Differential levels of antioxidants in paraquat-resistant and -susceptible Erigeron canadensis biotypes in Korea

To characterize the biochemical differences in paraquat-resistant and -susceptible biotypes of Erigeron canadensis L. collected from Korea, we investigated the constitutive levels of various antioxidants such as antioxidant enzymes and low molecular weight antioxidants in leaves, as well as after paraquat treatment. The activities of superoxide dismutase, peroxidase, ascorbate peroxidase, and catalase were higher in the paraquat-resistant biotype than in the paraquat-susceptible biotype. Reduced ascorbic acid content was higher in the resistant biotype, but the content of reduced glutathione was higher in the susceptible biotype. These results indicate that one of the paraquat-resistant mechanisms in E. canadensis in the present study might be related to protecting the activities of antioxidant enzymes, such as superoxide dismutase, peroxidase ascorbate peroxidase, and catalase, as well as the contents of low molecular weight antioxidants such as ascorbate and glutathione.     

加拿大一枝黄花入侵机理及控制策略

从遗传特征、繁殖特征、生理生态特点、环境的可入侵性、人类活动干扰、化感作用、与土壤微生物的作用7个方面介绍了加拿大一枝黄花的入侵机理,并提出了机械防治、化学防治、生物防治等控制策略.     

中辽1号杨在辽宁地区引种研究

对20世纪末新引进到辽宁并经初选的12个杨树无性系进行了引种试验研究,通过无性系多点生长对比试验、室内外物候观测、对杨干象抗性评价和材性测试等,筛选出生长快、适应强的杨树新品种中辽1号杨,其材积生长量分别超过当地对照种辽宁杨、沙兰杨、荷兰3930杨和I-214杨14.8%~68.1%。其生长进程中高生长最快期是在5~6年生,连年生长量最大数值达到3.6 m;胸径生长最快期是在3~5年生,连年生长量最大数值达到6.34 cm。而且干型好、材质优良,对杨干象有相对较强的抗性,可作为新品种在其适生区大面积推广。     

加拿大一枝黄花化感作用的初步研究

对外来入侵植物加拿大一枝黄花（Solidago canadenis L．）的化感作用进行了研究。结果表明，加拿大一枝黄花地上与地下部分的提取物以及根际土壤的水提取物都具有较强的化感效应，能明显抑制供试植物种子萌发和幼苗的生长，研究结果初步揭示了加拿大一枝黄花的化学入侵机制。     

应用酯酶同工酶研究加拿大一枝黄花和栽培品种黄莺的亲缘关系(英文)

采用聚丙烯酰胺凝胶电泳法(PAGE)对来自6处不同生境的加拿大一枝黄花(Solidago canadensisL.)和栽培品种黄莺(Solidago goldenwings)进行了酯酶同工酶测试、分析;并通过对酶谱特征进行数量化分级,根据欧氏距离及类平均法(UP-GMA)对6个供试样品进行聚类分析.结果表明:(1)6个样品都具有2条迁移率分别为0.62和0.66的酶带;(2)供试样品间共出现8种不同带型的酶谱表型差异显著,其中不同生境加拿大一枝黄花均聚成一组,显示其酶谱表型与生态型也一致,而栽培品种黄莺则单独成为1组.(3)加拿大一枝黄花与园艺栽培品种黄莺的亲缘关系较远.因此,采用酯酶同工酶测试方法,可以鉴别来自不同生境的加拿大一枝黄花及栽培品种黄莺.     

加拿大蓬水浸液对植物幼苗生长的影响

[目的]为阐明我国外来入侵植物加拿大蓬的化感作用提供依据。[方法]研究了加拿大蓬根、茎、叶不同浓度水浸液对9种植物幼苗生长的影响。[结果]加拿大水浸液对植物幼苗株高和根长生长均有明显的抑制作用,且随水浸液浓度的升高抑制活性显著增强,对植物根长生长明显大于对株高生长的抑制,其抑制活性为叶水浸液〉茎水浸液〉根水浸液。[结论]加拿大蓬的化感物质主要存在于叶中。     

Hypocholesterolemic effect of blue-green alga,ishikurage (Nostoc commune) in rats fed atherogenic diet

Nutritional quality of the castor meal protein isolate detoxified using boiling and lime cum heat treatments was evaluated in experiments with rats. Chemical scores of both the treated isolates were similar, threonine being the first limiting amino acid. The calculated nutritional indices (essential amino acid index) and PER were higher for the boiled isolate (1.3) than that was for lime-cum-heat treated (0.86). Though, necropsy examination of organs did not reveal any abnormalities, histopathological changes were observed in the organs — liver, kidney, intestine that could be attributed to the deficiency of essential amino acids in the detoxified castor protein isolates.     

蓖麻种子含油量与主要数量性状的相关及通径分析

以19个蓖麻品种为材料,对蓖麻种子含油量与主要数量性状进行相关及通径分析.结果表明:含油量除与生育期呈显著负相关外,与其它主要农艺性状间相关均不显著,而与籽粒自身的性状之间有着显著的相关,其中容重对籽粒含油量的直接通径系数最大,应在亲本选配和后代选择过程中作为一个主要因素考虑.在提高产量的同时注重选择籽粒容重大、籽粒短、生育期适中的类型对提高含油量有积极的作用.     

Long-term tillage and crop rotation effects on weed seedbank size and composition

Size and composition of the weed seedbank was assessed after 12 years of application of four tillage systems in two crop rotations. Mouldboard and chisel ploughing at 45 cm, minimum tillage at 15 cm and no tillage were compared in continuous winter wheat and a pigeon bean/winter wheat 2-year rotation. Weed control was based upon post-emergence herbicide application. Weed seedling emergence from soil samples taken at 0–15, 15–30 and 30–45 cm depths was assessed in a non-heated glasshouse for 12 months. The tillage system influenced weed seedbank size and composition to a much greater extent than crop rotation. Total weed seedling density was higher in no tillage, minimum tillage and chisel ploughing plots in the 0–15, 15–30 and 30–45 cm layers respectively. Density in the whole (0–45 cm) layer did not differ significantly among tillage systems. With no tillage, more than 60% of the total seedlings emerged from the surface layer, compared with an average 43% in the other tillage systems. Crop rotation did not influence either weed seedbank size or seedling distribution among soil layers, and only had a small influence on major species abundance. The weed seedbank was dominated (>66%) by Conyza canadensis (L.) Cronq. and Amaranthus retroflexus (L.), which thrived in chisel ploughing and no tillage respectively. Results suggested that crop rotation and substitution of mouldboard ploughing by non-inversion tillage (especially by minimum tillage) would not result in increased weed problems, whereas use of no tillage might increase weed infestations because of higher seedling recruitment from the topsoil.