山药漆腐叶斑病病原菌的鉴定及其生物学特性研究

在河南山药(Dioscorea opposita)主产品种‘铁棍山药’生产中出现了一种新的叶部病害,田间发病株率为6.6%。该病害主要发生在植株下部叶片,病斑圆形褐色,具同心轮纹,后期病斑上产生大量黑色孢子堆。对该病害的病原菌进行了组织分离培养和柯赫氏法则验证。其分生孢子座碗状或浅盘状,分生孢子梗呈笤帚状分枝,分生孢子梗顶端着生棒状产孢细胞;分生孢子长椭圆形、棒形、长卵形或梨形,透明无色,不分隔,两端钝圆,大小为1.7~2.5μm×4.9~6.8μm。病原菌菌落白色绒毛状,产生大量墨绿色胶质状分生孢子团,呈环状排列。用ITS通用引物对病原菌的基因组DNA进行扩增并测序(序列在GenBank的登录号为KY369166),同源性比对结果显示其与露湿漆斑菌(Myrothecium roridum)的一致性达到99%,结合形态学鉴定结果,确定该病害的病原菌为露湿漆斑菌。病原菌的最适生长温度为30℃,分生孢子致死温度为52℃,pH 5~10之间该菌生长良好,光暗(12 h/12 h)交替最有利于病原菌产孢,菌丝生长的最适碳氮源为乳糖和丙氨酸,产孢的最适碳氮源为果糖和酵母。     

优质块状紫山药新品种苏蓣1号的选育

苏蓣1号是从浙江紫莳药中通过系统选育方法筛选出的块状山药新品种。该品种属于粗短块状紫山药,生育期中等偏迟,155d(天)左右。单株结薯2个左右,块茎表皮紫褐色,肉紫色,长25cm左右,周长20cm左右,质量1.0kg左右,花青素和淀粉含量分别高达9.28‰和23.9%,不结零余子,每667m~2产量可达2000kg。适宜于江苏全省范围露地种植,优先推荐在沿江地区推广应用,适宜于机械化操作。     

山药在饲料中的应用进展

山药含有多种营养物质和活性成分,有巨大的经济价值,文章就山药在饲料中的应用进展作一综述。     

山药主要病害研究进展和生产中存在的问题

综述了近几年来山药主要病害的病原、症状和防治方法,提出了生产中存在的问题和今后的研究方向。     

黄姜皂素的提取新工艺

黄姜，又名盾叶薯蓣Dioscoren zingberensis C．H．Wright是我国特有的药用植物品种，其野生资源薯蓣皂甙元含量在世界薯蓣属植物中居高。目前皂素生产工艺主要采用自然发酵或直接酸水解法。生产过程中废水排量大，污染严重。有人用盐酸-丙酮混合液从穿龙薯蓣中提取皂素的工艺路线，由于各种原因，尚未见在生产中应用。本研究采用自然发酵的方法，使植物细胞壁破碎，然后用乙醇提总甙，再水煮总甙，分离水溶性皂甙加以利用，最后提取皂素。实验表明，总甙体积减少为原来物料的10％以下，酸用量、排污量减少，皂素收率提高，产品达到中华药典的出厂标准。现将结果报告如下：     

Detection and diversity of viruses infecting African yam (Dioscorea rotundata) in a collection and F1 progenies in Côte d'Ivoire shed light to plant-to-plant viral transmission

Yam (Dioscorea spp.) is a major staple food whose production is hampered by viral diseases. However, the prevalence, diversity, transmission, and impact of yam-infecting viruses remain poorly documented. This study reports on the symptomatology, prevalence, and molecular diversity of eight viruses in 38 D. rotundata accessions from a germplasm collection and 206 F₁ hybrid progenies maintained in Côte d'Ivoire. Mean severity scores as assessed from leaf symptoms ranged from 2 to 4 in the germplasm collection and from 1 to 3 in F₁ hybrids, respectively. Dioscorea mosaic-associated virus (DMaV), potexviruses, and yam mosaic virus (YMV) were detected by PCR-based diagnosis tools in single and mixed infections in both the D. rotundata collection and F₁ progenies, whereas badnaviruses were detected only in the germplasm collection. In contrast, cucumber mosaic virus (CMV), yam macluraviruses, yam asymptomatic virus 1 (YaV1), and yam mild mosaic virus (YMMV) could not be detected. No correlation could be established between severity scores and indexing results. Phylogenetic analysis performed on partial viral sequences amplified from infected samples unveiled the presence of two putative novel viral species belonging to genera Badnavirus and Potexvirus and provided evidence for plant-to-plant transmission of YMV, DMaV, and yam potexviruses.     

