A participatory farming system approach for sustainable broomrape (Orobanche spp.) management in the Near East and North Africa

Broomrapes (Orobanche spp.) are aggressive and damaging parasitic weeds which have a tremendous impact on agriculture in East Africa, the Mediterranean region and the Middle East. Despite the availability of technologies to control broomrapes in economically important crops, Orobanche infestation continues to increase, threatening the livelihoods of millions of farmers. Many of the technologies developed have not been effectively disseminated and there has been little or zero adoption by farmers—who continue to use ineffective management practices that exacerbate the problem. The adaptation and dissemination of appropriate management practices are major priorities in broomrape control. However, such work must take into consideration the specific socio-economic characteristics of individual farming systems. Orobanche is a community threat and effective management requires a community-based integrated management approach. Recognizing the central role of farmers in parasitic weed management, a technical cooperation project (TCP) involving FAO, ICARDA and seven countries in the Near East and North Africa (NENA) region was implemented to improve the dissemination of knowledge and skills by using a farmer field school approach: a form of education that uses experiential learning methods to build farmers’ expertise. This paper reviews conventional Orobanche research and development approaches, and highlights weaknesses in the management of the parasitic weed using these approaches as opposed to participatory approaches. The benefits and challenges of participatory farming system approaches in relation to integrated broomrape management (IBM) are also discussed. Lessons learned from achieving community ownership of, and institutional support for, IBM could be applied to other sectors (e.g. public health) in which there is a need for institutional learning and reform. Recommendations are made that include regional collaboration within the framework of a proposed Near East and North Africa Orobanche Management Network (NENAOMAN).     

向日葵抗列当育种研究进展

向日葵是世界四大油料作物之一,列当是对向日葵生长危害极为严重的一类寄生植物,且在全球范围内的发生面积逐年增加,对向日葵产业发展造成严重危害。培育抗列当品种是防治向日葵列当最为有效的途径,也是目前育种家的首要目标。育种家们通过传统的育种方法鉴定抗性基因,培育了一系列向日葵抗列当品种,并在世界范围内向日葵主栽区广泛种植,有效缓解了向日葵列当对该产业的冲击。然而,随着毒力更强的列当生理小种的出现与传播,亟待培育新的、抗性更强的品种。本文综述了新的、毒性强的列当生理小种的结构与分布,对如何利用分子标记辅助选择（MAS）策略提高向日葵的抗性分析,对向日葵抗列当基因序列信息做了归纳总结,对向日葵抗列当育种研究发展前景进行了分析与展望。     

瓜列当致病真菌的鉴定及其发酵产物活性研究

为筛选对瓜列当具有良好防治效果的生防真菌,本研究从新疆加工番茄田自然发病的瓜列当茎基部分离病原真菌,采用盆栽瓜列当接种无菌发酵滤液原液,筛选对瓜列当具有强致病性的菌株;采用共培养法测定菌株不同浓度无菌发酵滤液及其发酵产物萃取物对瓜列当种子萌发的影响;利用形态学特征和分子生物学方法对其进行种类鉴定。结果表明：盆栽瓜列当接种无菌发酵滤液原液可使瓜列当植株伤口变褐,严重的可造成整株萎蔫死亡;菌株JTF001发酵原液对瓜列当种子萌发抑制率可达100%,25倍、50倍稀释液抑制率分别为92.88%和87.62%;浓度为5μg/mL和1μg/mL JTF001发酵产物对瓜列当种子萌发抑制率均达100%;浓度为0.5、0.25μg/mL和0.1μg/mL的JTF001发酵产物对瓜列当种子萌发的抑制率分别为91.03%、81.87%和60.04%;结合形态学和基于rpb2、tef 1和gapdh基因序列分析,将菌株JTF001鉴定为交链格孢Alternaria alternata。上述结果表明菌株JTF001有作为开发防治瓜列当生物农药的潜力。     

