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.
Agharkar Research Institute Pune
Vijendra Baviskar, Balgounda Honrao, yashavanthakumar kakanur, Vilas Surve, Deepak Bankar, Vitthal Gite, Ajit Chavan, Vijay Khade, Juned Bagwan, Shrikant Khairanar, Sameer Raskar
Frontline demonstrations (FLDs,) on wheat were conducted by Agharkar Research Institute, Pune, during last five rabi seasons from 2012-13 to 2016-17 at farmer's fields of Pune and Satara district under wheat growing area of semi-arid tropics of western Maharashtra, India. Before conducting FLDs, a group meeting held every year in the selected village and specific skill training had imparted to the randomly selected farmers regarding adoption of different improved aspects of cultivation. FLDs comprised of improved wheat varieties viz., MACS 6222, MACS 6478, MACS 3125 (d) and MACS 2971(dic) for Peninsular Zone of India. About 50 ha of FLDs on improved wheat varieties were conducted with active participation of 50 farmers covered an average of 10 farmers and 10 ha per year. Two recent varieties, MACS 6222 and MACS 6478 had shown higher grain yield, ranging between 15 to 55 per cent more over local check and farmer practice than all other FLDs. Recommended packages and practices of wheat FLDs gave higher value of yield, net return and high benefit cost ratio as compared to local check over the years of study. The study has revealed that five years mean extension gap of 4.48 to 9.67 q/ha and technology gap ranging between 11.00 to 22.22 q/ha depending on the variety during the period of study. Net returns of Rs. 63042/ha was observed from improved practice than in the farmer's practice of Rs. 50108/ha and with benefit cost ratio of 3.07 and 2.79 respectively. On average basis, the incremental benefit cost ratio was found as 2.83. In frontline demonstrations, the yield potential of wheat has been enhanced largely due to the increase in the knowledge of farming community and adoption of improved production techniques by farmers.
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.
Panjab University Chandigarh
Sterol 14?-Demethylase Cytochrome P450 (CYP51) protein involved in ergosterol biosynthesis pathways is a crucial target for efficient fungicidal compounds. However, the recognition mechanism and dynamic behavior of CYP51 in wheat leaf rust pathogen, Puccinia triticina is still obscure. Previously, a mutation at codon 134 (Y134F) was reported in five European isolates of P. triticina, the structural basis of this mutation remain unclear. To address this problem, CYP51 wild type protein and its variant proteins were successfully modeled using I-TASSER, an ab initio based structure prediction pipeline. To gain valuable insights into structure-function behavior for the binding wild-type and mutant-type proteins, individually generated protein models was subjected to 50ns molecular dynamics (MD) simulations run. Observably, this comparative protein-ligand interaction analysis and binding free energy results revealed that impact of mutation on the thermodynamics and conformational stability of the CYP51 protein is negligible. In present study, we carried out structure-based molecular docking and identified potent novel fungicidal compounds from four different databases and libraries. Consequently through MD simulation and thermodynamic integration, four novel compounds such as CoCoCo54211 (CoCoCo database),ZINC04089470(ZINC database), Allyl pyrocatechol 3,4 diacetate (Natural compound library) and 9-octadecenoic acid (Traditional Chinese Medicine database) has been predicted as potent fungicidal compound against CYP51 with XPGlidedocking score of -11.41, -12.52, -7.40 and -7.55 kcal/mol, respectively. These compounds were found to directly bond to heme group of CYP51, subsequently disturbing the stability and survival of fungus and can be used to control leaf rust in wheat.
University of Delhi South Campus, New Delhi
Towards understanding the molecular mechanisms of heat stress tolerance, we have analyzed heat stressed substractive cDNA libraries and undertaken genome-wide transcriptome exploration for genes associated with spike photosynthetic efficiency during thermal stress. The photosynthetic efficiencies of Aegilops tauschii and Ae. speltoides were also compared. While the former displayed nearly complete recovery of PSII, the adverse effect was more pronounced in the latter. Functional characterization of heat stress-associated transcription factors and thermal stress-associated proteins was also undertaken e.g. TaHSF, TabZIP, TaZnF and TaMIPS, and TaLTPs in the Indian wheat germplasm. Functional characterization of the three heat stress transcription factors was upregulated under high temperatures and other abiotic stresses. They also showed early flowering and better performance with respect to their growth and yield after heat stress. Additionally, we have identified various interacting components associated with thermal stress-mediated plant signaling partners during thermal stress.
Institute of Agriculture and Food Research and Technology
Karim Ammar, Susanne Dreisigacker, Josí María Arjona, Conxita Royo
Understanding the effect of genetic factors controlling flowering time is crucial to fine-tune crop adaptation to each target environment and maximize yield.
A set of spring durum wheat inbred lines carrying all but one of the possible allelic combinations at Ppd-A1 and Ppd-B1 genes was developed through a collaboration between IRTA and CIMMYT. The collection was grown during several years at four sites at latitudes ranging from 19?N to 41?N in order to assess the effect of Ppd-1 genes on development, biomass production and allocation, as well as grain yield formation.
