Comparison of the resistance and susceptibility to downy mildew [<Emphasis Type="Italic">Hyaloperonospora parasitica</Emphasis>, constant. (Pers. Ex Fr)] of nine <Emphasis Type="Italic">Brassica olearacea</Emphasis> accessions in laboratory,seedbed, and field screens

The relationship between resistance in seedlings, young and adult plants is studied for the pathosystem Brassica oleracea–Hyaloperonospora parasitica. Genotypes identified in the laboratory as resistant or susceptible or exhibiting a differential reaction to a selection of H. parasitica isolates were tested in 1997–1999 in seedbeds and fields under natural infestation. Isolates tested in the laboratory were grouped in five pathotypes, of which four were presented by isolates from Brittany, France. Genotypes susceptible to all pathotypes in the laboratory were also susceptible in the seedbed and field tests, while genotypes expressing a differential response to pathotypes were either resistant or susceptible. Accessions Everest, DEGC, ESPG and RS1105 exhibiting resistance to all pathotypes except I, were resistant in all environments and remained resistant in 2000–2002. Pathotype I was not prevailing in the field and results support the hypothesis that accessions resistant under laboratory conditions will be resistant under field conditions, provided the same pathotypes are present under the laboratory and field conditions.     

Temporal change in carbon stocks of cocoa–gliricidia agroforests in Central Sulawesi,Indonesia

In a false-time series, the temporal development of cocoa–gliricidia carbon (C) stocks and soil organic carbon (SOC) were investigated in Napu and Palolo Valleys of Central Sulawesi, Indonesia. As a first step, the Functional Branch Analysis (FBA) method was used to develop allometric equations for the above- and below-ground growth of cocoa and gliricidia. FBA resulted in shoot–root ratios of 2.54 and 2.05 for cocoa and gliricidia, respectively. In Napu and Palolo, the trunk diameter and carbon levels per gliricidia tree were always much greater than that of cocoa. The highest aerial carbon levels were attained at year four in Napu (aerial cocoa–gliricidia = 20,745.2 kg C ha⁻¹) and at year five in Palolo (aerial cocoa–gliricidia = 38,857.0 kg C ha⁻¹). After years four or five, however, the reduced stocking density of gliricidia attributed to a loss of aerial C. During the time spans in question, SOC remained fairly stable though slightly decreasing in Napu and slightly increasing in Palolo. The SOC harbored a vastly greater amount of system C (one-half and one-third of SOC in the 0–15 cm stratum in Napu and Palolo, respectively) relative to tree components. Eight years (Napu) or 15 years (Palolo) after conversion of a rainforest to cocoa–gliricidia agroforestry caused an 88% and 87% reduction of aerial C-stocks in Napu and Palolo, respectively.     

利用MODIS数据监测大面积土壤水分与农作物旱情研究

[目的]更好地利用MODIS数据监测大面积土壤水分与农作物旱情。[方法]在叙述MODIS传感器优点的基础上,介绍了几种MODIS数据监测土壤水分与农作物旱情的方法,讨论了土壤水分遥感监测中存在的问题和发展趋势。[结果]热惯量法适用于裸露的土壤或作物前期生长的地区土壤水分监测,温度植被干旱指数法(TVDI)适用于植被覆盖度比较大地区的土壤水分监测,光谱法使用MODIS数据进行大面积、多时相土壤湿度监测是可行的,该方法从叶片光合作用和冠层温度两个方面研究了作物对水分胁迫的响应。[结论]必须加强土壤水文模型和遥感模型、遥感反演方法和数字土壤工程的研究。     

芸薹属作物分子遗传连锁图谱应用研究进展

 从芸薹属作物分子遗传连锁图谱的研究现状出发,综述了分子遗传连锁图谱在芸薹属作物重要农艺性状基因定位和辅助育种、比较作图、基因组结构和起源进化等方面的最新应用进展,对今后的研究方向提出了建议。     

An overview of general features of risk assessments of genetically modified crops

The intentional introduction into the environment or market of genetically modified organisms (GMOs) is nearly always governed by a framework of science-based risk assessment and risk management measures. This is usually implemented through the integration of hazard identification and characterisation of all of the elements of risk associated with a new GM crop or derived product. Typical categories of hazards arising from the introduction of transgenic crops include: possible unintended negative health effects in a susceptible subgroup of the consumer (target) population; the evolution of resistance in the targeted pest/pathogen populations when the transgene confers resistance to a pest or pathogen; non-target hazards associated directly or indirectly with the transgenic plant or transgene product outside the plant; and those associated with the integration and subsequent expression of the transgene in a different organism or species following gene flow. The consequences of likely exposure to these and other hazards are considered in this introduction to the main issues raised when evaluating the possible risks arising from the importation or cultivation of genetically modified crops.     

