Broadening the genetic base of lentil cultivars through inter‐sub‐specific and interspecific crosses of Lens taxa

Wild Lens taxa are invaluable sources of useful traits for broadening genetic base of cultivated lentil. Nine inter‐sub‐specific and interspecific crosses were made successfully between cultivated (Lens culinaris ssp. culinaris) and wild lentils (L. culinaris ssp. orientalis, odemensis, lamottei and ervoides). The effect of species groups, day length and temperature on crossability in lentils was evident under normal winter sowing in New Delhi and in summer Himalayan nursery at Sangla in Himachal Pradesh, India, although pollen fertility assessed in all the cross‐combinations showed no significant variation. True hybridity of nine inter‐sub‐specific and interspecific crosses was confirmed through morphological and molecular (ISSR) markers, in which three of 120 primers could confirm the hybridity of all the crosses. All cross‐combinations were also studied for important quantitative traits related to yield. The range, mean and coefficient of variation were estimated in parental lines, F₁ and F₂ generations to determine the extent of variability generated in cultivated lentils through the introgression of genes from wild L. taxa. A high level of heterosis was observed in F₁ crosses for important traits studied. Substantially higher variations for seed yield and its attributing traits were exhibited in F₂ generations indicating transgressive segregation. The results of the present investigation revealed that wild L. taxa can be successfully exploited for lentil improvement programmes, and the variations generated could be easily utilized for broadening the genetic base of cultivated lentil gene pool for improving the yield as well as wider adaptation.     

墒情监测站基座埋设对土壤水分分布的影响

为确定传感器埋设的合理位置,借助Hydrus-2D软件,对长、宽、高均为50 cm,顶面埋设在地面以下50 cm的基座,结合中国科学院南皮生态农业试验站冬小麦抽穗期的情况,建立了土壤水分运动模型,分别模拟了在有无基座的条件下各时期的土壤体积含水率,并计算了不同条件下因埋设基座而产生的偏差。结果表明,离基座越近,影响越明显。基座的埋设使得其周边土壤雨后的含水率偏大,灌前的含水率偏小。雨后的偏差主要表现在70 cm深度以下的土层,灌前的偏差主要表现在80 cm深度以内的土层。因此,在水平方向与基座的距离不小于70 cm的剖面上埋设传感器,含水率偏差的绝对值均控制在0.02以内,基座对含水率测量的影响可以忽略。     

联合收获机知识库数据多表联合查询方法研究

联合收获机知识库系统使用SQL Server数据库,数据库中的众多数据表具有独立性,便于构建和管理。但当知识库数据量达到一定规模后,对数据表逐一查询不具有可操作性,将全部数据表融合又会导致数据结构混乱、内容表述不清、技术无法实现。针对这一问题,提出联合收获机知识库数据多表联合查询方法。从多角度划分数据表类型,分析联合收获机知识库数据存储结构,设置多表联合数据管理范围;应用SQL(Structured query language)语言将多表信息融合为数据集并存入临时表中,实现多表联合运行;利用人机交互界面将用户查询需求转换成多表联合查询语句,生成查询结果,实现多表近似范围查询和多表精确定位查询。多表联合查询与传统单表知识查询之间的测试结果表明,多表近似范围查询比系统原有的单表近似范围查询节约用户操作时间50%及以上,最高达到90.4%;多表精准定位查询比系统原有的单表精准定位查询节约用户操作时间48.1%及以上,最高达到89.6%。多表联合查询的实现使联合收获机知识库系统具有实用性与可行性,可为同类知识库系统数据管理提供可借鉴的思路和方法。     

马铃薯收获机挖掘装置智能设计系统与评价方法研究

针对马铃薯收获机挖掘装置设计效率低、设计知识难以高效获取和运用的问题,构建了马铃薯收获机挖掘装置智能设计系统.在收集整理挖掘铲设计规则的基础上,以产生式、框架式和混合式的知识表示方法表达挖掘装置的设计知识并进行存储,建立智能设计系统知识库;利用Visual Studio软件搭建知识管理系统,对规则类和实例类知识进行管理...     

