Identification and characterization of <Emphasis Type="Italic">Choanephora</Emphasis> spp. causing Choanephora flower rot on <Emphasis Type="Italic">Hibiscus syriacus</Emphasis>

Hibiscus syriacus, as a national flower of Korea, is most popularly used for ornamental purposes and includes numerous cultivars, and it is widely planted in temperate zones that feature hot summers. We investigated Choanephora flower rot on H. syriacus from 2012 to 2014 in Korea and Japan and confirmed Choanephora infection in several localities in both countries. Here, our objectives were to identify the main causal agent of Choanephora flower rot on H. syriacus and describe its morphological and molecular characteristics. We identified 44 out of 50 isolates as Choanephora cucurbitarum and the remainder as C. infundibulifera based on morphological characterization and phylogenetic analysis. The sequences of the internal transcribed spacer region (ITS) of ribosomal DNA and the D1/D2 region of the large subunit (LSU) rDNA of examined isolates were compared with sequences obtained from GenBank, and the analysis of the results revealed 100 % identity with the corresponding sequences of C. cucurbitarum and C. infundibulifera strains. Classification of the Choanephora species performed here according to the key described by Kirk (1984) corresponded with the results of the phylogenetic analysis of this study. Through intraspecific and interspecific mating tests, the characteristics of zygospore were described in details. Pathogenicity tests using both species showed the same symptoms, causing blossom blight and soft rot on the flowers, which were identical to those observed in the field. All identified causal agents of Choanephora rot were indeed Choanephora species, where C. cucurbitarum was identified in the majority, while the others were in the minority of examined samples.     

Interactive effects of dietary magnesium and vitamin E on growth performance,body composition,blood parameters and antioxidant status in Japanese seabass (Lateolabrax japonicus) fed oxidized oil

A study was conducted to investigate effects and interactions of magnesium (Mg) and vitamin E (VE) on growth performance, body composition, hepatic antioxidant capacity and serum biochemistry parameters of juvenile Japanese seabass Lateolabrax japonicus under oxidative stress condition. Fish (initial average body weight of 6.10 ± 0.20 g) were fed 9 oxidized oil diets supplemented with 3 grade levels of Mg (0, 520 and 1570 mg kg^?1 diet) and VE (0, 60 and 200 mg kg^?1 diet) for 8 weeks in freshwater. The results showed that diets supplemented 520 mg kg^?1 Mg and/or 60 mg kg^?1 VE had highest growth and muscle lipid content. There were highest total superoxide dismutase, catalase, glutathione peroxidase activities and lowest malondialdehyde content in liver of fish fed diets supplemented 520 mg kg^?1 Mg and/or 60 mg kg^?1 VE. Contrary to Mg concentrations, Ca concentrations and Ca/Mg ratio in whole body were inversely related to dietary Mg levels. However, combined deficiency or excess of dietary Mg and VE led to the decrease of hepatic antioxidant capacity, body lipid deposition and growth of Japanese seabass under oxidative stress condition.     

高湿稻谷节能干燥工艺系统设计与试验

为了降低高湿稻谷干燥耗能、提高干燥系统作业效率,基于高湿稻谷干燥特性和干燥传递理论,绘制出了高湿稻谷贮存干燥仓内通风去湿降温过程状态参数变化图,设计出了高湿稻谷贮存干燥仓,能够利用常温自然空气实现高湿稻谷干燥和有效回收干燥系统的烟气余热。应用结果显示,在风量谷物比为149 m3/(h·t)时,每间隔1 h,通风2 h,累计贮藏干燥18 h,可使初始含水率31.3%的稻谷平均含水率降低11.36%,回收烟气废热55.3%。针对南方高温高湿的气候特点,设计出了5HNH-15型稻谷逆流热风干燥机和节能干燥工艺系统。试验结果表明,系统的单位耗热量为2 939 kJ/kg,与国标≤7 400 kJ/kg相比,最高节能可达60%。该文指出了实现高湿稻谷优质、高效节能干燥,合理的工艺系统设计应以客观能势的利用为主,人为提供主观热能消耗为辅。研究结果为粮食干燥设计指明了高效节能途径,为大型粮食集中干燥工艺系统设计提供了参考。     

