方式结合的缓冲带,3种混栽方式的NH4+—N、全P的去除效果最高分别为59.80%、56.81%。在径流中,草种不同栽种方式中3种混栽方式的NH4+—N、全P的去除效果最高分别为23.30%、22.30%;草皮与其他生物处理方式结合缓冲带,3种混栽+小沟对全P去除效果最高达27.4%,3种混栽+人工浮床对NH4+—N去除效果最高,达30.1%。在本试验条件下,3种混栽方式对渗流的净化效果较好,而草皮与其他生物处理方式结合的缓冲带对径流有较好的净化效果。     

The effect of metabolic stress disinfection and disinfestation (MSDD) on ‘Hass’ avocado fruit physiology and mortality of longtailed mealybug (Pseudococcus longispinus)

Metabolic stress disinfection and disinfestation (MSDD) is a potential quarantine treatment in which a combination of cycles of rapid decompression and compression are followed by exposure to ethanol vapour under decompression. The response of ‘Hass’ avocado (Persea americana Mill., cv. Hass) to MSDD treatment for control of longtailed mealybug (Pseudococcus longispinus) was investigated. The best treatment for the most resistant life stage (2nd/3rd instars) was 90-min MSDD treatment with 371 mg L⁻¹ ethanol. Early and late season ‘Hass’ avocados were subjected to MSDD treatments (with 371 mg L⁻¹ ethanol), or in air (control). Following the treatments, early season fruit were ripened at 20 °C and 25 °C. Half of the late season fruit were ripened at either 20 °C or 25 °C, and the remainder were stored at 5.5 °C for 6 weeks, then ripened at 20 °C. There were no significant difference in quality and rot incidence between non-treated controls and MSDD-treated fruit. The main disorders found were stem-end and body rots, vascular browning and flesh greying for the stored fruit. There were also no significant differences in fruit respiration rate or ethylene production. Thus, MSDD was shown to be a potentially ‘soft’ disinfestation treatment for surface pests of avocado.     

微生物有机肥对芋头产量品质性状及土壤微生物类群的影响

微生物有机肥在作物提质增效中逐渐引起重视,了解微生物有机肥对芋头的抗性和产量品质的影响,可对微生物有机肥应用在芋头生产上提供科学依据。本试验以炭步槟榔香芋为材料,通过施加微生物有机肥和复合肥,设计4种不同施肥模式,测定了芋头的产量、营养品质指标以及抗氧化活性指标,并深入探究了土壤微生物菌群的分布及代谢调控的变化特征。结果表明：相对于传统的发酵腐熟花生麸作基肥的施肥方式(CK),微生物有机肥作为基肥配合追施75 kg/hm²硫酸钾肥(T1)能提高芋头的Vc、总酚、总黄酮、直链淀粉和粗纤维等营养成分的含量,增加了芋头的磷含量。微生物有机肥作为基肥配合追施150 kg/hm²硫酸钾肥(T3)具有最高的产量、Vc、总酚、直链淀粉、粗纤维和全钾含量。微生物有机肥作为基肥配合追施112.5 kg/hm²硫酸钾肥(T2)的全氮和全磷含量最高,同时SOD、CAT活性和MDA的含量也最高。此外,微生物有机肥处理可有效增加土壤中魏氏杆菌、芽孢杆菌和念珠菌嗜酸杆菌的丰度,促进核苷酸代谢、DNA重组、复制和修复效率,提高蛋白翻译效率,进而有利于...     

不同灌溉处理对玉米生长及水分利用效率的影响

通过温室试验,研究了不同灌溉处理对玉米的生长状况,生理特性及产量和水分利用率的影响。结果表明,充分灌溉处理(FI)的植株株高、茎粗与叶面积长势优于其它处理,而地上部分及根系的干物质累积量低于其它处理。相同的灌溉量条件下,分根交替灌溉处理(PRD)的植株产生的脯氨酸含量高于调亏灌溉处理(DI),说明PRD处理能够使植株提高渗透调节能力。在产量构成中,FI处理的植株产量最高,PRD 75%(灌水量为充分灌溉的75%)处理的植株产量略低于FI处理,二者差异不显著,其次为D I75%处理(灌水量为充分灌溉的75%)。尽管FI处理的植株绝对产量最高,但是以牺牲水分利用率为代价的,而其它处理尽管绝对产量较FI处理略低,但由于其耗水量也低,水分利用率反而高于FI处理。特别是PRD 75%处理的植株绝对产量和水分利用率都有较好的表现。     

Effect of soil tillage and weed control methods on weed biomass and yield of lentil (Lens culinaris Medic.)

