ICARDA Conference Papers and Proceedings

Permanent URI for this collectionhttps://hdl.handle.net/10568/51689

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Harnessing Chat GPT (generative pretrained transformer) to engage youth and women in climate-smart and sustainable livestock farming
(Conference Paper, 2023-09-26) Ekule, Muluken; Rudiger, Udo
This literature review on harnessing Chat GPT focusses on how Chat GPT guides youth and women on feed production. least cost formulation, forecasting feed balance. It highlights advances, gaps and opportunities in literature.
Bacterial leaf blight disease of wheat (Pseudomonas syringae pv. syringae) in Syria: importance, characterization, and spread
(Conference Paper, 2023-05-15) Abo Bakr, Abdo; Kassem, Mohammad; Kumari, Safaa; Khatib, Fateh; Husien, Naiem; Nader, Asaad; Moukahel, Abdulrahman
The quantity and quality of wheat production are affected by a number of biotic and abiotic stresses, including bacterial wheat leaf blight disease caused by Pseudomonas syringae pv. syringae (Pss). Pss is considered one of the most important seed-borne diseases, as it can play an important role in the spread of the disease by seed and agricultural trade. The seriousness of Pss is that there are no specialized bacterial disinfectants, so it is very important to use rapid and accurate methods to detect Pss in order to limit its transmission through infected seeds to healthy fields. Therefore, the aim of the study was to investigate the spread of bacterial wheat leaf blight diseases in wheat-growing areas in Syria and to produce specific antibodies for Pss detection. In 2022, approximately 500 wheat leaf samples showing symptoms suggestive of bacterial infection were collected from 107 fields in the northern, central and coastal areas of Syria. A total of 56 bacterial isolates were selected using a semi-selective medium, and were characterized further using morphological, biochemical (LOPAT), and pathogenicity tests to identify the isolate’s virulence. Results showed that the bacterial wheat leaf blight disease was observed and recorded in 71.2% of the surveyed fields, and 85.7% of the isolates were found to belong to the genus Pseudomonas. A representative Pseudomonas isolates were further tested by polymerase chain reaction (PCR) using specific primers for the syringomycin production gene. Molecular analyses revealed that 12 isolates belong to Pseudomonas syringae pv. syringae (Pss). The bacterial suspension of one Pss isolate (H6), collected from a wheat field in central Syria, was inactivated by formaldehyde treatment and injected into a rabbit. The quality of produced antiserum was evaluated by Dot-blot Immunoassay using homologous and heterologous antigens, and the results obtained revealed that the produced antiserum was able to detect Pss with no cross-reactivity with other bacterial genera (e.g. Xanthomonas).
Detection and Characterization of Seed-Borne Bacterial Leaf Blight in Wheat
(Conference Paper, 2023-08-21) Kumari, Safaa; Moukahel, Abdulrahman; Abo Bakr, Abdo; Kassem, Mohammad
Wheat is one of the most important crops which contributes toward global food security and represents a main source of food and income for millions of smallholder farmers worldwide. Pseudomonas syringae pv. syringae (Pss) is the causal agent of bacterial leaf blight wheat disease which can cause up to 50% yield loss or more depending on the time of infection and region. In addition, Pss is transmitted by wheat seeds, which can play a role in longdistance spread. Therefore, developing and implementing effective management strategies for bacterial diseases is very important to reduce yield and quality loss. However, rapid and accurate detection of diseases is the first essential step for effective management strategies for control of this disease. Even though molecular tools for Pss precise detection and characterization has been developed, the most practical approach for rapid diagnosis is the use of serological assays using specific antibodies. A polyclonal antiserum against a Syrian isolate of Pss was produced and its quality was evaluated by Dot-blot Immunoassay using homologous and heterologous antigens. Results revealed that the produced antiserum was able to detect Pss up to 1×103 CFU/ml dilution using raw antiserum at a dilution of 1/160 with no cross reactivity with other bacterial species (e.g. Xanthomonas).
