链霉菌和壳聚糖对淮山土壤微生物活性与群落的影响

为探究链霉菌30702和壳聚糖对淮山土壤微生物活性与群落的影响,采用比色法和滴定法观测土壤酶活性的变化,采用高通量测序技术和Trimmomatic等软件,分析土壤微生物群落中细菌和真菌的发展变化。结果表明,链霉菌、壳聚糖、土壤原始微生物和培养时间等4个因素对淮山土壤的脲酶和过氧化氢酶活性均有显著影响,壳聚糖浓度在0~10.0 g/kg内,土壤酶活性随壳聚糖浓度的增大而提高;随时间的延长,先升再降;壳聚糖与链霉菌之间存在交互效应。链霉菌和壳聚糖能增加淮山土壤细菌的物种丰度,减少细菌的多样性,增加艾德昂菌属（Ideonella）和纤维弧菌（Cellvibrio）等有益菌属的相对丰度,而对真菌的物种丰度和多样性的影响较小,与对照之间的差异不显著,土壤优势菌属为腐质霉属（Humicola）、枝孢属（Cladosporium）、鞘氨醇单胞菌属（Sphingomonas）和uncultured_bacterium_ c_Subgroup_6。其中,链霉菌与2.5 g/kg壳聚糖复合处理的细菌物种丰度最大,细菌多样性最少。     

毛薯的营养成分分析和聚类分析

为选育出优良的毛薯种质,本研究以海南大学薯蓣种质资源圃里的80份毛薯为材料,以河南焦作温县的垆土铁棍山药为对照,采用苯酚硫酸法、考马斯亮蓝法以及蒽酮比色法对其干物质、粗多糖、蛋白、可溶性糖和淀粉含量进行测定和比较分析。结果表明:毛薯的干物质含量介于18.62%~38.88%,粗多糖含量介于2.88%~15.82%、蛋白含量介于5.14%~10.71%、可溶性糖含量介于0.1%~13.84%、淀粉含量介于11.94%~64.28%。与对照山药相比,Ds96所测品质均优于对照,可优先选择推广。此外,毛薯各营养品质之间存在着一定的相关性,干物质与糖类存在显著负相关,与蛋白和淀粉表现为正相关。通过对80份毛薯的营养品质进行聚类分析,在欧式距离为3.17时,可将其分为八类,按类群来看,类群Ⅳ各营养价值适中,其他类群在某些营养上比较优秀,可根据需要进行优良资源选择。      

Ploidy analysis in water yam, Dioscorea alata L. germplasm

Poor reproductive development in yams (Dioscorea spp.) has often been attributed to the polyploid nature of the crop. In this study, flow cytometry was used to determine the ploidy level of 53 accessions of Dioscorea alata, mostly from West African countries, Chad and Puerto Rico. Nuclei were isolated from young leaf material and stained with DAPI(4,6-diamidino-2-phenylindole). The nuclear genome size (2C) was measured as an indicator of the ploidy level. Dioscorea rotundata genotypes with known ploidy levels were used as standards. The results showed that the majority of plants were hexaploid (84.9%) with a smaller percentage of tetraploids (15.1%). A higher number of male plants were hexaploid than tetraploids. This is at variance with earlier findings, which reported that hexaploid male plants are rare. Higher ploidy levels were not directly related to sparse or erratic flowering as previously reported as profuse flowering occurred in some male hexaploid accessions. These findings have important implications for yam breeding in relation to yam genetic resources. This revised version was published online in August 2006 with corrections to the Cover Date.     

The association of sexuality with plant traits and tuber yield in white yam

Summary One 3-to 5-year clonal and two recent seedling-derived populations of white yam cultivars were grown and studied for the association of sex, flowering intensity, number of fruits and seed yield with vegetative characters and tuber yield. Yield was lowest in non-flowering plants and increased in the following order: male, monoecious and female plants; with females yielding almost twice as much as the non-flowering plants. The plants produced from small tuber setts, with higher leaf virus infection, low plant leafiness either had low flowering intensity, fewer fruits and seeds or even failed to flower. The sequence and timing of vegetative and reproductive processes in relation to the difference in yield between male and female plants is discussed. There is a strong indication that the intensity of flowering and fruiting is lower in plants from previous vegetative propagation compared to recent seedling-serived clones.     