Abstract

The study was carried out in dryfarming areas in Ankara, Turkey, over 2 years (2001 – 2002 and 2002 – 2003). The objective was to determine different soil tillage and weed control methods on weed biomass and yield components, yield of lentil (Lens culinaris). This study compared the effects of two tillage systems (shallow minimum tillage and traditional tillage) and three weed control methods (weedy check, hand weeding and herbicide) on weed biomass, growth characteristics, seed yield and some yield components of lentil. Significant differences were found among weed control methods for weed biomass and yield parameters of lentil. Tillage systems had no significant effect on weed biomass or yield of lentil. The highest yield and lowest weed biomass was found in the hand-weeded treatment compared to the other weed control methods. Results of this research indicate that weeds are a main constraint for lentil growing under dryland conditions. Grain yield of lentil was reduced more than 60% due to uncontrolled weeds.     

Suppression of damping-off of cucumber caused by Pythium ultimum with live cells and extracts of Serratia marcescens N4-5

Environmentally friendly control measures are needed for the soil-borne pathogen, Pythium ultimum. This pathogen can cause severe losses to field- and greenhouse-grown cucumber and other cucurbits. Live cells and ethanol extracts of cultures of the bacterium Serratia marcescens N4-5 provided significant suppression of damping-off of cucumber caused by P. ultimum when applied as a seed treatment. Live cells of this bacterium also suppressed damping-off caused by P. ultimum on cantaloupe, muskmelon, and pumpkin. Culture filtrates from strain N4-5 contained chitinase and protease activities while ethanol extracts contained the antibiotic prodigiosin, the surfactant serrawettin W1, and possibly other unidentified surfactants. Production of prodigiosin and serrawettin W1 was temperature-dependent, both compounds being detected in extracts from N4-5 grown at 28 °C but not in extracts from N4-5 grown at 37 °C. Ethanol extracts from strain N4-5 grown at 28 °C inhibited germination of sporangia and mycelial growth by P. ultimum in in vitro experiments. There was no in vitro inhibition of P. ultimum associated with ethanol extracts of strain N4-5 grown at 37 °C. Prodigiosin, purified from two consecutive thin-layer chromatography runs using different solvent systems, inhibited germination of sporangia and mycelial growth of P. ultimum. Another unidentified compound(s) also inhibited germination of sporangia but did not inhibit mycelial growth. There was no in vitro inhibition associated with serrawettin W1. These results demonstrate that live cells and cell-free extracts of S. marcescens N4-5 are effective for suppression of damping-off of cucumber caused by P. ultimum possibly due in part to the production of the antibiotic prodigiosin.     

农产品加工剩余物焚烧过程的干燥热解特性研究

为了积累垃圾焚烧炉设计的基础，对几种南方典型产品加工剩余物进行了工业分析和干燥、热解实验，得到不同温度下随时间变化的失重曲线图；分析了它们的着火和燃烬性能；拟合出相应的干燥、热解动力学曲线，得到了干燥、热解反应动力学参数。结果表明：实验的几种农产品加工剩余物的干燥、热解反应基本符合一级反应规律；这些农产品加工剩余物宜作焚烧处理，焚烧时应进行干燥或采用两段、两室炉型。     

施肥、刈割对短尖苔草生理生化特征的影响

短尖苔草(Carex brevicuspis)是洞庭湖分布面积最广的植物之一,具有生物量大、营养价值高等特点,是优良的畜牧饲料资源。为探明该植物对施肥、刈割的生理响应机制,从而为开发该饲料植物提供依据,研究了该植物在不同施肥量与刈割次数条件下的生理生化变化。结果表明:随着施肥量的增加,短尖苔草可溶性蛋白含量呈现先下降后上升趋势,较对照增加140.01%;叶绿素、可溶性糖、脯氨酸、丙二醛(MDA)含量以及超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性均呈现先上升后下降的趋势。随着刈割次数的增加,短尖苔草叶绿素含量呈现下降的趋势,其降幅达21.30%;SOD活性呈现先上升后下降的趋势,可溶性蛋白含量呈现先下降后上升趋势,POD、CAT活性则呈现上升趋势。可见施肥量为20 g/m2时可促进短尖苔草光合作用,增加抗氧化酶的活性;刈割两次促进了渗透调节物质的合成,为植物恢复生长提供了生理基础。     

施肥对新平县引进番木瓜生长的影响

对新平县引进番木瓜进行了不同施肥处理试验,并调查冠幅、冠层厚度、叶量以及开花结实情况,结果表明:以每株施肥100 g和150 g的处理对冠幅和叶量增长效果较好,施肥对冠层厚度的增长影响较小,每株施肥150 g对单株开花结实量的增加效果较好.