Wheat Program, National Agricultural Research Center (NARC) Islamabad
Sikander Khan Tanveer, Muhammad Sohail, Muhammad Shahzad Ahmed, Sayed H. Abbass, Sundas Wagar, Atiq Rattu, Muhammad Imtiaz
Wheat plays a vital role in multifaceted farming system of Pakistan. Like other many other countries, Pakistan's sustainable wheat production is also continuously threatened by a number of biotic and abiotic stresses. Among the biotic stresses, three rust diseases of wheat have been the most devastating. Stem rust was effectively controlled with adoption of the semi-dwarf spring wheats of the Green Revolution. However, the threat of the evolution of Ug99 race of stem rust in East Africa and its migration to Iran cannot be neglected. The Chance of of Ug99 migrating from Iran into Pakistan, coupled with the presence of dangerous new races of stripe and leaf rusts invites enormous efforts for development of rust resistant varieties for sustainable production of the wheat in the country. In this regard the Wheat Program, NARC, Pakistan initiated an intensive breeding program with financial and technical support of USDA and CIMMYT. Diverse sources of resistance to the three rusts particularly to the stem rust race Ug99 were introduced from CIMMYT. Through the rigorous selection procedure, four rusts resistant wheat varieties (NARC 2011, Pakistan 2013, Zincol 2016 and Borlaug 2016) have been released. These varieties are also resistant to Ug99. The varieties i.e. NARC 2011, Borlaug 2016 and Zincol 2016 are performing well in irrigated areas whereas Pakistan 2013 is suitable for rainfed conditions. The variety Zincol 2016 has high Zn content (35 ppm) in grain as compared to national standard check variety (25 ppm). These varieties are not only higher yielding but also possess good grain quality and other desirable traits. A considerable quantity of seed of the varieties is already present in the national seed system and will reduce the risk of Ug99 threat.
Kazakh National Agrarian University
Yerlan Dutbayev, Alexei Morgounov
Kazakhstan is among the ten largest grain exporters in the world. Winter wheat in Kazakhstan is mainly cultivated in the southern and south-eastern regions on an area of 1.5-2 million hectares, including 140-170 thousand hectares - in irrigated lands. Annual losses of wheat yield from diseases can reach up to 30-40% or more. For Kazakhstan, the most dangerous diseases of winter wheat are stripe rust and leaf rust. Work is under way in Kazakhstan to find new donors for resistance to leaf rust and stripe rust and the use of these donors in breeding. The aim of this research was to expand genetic diversity through crosses and development of lines obtained by the method of remote hybridization, as well as selection of new sources of resistance of bread wheat to leaf rust and stripe rust in southeast Kazakhstan. The subject of the research were 49 hexaploidsynthtic lines of Kyoto University (Japan) and CIMMYT and commercial varieties of winter wheat in the Almaty region. We screened synthetic hexaploid wheat for resistance to diseases. A collection of hexaploid synthetic wheat lines resistant to the diseases and adapted to various conditions of the Almaty region has been established. The character of inheritance of resistance to diseases in crosses of synthetic wheat with local cultivars based on comparison of the first generation and parents was studied. Evaluation of phenotypes inheritance of resistance in hybrids in the generation of F2, showed that 9crosses of synthetic wheat(LANGDON/IG 48042//ZHETISU, LANGDON/IG 48042//FARABI, LANGDON/KU-20-8//AJARLY, LANGDON/KU-2075//AJARLY, LANGDON/KU-2097// ZHETISU, LANGDON/KU-2075//FARABI, LANGDON/KU-2100//STEKLOV, LANGDON/KU-2144//NAZ, LANGDON/KU-2076//NAZ)possess the dominant resistance genes to leaf rust.Seven lines(LANGDON/ KU-2075/AJARLY, LANGDON/KU-2075/FARABI, LANGDON/KU-2092/FARABI, LANGDON/KU-2100/NAZ, LANGDON/KU-2097/STEKLOVINDAYA, LANGDON/KU-2097/ZHETISU, LANGDON/KU-2097/ AJARLY) possess from one to several dominant resistance genes to stripe rust.
