Coumarin compounds in cassava diets: 2 health implications of scopoletin in gari

Scopoletin has been isolated and identified in gari, a cassava food consumed in Nigeria (West Africa). Its levels in gari and cassava flour is not altered by post processing treatments such as sundrying, refrigeration and storage. Scopoletin has also been identified as an active principle in the traditional herbal infusion of the fruit ofTetrapleura tetraptera TAUB used in the ethnopharmacology of West Africa. It is a potent hypotensive and non-specific spasmolytic agent. These pharmacological effects of Scopoletin are probably the underlying factors in the slowly developing tropical neuropathy characterised by optic atrophy, nerve deafness and ataxia endemic among populations subsisting on cassava diets such as gari. Hitherto, these toxicities were attributed to cyanogenic glucosides (cyanide) present in cassava.     

Effect of prolonged consumption of gari (Cassava,Manihot Utilisima) on rat hepatic energy metabolism

Rats were fed high (35%, w/w) gari (Cassava,Manihot utilisima) — based diets for a prolonged period and sacrificed after 22/23 days, 30/31 days, 45/46 days and 59/60 days. Hepatic mitochondrial respiratory control for succinate oxidation was evaluated by four criteria (a) osmotic swelling/contraction cycle, (b) oxygen uptake, (c) ATPase activity and (d) Ca²⁺ uptake. A decrease (28–51% in respiratory control ratio (RCR)) in the degree of oxidative phosphorylation coupling, ATPase activity (19–24%) and increased swelling/contraction (30–75%) with no apparent effect on Ca²⁺ uptake were suggestive of moderate alterations in mitochondrial energy metabolism caused by the ingestion of garri based diet. The possible in vivo significance of these observations are discussed.     

阳离子对茶叶几种酶的作用机理研究

以秋梢鲜叶为材料,测定了多酶氧化酶、过氧化物酶和谷氨酸脱氢酶的活性以及脱辅基并用阳离子处理后的酶活性。结果表明,阳离子处理后,三种酶活性较对应的脱辅基酶活性均得到不同程度的提高;与脱辅基前活性相比却因阳离子的不同而异。即使是同一种阳离子也因浓度的不同而不同,据此可判断。阳离子对茶叶中酶的作用机理是作为酶的辅基或激活剂,并在茶树体内向幼嫩部位分布。     

做青过程中重要品质关联酶活性变化研究

以鸠坑种的夏茶对夹二、三叶新梢为原料,研究了两种做青方法过程中多酚氧化酶(PPO)、过氧化物酶(POD)的活性变化。结果表明两种做青方法PPO的活性在摇青阶段均呈现高→低→高的变化,且在第三次摇青后活性达到最高;而POD以鲜叶中的活性为最高,整个做青过程中略有下降但不明显。丙酮粉法比匀浆法测定酶活性更为稳定。     

Antidiabetic activity evaluation of glimepiride and Nerium oleander extract on insulin, glucose levels and some liver enzymes activities in experimental diabetic rat model

The present study is aimed to assess the therapeutic potential of sulfonylurea drug glimepiride in comparison with Nerium oleander plant extract on insulin, glucose levels and some liver enzymes activities in streptozotocin-induced diabetic rats. Rats were rendered diabetic by intraperitoneal injection of a single dose of 50 mg kg(-1) body weight streptozotocin. Rats with serum glucose levels > 200 mg dL(-1) were subdivided into three sub-groups: the first sub-group were remained without treatment and considered as diabetics. The second and third subgroups were orally administered 0.1 mg kg(-1) body weight/day glimepiride and 250 mg kg(-1) body weight/day Nerium oleander, respectively for 4 weeks. Streptozotocin-induced diabetic rats showed hypoinsulinemia and hyperglycemia compared to controls. Strong negative correlation (r = -0.8) was found between serum insulin and glucose levels in diabetic rats. This correlation was +0.4 and -0.3 in glimepiride and Nerium olender-treated rats, respectively implying that glimepiride and plant extract improved insulin and glucose levels with the former was more efficient. The activities of serum aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase were significantly increased in streptozotocin-induced diabetic rats compared to controls. Treatment of diabetic rats with glimepiride or Nerium oleander extract also improved liver enzymes activities.     