The Role of ICARDA’s Germplasm Health Unit (GHU) in Improving Plant Health and Safeguarding the Biodiversity of Legume and Cereal Crops
(Conference Paper, 2023-06-01) Kumari, Safaa; Moukahel, Abdulrahman; El Miziani, Inaam; Darwish, Iman
In order to safeguard countries from quarantine risks (insect pests, pathogens, nematodes, parasitic weeds) associated with the movement of legume (faba bean, lentil, chickpea, grasspea) and cereal (wheat and barley) germplasm, ICARDA’s Germplasm Health Unit (GHU) follows a regulatory and quarantine program implemented in close collaboration with competent institutions where ICARDA has platforms for crop breeding, germplasm multiplication and evaluation and genetic resources exchange. GHU serves as ICARDA’s gateway for legume and cereal germplasms exchange by ensuring compliance with the FAO International Plant Protection Convention (IPPC) procedures and the International Standards for Phytosanitary Measures (ISPMs) applied by National Plant Protection Organizations (NPPOs) to prevent the introduction and control the spread of pests along with plants or plant products. ICARDA’s GHU is involved in the following responsibilities: (1) Develop and validate diagnostic tools and procedures for germplasm health testing and share the updated technology with the NPPOs; (2) Create and adopt phytosanitary procedures to generate pest-free germplasm and avert the spread of quarantine pests in legume and cereal germplasm transfers; (3) Ensure that all movement of legume and cereal germplasms comply with guidelines of importing and exporting countries to avoid any breaches of the host and receiving countries’ quarantine protocols; (4) Conduct pest risk assessment of germplasm activities, including conservation, seed increase and transfers; (5) Organize GHU community of practice to form a network of centers for transboundary pest prevention; (6) Contribute to the phytosanitary capacity development.
Technical assistance to strengthen national agricultural research organizations’ capacity to use digital sequence information. A submission from CGIAR
(Conference Paper, 2023-07) López Noriega, Isabel; Rouard, Mathieu; Halewood, Michael; Sackville-Hamilton, N. Ruaraidh; Bhattacharjee, Ranjana; Carvajal Yepes, Monica; Domelevo Entfellner, Jean-Baka; Hearne, Sarah Jane; Hendre, Prasad; Kehel, Zakaria; Kreuze, Jan F.; Kuldeep, Singh; Manish, Pandey; Muchugi, Alice; Ndjiondjop, Marie-Noelle; Ng, Eng Hwa; Odeny, Damaris Achieng; Sansaloni, Carolina Paola; Mayes, Sean; Wricha, Tyag; Ziyomo, Cathrine
CGIAR submitted this report in response to an open request from the Plant Treaty Secretary, for submissions regarding, a) contracting parties’ and stakeholders’ capacity building needs for accessing and using digital sequence information (DSI)/genomic sequence data (GSD) and b) ‘technical assistance’ and ‘actions taken’ by stakeholders (including CGIAR) ‘to reduce the existing gap on capacity regarding DSI/GSD’. The primary objective of this paper is to respond to the second part of the request by sharing information about how CGIAR Centers and Initiatives have been assisting organizations outside CGIAR to access, generate, share, analyse, and use DSI for the conservation of plant genetic resources for food and agriculture (PRGFA) and for the use of PGRFA in pre-breeding and breeding. This paper does not provide an exhaustive account of all of the Centers’ relevant activities, but it does provide a general overview of the kinds of activities in which the Centers have been engaged. CGIAR very much appreciates the Governing Body’s initiative, as expressed in Resolution 16/2022, to ask the Plant Treaty Secretariat to gather and synthesize information about both demand for, and supply of, capacity strengthening related to DSI linked to plant genetic resources for food and agriculture, with the overall objective of working to close the capacity gap between developed and developing countries. It is our hope that, based on the outcomes of this exercise, CGIAR will be able to further adapt and improve its own approach to capacity sharing in response to needs prioritized by the Governing Body.
Epidemiology and management of legume and cereal viruses in Arab and Mediterranean regions
(Conference Paper, 2022-05-01) Kumari, Safaa; Najar, Asma; Nader, Asaad; Moukahel, Abdulrahman
In the Arab and Mediterranean regions, cool-season food legumes (chickpea, faba bean, lentil and pea) are infected naturally by many viruses, and the number of viruses involved continues to increase. However, at any specific location only a few of these pathogens are of economic concern. Yield losses resulting from virus attack vary widely, from little, as in the case of Broad bean mottle virus in Tunisia and Morocco, to complete crop failure when conditions permit widespread virus infection at the vulnerable early plant growth stage, as with Faba bean necrotic yellows virus in Egypt and Syria. Cereal crops (wheat, barley and oat) in Arab and Mediterranean regions are also affected by viruses, mainly Barley yellow dwarf virus-PAV, and this virus is reported to occur at epidemic levels in only Algeria, Morocco and Tunisia. Epidemic spread of most viral diseases was always associated with high vector populations and activity. Although virus disease management can be achieved through the combined effects of several approaches, development of resistant genotypes is one of the most promising control components. Experience over the last few decades has clearly showed that no single method of virus disease control reduces yield losses in legume crops. Some progress was made on the disease management of some legume and cereal viruses using combinations of healthy seed, host resistance, cultural practices (such as adjustments of planting date and plant density, and roguing of infected plants early in the season) and chemical control virus vectors.
