Nepal Agriculture Research Council, Nepal
Dipendra Pokharel, Thakur Prasad Tiwari, Mahesh Gathala, Hari Krishna Shrestha
Conservation agricultural practices have been found to be climate and labor smart, and sustainable, agricultural production technologies. The decline in productivity, increase in the cost of cultivation, labor intensive practice affected the cereal based farming system in Nepal particularly at the Indo-Gangetic plains. SRFSI has been working in response to concerns about the sustainability of the cereal based farming system at Sunsari and Dhanusha district of Nepal. This study was conducted to assess the adoption and scaling up of conservation agriculture in addition to input usage, production, net profit, B:C ratio, labour use, etc. of CA practice in Sunsari district, eastern Indo-Gangetic plains of Nepal. The study employed structured questionnaires survey and key informant survey as the main data collection tools. Project reports were taken as secondary data. The primary data related for the semi-annual report and annual report of the SRFSI project were collected jointly by the DADO, Sunsari and RARST, Tarahara. Study revealed that farmers had several tangible advantages and getting higher productivity through these practices. This study assessed the potential of CA based practices in Rice-Wheat and Rice-Maize farming system to improve the yields, net profit for sustainability of the cereal based farming system.
Department of Plant Molecular Biology, University of Delhi South Campus
The flag leaf and spike are the prime organs in wheat (Triticum aestivum L.) which contribute majorly for spike photosynthesis and eventually aid in grain filling. In this study we have tried to elucidate the effect of abiotic stress on the grain filling and spike photosynthesis. In order to unravel the role of flag leaf, awn, and spike in wheat grain filling and spike photosynthesis, 1000-kernel weight were calculated after removing flag leaves, awns, and by shading the spike in four wheat genotypes (PBW343, C306, K7903, HD2329) for two seasons (2014-2015, 2015-2016). A significant decrease in the grain filling was observed for all the genotypes. These results indicate the role of these organs in spike photosynthesis. The role of the awn tissue was investigated in PBW343 for its role in spike photosynthesis during heat stress. Deep transcriptome sequencing of the awn tissue (PBW343) was performed and it revealed 147573 unigenes. Out of these, 394 genes were differentially expressed genes (DEGs). These DEGs constitutes 201 upregulated and 193 downregulated genes. Genes involved in photosynthesis (Ribulose bisphosphate carboxylase/oxygenase activase B, NADH dehydrogenase, Fe-S protein2), membrane integrity (ATP-dependent zinc metalloprotease FTSH6), and ion channel transporters (two-pore potassium channel3) were prominently expressed. Gene Ontology (GO) enrichment analysis represents PSII associated light-harvesting complex II catabolism, chloroplast organization, photosynthesis light harvesting in photosystemI, ethylene biosynthesis, regulation of oxidoreductase activity, stomatal closure, chlorophyll biosynthesis categories, which are highly overrepresented under heat stress conditions. Therefore, utilizing the awn transcriptome information, Rubisco activase (RCA) gene was chosen for overexpression studies in wheat and rice with the aim to enhance the photosynthetic efficiency of the spike tissue leading to higher grain filling.
Abd El Badia
Wheat Disease Research Department
Mohamed Abdalla, Sobhy Negm, Adel Hagras
This work was carried out to study the response of five bread and two durum wheat cultivars to stem rust and its effect on grain yield under field conditions at Sids and Beni Sweif stations during the three growing seasons 2011/2012, 2012/2013 and 2013/2014. The loss in grain yield and kernel weight of the different wheat genotypes was variable according to the varietal response. Grain yield and kernel weight of the protected plots (protected by the effective fungicide Sumi-eight 5EC(CE)-1-(2,4-dichlorophenyl)1-4,4-dimethyl1-2-(1,2,4-triazol-y1)Pent -1-en -3-0L) at the rate of 70cm /200litter water per Fadden ) of all wheat genotypes were higher than the infected ones. Significant differences were found between infected and protected wheat genotypes.. Disease severity was recorded weekly to estimate area under disease progress curve (AUDPC). The AUDPC ranged from 85.33 to 405.00 (Sids 1 and Sohag 3) during 2011/2012, from 181.66 to 805.00 (Shandwel 1 and Sohag 3) during 2012/2013, and from 142.33 to 585.00 (Shandwel 1 and Sohag 3) during 2013/2014. Losses in kernel weight ranged from 3.39% to 31.03% (Sids 1 and Misr 1) during 2011/2012, from 9.79% to 44.18% (Sids 1 and Sohag 3) during 2012/2013,and from 5.67% to 26.86% (Sids 1 and Sohag 3) during 2013/2014. Yield losses ranged from 5.70% to 37.52% (Shandwel 1 and Misr 1) during 2011/2012, from 7.75% to 45.78% (Shandwel 1 and Misr 1) during 2012/2013, and from 7.14% to 30.59% (Sids 1 and Sohag 3) during 2013/2014. Yield losses correlated strongly with AUDPC. The results of this study indicate that bread wheat cultivars are (Giza 168,Sakha 93, Sids 1, Misr 1, Misr 2 and Shandwel 1) and Durum wheat are ( Beni Sweif 5 and Sohag 3) more tolerant than durum wheat cultivars. The Egyptian bread wheat cultivars Sids 1 and Shandawel 1 are more tolerant than the other bread wheat cultivars.