虚拟水价值视角下新疆主要农作物种植偏好及布局研究

选取新疆主要农作物小麦、玉米、棉花、水稻、甜菜、薯类为研究对象,在采用Penman-Monteith公式计算新疆14地州及64个主产县6种主要农作物单位虚拟水产量的基础上,明晰了主要农作物的单位虚拟水价值。并借助IBMSPSS软件进行对应分析,从虚拟水价值的视角研究了新疆主要农作物种植偏好与布局。结果表明:①6种主要农作物中虚拟水价值最高的是薯类(8.34元/m^3),最低的是棉花(1.51元/m^3);②从虚拟水价值视角看,农作物的种植偏好与种植规模存在显著差异。县际层面上,按照农作物虚拟水价值由高到低排序,前三位的县与自治区“十三五”规划(种植业)的契合度较高;③调整种植业结构后农作物的虚拟水总产值可增加601.25亿元,可实现“十三五”规划(种植业)中“调棉减水”的目标。研究认为:不同农作物单位虚拟水价值在农作物种类与地区上存在显著差异,优化水资源配置可以带来种植业生产总值的增加,新疆应在调整外显性种植结构的同时注重内涵式品质的提升,生产特色高质产品。     

茄科作物绿原酸的生物合成及调控机制研究进展

绿原酸是植物体内重要的多酚类化合物,在植物生长发育、抗病虫害、抗寒及其他逆境等方面发挥重要作用,同时具有多种药理功能,包括抗炎、抗菌、抗病毒、抗癌、抗紫外光与辐射、免疫调节、降血脂、降血糖等,在功能性食品、营养补充剂、食品原料、化工和新药开发等方面的应用潜力巨大。番茄、茄子、辣椒、马铃薯和烟草都是世界上重要的经济作物,它们均是茄科植物的重要种类,也是绿原酸的重要来源,其果实或营养器官中的绿原酸含量具有较大差异,且绿原酸合成代谢是遗传和环境等因素共同决定的复杂生物学过程。因此,茄科作物绿原酸的生物合成及其调控的分子机制研究对作物遗传改良具有重要的理论意义与应用价值。本文概述了绿原酸在以上 5 种茄科作物中的含量情况、绿原酸的生物合成途径及其转录调控分子机制,以及基因型差异、环境因素、栽培措施等因素对茄科作物绿原酸含量影响等方面的研究进展,旨在为茄科作物绿原酸开发利用、高绿原酸茄科作物种质资源创制以及新品种培育等提供理论依据。     

作物分蘖影响因素研究进展

分蘖作为禾本科作物的重要农艺性状,是评估作物生产潜力的关键指标,并对作物高产目标的实现有重要意义。本文从植物激素、遗传基因及外界环境因素3个方面阐述了作物分蘖发生的主要影响因素,以期为作物分蘖研究提供一定的理论参考。     

不同茬口对小麦养分利用和产量的影响

为了探究不同茬口对小麦生产的影响,在测定玉米、大豆、花生、甘薯4种不同作物收获后土壤养分状况的基础上,对不同茬口下小麦植株养分吸收、利用和产量进行了研究。结果表明,与玉米茬相比,大豆茬的土壤速效磷含量降低,土壤速效氮和速效钾含量提高,花生茬的土壤速效氮和速效磷含量提高,甘薯茬的土壤速效氮和速效钾含量下降;大豆、花生和甘薯茬有利于小麦植株养分的积累,并能显著提高千粒重,但甘薯茬的小麦产量显著低于玉米茬。因此,大豆和花生可作为冬小麦种植区两熟复种模式的适宜前茬作物。     

设施作物蜂授粉研究的文献计量学分析

了解国内设施作物蜂授粉方面的研究现状和动态变化,为设施作物蜂授粉科研工作者与决策者提供数据参考。以《中国知网》的《中国期刊全文数据库》为数据源,运用文献计量学的原理和方法,对设施作物蜂授粉研究的年代、作者、机构、载文期刊、研究内容及基金资助进行分析。结果表明,检索出1988-2017 年国内设施作物蜂授粉研究专题167名作者在77种刊物上发表的220篇文献,揭示了29年间国内该领域研究的动态变化和基本态势。中国设施作物蜂授粉发文量自1988年和1989年的3篇,发展缓慢,到2004年后出现波浪式的增长趋势,2015年达到最高峰,26篇;文献刊发的期刊层次不是很高;高产机构不多;核心作者群没有形成;研究内容丰富。可见此领域的研究还有很大空间,有待进一步的深入研究。