Characterization and distribution of Pseudomonas syringae pv. syrinae on wheat in Syria
(Conference Paper, 2022-05-01) Kassem, Mohammad; Nader, Asaad; Kumari, Safaa; Moukahel, Abdulrahman
Bacterial leaf blight, caused by Pseudomonas syringae, threaten wheat production in many regions. Approximately 500 wheat leaf samples showing symptoms suggestive of bacterial infections were collected from 107 fields in north, central and coastal areas of Syria during the 2021 growing season. Disease symptoms consisted of water soaked dark green to brown lesions on expanding leaves which became necrotic and turned from grey-green to tanwhite. A total of 56 isolates were selected using a semis elective medium, and were characterized further using morphological, biochemical (LOPAT), and pathogenicity tests to identify the virulent properties of isolates, and molecular characterization with PCR using specific primers for the syringomycin production gene. Field observations showed that leaf blight severity was approx. 54%, whereas the coastal area isolates gave high disease severity (61.5%), followed by the central area isolates (56%). The pathogenicity tests showed that all the isolates were pathogenic to wheat under greenhouse conditions, with 63% of ranked as highly virulent. The PCR results confirmed that the isolates were P. syringae pv. syringae. This study increased understanding of the ecology, distribution and severity of the microbial wheat communities in Syria.
Multi-location testing of a global collection of elite chickpea genotypes to identify stable sources of resistance to Ascochyta blight
(Conference Paper, 2022-10-14) Istanbuli, Tawffiq; Can, Canan; Talapov, T.; Kharrat, Mohamed; Bouhadida, Mariem; Omri, Noura; Fikre, A.; Zewdie, Asrat; Singh, Sarvjeet; Rani, Upasana; Tawkaz, Sawsan; Kemal, Seid Ahmed; Hamwieh, Aladdin
Ascochyta blight (AB) of chickpea (Cicer arietinum L.) caused by Ascochyta rabiei (Pass.) Lab. is the most devastating disease that limits the productivity and production of chickpea in the world. The lack of high levels of stable sources of resistance makes chickpea production a risky business. The search for durable resistance genotypes and differentials to monitor shifts in pathogen populations are becoming a pressing research agenda. There is a need to understand the evolution of pathogen virulence and the number of resistant genes available in chickpea germplasm. Therefore, this research aimed to evaluate the global Ascochyta blight reference set in chickpea (GABRSC), which is expected to carry some of the resistant genes to AB has been identified in many countries. The GABRSC set (200 diverse genotypes) was evaluated in six geographic locations where AB is a major disease. The testing sites were Kafarshakhna (Lebanon), Merchouch (Morocco), Alem Tena (Ethiopia), Punjab University (India), Beja (Tunisia), and Gaziantep University (Turkey). The genotypes were planted following Alpha Lattice design in two replications in the 2021–22 cropping season. Disease severity was rated using a 1–9 rating scale. The REML analysis showed significant differences among genotypes (G), environments (E), and G x E interactions showing the possibility of different pathogen populations in different locations. The GGE biplot analyses showed that all environments were positively related. A total of 11 genotypes (S160454, SE26IN, S0110227, M 2635, S0110075, S160353, S0110028, 0110088, S0110195, S0110211, and S160483) were consistent in their resistance across sites with an average rating of ≤ 4. On the other hand, genotypes showed crossover interactions across locations. For example, PBA HatTrick was resistant in Ethiopia (but susceptible in Lebanon and FLIP84-48C was resistant in India but susceptible in Lebanon. This study will help us to understand the relationship between the host and pathogen and to design new AB differential sets. However, the resistant genotypes across locations identified in the present study would be useful in breeding programs.