施用有机肥对春玉米生育后期叶片酶活性的影响

为了防止春玉米早衰,探讨施用有机肥对春玉米生育后期叶片酶活性的影响。我们采用盆栽方法,测定春玉米灌浆期和蜡熟期穗位叶超氧化物歧化酶（SOD）活性、过氧化物酶（POD）活性、丙二醛（MDA）和可溶性蛋白质含量。结果表明：随着有机肥（鸡粪）施用量的增加丙二醛的含量随之降低,超氧化物歧化酶（SOD）活性、过氧化物酶（POD）活性和可溶性蛋白质含量则随之提高。施用有机肥（鸡粪）26.7 g/kg土的处理,春玉米穗位叶的过氧化物酶（POD）活性和可溶性蛋白质含量下降。玉米灌浆期的穗位叶超氧化物歧化酶（SOD）活性普遍高于蜡熟期的。适量的施用有机肥可以提高春玉米生育后期叶片保护酶活性,防止或延缓春玉米的衰老。     

寡聚糖对大豆防御酶活性的影响

采用寡聚糖处理大豆叶片,并在诱导后接种大豆花叶病毒(SMV),用比色法测定3种防御酶活性。结果表明,寡聚糖2号、6号和7号诱导后或诱导后接种大豆花叶病毒(SMV),均使大豆叶片过氧化物酶(POD)和多酚氧化酶(PPO)活性提高,其中寡聚糖7号提高幅度大于2号和6号。     

草甘膦对蚯蚓体内抗氧化酶和AChE酶活性的影响

蚯蚓是土壤健康的关键指示生物,为了更好地评价草甘膦对土壤无脊椎动物的影响,本研究采用土壤法测定草甘膦对蚯蚓的急性毒性;用不同浓度的草甘膦分别测定不同暴露时间下对蚯蚓超氧化物歧化酶、过氧化氢酶、过氧化物酶、谷胱甘肽S转移酶、乙酰胆碱酯酶活性的影响。结果显示,土壤法测定草甘膦对蚯蚓的LC₅₀>1000 mg/kg;在草甘膦的影响下,随着暴露时间的延长,蚯蚓SOD酶活力有着先增高后下降的趋势,CAT酶活力呈现着先下降后升高的趋势,随着时间和浓度的增长POD酶活力在草甘膦的影响下有逐渐下降的趋势;相对于空白对照,处理组AChE酶活力在草甘膦暴露14 d时显著降低。研究结果将为合理评价和监测草甘膦造成的土壤污染水平提供科学依据。     

土壤生态改良对农田老参地土壤酶活性的影响

目的从土壤理化性质、微生物环境、营养条件三个方面对农田老参地土壤进行改良。方法研究该土壤改良技术对土壤脲酶、过氧化氢酶、蔗糖酶、磷酸酶四种酶活性的影响。结果与对照组相比,生态改良处理组土壤脲酶活性提高37.48%~74.99%,过氧化氢酶活性提高9.16%~22.90%,蔗糖酶活性提高16.00%~101.31%,磷酸酶活性提高1.24%~74.38%。结论该生态改良技术可明显提高土壤酶活性,对农田老参地土壤改良效果显著。     

污水灌溉对小麦幼苗生理特性及抗氧化酶活性的影响

用不同浓度的污水分别对小麦幼苗进行处理,测定其根系活力、细胞膜透性、超氧化物歧化酶（SOD）活性、过氧化氢酶(CAT)活性、过氧化物酶(POD)活性及丙二醛（MDA）含量。研究了污水对小麦生理特性及抗氧化酶活性的影响。结果表明：随着污水处理浓度的提高,根系活力不断降低,细胞膜透性不断升高, SOD、CAT及POD活性均表现为先升后降的趋势, MDA的含量呈逐渐上升的趋势。     

盐胁迫对不同水稻品种光合特性和生理生化特性的影响

 用2个耐盐水稻品种和2个盐敏感型水稻品种为材料,研究盐胁迫对水稻植株生物量积累、光合特性等生理特性的影响。结果表明,在盐胁迫条件下,耐盐水稻品种和盐敏感型水稻品种地上和根系的干鲜质量均呈下降趋势,其中,以盐敏感型水稻品种的地上部鲜质量与根系干质量的下降最为显著。盐胁迫条件下,水稻叶片的净光合速率（Pn）、气孔导度（Gs）、蒸腾作用（Tr）和表观叶肉导度（AMC）均呈不同程度的下降趋势。其中,耐盐水稻品种Pn、Gs、Tr和Pn/Ci的下降均低于盐敏感型水稻品种。同时,耐盐品种水分利用效率（WUE）也高于盐敏感型品种。盐胁迫条件下,耐盐水稻品种和盐敏感型水稻品种的胞间二氧化碳浓度（Ci）变化并不明显,气孔限制百分率（Ls）均较低,品种间差异也不显著,而表观叶肉导度显著下降,由此推测盐胁迫条件下Pn的下降并非因为气孔的限制,而与RuBPCase活性的下降有关。盐胁迫条件下水稻叶片和根系的渗透性调节物质脯氨酸、总氨基酸和可溶性糖含量上升,其中以可溶性糖含量上升最为显著（P＜0.01）。盐胁迫下叶片保护酶SOD、POD和CAT活性增强,膜透性增强,丙二醛含量增加,同时,根系活力下降。     