Agriculture and Agri-Food Canada, Lethbridge, Alberta
Gurcharn Brar, Randy Kutcher, Raman Dhariwal
Stripe rust of wheat, caused by Puccinia striiformis f. sp. tritici (Pst), is one of the most important diseases of wheat in western Canada. Although stripe rust was an issue in southern Alberta for many years, it became important in other parts of the country after a dramatic population shift in 2000, resulting from an invasive race. Sporadic epidemics of the disease are common and cause considerable loss, due to which, an intermediate level of resistance to stripe rust was required for new varietal registrations beginning 2017. Virulence surveys are of key importance in germplasm and cultivar development as they provide breeders and pathologists the information needed to better understand host-pathogen interactions and the effectiveness of Yr genes. Virulence characterization revealed a wide range of virulence phenotypes exhibited by 33 Pst races in western Canada, although only 2-3 races were predominant. The expression of Yr genes may differ between controlled conditions and natural field conditions as previously reported. Thus, stripe rust differentials and wheat cultivars grown in western Canada are also screened at multiple locations in every year. At present, all stage resistance genes Yr1, Yr4, Yr5, Yr15, Yr76, and YrSP are effective against the predominant Pst races, whereas at the adult stage under field conditions, Yr2, Yr17, Yr28, or those carried by Yamhill are also effective. Seedling resistance genes Yr7, Yr10, Yr17, or Yr27 were the most common in Canadian wheat cultivars. Of these, only Yr17 is effective under field conditions. Adult plant resistance genes Yr18 and Yr29 are carried by many cultivars, but are not effective under high disease pressure. The effectiveness of each resistance gene may vary between the eastern and western prairies of western Canada due to differences in virulence. Regular virulence surveys using contemporary and regional cultivars facilitate the development of rust resistant cultivars.
Sathguru Management Consultants
Venugopal Chintada, Vijay Paranjape, Mansi Naithani, Aishwarya Vardhan
Nepal is an important wheat producer country in the South Asian region; with wheat being the third most important crop in the country after paddy (rice) and maize. Additionally, high-quality, disease free, processed seed is vital to establishing food security in South Asia. The Agriculture and Forestry University or AFU, located in the fertile Chitwan region of Nepal, is the only agriculture university catering to the needs of the Terai region and has the capability to provide innovative wheat seed solutions for small wheat-growing farmers. In the Delivering Genetic Gain Project or DGGW, the AFU has an active involvement in seed production, processing, and distribution. These activities play a major role in human capacity building in the country involving women empowerment, whole family participation in varietal selection and entrepreneurship for sustainable livelihood and overall development. Currently, under the DGGW?s Innovative Seed System in Nepal, AFU produces and aggregates seeds from farmers in the area and process it through a new seed processing unit, which is a cost-efficient version of machines commonly seen in larger agricultural facilities. At full capacity, the unit can operate up to 18 hours a day and process one ton of seed per hour. The unit it is also capable of processing rice and maize during other cropping seasons. By March 2017, more than 200 farmers applied to be part of the inaugural cohort of farmers trained in producing disease free wheat seed. The inaugural wheat season for the Seed Systems for Nepal Initiative has concluded successfully, with a total of 14 metric tons of disease-free wheat seed processed. The DGGW Seeds Systems for Nepal Initiative envisions to increase the number of empowered farmers next season, which commences on November, 2017.