Assessment of Pathogenicity Assay of Ascochyta rabiei Isolates Using Chickpea Differential Genotypes
(Conference Paper, 2022-10-12) Istanbuli, Tawffiq; Tawkaz, Sawsan; Moukahel, Abdulrahman; Kemal, Seid Ahmed; Hamwieh, Aladdin
Ascochyta blight caused by Ascochyta rabiei, is the most destructive disease in many chickpea growing countries. Many chickpea varieties were out of production due to increased virulence/aggressiveness of the pathogen in some countries. The aim of this study was to assess variation in pathogenicity of 25 A. rabiei collected in different years from Syria, Lebanon, Uzbekistan, and France. The pathogen phenotyping was done using five genotypes (ILC3279, ILC482, ICC3396, ICC12004, and Genesis090) under controlled conditions (humidity >85, temperature 18-20 °C, light/dark 18:6 h) at the International Center of Agricultural Research in the Dry Area (ICARDA), Terbol station, Lebanon. Five genotypes carrying different resistant genes have been used in this study, and a highly susceptible genotype (ILC263). was used as a control. A total of 25 sets of these genotypes, each genotype has two replications that have been planted and inoculated with the 25 A. rabiei isolates. The symptoms were measured two times using a 1–9 disease symptoms rating scale (RS) when the susceptible control was RS >6. The result showed high significant differences between genotypes (G) (P<0.001), and isolations (P<0.001). The average of resistance for the five genotypes was 3.5 compared to the susceptible check which scored ≥6. The results indicated 5 isolates were highly aggressive isolates Pathotype 4 & race 4 from Syria, Uz3-2 from Uzbekistan, and FR-2926 & FR-3248 from France). Further large-scale evaluation of these isolates on the AB differential set may help to identify a better understanding of the resistant genes available in chickpeas.
Viruses causing yellowing and stunting symptoms in chickpea and applying integrated eco-friendly approaches for its effective control in Syria
(Conference Paper, 2022-10-16) Nader, Asaad; Kumari, Safaa; Kasem, Amin; Moukahel, Abdulrahman; Essa, Ertyad
Chickpea (Cicer arietinum L.) ranks third among the pulse crops that attribute to global food security. Viruses that cause yellowing and stunting symptoms are considered a main threat to chickpea production worldwide. Currently, there is a great interest in applying eco-friendly smart technologies to achieve best control results. Results of serological [Tissue blot immunoassay (TBIA)] and molecular assays [Reverse transcription-polymerase chain reaction (RT-PCR)] used in field surveys carried out during four growing seasons (2006, 2007, 2017 and 2018) in chickpea fields, revealed that the polerovirus Chickpea chlorotic stunt virus (CpCSV) was dominant in all seasons. Thus, the objective of this study was to identify practices to reduce the effect of viruses causing yellowing and stunting of chickpea under Syrian ecology. This approach included screening 80 chickpea genotypes for virus resistance (obtained from ICARDA Gene Bank under open filed conditions. To reduce virus incidence in the field several practices such as planting date, plant density, locations, cultivars (Ghab-3, Ghab-4, Ghab-5, promising variety FLIP95-65C and susceptible variety JG62), as well as intercropping between chickpea and other crops like flax (Linum usitatissimum), black cumin (Nigella sativa) and coriander (Coriandrum sativum) were evaluated. Results revealed that few chickpea genotypes (such as IG9000, IG69434, IG69656, IG69693, IG71832 and IG128651) were found resistant/tolerant for CpCSV and it could be used as a resistance source in chickpea breeding programs. Virus infection was decreased around 50-80% and crop yield was increased by 5-35% with high significant differences when chickpea was planted during the first half of December with plant density of 20-30 plants/m2. In addition, yield was improved with low virus infection when chickpea was intercropped with flax in alternate lines or with coriander (1 line of coriander each 5-6 chickpea lines). Generally, the results confirmed the importance of the interaction between a number of practices which together formed an integrated system that influenced virus spread and can be considered a potential approach for sustainable virus diseases management.
