茭白肉质茎膳食纤维含量及理化特性的研究

以茭白(Zizania latifolia Turcz.)单季品种蒋墅茭和双季品种葑红早为试验材料,测定不同膨大阶段肉质茎可食部分干物质中膳食纤维及其主要组分和粗纤维含量,以及持水力、膨胀力的变化。结果表明:不同大小的茭白总膳食纤维含量达400 g·kg~(-1)左右,以不溶性膳食纤维为主,可溶性膳食纤维含量较低且在膨大过程中逐步下降;主要组分中纤维素和半纤维素所占比例较高,木质素和果胶的比例较低,在肉质茎膨大过程中呈不同变化规律;粗纤维含量100 g·kg~(-1)左右,膨大过程中呈缓慢上升趋势。干物质持水率和膨胀力分别在530%、4.9 mL·g~(-1)以上,且随肉质茎膨大而明显上升,不同品种间稍有差异,认为茭白属于优良的膳食纤维食品。     

离子色谱法测定茭白中总亚硫酸盐的应用研究

以茭白为研究对象,建立了基于离子色谱法的茭白中总亚硫酸盐的检测方法。试验确定了离子色谱测定条件,经样品前处理条件优化,实现对茭白中总亚硫酸盐的定性和定量分析,并与国标蒸馏法进行了对比测定试验。结果表明：利用本研究所提出的方法检测,二氧化硫标准溶液在0.1～10.0 mg·L-1范围内线性良好,不同浓度添加回收试验所得茭白样品回收率为86.1%～91.7%。该方法的精密度（RSD）为2.9%～4.2%,样品定量限为1.0 mg·kg-1。     

双季茭白新品种‘龙茭2号’

‘龙茭2号’是由‘梭子茭’优良变异单株选育而成的双季茭白新品种。该品种长势较强,株形紧凑直立,分蘖力强,耐肥力中等,抗病虫性好。秋茭晚熟,极耐低温,茭白个体大,表皮光滑,肉质细嫩,商品性好。秋茭壳茭质量129.0～148.4g,净茭质量89.1～101.2g,产量22395～25335kg.hm-2,平均23340kg.hm-2;夏茭壳茭质量142.7～158.2g,净茭质量105.3～113.3g,产量44145～46260kg.hm-2,平均44790kg.hm-2。     

茭白叶黑斑病的病原鉴定和防治药剂筛选

In recent years, in addition to brown spot disease, leaf black spot has occurred frequently and seriously affected the yield and quality in the production areas of Zizania latifolia in China. In order to identify the pathogen, diseased samples were collected from Lu'an, Suzhou, Tongxiang, Yuhang, Yuyao, Jinhua, Shengzhou. Finally, 90 fungal strains were obtained by tissue isolation method, in which 25 strains causing black spot disease of Z. latifolia was identified as Nigrospora oryzae by morphological observation, multiple sequence alignment analysis and pathogenicity test. Toxicity test of 12 fungicides commonly used in fields was carried out in laboratory conditions. The results showed that the effect of 250 g·L^-1 prochloraz EC was best, with the EC₅₀ of 0.002 mg·L^-1; followed by 30% Pyraclostrobin SC and 60% Difenoconazole WG, with the EC₅₀ of 0.056 and 0.057 mg·L^-1, respectively. Combined with the inhibitory effect of the 12 fungicides on Ustilago esculenta, 250 g·L^-1 prochloraz EC was the best choice as a control agent. This study provided scientific basis for the identification and control of leaf black spot of Z. latifolia.     

14条环太湖河流水质与茭草、水花生氮磷含量

选取环太湖14条主要河流为研究对象,分析河流水质和水生植物优势种（水花生和茭草）中氮磷含量,探讨两者的相关性。结果表明：自实施综合整治以来,环太湖河流水质有所好转,氮污染是目前环太湖河流的主要污染特征,有效削减其入河量是太湖入湖河流治理的重要任务;水花生总氮（TN）和总磷（TP）累积能力均强于茭草,水花生叶（茎）中TN、TP含量分别是33.88~55.70 g·kg-1（22.10~29.96 g·kg-1）、4.44~8.96 g·kg-1（3.43~8.02 g·kg-1）;茭草叶（茎）中TN、TP含量分别是12.30~21.41 g·kg-1（21.75~31.22 g·kg-1）、2.06~6.58 g·kg-1（2.60~7.81 g·kg-1）。水花生和茭草叶茎中TN含量与水体中TN浓度均无显著相关性,但两种植物叶茎中TP含量与水体中TP浓度呈显著正相关,即在一定浓度范围内,水体中P浓度越高,水花生和茭草体内P的累积量越大。     