Yam (Dioscorea ssp.) domestication by the Nago and Fon ethnic groups in Benin

Guinea yams (Dioscorea cayenensis-rotundata complex; D. rotundata Poir. and D. cayenensis Lam.) have been described as resulting from a process of domestication of wild yams of the section Enantiophyllum by African farmers. Although currently practised by few farmers, the process of yam domestication is still on-going in Benin. In order to document the practices used and the indigenous knowledge maintained by Nago and Fon farmers, 27 villages were surveyed. In total, 57 farmers domesticating yam were identified, and 68 yams newly domesticated (or in domestication) were collected. Fon and Nago farmers domesticate yam mainly to widen the genetic basis of the existing diversity or for simple curiosity. Among the three wild yams species (D. abyssinica Hochst. ex Kunth, D. praehensilis Benth. and D. burkilliana J. Miège) used, D. praehensilis is the most important and the most exploited. Tuber of the wild yams are collected either in the bush (most often near the village) or in the forests (far from the village) during hunting. The domestication process consists of bringing into cultivation selected individuals which go through intense vegetative multiplication and selection procedures (over a lengthy but variable period of time) that induce morphological and biochemical changes in the plant mainly at the tuber level. Individuals resulting from these manipulations were found to be, either similar or identical to known landraces or completely new based on both morphological and isozyme analysis. Because it leads to some new cultivars, this process of domestication has potential in yam breeding and appears to be a strategy that could be useful to breeders, while developing a methodology for participatory breeding of yam.     

江西省山药病原线虫种类鉴定及地理分布

为明确江西省山药病原线虫的种类及地理分布,对采自主产区的157份山药样品进行了线虫分离与形态学鉴定,并对主要病原线虫种类进行rDNA-ITS和28S的序列比对和种群系统进化分析。形态学和分子鉴定结果表明：山药病原线虫种类为咖啡短体线虫Pratylenchus coffeae和南方根结线虫Meloidogyne incognita。调查结果表明,咖啡短体线虫在江西省大部分山药产区广泛分布,是优势种群。吉安市永丰县和泰和县山药线虫危害最为严重,山药样品中线虫检出率分别为66.7%和88.9%。南方根结线虫在江西省山药产区不是优势种群,呈零星发生。此外,山药样品中存在两种线虫的单一种群侵染和复合种群侵染,分别占总样品数的87.1%和12.9%。综上,本研究明确了江西省山药主产区病原线虫的优势种是咖啡短体线虫,为江西省山药病原线虫的科学防控提供了有价值的参考依据。     

Influence of heat processing of African yam bean seed (Sphenostylis stenocarpa) flour on the growth and organ weights of rats

The influence of heat processing of African yam bean seed flour on the growth and organ weights of rats was studied. Body weight change, feed utilization and feed conversion ratio were improved by heat processing. All rats significantly (p0.05) gained weight except those fed raw African yam bean and basal diets (diets 3 and 1 respectively). Raw African yam bean diet decreased the growth of rats and had negative effect on the organ weights especially the pancreas which was enlarged. The results indicate that heat processing improved the growth of rats and organ weights due to heat inactivation of toxic factors especially trypsin inhibitors.     

发酵山药酸奶的工艺探讨

用山药发酵法生产营养奶口感好,而且营养丰富,具有药食同源的功效.本文介绍了山药营养奶的生产工艺、操作要点、配方和产品的特点.