铁皮石斛多糖提取工艺的研究

本文探讨了铁皮石斛多糖提取工艺条件对提取率的影响,采用单因素实验和正交试验设计研究了提取时间、提取温度、料液比等多种因素对铁皮石斛多糖提取率的影响。最终得到提取铁皮石斛多糖的最佳工艺条件为提取时间5h、提取温度70℃、料液比1∶30,该工艺条件下铁皮石斛多糖的提取率为3.55%。     

Characterization of under-utilized fruits by molecular markers. A case study of loquat

The usefulness of RAPD markers for genotyping a minor fruit species such as loquat has been tested in order to assess their ability for identifying accessions and to provide a set of markers suitable for use by different groups of scientists and curators. Twenty-nine polymorphic markers selected from a previous study of 33 accessions were tested in 46 new accessions added to the collection. Using the same PCR standard conditions, only 20 markers out of 29 selected in the previous study gave consistent amplifications in the new set of plant material. The rest required optimization of reaction conditions. This fact pointed out that RAPD markers were sensitive to the experimental conditions, hence a standard technique did not guarantee reproducibility. To overcome this problem markers for plant fingerprinting should be selected after comparison across accession sets. Only those markers reproducible with different sampling and checked in several sets of accessions are suitable for germplasm fingerprinting. In the present study we propose 31 RAPDs for fingerprinting loquat that accomplished these characteristics.The markers obtained were sufficient for determining origin and relationships of cultivars, for identifying synonyms and derived varieties from bud-sports. All bud sports were identical for all RAPDs selected.     

Changes in fruit maturity indices along the harvest season in ‘Algerie’ loquat

Loquat is a subtropical fruit tree that presents an annual cycle reverse to that of the well-known temperate fruit crops. Loquat rests during summer, blooms in autumn, develops its fruit through winter and ripens them in early spring. Its unusual phenology allows growers to obtain high prices for its fruits, especially for early harvests. Although loquat is harvested based on skin colour, a minimum soluble solid content (TSS) of 10° Brix is often required for commercialization. However, we have noticed that the relationship between skin colour and eating quality seems to change along the season leading costumers to complain for the high acidity of the earliest fruits. In order to establish a reliable maturity index, we have evaluated the changes in different fruit maturation parameters along the harvest period in four consecutive seasons for ‘Algerie’ loquat. The results show that in samples collected with similar skin colour, TSS and, especially, fruit titratable acidity (TA) tend to decline as harvest season progresses. This makes fruit skin colour on its own not suitable as a harvest index to assure an adequate fruit quality under all circumstances. We propose instead to monitor continuously TSS and TSS/TA ratio along the season in order to fulfill consumer's expectations.     

鼓槌石斛组培快繁技术体系研究

以鼓槌石斛八成熟蒴果为外植体,通过对其种子无菌萌发培养、原球茎继代增殖及生根壮苗培养基的筛选,建立鼓槌石斛的组培快繁技术体系。结果表明：1/2 MS＋1.0 mg/L NAA＋8.0%土豆泥＋0.10%活性炭培养基效果较理想,种子萌发率较高,发芽快;最适增殖培养基为3/4 MS+3.0 mg/L 6-BA＋8%香蕉泥,增殖系数可达7.23;最佳生根培养基为3/4 MS＋1.0 mg/L NAA＋0.5 mg/L CA＋8%香蕉泥,平均根数量达7.49条。炼苗移栽到松树皮作为栽培基质的苗床上,1个月以后,成活率均达80%。     

3个三华李品种在南亚热带低海拔地区生长发育规律研究

通过对栽植在广州市天河区华南农业大学果园(北纬23°09.6′,东经113°21.3′,海拔30m)的早食李、大蜜李和从化三华李等3个三华李品种的生长发育情况进行了连续3年的测定,研究了李在南亚热带低海拔地区的生长发育规律。结果表明,大蜜李和从化三华李生长发育紊乱,而极早熟的早食李生长发育正常。早食李的物候期比原产地提早3～5天;每年抽生2～3次新梢;果实发育期约70天,有2个生长较快时期,成熟期可分青熟、黄熟、红熟和过熟等4个阶段,是一个设施栽培和南亚热带低海拔地区有栽培前景的品种。     