Safe movement of food and forage crops germplasm: ICARDA’s experience in the Arab region
(Conference Paper, 2022-10-16) Kumari, Safaa; Moukahel, Abdulrahman; El Miziani, Inaam
Germplasm exchange for research and breeding purposes is essential for crop improvement in the face of climate change and population growth. To contribute towards achieving sustainable development goals, the germplasm exchange need to accelerated to keep up with a world-changing food demand at an ever-increasing pace. However, the movement of living materials is not without the risk of inadvertent movement of associated organisms, including pests. Therefore, extreme care is required to ensure that exchanged germplasm is pest-free. The Consortium of International Agricultural Research Centers (CGIAR) is a global partnership that unites international organizations engaged in research about food security. CGIAR centers have established Germplasm health units (GHUs) to ensure the safety of exchanged plant materials, and compliance with the FAO International Plant Protection Convention (IPPC) procedures and the International Standards for Phytosanitary Measures (ISPMs) used by National Plant Protection Organizations (NPPOs) to prevent the introduction and control the spread of pests along with plants or plant products. Within the framework of the CGIAR, ICARDA has the world mandate for the improvement of barley, lentil and faba bean. It also has a regional mandate for the improvement of wheat (bread and durum), Kabuli chickpea and pasture and forage crops in the dry areas, including the Arab region. The development of improved germplasm and elite genotypes for use by national, regional and international breeding programs is the major objective of the ICARDA crop improvement program. In order to safeguard countries from quarantine risks (insect pests, pathogens and weeds) associated with the movement of germplasm, ICARDA follows a regulatory and quarantine program working in close collaboration with competent institutions where ICARDA has platforms for crop breeding, germplasm multiplication and evaluation and genetic resources exchange in Lebanon and Morocco. ICARDA’s GHU is responsible for the monitoring, clearance and documentation of safe germplasm movement at the center, to do so, all incoming and outgoing genetic resources and breeding germplasm must go through a strict quarantine monitoring system (seed health testing, quarantine clearance based on national and international procedures and rules). Annually, ICARDA’s GHU tests more than 100,000 exchanged seed samples from ICARDA mandate crops to be distrusted for more than 70 countries, including Arab region. The center is fully equipped with a seed science and technology and data management staff, in addition to the necessary crop management and post-harvest seed operation facilities. The seed production process is monitored by an independent GHU in coordination with the quarantine systems of the host countries in which ICARDA operates. The role of ICARDA’s GHU in the safe exchange of germplasm in the Arab region will be presented.
Characterization of faba bean and chickpea viruses causing yellowing and stunting symptoms in Tunisia
(Conference Paper, 2022-10-16) Mghandef, Samia; Kumari, Safaa; Najar, Asma
In Tunisia, faba bean (Vicia faba) and chickpea (Cicer arietinum) are considered as strategic crops because of their economic and social relevance and significant direct contribution towards the national food balance. However, production levels of these crops remain quite low which is often attributed to abiotic and biotic stresses that are prevailing in the major growing areas. Viruses causing yellowing and stunting symptoms represent one of the major constraints that reduce the genetic potential of most cultivated species and varieties. To characterize these viruses in Tunisia, field surveys were conducted in five main regions (Béja, Bizerte, Cap-Bon, Jendouba and Kef) during 2018 and 2019 growing seasons. A total of 389 faba bean and 182 chickpea samples with yellowing and stunting symptoms were collected and tested by tissue blot immunoassay (TBIA) using specific monoclonal antibodies (MAbs). Laboratory results showed that Chickpea chlorotic stunt virus (CpCSV) was the most common virus detected in 47.6% of faba bean and 18.7% of chickpea tested samples, followed by Beet western yellows virus (BWYV) (28% in faba bean and 4.4% in chickpea). Whereas, only 8.8% of faba bean samples were infected with Faba bean necrotic yellows virus (FBNYV), and Bean leafroll virus (BLRV) in faba bean (6.7%) and chickpea (9%) samples. To confirm the presence of yellowing viruses in Tunisia, total RNA was extracted from 5 faba bean and 27 chickpea samples that showed positive reaction to BLRV MAb (8 samples: 2 faba bean, 6 chickpea), BWYV MAb (7 samples: 2 faba bean, 5 chickpea) and CpCSV MAb (17 samples: 1 faba bean, 16 chickpea). Reverse transcription-polymerase chain reaction (RT-PCR) was performed using specific luteovirus primer pairs. RT-PCR amplicons of the expected size of each primer were obtained from 32 samples and were sequenced in both directions. Molecular results showed that BWYV and CpCSV (both belong to genus Polerovirus, family Solemoviridae) and BLRV (belong to genus Luteovirus, family Tombusviridae) were identified in Tunisia, and the coat protein nucleotide sequence analysis of the Tunisian isolates showed 99% homology to Moroccan isolate (CpCSV), 97% homology to the French isolate (BWYV), and 98% homology to Argentina isolate (BLRV).
