玉米早熟性的相关和遗传研究

以包含11个早熟自交系的共24个自交系及由它们配成的含有正、反交组合的116个单交组合(1991年)和122个单交组合(1992年)为材料,研究了玉米早熟性及产量与有关性状的相关性、早熟性的遗传特点。结果为单交组合生育期与其小区产量呈正相关,但也有个别组合表现既早熟又较高产的,单交组合生育期与其株高、单株叶数均呈正相关,单交组合单株籽粒产量与株高、行粒数、百粒重呈正相关,与穗行数基本无相关;杂交组合生育期多数介于双亲生育期之间,并稍偏晚熟亲本,早熟的显性度为0.22(1991年)和0.37(1992年),杂交组合F_1生育期与双亲生育期平均敷(x)之间存在显著正相关关系,回归方程为y=-10.9 1.17x;早熟性的正、反交组合之间不存显著差异。     

43份割手密资源农艺性状遗传多样性评价

为揭示割手密种质资源的遗传多样性,对野外采集的43份材料的株高、叶长、叶宽、茎径、节数等15个重要农艺性状进行检测和分析。结果表明,参试材料在这15个性状上都表现出较大的遗传变异,变异系数在9.87%~206.37%之间。主成分分析显示7个主成分对变异的累计贡献率达86.66%,可作材料选择的重要依据。聚类分析将参试材料分为3类,其遗传关系与地理来源没有必然联系。     

青海小麦品种的种子表型性状分析

为充分了解青海省小麦品种的种子表型性状特征及其相关性,以1957年以来审定的66个小麦品种为研究对象,在青海小麦高产区(柴达木盆地)对种子长、宽、长宽比、面积、密度指数和千粒重6个种子表型性状的3年数据进行了比较分析.结果表明,依据种子表型性状可以将这些品种聚为4个类群;千粒重与种子长宽比显著相关,与其他4个性状极显著相关,这些性状均可以作为千粒重选择的指标;不同阶段审定品种的千粒重变化不大,说明青海省在千粒重方面育种改良效果不明显,在今后的育种工作中有待加强;3年平均千粒重超过60 g的品种有4个,它们为高千粒重育种提供了资源.     

171份小麦种质面粉糊化特性及其与品质性状的相关性分析

为了解我国现有小麦种质的面粉糊化特性,以来源于不同区域的171个小麦品种(系)为试验材料,分析了小麦面粉糊化特性及其与品质性状的相关性。结果表明,品种对面粉糊化参数有极显著影响(P0.01);糊化参数基本呈正态分布,约有81.9%的小麦峰值黏度集中在2 250～3 000 cP,筛选出峰值黏度较高的6个小麦品种(系)。糊化参数在不同小麦类型区的材料间差异程度不同,其中长江中下游冬麦区的峰值黏度显著高于北方冬麦区,与西南冬麦区、黄淮冬麦区和国外引进材料差异不显著。相关分析表明,峰值黏度与其他所有糊化参数均呈极显著正相关;与面粉白度、L~*值、稳定时间和粉质质量指数呈显著或极显著正相关,与b~*和吸水率则呈极显著负相关。     

Characterisation of sweet stem sorghum genotypes for bio-ethanol production

In an effort to characterise and select promising sweet stem sorghum genotypes with enhanced biofuel productivity, the present study investigated phenotypic variability present among diverse sweet stem sorghum genotypes based on ethanol production and related agronomic traits. One hundred and ninety genotypes were evaluated. Data were subjected to variance, cluster, correlation, path coefficient and principal component analyses. Significant differences (P?<?0.01) were detected among tested genotypes for all measured traits. Days to flowering varied from 62 to 152 with a mean of 93. Plant height varied from 90 to 420?cm with a mean of 236?cm. Stem diameter ranged from 7 to 31?mm with a mean of 16?mm. Biomass yield varied from 6.668 to 111.2?t?ha^?1 with a mean of 30?t?ha^?1. Stalk dry matter content ranged from 17.2% to 44.2% with a mean of 29.8%, while fibre content varied from 8.92% to 34.8% with a mean of 17.2%. The stalk brix yield varied from 3.3% to 18.9% with a mean of 12.1%. Ethanol productivity ranged from 240.9 to 5500?l?ha^?1 with a mean of 1886?l?ha^?1. The best ethanol producing genotypes were AS203, AS391, AS205, AS251 and AS448. Days to flowering, plant height, stalk brix and stem diameter exerted the greatest indirect effects on ethanol production through higher biomass production. Biomass yield had the greatest direct effect on ethanol production. Therefore, the above traits should be considered during breeding sorghum for bio-ethanol production. Also, the traits had high heritability values, hence selection should provide for good genetic gains. Overall, the above sweet stem sorghum genotypes are useful genetic resources for breeding of sorghum with enhanced bio-ethanol production.     