枇杷果实锈斑病的发生原因及其控制

以早钟6号、长红3号和解放钟3个枇杷品种为试材,观察果实锈斑发生规律,探讨发病原因,并提出其防治的措施。3个枇杷品种锈斑病的易感性有很大的差异,早钟6号最感病,解放钟次之,长红3号锈斑果发病率最低;果皮蜡质层和细胞壁自发荧光强弱与锈斑病的感病程度有密切的关系,发病率高的早钟6号果皮蜡质层薄,果皮细胞壁自发荧光最弱,而发病率低的长红3号果皮蜡质层最厚,细胞壁自发荧光强且均匀。枇杷果实锈斑的发生主要原因是在不良外界条件下形成微创口,随着果实膨大生长,伤口撕裂,表皮下的局部细胞恢复分生能力,形成木栓形成层,木栓细胞团突破表皮而形成肉眼可见的锈斑;人工抹去表皮毛,可形成微创口,显著加剧锈斑果的发生,而套袋处理可大大降低锈斑发生率,并且越早套袋效果越好。     

金线莲根部内生菌多样性宏基因组的分析

金线莲(Anoectochilus roxburghii(Wall.)Lindl)是中国传统中药,具有重要的药用价值,现代医学用来治疗糖尿病和癌症。金线莲作为兰科植物,与内生菌在长期的生长过程中建立起和谐的共生关系,内生菌产生多种次生代谢产物,帮助宿主植物抗菌防虫。现有实验条件下,环境中绝大多数的微生物不能培养,而宏基因组学是认识环境中不可培养微生物的重要手段。本研究对福建金线莲根部内生菌富集进行探索,提取混合内生菌样品宏基因组DNA,并对宏基因组DNA纯化,PCR扩增微生物16S r DNA片段,克隆至大肠杆菌(Escherichia coli)并测序。根据16S r DNA信息初步对富集的内生菌群落分析,内生菌主要是不可培养细菌(uncultured bacterium)、不可培养堆肥细菌(uncultured compost bacterium)、肠杆菌科(enterobacteriaceae)、类芽胞杆菌属(Paenibacillus sp.)、芽胞杆菌属(Bacillus sp.)和短芽胞杆菌属(Brevibacillus sp.)的微生物。本研究为挖掘金线莲内生菌资源提供基础资料。     

中药陆英研究进展

从本草考证、化学成分、生药鉴别和药理作用等方面综述了中药陆英的现代研究概况,为进一步开发利用提供文献依据。     

云南山茶籽油理化性质及主要成分分析

 云南山茶籽油有较高的营养价值和丰富的微量元素,其中产于云南腾冲的品种在民间已用于制取食用油,但产于云南镇沅和四川盐边的品种尚未开发利用,为评估其食用性,检测了3个产地的云南山茶籽油理化指标及其脂肪酸、矿质元素组成,并对检测结果进行了对比分析。结果表明：云南山茶籽含油率约50%;云南镇沅及四川盐边产山茶油的碘值分别为79.85和72.09,属干性油脂,易于保存;皂化值分别为185.0和176.7;折光率约1.4727。镇沅及盐边产云南山茶籽油中主要含五种脂肪酸,其中不饱和酸（亚油酸、油酸、二十碳烯酸）总量占脂肪酸总量的80%以上,符合食用油发展趋势;此外,镇沅及盐边产云南山茶籽油富含多种矿质元素,其中铁元素含量是腾冲原产山茶籽油的3倍多,有作为功能保健食用油的潜质。     

枳椇子总黄酮提取工艺优化及其抗氧化活性研究

以枳椇子为原料,采用乙醇浸提法提取枳椇子总黄酮,并考察其抗氧化活性.通过单因素试验和正交试验优化的枳椇子总黄酮提取工艺为:乙醇体积分数40％,料液比1:50(g/mL),浸提温度40℃,浸提时间15 min,枳椇子总黄酮提取率为4.52％±0.043％.枳椇子总黄酮抗氧化性能试验结果表明:枳椇子总黄酮对羟自由基、超氧阴离子自由基、DPPH自由基和ABTS自由基均具有清除效果,具有较强的抗氧化能力,不同浓度枳椇子总黄酮的抗氧化能力差异较大,且呈现明显的剂量效应.