Morphological characterization and pathogenicity of nine Fusarium spp. isolates collected from barley seeds (Hordeum vulgare L.) in Morocco
(Conference Paper, 2022-10-16) El Miziani, Inaam; Boukhou, Yassine; Udupa, Sripada M.; Ibijbijen, Jamal; Elbouazaoui, Amine; Kumari, Safaa
Barley (Hordeum vulgare L.) is the most produced and consumed grain in the world, and is an important source of food, forage and livestock feed in many developing countries including Morocco. Fusarium head blight (FHB) is one of the main fungal diseases of grain crops such as wheat, barley and maize caused by different species of the genus Fusarium. The FHB species complex produces mycotoxins that affect livestock feed, the baking, milling quality of wheat, the malting and brewing qualities of malt barley. Nine isolates of Fusarium spp. causing necrosis with typical FHB symptoms were isolated from infected barley genotypes planted at ICARDA’s Merchouch station, Rabat, Morocco. After seeds harvesting, all nine FHB isolates were purified and morphologically identified by characterizing their culture appearance (colony color, texture, form, and margin), shape and size of the macroconidia, and presence or absence of microconidia. Pathogenicity of these isolates was studied under controlled conditions using two inoculation methods (soil inoculation and hydroponic culture) on 12 barley varieties (Flinders, Litmus, Oxford, Commander, Latrobe, Vlaming, Fleet, Granger, Rosalind, Buloke, Keel and Campus). Morphological characterization using the Leslie and Summerell key, implied 5 different macroscopic and microscopic morphologies very similar to: Fusarium acuminatum (two isolates), F. crookwellense (two isolates), F. avenaceum (two isolates), F. sambucinum (one isolate) and Fusarium culmorum (two isolates). All 9 isolates caused FHB symptoms on all 12 barley varieties tested in both inoculation methods and the number of infected spikelets was assessed. Four barley varieties (Keel, Buloke, Latrobe and Commander) showed a heavy fungal infection (infected spikelet over 65%) and were considered susceptible to infection with the disease. Whereas, four barley varieties (Campus, Oxford, Vlaming and Granger) were resistant to the nine isolates compared to the other barley varieties (infected spikelet less than 35%). In addition, a significant difference (P < 0.05) was observed between Fusarium species.
Coping Strategies and Perceived Effects in Response to Climate Shock Exposure: Household resiliency toward food insecurity related to drought in central Tunisian rural communities
(Conference Paper, 2022-11-25) Zaidi, Samar; Abdeladhim, Mohamed Arbi; Dhehibi, Boubaker; Dhraief, Mohamed Zied; Rudiger, Udo; Frija, Aymen; Rekik, Mourad
Climate change exacerbated droughts by making them more frequent that increased risks of food insecurity faced by rural families in arid areas. Adopting coping mechanisms are necessary to reduce the vulnerability of rural agricultural communities and enhance their resilience to climate change. The main objectives of this paper are i) to assess effectiveness of the adopted coping strategies in rural areas by measuring resilience properties of household livelihoods and ii) to identify their key drivers. we will measure. A cross-sectional survey among 671 sample households was conducted in Kairouan and Zaghouan. To understand the key drivers of each livelihood coping strategy and compare different livelihood strategies we used an updated version of we used and updated the resilience analysis framework. A special attention was given understand how household-level characteristics correspond to household coping strategies towards an identification and assessment of the coping mechanisms adopted by farmers to mitigate the impact of drought on their livelihood and food security. Results showed income and food access, assets possession, access to basic services, adaptive capacity, and social safety nets have positive and significant effect on farm households’ resilience to food insecurity. Climate change and stability have a negative and significant effects. This could be due to the negative effect of the climate change especially drought on the household resilience.