Environmental constraints were responsible for most of the observed variation for flowering time and yield components. Latitude was a main driver of flowering time, which was later in northern sites and associated with lower minimum temperatures before flowering. Data on environmental constraints explaining a large proportion of grains m-2 and kernel weight variation will be presented. The effect on flowering time of Ppd-A1 alleles conferring photoperiod insensitivity was enhanced at sites with average daylength before flowering lower than 12h. Ppd-A1 caused a stronger effect on flowering time than Ppd-B1, which was found responsible for differences in grains m-2, associated with longer photoperiods from double-ridge to terminal spikelet stages. These differences in grains m-2, however, did not result in higher yields due to kernel weight compensation. Late flowering genotypes carrying alleles conferring photoperiod sensitivity had greater biomass at anthesis but it did not confer superior yields. Early flowering times were associated with higher yields in autumn-sowing sites due to a large contribution to yield of current photosynthesis during grain filling. Early flowering genotypes tended to yield more due to higher kernel weights, and the interaction of allele combination x environment will be discussed in the context of using allelic information as environment-specific guideline in breeding efforts.
Agriculture & Agri-Food Canada
Wheat cultivar McNair 701 carries resistance gene SrMcN and is used as a differential line to identify Pgt races using the international letter code nomenclature. The inheritance and location of the resistance gene has not been characterized. We developed a doubled haploid (DH) population from cross LMPG/McNair 701 to study the genetics and chromosomal location of SrMcN. A DH population inoculated with race QCCJB segregated 100 resistant : 94 susceptible, a 1:1 ratio (?2=0.186, P=0.666, NS) indicative of segregation at a single locus. This gene was mapped to chromosome 2DL using the Infinium 90k platform. The map position of SrMcN was similar to that of Sr54, one of two genes previously found in Norin 40. Comparison of stem rust seedling reactions using 12 diverse Pgt races indicated that McNair 701 and an Sr54 line derived from Norin 40 had an identical pattern of responses and similar low infection types (IT=12-) to races LCBNB and QCCJB. Based on the chromosomal location on 2DL and identical seedling responses to Sr54, it is likely that the resistance gene in McNair 701 formerly known as SrMcN is Sr54. This finding will be confirmed by a test of allelism.
Central Research Institute for Field Crops, Yenimahalle, Ankara, Turkey
Berberis species are important alternate hosts and generate new races of stem rust fungus, Puccinia graminis f. sp. tritici and yellow (stripe) rust fungus Puccinia striiformis. Berberis species are common in Kastamonu province of Turkey. In 2016 and 2017, surveys were conducted in Kastamonu province in order to elucidate aecial infection status of Berberis species in this region. In 2016, the central region and A?l?, Ara?, Daday, ?hsangazi, Seydiler, Ta?k?pr? and Tosya regions and in 2017 central region and Ara?, Daday, Han?n?, P?narba??, Seydiler, Ta?k?pr? and Tosya regions of Kastamonu province were investigated. It appears that there are at least two different Berberis species exist in that area. Berberis species showed variation in terms of fruit color and morphological characters. In 2016, 50 Berberis plants were examined and aecia were present in 38 plants (76%). Percentage of plants parts infected with aecia ranged between 3-80%. In 2017, 64 Berberis plants were examined. Aecia were present in 34 plants (53%). Percentage of plants parts infected with aecia ranged between 3-85%. Aecia were mainly observed on leaves but also observed on other plant parts including flower parts, fruit and young twigs. The role of these aecia and Berberis spp. on rust diseases in Kastamonu province of Turkey should be investigated.
This study was supported by General Directorate of Agricultural Research and Policies, Turkey (Project No: TAGEM-BS-15\12-01\02-02).
Laboratory of Molecular Plant Physiology, Biotechnology Center of Borj Cedria (CBBC)
Mahmoud Gargouri, Hesham A.Y Gibriel, Richard B. Todd, Michael F. Seidl, Gerrit H.J. Kema
Septoria tritici blotch disease, caused by the fungus Zymoseptoria tritici, is a major threat to global wheat production. With the recent advances in high-throughput DNA-based technologies, Z. tritici has become a powerful model system for the discovery of candidate determinants that underlie virulence and host specialization. Although a few important virulence/regulatory genes have been identified, a global understanding of the larger regulatory network has not been developed. Therefore, to uncover the transcriptional regulatory networks of the infection cycle and most particularly the regulatory hubs that control the switch between the biotrophic and necrotrophic phases, we applied an integrated approach combining transcriptomics, proteomics, and metabolomics analyses based on the identification of plant and fungal transcription factors and regulators, which we characterized from the newly annotated genome sequence of the reference isolate IPO323 (Grandaubert et al., 2015) and using datasets from Rudd et al. (2015). Bread wheat transcription factors and regulators were identified by querying the proteome and subsequent categorization from the Plant Transcription Factor database (PTFDB). Similarly, Z. tritici transcription factors and regulators were identified and categorized using the PFAM TF family databases, and following fungal transcription factor rules as outlined by Todd et al. (2014) and rules we developed for fungal transcription regulators. Insights into transcription factors and regulators will enable synthetic biology approaches to alter the Z. tritici-wheat interaction and lead to rewiring of the regulatory networks thereby turning off the fungal infection process. Beyond providing insights into the regulatory systems-levels involved in Z. tritici-wheat interaction, we believe that our dataset and approach sets the stage for an emerging series of studies that will decipher the dynamic regulatory networks in other plant-pathogen interactions.
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.