Evaluation of Nitric Acid Extraction of Elements from Soils and Sediments in Two watersheds in East Tennessee

Determining the total elemental concentrations of soils requires a total dissolution method, in which hydrofluoric acid (HF) is commonly used. However, this method is tedious and risky due to the dangerous reagent HF. This study compared a single acid extraction technique using a nitric acid (HNO₃) extraction method to total dissolution (HF + microwave assisted aqua regia) for evaluating the total elemental concentrations in soils and sediments. The two methods were used to analyze the elemental content of soils and sediments from the Oostanaula Creek and Pond Creek watersheds in East Tennessee. Twenty-one elements (Al, Ba, Ca, Co, Cr, Cu, Fe, K, La, Li, Mg, Mn, Nd, P, S, Si, Sr, Ti, V, Zn, and Zr) were subsequently measured using inductively coupled plasma optical emission spectrometry (ICP-OES). The extraction efficiency for HNO₃ relative to the total was compared and discussed. In general, HNO₃ can extract the elements in absorbed phases and those residing in non-silicate minerals. Six elements (Ba, Co, Fe, Ca, Mn, and P) generated significant correlations between total and HNO₃ in both OC and PC watersheds. Finally, the elements were grouped according to the interrelationships of their total elemental concentrations based on the dendrogram plots, suggesting their geochemical association in soils and sediment forming minerals.     

茬口和施氮水平对小麦品质性状及其变异系数的影响

通过在山西省临汾市尧都区建立夏季小麦收获后复播大豆、油葵、玉米和夏季休闲4个茬口,进行不同茬口、施N水平对下季种植的小麦品质性状及其变异系数的研究.结果表明:小麦千粒重、容重、蛋白质含量、沉降值及湿面筋品质性状等各茬口问存在差异,大豆茬口可较好地协调各品质性状.千粒重和容重在休闲茬口中均以高N水平(E、F)较高,而在其他茬口中则以低N水平较高;蛋白质含量、沉降值和湿面筋3个性状在4个茬口中的平均值则以高N水平(E)较高;茬口和施氮水平对各品质性状的变异系数影响分别为沉降值>湿面筋>蛋白质含量、沉降值>蛋白质含量>湿面筋.该项研究为专用小麦标准化生产提供了理论依据.     

60Co-γ辐射对谷稗幼苗生长和微量元素吸收的影响

用不同剂量⁶⁰Co-γ辐射对‘朝牧1号’谷稗（Echinochloa crusgalli）种子进行处理,研究⁶⁰Co-γ射线辐射对谷稗幼苗生长和微量元素含量的影响。结果表明：50~200 Gy辐射组促进了最长根的生长,但抑制了幼苗株高和总长度;随着辐射剂量的增加,茎叶Fe、Mn、Zn、B、Ni元素含量和根部B元素含量呈先增后减趋势,根Fe、Mn、Ni元素含量随辐射剂量增加而呈增加趋势,Zn元素含量呈降低趋势。     

基于CNKI《中国引文数据库》的《现代农业科技》2005-2015年核心作者群分析

以中国知网(CNKI)《中国引文数据库》为数据统计源,利用普赖斯理论和综合指数法对《现代农业科技》2005-2015年的作者发文情况进行了统计分析,确定该刊的核心作者.对核心作者的研究主题、合作情况、地区分布、机构分布等方面进行了深层次分析,并进行了发文量、被引量、综合指数之间的相关性分析.综合分析被引量和发文量,可以科学地测评作者群;《现代农业科技》2005-2015年的核心作者有207位,绝大部分分布在该刊出版地的相邻省份;科研院所和技术单位是该刊最重要的核心作者来源机构.     

枇杷成熟果实中可溶性糖组分及含量分析

[目的]为枇杷果实糖代谢、果实品质形成与改良研究奠定理论基础。[方法]对不同枇杷品种成熟果实可溶性糖组分及含量进行测试分析。[结果]不同品种枇杷果实的总糖含量、甜度值差异显著,白肉型品种的总糖含量与甜度值变化趋势一致,红肉型品种的总糖与甜度值的变化趋势相近;枇杷成熟果实可溶性糖主要为果糖,其含量平均值为42.33 mg/g(FW),占总糖的42.74%;山梨醇的含量最低,含量平均值为2.66 mg/g(FW),占总糖的2.69%。相关性分析表明,枇杷果实果糖与甜度值、总糖与甜度值的相关性极强(均为r=0.90**),总糖与果糖显著相关(r=0.79*),总糖与葡萄糖、山梨醇、蔗糖之间相关性不显著。[结论]果糖是构成枇杷果实总糖的重要因素,一定程度上果糖和总糖可以反映枇杷果实甜度值的高低。