Comparison of serological and molecular methods for diagnosis of viruses causing yellowing and stunting symptoms for the pulse crops
(Conference Paper, 2022-10-16) Moukahel, Abdulrahman; Kumari, Safaa; Hamed, Abdelmagid Adlan; Sharman, Murray
The diagnosis of plant viruses that belong to the families Solemoviridae and Tombusviridae, which cause yellowing and stunting symptoms, is very complicated due to the serological cross-reactivity among these viruses. The main objective of this research was to study the efficiency of serological assays (tissue-blot immunoassay-TBIA) using specific monoclonal antibodies (MAbs) versus molecular assays (RT-PCR and sequencing) using generic and specific primer pairs. Legume samples (faba bean, chickpea and lentil) were collected from five different geographic regions: Ethiopia (11 samples), Lebanon (8 samples), Morocco (5 samples), Sudan (33 samples) and Uzbekistan (34 samples). All these samples reacted positively by TBIA with one or more MAbs and amplified by one or more primer pairs by RT-PCR. The comparison of serological with molecular results revealed the similarity between detection methods for both Bean leafroll virus (BLRV) and Soybean dwarf virus (SbDV) (both belong to genus Luteovirus, family Tombusviridae), as BLRV was detected in samples from Uzbekistan, and SbDV was detected in samples from Ethiopia and Uzbekistan only. On the other hand, the results of the serological and molecular methods for the virus species that belong to the genus Polerovirus (family Solemoviridae) were not comparable, especially in the samples collected from Sudan and Uzbekistan, as a number of samples collected from the five countries reacted positively with specific MAbs of Beet western yellows virus (BWYV) and Chickpea chlorotic stunt virus (CpCSV), but CpCSV and BWYV were identified only molecularly in the samples collected from Ethiopia, Lebanon and Morocco. Based on the nucleotide sequences obtained, new virus species that belong to the genus Polerovirus was identified in the samples collected from Sudan and Uzbekistan [e.g. Cucurbit aphid-borne yellows virus (CABYV) and Cotton leafroll dwarf virus (CLRDV)], and CpCSV was not identified molecularly in the samples from Uzbekistan or Sudan, in spite of the fact that a number of samples did react serologically with CpCSV MAb. The results obtained clearly showed that molecular assays are essential along with serological assays for more accurate and specific identification of Solemoviridae members, which is highly needed for the development of management strategies based on virus vector control and breeding for virus diseases resistance.
Efficiency of Crop–Livestock Production Systems Under Conservation Agriculture: Scope for sustainable system transformation to Achieving Food Security in Rain-Fed Drylands of Tunisia
(Conference Paper) Dhehibi, Boubaker; Souissi, Asma; Fouzai, Ayoub; Frija, Aymen; Abdeladhim, Mohamed Arbi; Rekik, Mourad
The objective of this study is to evaluate the technical efficiency of farmers engaged in mixed crop–livestock systems under conservation agriculture (CLCA) in Tunisian rainfed areas who are using Resource-Conserving Technologies (RCTs) such as forage mixture, minimum and zero tillage, and small machinery.
What forage tree-shrub species are recommended in alley cropping systems under west Asia conditions?
(Conference Paper) Louhaichi, Mounir; Hassan, Sawsan
Alley cropping is an agroforestry practice of planting arable crops between trees or shrubs. The integration of forage treeshrub species in an alley-cropping system was examined as an approach to mitigate the effects of climate-induced drought, to improve soil quality and to secure better livelihoods for smallholder famers in West Asia. Forage tree-shrub performance was evaluated in an alley-cropped system using seven leguminous forage species (Medicago arborea, Colutea istria and Coronilla glauca), three Atriplex species (A. canescens, A. nummularia, A. undulata) and spineless cactus pear (Opuntia ficus indica) intercropped between annual crops of wheat, vetch and barley at the Mushaqqar Research Station in Jordan. Growth characteristics were measured by monitoring tree-shrub stem diameter, stomatal conductance, plant height and estimating tree-shrub biomass production. The suitability index was based on growth characteristics for each tree-shrub. Results showed that the Atriplex species showed a higher suitability index compared to leguminous shrubs and cactus pear. Among the Atriplex species, Atriplex canescens recorded the highest plant height, stem diameter and estimated biomass production across all three field crops. Leguminous species recorded low biomass productivity at the beginning of summer but with a low suitability index. Despite their vital role in soil nutrient improvement, there were found to be unreliable in providing supplement forage for livestock. The cactus pear recorded a low suitability index and is not recommended. When implementing alley cropping systems, a balance should be considered between high forage biomass shrub species accessible to livestock after harvesting crops and shrubs that enhance soil nutrient status for improving field crop growing conditions.