Kenya Agricultural and Livestock Research Organization
Ruth Wanyera, Bernard Otukho, Bernice Waweru, Hellen Wairimu, Sridhar Bhavani
Emergence of Pgt race Ug99 and rapid proliferation of lineal highly virulent races imminently threaten Kenyan wheat. Devastating epidemics have led to huge losses among smallholder farmers who invariably are unable to spray appropriately and in situations where susceptible varieties are grown. To combat stem rust, the Kenya wheat improvement program seeks to release high yielding stable genotypes with suitable levels of disease resistance. Moreover, detection of genotypes that are adapted to rain-fed environments is an overarching objective. Six hundred and seventeen genotypes from various CIMMYT nurseries (PCBW, EPCBW, PCHPLUS, and 9th SRRSN) were selected based on plant type and reaction to stem rust at Njoro. The reconstituted nursery-KSRON, was sown in the main season of 2016 at Njoro and Timau for further evaluation. Forty red grained lines depicting R-MR infection types, severity of 30% or less, and average Thousand Kernel Weight of >40g were then selected to constitute a yield trial. At each of eight diverse environments, trials also comprising four commercial varieties as checks, were designed in RCBD, three replicates laid out in contiguous array of 8 rows x 10 m plots. Genotype (G), Environment (E) and GE interactions effects were estimated by fitting the AMMI model to yield data, supported by a biplot visualization of the results. Analysis revealed significant (P ?0.01) genotype (G), environment (E), and GE interactions. The first three principal components (PC) explained ~78% of the observed variation. Environment was the predominant source contributing over 85% to total sum of squares. The biplot pointed to at least four environments that were highly correlated. By classifying genotypes based on Shukla's stability variance and Kang's stability rating, six genotypes (R1402, R1411, R1424, R1481, R1484, and R1486) were deemed high yielding and stable, and thus suitable candidates for further testing through the release pipeline.
Ahi Evran University, Agriculture Faculty, Plant Protection Department K?rsehir/Turkey
Nilofer Akci, Marta da Silva Lopes
Stem rust (Puccinia graminis f. sp. tritici) is a fungal disease that can significantly reduce wheat yields and quality. The goal of this study was to screen 281 winter bread wheat landraces genotypes for their reaction to stem rust disease in seedling and adult plant stage.
For seedling stage, the experiment was carried out under greenhouse conditions in Field Crops Central Research Institute in Ankara, Turkey during 2017 growing season. The genotypes were grown at 20?4?C under greenhouse condition and inoculated (avirulent on Sr24, 26, 27, and 31 resistance genes) with urediniospores in mineral oil suspension at Zadoks growth stage 11 or 12. After inoculation, the genotypes were incubated at 20?1?C with 100% humidity during 24 hours then at 18-25?C. Scoring took place after 14 days using a 0-4 scale. Infection types on the susceptible checks (cv. Gun-91 and Thatcher) were 3+ scores. For adult plant reactions, the genotypes were screened under natural epidemic conditions for Pgt (virulent on Sr5, 6, 7b, 8a, 8b, 9b, 9g, 10, 30, Tmp and Mcn resistance genes) in Seydiler-Kastamonu, Turkey. The materials were sown in a one-meter row with three replications. Stem rust development on each entry was scored using the modified Cobb scale (Little Club had reached 80-100S) in August 2017. Coefficients of infections were calculated and values below 20 were considered to be resistant.
Two (1%) (Seedling stage) genotypes and 15 (5%) (Adult stage) genotypes were resistant to Pgt. The resistance genotypes identified in this study can be used in breeding programs. SNP markers will be identified for stem rusts resistance identified in the landrace population.
