钴对玉米幼苗生长发育及钴含量的影响

试验采用完全随机区组设计、盆栽与室内分析相结合的方法,研究了钴对玉米幼苗生长发育及其钴含量的影响,以期为玉米优质高产提供理论依据。研究结果表明:施用钴会降低玉米幼苗中叶绿素的含量,提高玉米幼苗氮的含量,但钴超过一定的浓度,玉米幼苗中的含氮量会下降;施用钴对玉米幼苗中磷和钾含量也有一定影响;施用钴会降低玉米幼苗根系活力,提高玉米幼苗地上、地下部分全钴含量。     

贵阳市主要土壤重金属状况研究

通过对2000～2003年贵阳市的白云区、修文县、开阳县、清镇市、息烽县、乌当区、小河区以及花溪区的多个旱地的表土和底土（53个样品）中重金属元素（汞、砷、铅、镉、铬）含量进行检测，以GB／T18407．1—2001《农产品安全质量无公害蔬菜产地环境要求》为标准，采用单因子指数法及N．L．Nemerow综合指数法进行评价，分析结果表明：贵阳市无公害蔬菜生产基地的大部分土壤中的5种重金属元素的含量基本在GB／T18407．1—2001规定的范围内，但也有个别区域内土样中砷、镉含量达到了警戒线的含量范围，如白云区底土中砷的单因子综合污染指数达到0．7968、乌当区表土中镉的单因子综合污染指数达到0．7542，两者都属于0．7～1．0污染警戒线范围内。总体土壤的表土、底土重金属综合污染指数分别为0．3785、0．4204，小于0．7，污染等级属于安全，污染水平为清洁，土壤环境质量为1级。     

Effect of alien cytoplasm and fertility restorer genes on agronomic and physiological traits of Brassica juncea (L.) Czern

To assess the effect of alien cytoplasm and fertility restorer genes on agronomic and physiological traits in Brassica juncea, cytoplasmic male sterile (CMS) and fertility restorer lines involving five alloplasms in three nuclear backgrounds were constituted through repeated backcrossing. These lines were evaluated along with euplasmic lines for agronomic traits in field experiments. Respiration efficiency of in vitro cultured hypocotyls, and chlorophyll content in leaves were also estimated. Significant adverse effects of trachystoma and catholica cytoplasms on yield‐contributing traits and yield were noticed. The restorer gene corrected the floral defects in CMS trachystoma and restored yield to the level of euplasmic line, while it did so only partly in CMS catholica. Restorer genes had no adverse effect on traits in any of the systems. On the contrary, the Rf gene of moricandia CMS system exerted a positive effect on leaf chlorophyll content. Likewise, in vitro assay indicated the moricandia CMS system as vigorous. The moricandia CMS plants gave higher seed yield perhaps due to overall better vigour and higher leaf chlorophyll content.     

不同水肥处理对有机基质型砂培番茄产量和品质的影响

以番茄(金鹏一号)为试材,采用简易有机基质槽培,研究不同灌水量和施肥水平对番茄产量和品质的影响。设置3个水分处理,分别是高水(95±5)%(H1)、中水(80±5)%(H2)、低水(65±5)%(H3);4个施肥处理分别是只用有机基质栽培,不追施无机化肥(T1);追施化肥,尿素1 084.665 kg/hm2,硫酸钾483.06kg/hm2(T2);尿素1 812.825 kg/hm2,硫酸钾1 115.775 kg/hm2(T3);尿素2 540.835 kg/hm2,硫酸钾1 748.505 kg/hm2(T4);采用完全随机组合,共12个处理。结果表明,在基质相对含水量相同时,番茄不同施肥处理中可溶性糖、可溶性蛋白及产量均以T3为最高,Vc及可溶性固形物则以T4为最高;在相同肥力情况下,番茄不同水分处理中H1的产量远远高于其他两个水分处理,但是品质却随着含水量的降低而呈现显著增高的趋势,以H3最好;综合考虑水分和肥料双因素对产量和品质影响,处理H2T3为最佳处理,其次为处理H2T4,也可以提高番茄的产量和品质。     

截形叶螨危害下枣叶片叶绿素含量高光谱估算模型

以不同截形叶螨(Tetranychus truncatus Ehara)危害等级下枣叶片高光谱和叶绿素含量数据为基础,分析不同截形叶螨危害等级(0级、1级、2级、3级、4级)下枣叶片高光谱特征,构建基于一阶微分光谱的不同截形叶螨危害等级枣叶片叶绿素含量高光谱线性回归估测模型。结果表明:截形叶螨危害造成叶片中叶绿素含量减少,导致光谱反射率降低,表现为随危害等级的增加叶绿素含量呈逐级减少趋势。在不同截形叶螨危害等级枣叶片叶绿素估测模型中,危害等级为0级时,模型拟合度最好,达到0.810,表明利用高光谱数据构建不同危害等级枣叶片叶绿素含量估算模型具有一定的潜力,对危害植被叶片的虫害诊断意义重大。     