A Scalable and Participatory Sustainable Rangeland Management toolkit with a holistic and multidisciplinary approach to rehabilitate degraded rangelands
(Conference Paper) Louhaichi, Mounir; Gamoun, Mouldi; Hassan, Sawsan
Rangelands contribute significantly toward improving livelihoods, offering food security, trade, and tourism for pastoral communities. Numerous challenges include poor government policies, loss of indigenous knowledge, and top-down approaches toward sustainable rangeland rehabilitation that often fail to consider local development adoption and sustainability. In such situations, effective management is needed for sustainable rangeland ecosystem goods and services in a context characterized by rainfall unreliability, poor soil nutrient status, and high uncontrolled grazing. This paper presents a new comprehensive toolkit for identifying and combining suitable and site-specific interventions aimed at reversing the trend of degraded arid rangelands. This toolbox is founded on science-based evidence and experienced practitioners. For severely degraded arid rangelands, the preference of applying an isolated technology may be insufficient to halt degradation. Through targeting a landscape scale that uses an integrated and multidisciplinary approach, this promising tool/approach aims to address the biophysical and socioeconomic linkages and trade-offs existing between the different land uses. The approach highlights the important role of rangeland governance. It also underscores the need to base decision-making on both indigenous knowledge and modern science, in order to empower communities to make good choices based on the best information available.
Effect of high-intensity, short-duration grazing on species density and botanical composition of arid rangelands
(Conference Paper) Louhaichi, Mounir; Gamoun, Mouldi; Gouhis, Fethi; Belfekih, Ezzeddine; Abdelkader, Mohamed
Rangelands are the mainstay of pastoral and agropastoral livelihoods worldwide. They have provided forage for livestock and wildlife for centuries, but steady degradation of rangelands is causing increasing concern. Many rangeland managers believe exclusion of livestock grazing for extended periods would allow degraded rangelands to recover. The purpose of this current ongoing research is to evaluate the effect of high-intensity short-duration grazing on plant density, species richness and botanical composition on arid rangelands during favorable years. The site, which is protected for two years in southern Tunisia and covers an area of 6 ha, was grazed by a flock of about 150 heads of sheep for one week. The grazing took place towards the end of the spring season just after seed dispersal. The measurements were taken before and after grazing using the quadrats method. Preliminary findings revealed no significant difference in plant density, richness, and botanical composition of perennial species. On the contrary, the annual species decreased. In conclusion, short-duration grazing systems do not affect perennial plants that permit greater forage selectivity. As temperatures start rising in late spring, livestock is forced to select annual plants due to their higher palatability and higher water content without damaging perennial plants. In addition, grazing removes oxidized plant material from perennial species that would otherwise remain on top of the plants, prevent photosynthesis, and cause the plant’s death after several years.
Rangelands and pastoralism of the Middle-East and North Africa, from reality to dream
(Conference Paper) Naghizadeh, Nadia; Badripour, Hossein; Louhaichi, Mounir; Gamoun, Mouldi; Niamir-Fuller, Maryam
The Middle East and North Africa (MENA) is a vast area covering 20 countries from western Asia to North Africa, with nearly 9,000,000 Km2 and 303 million hectares of total rangelands. Rangelands play an essential role in supporting people’s livelihoods and food security. Mobile pastoralism is the most viable and resilient form of production and land use in the fragile drylands of MENA. However, the region’s governments have considered nomadic pastoralism backwards mainly because it was challenging to deliver mobile services. They designed various policies that were not in harmony with pastoralists’ customary rules and norms and severely weakened their mutual aid associations and governance systems for natural resources management. Nowadays, pastoralists’ rangelands and customary territories are shrinking, fragmenting, and degrading due to various reasons, but mainly the expansion of agricultural or industrial needs. Based on pastoralists and rangelands’ socio-ecological values, the world needs to apply the evidence-based experiences and Indigenous knowledge of pastoralists in preventing rangeland degradation. It is urgent to start a new paradigm shift for an inclusive interaction, establishing pro-poor livestock policies. These policies would address the barriers and bottlenecks faced by pastoral and agro-pastoral communities and secure land tenure at community and landscape levels through multi-stakeholder dialogue, including during the International Year of Rangelands and Pastoralists (IYRP). It is time to call for respect of customary governance systems of pastoralists, recognition of their territories as Indigenous and Community Conserved Areas (ICCA3s—territories of life) under various and norms in the region like Qoroq, Hima, Agdal, and any other form of local conservation to prevent fragmentation of pastoralists territories and rangelands degradation leading to desertification.

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