Seed set and seedling variation in greater yam (Dioscorea alata L.)

Summary A high degree of fruit and seed set was obtained in Dioscorea alata L. by hand pollination. The sexual progeny was studied in comparison with the clonal plants. In general, the seedlings were poor in growth vigour, flowering and tuber production but the variations observed in the different characters were unprecedented, indicating scope for efficacious genetic improvement in this vegetatively propagated crop.     

怀山药种质资源的玻璃化法超低温保存

本文对怀山药种质资源的玻璃化法超低温保存技术进行了研究。结果表明,怀山药带芽茎段玻璃化法超低温保存较佳的技术体系是继代生长60 d的怀山药无菌苗置4℃冰箱低温锻炼7 d;在无菌条件下切取1~1.5 cm的带芽茎段,转至含5%蔗糖+3%甘露糖的培养基内,置4℃冰箱预培养2 d;用60%的PVS₁（22%甘油+13%乙二醇+13%聚乙二醇+10%二甲基亚砜）在室温下处理60 min,再用100%的PVS1在0℃条件下处理60 min,随即迅速投入液氮;保存24 h后,在37℃水浴中快速化冻,用含5%蔗糖的MS培养液洗涤4次,每次停留10 min;转至再生培养基（MS+KT 2 mg/L+NAA 0.02 mg/L）再培养,成活率可达77.14%,再生苗与常温苗形态指标差异不大。     

快速测定黄姜中薯蓣皂甙元含量方法的研究

经研究将测定黄姜中薯蓣皂甙元含量的方法改进为微量浸提分光光度法。此法采用微量样品以无水酒精浸提代替传统的回流抽提法, 以香兰素-浓硫酸作显色剂, 冰醋酸作溶剂, 在460NM处测定薯蓣皂甙元的含量。与传统的重量法、抽提分光光度法相比较, 此法测定方法简便, 结果准确, 成本低, 效率高。     

武当山地区盾叶薯蓣薯蓣皂苷元含量及生物特性的相关性研究

通过对武当山地区盾叶薯蓣(Diosorea zingiberenzis C．H．Wright)4个居群29个单株根茎的单株质量、折干率、生长速率、薯蓣皂苷元含量检测，及其各生物学特征的差异的研究，探讨了薯蓣皂苷元含量及其它生物特性的相关性。结果表明：武当山地区野生盾叶薯蓣根茎薯蓣皂苷元含量绝大多数在1．6％以上，含量超过2．0％的单株为79％，含量超过3．0％的单株为31％，最高含量达3．51％；武当山泰山庙盾叶薯蓣居群的根茎平均单株质量、平均生长速率、薯蓣皂苷元平均含量显著高于其它3个居群，折干率显著低于其它居群。盾叶薯蓣根茎的薯蓣皂苷元含量与根茎单株质量呈极显著正相关性，相关系数为0．6078，与根茎折干率呈极显著负相关，相关系数为-0．5989，与根茎生长速率不显示显著的相关性；盾叶薯蓣根茎单株质量和生长速率呈极显著正相关，相关系数为0．7199；武当山泰山庙盾叶薯蓣居群为优良的盾叶薯蓣种质，武当山区适合建立野生盾叶薯蓣的种质保护基地。     

山药研究进展

对山药的多糖提取方法、药理作用、组织培养及根际微生态方面的研究现状和最新进展进行了综述。     

穿龙薯蓣根茎龄级的判定及繁殖研究

试验观察结果表明,穿龙薯蓣的根茎龄级可通过根茎环状凹陷判定,陇南市武都区的野生穿龙薯蓣根茎龄级大多为4～5年生;根茎龄级和药剂处理均对穿龙薯蓣根茎成活率有极显著影响,以1年生根茎、每段3个芽孢、200 mg/kg生根粉（ABT）处理8 h的根茎成活率最高,达96.33%。