Habitat characterization of Texas wild‐rice (Zizania texana Hitchcock), an endangered aquatic macrophyte from the San Marcos River,TX, USA

1. The habitat of Texas wild‐rice (Zizania texana Hitchcock), known only from the spring‐fed upper San Marcos River in Central Texas, was classified in terms of physical and chemical conditions, depth, current velocity, associated aquatic macrophytes, and substrate composition. 2. Randomly selected transects in sites with and without Texas wild‐rice were evaluated during May, August and January 1994–1995. Physical and chemical conditions (temperature, dissolved oxygen, specific conductance, pH) were found to be nearly constant and uniform both among transect types and sampling dates. Chemical analysis of the substrate likewise showed few differences among transect types. Turbidity was found to be significantly different among transect types on only one sampling date (Kα_0.05=0.60; p=0.009), but even non‐significant levels of turbidity may present biologically significant impacts to wild‐rice plants. 3. Differences in substrate particle size were highly significant (Kα_0.05=0.71; p=0.001) with Texas wild‐rice occupying sites having moderately coarse to coarse sandy soils (73%) compared with the moderately fine to fine clay soils found at non‐rice sites (82%). However, no significant differences were found in organic matter content among rice and non‐rice transects ( =2.09 and 2.56%, respectively). 4. Texas wild‐rice was found primarily in shallow areas of the river (<1 m) and at higher current velocities than those of non‐rice sites ( ≥0.46 m s⁻¹ and ≤0.22 m s⁻¹, respectively). 5. Texas wild‐rice appears to be more commonly associated with other native species rather than exotic species. Mean percentage composition of exotic macrophytes did not exceed 29% in areas where Texas wild‐rice grew, but they accounted for nearly 47% of the composition in areas where rice did not grow. 6. The results of this study will allow for reliable and accurate identification of the remaining suitable habitat of Texas wild‐rice in the San Marcos River for possible reintroduction and development of management plans. Copyright © 1999 John Wiley & Sons, Ltd.     

茭白对镉、铅吸收分配的差异研究

以单季茭白品种蒋墅茭和双季茭白品种葑红早为试材,采用土壤为栽培介质,对Cd2+,Pb2+的单一及其复合胁迫,进行有机肥和无机肥处理,测定了茭白根、短缩茎、叶及产品器官中Cd2+.Pb2+的积累量.研究结果表明,Cd22+,Pb2+的积累量在茭白不同器官间表现为根>短缩茎>叶>肉质茎;两品种中复合胁迫时的Cd2+.Pb2+积累量均明显高于单一胁迫;不同肥料间以有机肥处理下茭白各器官中Cd2+.Pb2+的积累量同比均显著低于无机肥处理.品种问存在明显差异,蒋墅茭对Pb2+的积累能力强于葑红早,对Cd2+的积累能力则低于葑红早.茭白根系对Cd2+,Pb2+的富集系数表现为无机肥处理和复合胁迫处理时分别显著大于有机肥处理和单一胁迫.     

茭白肉质茎膨大发育的生化基础研究

文研究了茭白肉质茎不同发育阶段的碳水化合物、蛋白质以及几种酶的变化情况 ,分析了这些生化代谢与茭白肉质茎发育的可能关系。结果表明 :茭白肉质茎发育的早期主要表现为重量的快速增加 ,后期则为重量和体积均快速地增长。碳水化合物中总糖和还原糖在肉质茎发育的早期迅速上升 ,之后有所下降。而蔗糖则呈现先上升 ,后稳定的趋势。淀粉的含量在肉质茎发育过程中一直上升。木质素和纤维素在肉质茎发育的早期含量较高 ,随着茎的发育 ,其含量持续下降 ,发育后期二者的含量又明显上升。蛋白含量前期上升 ,后期下降。对茭白肉质茎发育过程中酶活性的研究表明 ,超氧化物歧化酶和过氧化氢酶活性不断下降 ,而过氧化物酶活性持续上升。苯丙氨酸解氨酶活性在茎发育过程中不断下降 ,后期又有所上升。     

软包装贮藏切片茭白微生物及感官特性研究

针对茭白不易贮藏的现象,对软包装切片茭白(Zizania lactifolia Turz)贮藏过程中微生物及感官特性进行研究,同时进行相关分析。结果表明：贮藏在-2℃和4℃时,微生物菌落总数分别在贮藏第10天和第7天超过10⁶ cfu/g,感官质量在贮藏第11天和7天显著下降。改进的Gompertz模型能够很好地拟合茭白贮藏过程中腐败微生物的生长,其拟合度(R²)在0.945~0.984。乳酸菌和酵母菌是茭白贮藏过程中的主要优势菌,并与茭白的整体感官分数、硬度、色度、色泽和脱水程度等感官质量具有较高的相关性(P＜0.05)。