枯草芽孢杆菌DNKAS对加工番茄分枝列当的防治应用

分枝列当（Orobanche aegyptiaca）是一种根寄生植物,严重影响加工番茄的产量。为减轻其危害,首先通过皿内芽管生长试验,明确了枯草芽孢杆菌DNKAS对分枝列当芽管生长有显著抑制作用;并通过田间小区随水滴灌方式,设置清水对照（CK）、3 kg·hm^-2 DNKAS菌剂（D3）、4.5 kg·hm^-2 DNKAS菌剂（D4.5）、6 kg·hm^-2 DNKAS菌剂（D6）、9 kg·hm^-2 DNKAS菌剂（D9）、12 kg·hm^-2 DNKAS菌剂（D12）、7.5 kg·hm^-2黄腐酸钾（FA-K）、4.5 kg·hm^-2 DNKAS菌剂+7.5 kg·hm^-2黄腐酸钾(D4.5+FA-K) 共8个处理,研究不同处理对分枝列当的防治效果和增产效果;随后采用 Biolog-ECO微平板检测法,分析菌剂施用后土壤微生物群落的生态及代谢多样性变化,明确菌剂对作物及环境的影响。结果表明,纯菌剂施用条件下,D12处理的防治效果最佳,防效为52.33%,列当寄生数量最低为493个,寄生度为1.30,番茄产量为133 455 kg·hm^-2,增产56.48%。黄腐酸钾与菌剂混合施用效果明显优异于其单独施用,防治效果提高了14%,寄生度和寄生数降低约10%,番茄产量提高14%。不同处理的微生物代谢活性表现为：D4.5+FA-K > FA-K > D12> D9,不同处理间的碳源利用率差异不明显,Shannon多样性指数差异显著,表明生防菌DNKAS可增加土壤群落丰富度,生防菌KNKAS及其与黄腐酸复配可提高防效,适用于分枝列当防治。     

Revisiting strategies for reducing the seedbank of Orobanche and Phelipanche spp.

Weedy Orobanche and Phelipanche species are important in Southern and Eastern Europe, the Middle East and North Africa, and have recently been reported in the USA, Australia and some countries in South America. Rather than being controlled, the Orobanche and Phelipanche problem is increasing, both in intensity and in acreage. Large areas of new territory are at risk of invasion, if care is not immediately taken to limit the introduction of parasitic seeds and to educate farmers and others to be alert for new infestations. There is an urgent need to re-evaluate novel integrated Orobanche and Phelipanche management programmes that will allow a better control of the parasite species and limit their distribution. The main obstacle in the long-term management of Orobanche and Phelipanche infested fields is the durable seedbank, which may remain viable for decades in the field. Large quantities of long-lived seeds give the parasite genetic adaptability to changes in host resistance and cultural practices. As long as the seedbank is not controlled, the need to control the parasite will persist whenever a susceptible host is grown in the infested field. We discuss strategies for seedbank reduction, paying particular attention to cultural practices, whereas chemical and biological control methods are covered by other reviews in this issue.     

Understanding Orobanche and Phelipanche–host plant interactions and developing resistance

Orobanche and Phelipanche spp. (broomrapes) are parasitic plants that can be responsible for devastating losses in several important crops. The development of resistant cultivars is one of the key strategies in the fight against this pest. However, the nature of resistance is complex and the basis of the interaction between the host and the parasite is still largely unknown. Despite the progress achieved during the last century through breeding programmes, sources of resistance are often scarce (e.g. the legumes). The resistance that is available is often not durable, with field resistance being overcome by new races of the parasite (e.g. sunflower). This review summarises efforts made to improve the resistance of crop hosts for broomrapes through classical breeding programmes and looks forward to the integration of new knowledge generated from molecular and morphological studies. Emphasis is given to the need for a multidisciplinary approach to achieve success, ranging from improved field phenotyping to genetic and biotechnological studies. All components are necessary to understand this particular and characteristic interaction: a plant parasitising another plant.     

Extent and pattern of genetic differentiation within and between European populations of Phelipanche ramosa revealed by amplified fragment length polymorphism analysis