桃色顶孢霉发酵液对大豆的促生及其抗逆酶活性的影响

本实验采用了管碟法和种子萌发法研究了实验室分离获得的桃色顶孢霉对茄病镰刀菌F. solani.的拮抗作用以及对大豆的促生作用,并采用愈创木酚法、紫外吸收法、氮蓝四唑光化还原法研究了顶孢霉发酵液对POD、CAT、SOD三种抗逆酶活性的影响。结果表明：顶孢霉发酵液对镰刀菌菌丝生长有明显抑制作用,菌丝变稀疏。大豆种子经不同浓度桃色顶孢霉发酵液处理后,萌发率及种子酶活性均产生变化。不同浓度的发酵液对种子萌发促进作用不同,当发酵液浓度为10%时,胚根长,胚芽长,胚根鲜重,胚芽鲜重均达到最高值,分别为2.91cm,0.037g,4.07cm,0.1666g。与对照相比分别提高了49.37%,63.24%,30.54%,45.80%。当处理种子的发酵液浓度为60%时,种子萌发率最高为83.67%,与对照相比提高了23.90%;酶活性最强,POD、CAT和SOD分别为683U、160.67U和301U,与对照相比分别提高 73.50%,43.78%,76.73%。初步证实了桃色顶孢霉发酵液中含有能够促进大豆种子的萌发及抗逆酶活性升高的物质。     

铅污染对茶树生育及相关保护酶活性的影响

采用盆栽试验,选取龙井43和浙农117两个茶树品种,进行了铅污染对茶树生育及相关保护酶活性的影响研究。结果表明,在试验处理浓度范围内,铅能促进龙井43的生长;浙农117在160mg／kg铅处理浓度下,初期对生长有促进作用,之后作用消失。浙农117在铅浓度160mg／kg时,净光合速率已受影响;龙井43品种在160mg／kg浓度条件下还会对光合作用起到促进作用,430mg／kg铅处理浓度下对茶树光合作用产生抑制;随着铅污染浓度增加,浙农117的过氧化物酶和超氧歧化酶的活性均升高;龙井43的过氧化物酶活性先升高后降低,而超氧歧化酶的活性增强。     

Effect of traditional processing of cassava on the cyanide content of gari and cassava flour

Detoxification of cassava cultivars (30572 TMS and 30555 TMS) during their traditional methods of processing to produce gari and cassava flour has been investigated. The HCN quantitative determination was done using the enzymatic assay. Fermentation of cassava pulp for 96 hours during cassava processing for gari reduced the HCN by 22 ppm (52.4 percent) and 20 ppm (57.3 percent) for 30572 TMS and 30555 TMS respectively. There was no significant difference (P>0.05) in the HCN content of the two cultivars. Soaking of the sliced cassava tissue for 24 hours in cassava flour production prior to sundrying resulted in 16 ppm (38.1 percent) and 15 ppm (38.4 percent) HCN reduction for 30572 TMS and 30555 TMS respectively. HCN loss during sundrying was 6 ppm (14.3 percent) and 5 ppm (12.8 percent) for the two cultivars. There was significantly (P<0.05) higher HCN loss in processing of gari than cassava flour. The residual cyanide in gari was 12 ppm for 30572 TMS and 10 ppm for 30555 TMS and that in the flour was 20 ppm for 30572 and 19 ppm for 30555 TMS.     

磷对不同磷效率基因型大豆保护酶的影响

选用不同磷效率型大豆品种,设低磷(0 kg·hm-2)、中磷(82.5 kg·hm-2)和高磷(165 kg·hm-2)3个磷处理,测定了不同磷效率基因型大豆叶片的SOD、POD和CAT的活性及MDA含量的变化,并探讨了这些指标与产量的关系.结果表明,低磷条件下,磷高效品种的SOD、POD和CAT的活性在整个生育时期均保持较高水平,而MDA含量较低.中磷和高磷对磷高效品种SOD和POD活性影响较小,生育后期CAT活性下降减缓,且可以增加磷低效品种生育后期的SOD和POD活性,使CAT活性下降时期延迟至鼓粒期.与低磷条件相比,在中、高磷条件下,磷高效品种的MDA含量分别下降了10.0%和4.8%,磷低效品种分别下降了20.9%和17.9%.说明磷高效品种具有较强的植株活性氧清除能力,能保持生物膜结构的稳定性,使其具有抵抗低磷胁迫的能力,从而获得较高产量.     