Effect of water shortage on yield, and protein and mineral compositions of drip-irrigated sweet corn in sustainable agricultural systems

Water is a natural resource of prime value that is very often limited and costly, particularly in semi-arid regions. While traditional irrigation methods increase the amount of surface runoff, drip irrigation provides efficient use of the limited water resources. This study was conducted to determine the water-yield relationship and the quality of sweet corn grown under deficit drip irrigation in 1998 and 1999 in Sanliurfa, Turkey. Irrigation treatments analysed in this study were full irrigation as well as 10, 20 and 30% deficiency of Class A pan evaporation. In both years, water use efficiency ranged between 1.18 and 1.36 kg m⁻³, and irrigation water use efficiency ranged between 1.36 and 1.62 kg m⁻³. The yield response factor (k_y) or the ratio of the decrease in relative yield to the decrease in relative water consumption varied from 0.82 to 1.43, and the water-saving rate ranged from 10.9 to 31.1%. The relationships between fresh ear yield and the irrigation treatments were statistically significant (P < 0.01), and the yield decreased with increasing deficit irrigation. Root dry matter increased with water shortage. Maximum values of leaf area index were obtained at full irrigation, whereas the lowest values were found at 30% water deficiency. The values of the deficit irrigation stress index increased with decreasing water application. Although the protein content increased, the Fe, Zn and Cu concentration of the kernels decreased with increasing water deficiency. Despite the reduction of fresh ear yield with deficit irrigation, the number of marketable ears at 10% water deficiency was still high and acceptable for sweet corn (var. Reward) in south-eastern Turkey.     

阿拉尔灌区微咸水滴灌对土壤水盐分布影响的试验研究

利用不同矿化度微咸水对试验地进行灌溉,同时采用滴灌的灌水方式,分析了灌溉前后土壤水盐运移及盐分离子的分布状况。研究结果表明:微咸水灌溉对含盐土壤具有淋洗作用,这一作用随着灌溉水矿化度的提高而上升,这为干旱区节水农业技术提供了依据。     

温室环境管理智能决策支持系统的研制

以Delphi 7.0为软件开发环境,构建了温室环境管理智能决策支持系统,提出了温室环境管理智能决策支持系统的研究思路及系统实现的技术路线;采用Database Desktop来设计系统中的知识库和数据库.以数据库为基础的系统,有助于系统对知识、模型和相关数据的管理.对系统决策的过程采用基于数据库的方法进行编写,解决了温室管理智能决策过程中推理困难的问题,同时提高了决策的准确程度,经实际运用达到了预期的效果.     

葡萄糖-丙酮-BrO3--Mn2+-H2SO4体系的化学振荡反应研究及在其分析中的应用

本文通过研究甲醛及常见离子参与下的振荡反应非线性动力学行为,并对其可能的机理进行了探讨,找出了待测物质浓度与某些动力学参数(如诱导期、周期、寿命等)之间的线性关系,为未知浓度的甲醛及常见离子的定量检测获得基本实验数据。从而为甲醛及离子的定量检测提供一种新的方法和理论依据。     

基座运动对并联调整机构动力学性能的影响

以上海65 m射电望远镜六自由度并联调整机构为研究对象,研究基座运动对并联调整机构动力学性能的影响。首先阐述了并联调整机构的构型与位姿状态;然后分析了基座运动对动平台和驱动分支受力的影响,计算了基座运动引起的动平台和驱动分支惯性力和惯性力矩的变化,并分析计算了基座运动过程中引起的重力矢量方向的变化;进而采用具有高实时性特点的Kane方法分别建立了基座固定和基座运动两种情况下并联调整机构的动力学方程,最后分别采用Matlab和ADAMS软件仿真分析了基座运动对机构动力学性能的影响。仿真结果验证了所建动力学模型的正确性,同时也发现基座运动对此类机械系统动力学性能影响较为明显,在结构强度校核和控制系统参数设定时应加以考虑,以提高控制系统的准确性和结构强度的可靠性。     

基于互联网的农业专家系统发展研究

农业专家系统是农业信息技术中的一项重要技术。阐述农业专家系统的概念、国内外发展现状,农业专家系统网络化的研发意义,介绍农业专家系统的网络化开发研究方案,以及农业专家系统的研发过程、实现方法等,并对农业化专家系统网络化发展趋势进行理论性探讨。