The extent and pattern of genetic differentiation between Phelipanche ramosa populations colonising tobacco in different European regions were investigated by amplified fragment length polymorphism (AFLP) analysis, in order to determine levels of variation for tobacco resistance breeding and management programmes. Four different AFLP primer pairs amplified a total of 1050 clear and reproducible bands, of which 962 (91.62%) were polymorphic among the 35 individuals taken from four P. ramosa populations collected in Spain, Italy, Bulgaria and Germany. Cluster analysis based on the AFLP data categorised the plants into distinct groups, in line with their geographical origin, denoting clear genetic differentiation among the four populations. This differentiation was supported by both high bootstrap values and significant results of the analysis of molecular variance. The most divergent population was the one from Bulgaria. The majority of the genetic diversity was attributable to differences among populations (77.80%), as expected from the predominant autogamous behaviour of this species. Populations differed significantly in within-population diversity, as measured by Shannon's information index. The German population presented the lowest genetic diversity and the Italian population harboured the highest level of within-population genetic diversity. There are significant differences in genetic diversity level among the studied P. ramosa populations and clear population-specific genetic diversity structures. These need to be taken into account, together with the potential differences in parasite aggressiveness, when planning breeding and management strategies for P. ramosa control in tobacco cultivation.     

向日葵抗列当品种(系)筛选及其应用评价

为了全面评价不同向日葵品种(系)对列当的抗寄生性和其在生产中的应用价值,对‘TP3313’等50个食葵品种(系)、‘内蒙杂4号’等6个油葵品种(系)进行了田间自然寄生试验,结果表明:食葵‘TP3313’为对列当免疫的品种,且病虫害发生较轻,产量相对较高(261.11kg/667m~2),因而具有极高的推广应用价值;‘TP3314’为高抗列当品种,但是受向日葵菌核病危害较重,产量为219.64kg/667m~2;‘SH361-L’、‘SH338-M’等8个品种表现为中感,属耐列当品种(系),并且产量相对较高,在生产中具有一定的应用价值。     

新疆阿勒泰地区和内蒙古乌拉特前旗抗列当向日葵品种(系)的鉴定

向日葵列当是向日葵生产中重要的寄生性杂草。新疆阿勒泰地区和内蒙古乌拉特前旗是国内向日葵列当发生的重灾区。为筛选并为抗列当育种工作提供优质抗性材料,从根本上防治向日葵列当,利用田间自然发生向日葵列当的田块,采用随机区组设计设置小区试验;通过寄生率、寄生程度2 个指标判定对列当的抗感性。于2012 年在新疆阿勒泰对56 个向日葵品种（系）,2013—2014 年在内蒙古乌拉特前旗分别对22 个品种（系）和20 个品种（系）,进行抗列当鉴定。结果表明：在新疆22 个油葵品（系）中‘陇葵杂1 号’、‘F08-1’、‘辽丰F53’、‘赤CY101’、‘S26’、‘MGS’、‘S31’等16 个品种,34 个食葵品种（系）中‘JK106’品种,表现为免疫;在内蒙古乌拉特前旗2013—2014 年24 个油葵品种（系）中,‘赤CY102’、‘F08-1’等2 个品种表现为免疫,‘MSG’、‘新葵杂5 号’、‘赤029×115R’、‘赤128A×116R’等4个品种（系）表现为高抗,而18 个食葵品种（系）中,没有免疫品种,只有‘JK103’和‘JK106’表现为抗列当,其余16 个品种（系）均表现为感病和高度感列当。其中油葵品种‘赤CY102’在新疆和内蒙古抗列当鉴定中均表现免疫。在2 个不同地区进行向日葵品种抗列当鉴定,新疆地区表现免疫和高抗的品种较内蒙古地区多,说明内蒙古乌拉特前旗列当生理小种级别高于新疆阿勒泰地区列当生理小种。另外,油葵品种对列当的抗性较食葵高。     

烟草向日葵列当化学防治研究

选用芽前和芽后两种不同类型的除草剂,以单剂和混配形式筛选防除向日葵列当(Orobanchecumana Wallr)的有效药剂,并确定最佳浓度。结果表明,单剂效果较好的是精喹禾灵,其次是烯禾啶;在药剂较高浓度混配时从中筛选出效果好的有以下组合:草甘膦异丙胺盐+7种除草剂(2.4-D丁酯、精-异丙甲草胺、氧氟.乙草胺、丁.异.莠去津、乙草胺、乙氧氟草醚、氟乐灵)的任一种,防治效果均超过98%;进一步试验结果表明,防治效果好且又经济的混配药剂为41%草甘膦异丙胺盐水剂12 L/hm2+57%2.4-D丁酯乳油1.2 L/hm2、41%草甘膦异丙胺盐水剂12 L/hm2+96%精-异丙甲草胺乳油1.2 L/hm2。