Improved solvent extraction procedure and high-performance liquid chromatography-evaporative light-scattering detector method for analysis of polar lipids from dairy materials

A normal-phase high-performance liquid chromatography-evaporative light-scattering detector method employing dichloromethane, methanol, and acetic acid/triethylamine buffer as the mobile phase was developed for analysis of polar lipids (PLs). This method was applicable for analysis of PLs from both dairy materials and soy lecithin. All of the PLs of interest such as glycolipids, phospholipids, and sphingomyelin were well separated with a total run time of 22.5 min and without necessitating the removal of neutral lipids beforehand. Peak retention times were stable, and the method was reproducible. In this study, a modified method of using solvents for extraction of PLs from dairy matrices was also investigated. The modified method offered higher extraction efficiency, consumed less time, and in some cases saved solvent use.     

鲆鲽鱼营养生理研究进展

本文综述了鲆鲽鱼类营养生理的研究进展,涉及鲆鲽鱼对蛋白质、氨基酸、脂肪、必需脂肪酸、碳水化合物、维生素和微量元素的需要量及各种营养元素的生理功能,评价饲料中各营养素缺乏和过量对鲆鲽鱼生长的影响,以及各营养素之间的相互关系。     

连香树离体快繁初步研究

 连香树为我国珍稀濒危树种, 具有较高的经济价值和观赏价值。本文研究了3年生连香树(Cercidiphyllum japonicum Sieb. et Zucc. ) 带芽茎段的离体培养。筛选出最佳培养基: (1) 腋芽诱导培养基: MS +NAA 0.01 mg·L ^{- 1} ; (2) 丛生芽诱导培养基: MS +BA 1.0 mg·L ^{- 1} ; (3) 丛生芽增殖培养基:MS +BA 2.0 mg·L ^{- 1} + 2,4-D 0.01 mg·L ^{- 1} ; (4) 生根培养基: 1 /2MS + IBA 1.0 mg·L ^{- 1}。     

滴灌条件下西北干旱区农田生物排盐研究进展与展望

20世纪末以来,膜下滴灌技术在我国西北干旱区得到了大规模的推广和应用,极大推动了绿洲农业的发展。然而,滴灌带入盐分无法排出导致的农田土壤积盐问题,使得干旱区绿洲农业的可持续发展面临巨大挑战。如何在水资源短缺的情况下防治农田次生盐渍化和利用西北干旱区广泛分布的盐碱地资源,是我国干旱区农业可持续发展中迫切需要解决的问题。本文结合西北干旱区膜下滴灌农田水盐运移的特点,主要从盐生植物耐盐机制及其生长发育对盐分的响应、盐生植物排盐与盐碱土改良的互馈效应以及种植盐生植物对土壤水盐动态的影响等方面对生物排盐的研究进展进行了比较系统的梳理,同时指出了目前西北干旱区在农田生物排盐研究方面存在的不足,并对今后需要开展的研究工作进行了展望,以期为旱区农业制定合理高效的综合排盐制度提供决策依据,对于实现农田盐分平衡、缓解土壤次生盐渍化危机和土壤可持续利用具有重要意义。     

Amphidinolide C2, New Macrolide from Marine Dinoflagellate Amphidinium Species

A new cytotoxic 25-membered macrolide, amphidinolide C2 (1), has been isolated from marine dinoflagellate Amphidinium sp. (Y-71 strain), and the structure 1 was elucidated on the basis of spectroscopic data and chemical means.     

应用组织培养技术快速繁殖香荚兰

比较系统地研究了香荚兰的组织培养技术。通过“丛生芽的诱导”和“微型扦插”年增殖可达千倍以上。比较了不同细胞分裂素对香荚兰增殖率的影响。以培养50天的增殖率计,氨基嘌呤(6-BA)的效果最佳(279.5％),玉米素(Zea)次之(206.8％),激动素(KT)效果最差(140％)。以2毫克/升浓度的BA增埴率最高。香荚兰容易生根,几种生长素对香荚兰都有促根作用。以吲哚丁酸(IBA)的效果最佳,培养17天生根率达100％,吲哚乙酸(IAA)次之(86.7％),NAA更次之(71.4％)。对照不加生长素最差(57.1％)。IBA以0.5毫克/升浓度的处理效果最好。