魔芋中脑苷脂类化合物的分离与结构鉴定

首次从魔芋中分离出由特殊羟基脂肪酰基构成的脑苷脂类化合物.通过光谱和化学方法鉴定为1-O-β-D-吡喃葡萄糖-(2S,3R,4E,8Z)-2-(2'R-羟基脂肪酰基)-正十八碳-4,8-二烯鞘胺醇.其中羟基脂肪酰基主要由2-羟基-正十六酰基,2-羟基-正十八酰基,2-羟基-正二十酰基,2-羟基-正二十二酰基,2-羟基-正二十四酰基组成.     

不同光照强度下花魔芋（Amorphophallus konjac）与谢君魔芋（Amorphophallus xiei）光合特性及光保护机制研究

为探讨不同耐光性植物光合特性及光保护机制,本研究以耐高光的喜阴植物花魔芋（Amorphophallus konjac K.Coch）和典型的喜阴植物谢君魔芋（Amorphophallus xiei H.Li & Z.L.Dao）为材料,测定与分析在透光率为100%、15%及2%光照条件下两种魔芋的光合能力、抗氧化酶活性及抗氧化物和光合色素组分的含量。结果表明,花魔芋最大光合速率和气孔导度随着生长环境光照强度降低而显著降低（P<0.05）,谢君魔芋在透光率为15%时最大光合速率达最大值。大部分情况下,花魔芋的超氧化物歧化酶、抗坏血酸过氧化物酶、过氧化氢酶、谷胱甘肽还原酶活性比谢君魔芋高（P<0.05）,而谢君魔芋具有较高的过氧化物酶活性（P<0.05）。总的来看,在中高光照环境下两种植物的抗氧化酶活性较高（P<0.05）。在透光率15%时,花魔芋谷胱甘肽和抗坏血酸显著比谢君魔芋高（P<0.05）。谢君魔芋的光合色素含量在透光率为15%时最高（P<0.05）;相应地,花魔芋的光合色素含量在透光率为2%时含量最低（P<0.05）;在不同光照强度下花魔芋光合色素含量基本上显著高于谢君魔芋（P<0.01）。本研究结果暗示,喜阴植物花魔芋耐受高光可能源于相对较高的光合作用能力和有效的光保护机制。     

魔芋良种繁育技术体系建设概况

概述了魔芋良种繁育技术体系建设的发展历程,重点介绍了魔芋种芋的三级繁育体系、根状茎两年速成法和(试管芋)二年速成良种繁育技术,为魔芋产业发展中成果的转化应用起到了引导作用.     

Taro koji of Amorphophallus konjac enabling hydrolysis of konjac polysaccharides to various biotechnological interest

ABSTRACT

Due to the indigestibility, utilization of konjac taro, Amorphophallus konjac has been limited only to the Japanese traditional konjac food. Koji preparation with konjac taro was examined to utilize konjac taro as a source of utilizable carbohydrates. Aspergillus luchuensis AKU 3302 was selected as a favorable strain for koji preparation, while Aspergillus oryzae used extensively in sake brewing industry was not so effective. Asp. luchuensis grew well over steamed konjac taro by extending hyphae with least conidia formation. Koji preparation was completed after 3-day incubation at 30°C. D-Mannose and D-glucose were the major monosaccharides found in a hydrolyzate giving the total sugar yield of 50 g from 100 g of dried konjac taro. An apparent extent of konjac taro hydrolysis at 55°C for 24 h seemed to be completed. Since konjac taro is hydrolyzed into monosaccharides, utilization of konjac taro carbohydrates may become possible to various products of biotechnological interest.     

魔芋试管芋营养液栽培生产原原种技术研究

在温室对魔芋试管芋立体多架层营养液栽培生产原原种技术进行了研究。以不同质量分数和比例的N、P、K、Ca、Mg等大量元素和MS培养基的微量元素配制成营养液,对魔芋试管芋进行立体多架层无土栽培试验,结果表明:生长状况和原原种的产量均以N∶P∶K∶Ca:Mg的比例为4∶1∶2.4∶0.2∶0.7的Ⅴ号营养液最高,光照强度以2000~6000 Lux为宜。该试验为魔芋营养液的配方研制及栽培管理技术提供了理论依据。     

Konjac-mannanase from the Tubers of Amorphophallus konjac C. Koch

A crude enzyme preparation hydrolyzing konjac mannan was extracted from germinating konjac tubers, and purified by chromatography with DEAE-cellulose and alkali-swollen cellulose, and by gel-filtration on Sephadex G-100. The purified enzyme preparation showed optimal activity at pH 4.7, optimum temperature at 40°C. It was considerably stable at pH’s between 4.0 and 8.0, but inactivated rapidly by temperaters above 50°C. Hydrolysis of the mannan by this enzyme proceeded by typical random mechanism, and the rate was in agreement with an empirical equation, p=0.43 E^0.77 to^0.5. As the Km and V_max values for mannan, 7.14×10^-2(%)and 23.8×10^-3 (ΔOD_500nm) were obtained, respectively.     

魔芋组培良种繁育技术体系新进展

介绍了近年来魔芋组培良种繁育技术体系建设研究中的多项成果,主要魔芋组培原原种工厂化生产技术、种芋包衣技术、质量监控技术和大田栽培配套技术等一系列关键技术研究方面的进展,为魔芋产业发展中成果的转化应用起到了支撑作用.     

花魔芋球茎发芽抑制物质的提取、分离与鉴定

从休眠花魔芋球茎中获得挥发性、酸性、酚类、碱性和中性５类提取物,分别用它们及其硅胶薄层层析带处理小白菜种子和已解除休眠的魔芋种子,其中酸性提取物对两种种子发芽均有显著的抑制作用。酸性提取物用ＤＥＡＥ－纤维素柱层析和硅胶薄层层析分离纯化,气谱－质谱联用仪鉴定含有脱落酸、阿魏酸和油酸。用其外源有机酸溶液分别处理已解除休眠的魔芋球茎,ＡＢＡ和阿魏酸对球茎顶芽萌发及生长有明显的抑制作用。     

Composition of Soluble Nucleotides in Growing Corms of Amorphophallus konjac C. Koch

The nucleotides and the activities of both sucrose synthetase and granular starch synthetase in the konjak corm (Amorphophallus konjac C. Koch) have been investigated as a preliminary experiment on konjak mannan biosynthesis. On chromatographic separation on anion exchange resin and paper of compounds present in the acid ethanol extract from the corms, ascorbic acid, AMP, ADP, ATP, ADP-glucose, UTP, UDP-glucose, GTP, and GDP-mannose were isolated and tentatively identified. An unidentified nucleotide was also isolated.

Of the three nucleotide sugars, UDP-glucose was the most plentiful, while ADP-glucose was the least. The sucrose synthetase in konjak corms was as active as that in other plants. These observations suggest that the mechanism involved in sucrose cleavage in konjak corms is the same as that in other plants, such as sweet potato roots. Starch synthetase bound to starch granules in konjak corms was also found to be active when ADP-glucose was used as glucose donor. But UDP-glucose could not be substituted for ADP-glucose.

Based on these observations the mechanism of konjak mannan biosynthesis is discussed.