甘蓝型油菜含油量的遗传研究

采用7×7双列杂交设计,研究了甘蓝型油菜含油量的基因作用和其它遗传参数,以及含油量与其它农艺性状、品质性状的关系。结果表明:含油量的遗传符合加性—显性遗传模型,有关基因在亲本中呈独立分布;显性指向增效,表现超显性作用;亲本中显性基因比隐性基因多,增效基因比减效基因的频率大;控制含油量并表现显性的基因约为4组;含油量的广义和狭义遗传力分别为81.16％和30.90％。单相关和逐步回归分析一致表明,单株产量、每角粒数、主花序长度和株高对含油量有较强正向作用,但角果长度和全株总角果数的作用为负。本文还讨论了基因作用分析在探讨配合力的基因效应成分和杂种优势产生的可能原因中的意义,及其在选择中的应用。     

基于电容式湿度传感器的植物粉料含水率测量

提出了一种基于电容式湿度传感器的植物粉料含水率测量方法。由电容式湿度传感器和数据采集卡组成的测量系统获取植物粉料含水率数据,应用一阶差分法剔除奇异值后,通过惯性滤波法处理数据。由菊花粉含水率的13个测量值与烘干法测得的真值对比试验结果可知,测量值与真值之间的最大相对误差为1.61%,平均相对误差为0.76%,均小于5%(测量样品数为5时置信区间为95%),表明该方法能够用于测量低水分植物粉料的含水率。     

绿地精准灌溉控制系统设计与最优灌溉量分析

为了提高绿地精准灌溉控制系统中两点法测量土壤墒情的测量精度,通过对土壤水分传感器一体化的研究,设计了双层复合土壤水分传感器,相比于传统的两个传感器策略,使用该复合型土壤水分传感器测量结果更加精确,且降低了能耗。为了获得绿地作物的最优灌溉量,确保灌溉水不浪费且能满足作物正常生长的需求,以高羊茅为例,通过实验,在综合分析高羊茅生长需求、土壤墒情和部分气象资料的基础上,得出适合于高羊茅的最优灌溉量为12 mm。     

Variability and Correlation between Exchangeable Sodium Percentage and Sodium Adsorption Ratio in Vertisols of Sudan

Vertisols in the Sudan occur under different climatic zones, ranging from arid in the north to tropical monsoon in the south, with rainfall varying from 150 mm to 1000 mm per annum. In this study, the exchangeable sodium percentage (ESP) was estimated from the sodium adsorption ratio (SAR); values of SAR and ESP for all identified soil series of Vertisols in the Sudan were extracted from the available data. These data were used to examine the variability in SAR and ESP in these soils using coefficient of variation (CV) as an index and then to regress ESP on SAR for the three master horizons (A, AC, C) and pooled data for all horizon. Curvilinear, linear, quadratic, and cubic equations were used to examine the relation between ESP and SAR. The significance of the F ratio and correlation coefficient was tested for individual equation. The soil series were then sorted out into saline and nonsaline, sodic and nonsodic, and the ESP was regressed on SAR once again. The equations used for the regression were curvilinear and first‐, second‐, and third‐degree polynomial equations. Then analysis of variance (ANOVA) was used to screen any significant difference between the estimated values of ESP (using these equations and USDA salinity laboratory equation) on one hand and the actual (measured) values of ESP. The results revealed that ESP and SAR are highly variable irrespective of depth despite slight decrease with depth. Furthermore, ESP is more variable than SAR in horizons A and AC but less variable in horizon C. The regression equations indicated that ESP might be reasonably estimated from SAR. However, different equations were appropriate for different horizons. Moreover, the result indicated that in most of the cases the relation between ESP and SAR better fits quadratic equations. But for simplicity, linear equations for all horizons could be used to estimate ESP from SAR.     

Impact of Variable Potassium on Metabolism,Oil, and Seed Quality of Groundnut

To study the impact of variable potassium (K) on biomass, economic yield, and role of K in groundnut (Arachis hypogeae L.) metabolism, plants were grown in refined sand at different levels of K, ranging from 0.5 to 16 mM. The concentration of K increased with increase in supply in all parts of groundnut. Both low (<4 mM) and excess (>4 mM) K increased the activity of peroxidase, ATPase, and acid phosphatase and decreased the concentration of chlorophyll in leaves significantly. Low (<4 mM) and excess (>4 mM) concentrations of K inhibited pod and kernel (seed) formation in groundnut. Potassium stress (both low and excess) deteriorated the quality of groundnut seed by decreasing the concentrations of starch, protein, and oil and increasing that of sugars in seeds. The activities of certain enzymes also altered in K stress in leaves and seeds of groundnut.