拮抗菌XB16在香蕉体内的定殖及对抗病相关酶活性的影响

XB16(Bacillus subtilis)是分离自香蕉根部组织的芽孢杆菌,该菌株对香蕉枯萎病有显著的拮抗作用。为进一步研究XB16在香蕉体内的定殖情况及对抗病相关酶活性的影响,通过浓度梯度诱导法,获得在含有300μg/mL利福平的NA培养基上稳定生长且对病原菌拮抗能力保持不变的XB16突变株。在温室条件下采用3种不同的接种方法,研究XB16在香蕉体内的定殖动态。结果表明,采用伤根淋菌液法和灌根法接种,XB16均能在香蕉体内定殖和传导,显示出该菌株在香蕉体内有较好的定殖能力。两种接种方法中,定殖菌数量在香蕉各组织中的消长动态均表现为先增长后缓慢下降;但是采用喷雾法接种XB16后在香蕉各组织中没有检测到标记菌,说明该接种方法不能使XB16在香蕉体内定殖。灌根法接种XB16后取香蕉假茎组织测定了香蕉体内抗病相关酶的活性。结果表明,拮抗菌株处理后过氧化物酶(POD)和多酚氧化酶(PPO)均比接种病原菌和清水对照明显提高,PPO和POD酶活最高峰分别出现在接种后第5天和第7天。两种酶在接种后的第15天仍保持较高活性,推测诱导抗性是XB16菌株的防病机制之一。     

The effect of storage temperature on reducing sugar concentration and the activities of three amylolytic enzymes in tubers of the cultivated potato,Solanum tuberosum L.

Summary Reducing sugar content, and activities of three starch hydrolysing enzymes, alpha-amylase, beta-amylase and debranching enzyme were measured over several months in tubers of five cultivars stored at 4°C or 10°C. Cultivars differed in their sensitivity to storage temperature. Reducing sugar content of tubers and the activities of three starch hydrolysing enzymes increased sharply during the first weeks of storage at 4°C. At 10°C, reducing sugar content, and the activity of the three enzymes remained constant or increased only slightly. Deceased.     

株行距和施肥量对木薯产量及生长的影响

采用裂区试验设计方法,研究株行距和施肥量对华南5号木薯产量和生长的影响.结果表明:在本试验株行距和施肥量条件下,施肥量对木薯产量和生长的影响比株行距大.密植(0.6～0.8 m)有利于提高淀粉产量、鲜薯产量和鲜薯淀粉含量,以0.8m株行距最佳,而疏植(1.2～1.4m)有利于提高单株薯数、单株鲜薯重、单株鲜茎叶重、收获指数和茎径.施肥有利于提高淀粉产量、鲜薯产量、单株鲜薯重、单株鲜茎叶重、茎径、株高和单株薯数,但降低鲜薯淀粉含量和收获指数.丰产栽培技术要兼顾单位面积株数、单株鲜薯重和鲜薯淀粉含量.建议在土壤肥力差和少施肥时,用0.6 m株行距;土壤肥力中等且较高施肥时.采用0.8 m株行距;土壤肥力中上且优越水肥管理,采用1.0 m株行距.     

平衡施肥对木薯产量及品质的影响初报

采用"3414"完全随机区组设计,开展木薯平衡施肥田间试验,研究施肥对木薯产量及品质的影响.其结果表明:(1)施肥对木薯产量有极显著的增产效应,氮、磷、钾肥增产的主次顺序为K>N>P.(2)木薯最高产量的氮、礴、钾优化施肥组合为N:150.00 kg/hm2,P2O5:36.75 kg/hm2,K2O:150.00 kg/hm2,此时最高产量为36.04t/hm2,其最佳施肥配比为N:P2O5:K2O=4:1:4;木薯最佳施肥利润的氮、磷、钾优化施肥组合为N:150 kg/hm2、P2O5:29.50 kg/hm2、K2O:150 kg/hm2,其最佳施肥利润达10 780.11元/hm2,此时产量为36.00 t/hm2,其最佳施肥利润配比为N:P2O5:K20=5:1:5.(3)施肥对木薯淀粉含量有极显著的影响,氮、磷、钾肥对木薯淀粉含量影响的主次顺序为:N>K>P.