National Institute of Agronomy of Tunisia, INAT
Maroua Ouaja, Hanen Sbei, Bochra Bahri
Septoria tritici blotch (STB) caused by the fungal pathogen Mycosphaerella graminicola (anamorph: Zymoseptoria tritici) is one of the most important foliar diseases of durum wheat (Triticum turgidum ssp. durum) in Tunisia. It attacks plants from seedling stages to maturity causing serious yield losses. Breeding for resistance to STB in durum wheat can provide an effective, economic and environmentally-safe strategy to reduce yield losses. However, this is hampered by lack of sources of resistance. In this context, a collection of 420 accessions of durum wheat from the National Bank of Gene (BNG) were evaluated for resistance to two virulent isolates of Z. tritici, namely TunBz-1 (across two environments) and TM220 (across one environment) under field conditions at three different development stages. The evaluation scale was ranged from 0% (immune plant) to 100% (100% of leave covered with symptoms). Three effects were studied on the collection: environmental effect E1-E2 (years 2016-2017), isolate effect I1-I2 (TunBz-1 and TM220) and physiological stage effect S1-S2 (seedling and adult). Results highlighted different sources of resistance between both seedling and adult stages. Moreover, 51 and 67 accessions have differential response to the two studied isolates respectively in seedling and adult stage. Furthermore, the Venn diagram has identified 23 accessions in the collection that are resistant to both isolates at both stages and that resistance was stable across environments. These accessions are located mainly in the center of Tunisia. Resistance to isolate TunBz-1 is expressed since seedling stage and there is stability of this resistance throughout the environments. The center of Tunisia seems to be a diversity center that includes different sources of resistance to STB. This collection could be the subject of a genome-wide association study (GWAS) as it presents different types of STB resistance categories that can be targeted via SNPs.
Hawassa Agriculture Research Centre
Agdew Bekele, Waga Mazengia, Shimekt Maru
Shortage of seed of rust resistant varieties is a challenge of small holder farmers in wheat production. To successfully address this issue, one of the essential elements in wheat production system is farmer's access to quality seed of improved varieties. This paper presents the experience of on-farm basic and pre-basic seed production of newly released rust resistant wheat varieties. For the first time in the country, On-Farm basic and pre-basic seed production of wheat varieties was carried out in two districts/woredas (Silti and Soddo) of two specific locations (Loke faka and Wacho) where the Edget Farmers' Seed Multiplier and Marketing Union was licensed to produce some crop varieties (cereals and pulse), beginning in the 2011/2012 cropping season. Model farmers from primary cooperatives were selected based on the past experience they had with the union in producing certified seed. Selected farmers and relevant experts were trained on how earh seed of wheat is produced. Accordingly seed multiplication of four wheat varieties was conducted with frequent monitoring and evaluation at the course of multiplication.
As a result sufficient and quality basic seed of newly released wheat varieties was produced on-farm in both Loke and Wacho locations for own utilization and seed market. The result of the experiment revealed that it was possible to multiply quality wheat seed provided that partnership (with GOs and/or NGOs) is well-built and cooperative farmers do farm management practices as per the recommendations. On-farm seed production can be sustainable if the strong partnership exists among stakeholders, and wheat seed growers are given premium prices for their seed which is supported by the legal frame work that encourages the seed production of early generations. More importantly, the result of this experiment has a useful implication on government policies and strategies and government institutions' practice on farm early seed generation production and marketing.
School of Agricultural Biotechnology, Punjab Agricultural University, Ludhiana-141004 India
Ahmed Elkot, Satinder Kaur, Parveen Chhuneja
Stripe rust and leaf rust are two most widely distributed diseases of wheat despite the fact that major emphasis has been made globally to develop rust resistant varieties. The wild tetraploid wheat Triticum araraticum (AAGG) evolved in the eastern part of Fertile Crescent is a source of useful traits for the improvement of wheat including resistance to disease. T. araraticum acc. pau4692 and a derived advanced backcross introgression line (IL) in susceptible T. durum cv. Malvi local background showed high level of seedling resistance against Indian pathotypes of leaf rust and stripe rust. The F5 Single seed descent (SSD) population developed from the crosses between T. araraticum IL with T. durum cultivar PBW114 was screened with commonly prevalent pathotypes of leaf rust and stripe rust in India at the seedling stage. The genetic analysis indicated that the leaf rust resistance is conditioned by two genes and stripe rust resistance by a single gene. The SSR markers mapped on A and B genome were used for parental polymorphism along with resistant and susceptible bulks for leaf rust and polymorphic markers between bulks were used on the whole population. The molecular marker data using single marker analysis showed that leaf rust resistance genes were mapped on chromosome 2A and 7A linked to SSR markers Xwmc149 and Xbarc49, respectively. The genes have been temporarily named as LrAr1 and LrAr2. Bulked segregant analysis (BSA) for mapping stripe rust resistance is in progress.