Analysis of total inositol phosphates in municipal solid waste compost-treated soils by two extraction methods

 Humic substances are the most dynamic component of agricultural soils. In this study, humic substances were extracted from soils based on standard acid/base solubility and by gel filtration using Sephadex G25. Organic P is a component of humic substances, and inositol phosphates are considered to have high prominence in organic P. The objectives of the study were to determine the effects of municipal solid waste (MSW) compost on the amount of inositol phosphates (IP) present in soils, and compare methods of extracting humic substances from soils. Total IP (IP_T) in soil extracts was determined following separation using a AG-1× 8 anion exchange resin, acid digestion and ICAP analysis for P. The percentage of IP (%IP) of the total P in the soil was also determined by colorimetric analysis. The soils were part of an experiment to study the effects of three rates of MSW compost and fertilizers on three crops grown in a Pugwash sandy loam (Humo-Ferric Podzol). The data were compared using ANOVA atP≤0.05; extraction methods, fractions [humic/fulvic, high/low molecular (MW)], and five treatments (three different rates of compost, fertilizer, and untreated soil) were compared. The gel filtration method extracted significantly more IP_T and %IP than the solubility method. In the solubility method, humic and fulvic acids contained the same amounts of IP_T and %IP, while the high MW fraction always contained more IP_T and %IP than the low MW fraction in the gel filtration method. Fulvic acids and the low MW fraction contained similar amounts of IP_T and %IP. There were differences in %IP between compost-treated soils and the non-compost-treated soils, although there were no differences in IP_T due to rate of compost addition. Received: 20 October 1999     

水稻白转绿突变体的特性、遗传及其育种应用

对通过辐射诱变获得的具有白化转绿特性的水稻光温敏核不育突变体的遗传及其生物学特性进行了研究。结果表明,这些突变体可分为3种类型：白化转绿类型(W2、W3、W4和W10),白化转黄绿类型(W9)和白化转绿后期转白复绿类型(W1和W7)。这些突变体的白转绿特性都是受一对隐性基因控制,具有与原不育系“培矮64S”相似的农艺性状和育性转换特性,它们的杂种具有与原杂交稻相似的株叶形态,分蘖和株高生长动态,但是它们的产量构成因素依不同的突变系而表现不同,其中W1、W2和W3的杂种具有与原杂交稻相似的产量潜力,具有较好的育种应用价值。     

谷子黄叶色突变体光合特性研究

为解析谷子黄叶色突变体高光合特性机理,以野生型豫谷1号为对照,分析了谷子全生育期黄叶色突变体ylm-1和ylm-2的光合色素、光合速率、气孔特性、荧光参数、光合关键酶活性和产量性状。结果表明,突变体光合色素含量为野生型豫谷1号的50%~60%,强光下突变体光合速率(Pn)较野生型显著提高,且无明显的“午休睡眠现象”;ylm-1和ylm-2气孔导度(Gs)显著增加。荧光参数结果显示,与野生型相比,突变体的光能利用效率和转化效率明显增加,光合关键酶1,5二磷酸核酮糖羧化酶(Rubisco)活性明显降低,而ylm-1和ylm-2磷酸烯醇式丙酮酸羧化酶(PEPCase)和苹果酸酶(NADP-ME)活性分别增加了23.3%、24.4%和12.9%、15.5%。产量相关性状分析表明,突变体单穗质量、穗粒质量及千粒质量较野生型显著增加。本研究结果为谷子高光效及分子标记辅助选择育种提供了重要的理论依据。     

鸡脚重性状的全基因组关联分析

鸡(Gallus gallus)脚重性状为鸡产业中的重要经济性状.为了揭示鸡脚重性状的遗传基础,寻找可用于鸡脚改良的分子标记,本研究以核心群京海黄鸡为实验动物,测定其脚重,利用简化基因组测序技术在整个基因组范围内检测与脚重相关的SNPs.共检测到16个与脚重相关的SNPs位点,其中13个集中分布在4号染色体上72.8～77.9 Mb区域;2个SNP位点rs475641139和rs475548810达到5％ Bonferroni全基因组显著水平(P＜5.5E-07),其余位点达到全基因组潜在显著水平(P＜1.1E-05).筛选每个SNP周围1 Mb区域内的基因,共找到9个可能的候选基因,并使用基因本体论(Gene Ontology,GO)数据库对9个候选基因的细胞组分、分子功能和参与的生物学进程进行了分析.结果表明二氢蝶啶还原酶(dihydropteridine deductase,QDPR)基因、LIM域结合蛋白2(LIM domain-binding protein 2,LDB2)基因、类184B家族(family with sequence similarity 184 memberB,FAM184B)基因、复合信号免疫球蛋白J结合蛋白(recombination signal binding protein for immunoglobulin kappa J region,RBPJ)基因、纤维母细胞生长因子结合蛋白2(fibroblast growth factor-binding protein 2,FGFBP2)基因、富亮氨酸重复蛋白5(F-box and leucine-rich repeat protein 5,FBXL5)基因、胆囊收缩素受体A(cholecystokinin receptor type A,CCK1R)基因、肌动蛋白互作蛋白1 (WD repeat containing protein 1,WDR1)基因和类桶状蛋白4(tubby like protein 4,TULP4)9个基因和4号染色体72.8～77.9 Mb区域可能为影响鸡脚重性状的重要候选基因和潜在功能区域.本研究为鸡脚重性状的标记辅助选择提供了理论依据.     

番茄叶片和果实热容量的热平衡测定方法

为了分析植物器官体温形成机制的需要,即在植物与环境间热平衡分析时,有准确的植物器官热容量参数,该文采用热平衡法测定了番茄叶片和果实的热容量参数。考虑胁迫生态环境植物传热分析问题,也选择了侧柏等生态恢复先锋树种,以及作为参照的肉质植物芦荟的热容量参数。结果表明,番茄叶片热容为3253.7±97.10J/(kg℃),与针叶植物侧柏和肉质叶植物芦荟叶片的热容相近;番茄果实热容为3517.4±68.50J/(kg℃)。热平衡法可以用来测定植物器官的热容量;其热容量均低于水的热容量。对前人用热平衡法测定生物质热物性参数的方法,进行了改进和完善。该文既为其他生物质的热容量测定提供了试验方法,也为植物气候空间研究提供了热物性参数基础数据。     

超微粉碎对桑叶粉理化性质的影响

为拓展超微粉碎技术在食品添加剂和药品开发中应用,以桑叶为原料,分别对桑叶粗粉进行干法超微粉碎2 、4、6、8 h,得到4种不同粒径大小的桑叶超微粉,并对桑叶粗粉与4种超微粉的理化性质进行比较。研究结果表明,超微粉碎能明显减小桑叶粗粉的颗粒粒径（P＜0.05）,随着超微粉碎时间的增加,超微粉的粒径减小,粉体的粒径分布范围变窄,比表面积和体积密度显著增加（P＜0.05）,休止角、滑角和膨胀性显著降低（P＜0.05）,水溶性/持水力、持油力、蛋白质的水溶性和多糖的水溶解性均有不同程度的增加,但多酚含量变化不显著（P＞0.05）。扫描电镜结果显示,粗粉经超微粉碎后,其颗粒呈零散的分布形态。说明超微粉碎可改善桑叶粉的部分理化性质,可将这些性质应用于食品添加剂和常规食品开发与加工中。所得研究结果将为超微粉碎技术在桑叶食品中工业化应用提供数据支持和理论依据。     

Quantitative methods for estimating foliar uptake of zinc from suspension‐based Zn chemicals

The present study developed methods for quantifying foliar Zn uptake from suspension‐based Zn chemicals of low solubility, which were ZnO (particle size: 0.15^–1.34 μm) and a newly synthesized Zn hydroxide nitrate crystal (Zn‐HNC) (50^–100 nm thickness and 0.2^–1 μm lateral dimension). Recently matured leaves of citrus (Citrus aurantium L. cv. Valencia), capsicum (Capsicum annume L. cv. Giant Bell), and/or tomato (Solanum lycopersicum L. cv. Roma) were in vitro–treated with microdroplets (5 μL per droplet) of Zn‐HNC‐ and ZnO‐suspension solutions on the adaxial surface and incubated under controlled conditions for up to 72 h. Leaf‐washing protocols were compared, including: dilute ethanol (3%), dilute nitric acid (2%), and their combination. The methods for quantifying Zn uptake were: (1) whole‐leaf loading by which droplets of the Zn suspension solutions were loaded onto central regions of both left and right sides of leaf blades and (2) half‐leaf loading by which soluble‐Zn (ZnSO₄) droplets were loaded onto only one side of leaf blades while the other was used as the background Zn control. Foliar‐surface characteristics of the plant species affected the effectiveness of the washing methods. The dilute nitric acid (2%; ± 3% ethanol) was required to remove residue particles of the ZnO and Zn‐HNC suspensions from foliar surfaces of capsicum and tomato (highly trichomatic), but the residue Zn chemicals on citrus leaves (nontrichomatic and highly waxy) were similarly and effectively removed by the three washing methods. For quantifying Zn uptake by the leaves, the half‐leaf loading method showed its advantages over the whole‐leaf loading method, because it did not stringently require similar background Zn concentrations in the control and treated leaves at the start and had little risks of secondary absorption of soluble Zn in the washing solution.     

肉桂人工林叶片营养元素季节累积特点及其相互关系

研究了不同林龄（3a和6a）肉桂人工林叶片5种营养元素（N，P，K，Ca和Mg）含量、季节变化动态及营养元素之间的相互作用关系。结果表明．不同林龄肉桂林叶片营养元素含量均为N〉K〉Ca〉Mg〉P，不同季节间营养元素的变异系数以Ca为最大．其次是Mg和K．然后是N，最小是P；不同林龄肉桂林叶片营养元素的季节变化规律相似，N以生长初期（3月中旬）最高，生长末期（12月中旬）最低；P和K以生长初期最低或较低．第一个生长高峰期（6月中旬）或第二个生长高峰期（9月中旬）最高或较高；Ca以第一个生长高峰期最低．生长末期最高或较高；Mg以生长初期最低．生长末期最高。肉桂植株P和K代谢之间呈正相关关系，P与Ca之间则存在显著的颉颃作用。     

马棘的γ辐照效应与彩叶突变选育

用0~450Gy 8种剂量60Co γ射线辐照马棘干种子,研究表明：150Gy以下低剂量辐照对种子具有刺激效应,350Gy以上的高剂量具有显著的抑制作用,200～450Gy之间时,剂量与出苗率、成苗率和苗高显著相关,综合考虑苗高和成苗率,初步认为马棘种子辐照以300Gy为佳。经300Gy辐照诱变2代出现黄色、白色、虎斑、紫色等4大类型的10种叶色变异,尤以黄色突变谱最丰富。并对比分析了黄色、紫色和银白3种叶色突变体材料的物候期、成枝量、分枝长度、主干花序数、结荚果数、成熟种子数、耐逆性与适应性等特征特性。