Ravi,Singh, Julio, Huerta-Espino, Mandeep, Randhawa, , , , , , , , , , , , , , , , , , , , , , , ,
Wheat leaf rust (LR) and stripe rust (YR), caused by the air-borne fungi Puccinia triticina (Pt) and Puccinia striiformis f. sp. tritici (Pst), respectively, are considered the primary biotic threats to bread wheat and durum wheat production globally. Growing resistant wheat varieties is a key method of minimizing the extent of yield losses caused by these diseases. Bread wheat lines Francolin #1, Kenya Kongoni, Kundan and Sujata, and CIMMYT-derived durum wheat lines Bairds and Dunkler display an adequate level of adult plant resistance (APR) to both leaf rust and stripe rust in Mexican field environments. Six recombinant inbred line (RIL) populations developed from crosses Avocet/Francolin #1, Avocet/Kenya Kongoni, Avocet/Kundan, Avocet/Sujata, Atred#1/Bairds and Atred#1/Dunkler were phenotyped for leaf rust response at Ciudad Obregon, Mexico, and the bread wheat populations for stripe rust response at Toluca for under artificial inoculations for multiple seasons. The RIL populations and their parents were genotyped with the 50 K diversity arrays technology (DArT) sequence system and simple sequence repeat (SSR) markers. Known pleotropic APR genes Lr46/Yr29 mapped in all of six populations, and explained 7.4-65.1% and 7.7-66.1% severity variations for LR and YR across different bread wheat populations and accounted for 12.4-60.8% of LR severity variations over two durum wheat populations. In addition, several new APR loci identified on chromosomes 1AS, 1DS, 2BS, 2BL, 3D and 7BL in bread wheat and QTL on chromosome 6BL in durum wheat. Among these loci, QTL on chromosomes 1AS, 3D and 7BL might be represent new co-located/pleotropic loci conferring APR to LR and YR. RILs combining these APR loci can be used as sources of complex APR in both bread wheat and durum wheat breeding. In addition, the closely linked single nucleotide polymorphism (SNP) markers have been converted into breeder-friendly kompetitive allele specific PCR (KASP) markers and their diagnostic verified.
John Innes Centre
Burkhard,Steuernagel, Caixia, Lan, Miroslava, Karafi?tov?, Ksenia, Krasileva, Jaroslav, Dole?el, Evans, Lagudah, Ravi, Singh, Brande, Wulff, , , , , , , , , , , , , ,
Adult Plant Resistance (APR) genes are broad-spectrum, partial-resistance genes that have the potential to contribute to sustainable control of wheat rust diseases. However, their isolation and characterization are complicated by the lack of precise molecular markers required for their identification, and therefore their use in plant breeding programs has been limited. Recent developments including the falling cost of sequencing and the increasing use of sequence capture methods to reduce genome complexity have enabled previously intractable methods such as mutational genomics to clone genes in wheat. Despite their increasing ease of use, many of these approaches require prior knowledge of the gene space and, in some cases, the gene family of the target gene to be cloned. As the APRs cloned so far do not belong to any common gene family, it is not possible to use general features of these identified APRs to conduct biased searches for novel APRs. This project aims to use an unbiased gene isolation technique called MutChromSeq, which combines chromosome flow-sorting and mutational genomics, and is independent of fine mapping, to rapidly clone the recently discovered APR gene Lr68 (Leaf Rust 68). Cloning APRs allows breeders to trace genes cheaply and quickly using gene-specific markers, enabling them to build effective and durable resistance gene pyramids. It also allows us to elucidate any common mechanism of action they have, helping researchers and breeders understand better the basis of their durable resistance. At the same time, the generation time of wheat has become one of the major limiting factors for the response time of breeders to rust epidemics. Thus, this project also aims to combine marker-assisted selection with accelerated generation advancement ('speed breeding') for rapid germplasm structuring and field performance evaluation.
John Innes Centre
Christopher,Judge, Francesca, Minter, Nik, Cunniffe, Richard, Morris, Diane, Saunders, , , , , , , , , , , , , , , , , , , ,
Wheat yellow rust is a disease caused by the fungus Puccinia striiformis f. sp tritici (PST) that is a significant threat to wheat production worldwide. Recently, a novel approach called "Field Pathogenomics" was developed that allows acquisition of genotypic data from field samples of PST-infected wheat. This has enabled us to study the re-emergence of this pathogen in the UK and understand the different races that form the current PST population. However, the dynamics of pathogen transmission and dispersal still remain unknown and understanding this is essential for designing effective surveillance. The objective of this project is to develop a spatially-explicit model for the spread of PST that can contribute to better management of the disease and be used as a warning system for wheat yellow rust infection in the UK. The first aim is to study how PST spreads at the field level and determine whether there are differences between PST races in terms of disease dynamics. To this end, a set of markers have been designed that can be used to genotype field-collected isolates and determine which race they belong to. Field trials were also undertaken across the UK using wheat varieties that are known to be susceptible to the disease, with PST-infected wheat samples collected during the 2015-2016 and 2016-2017 seasons. These samples will be genotyped to study the prevalence of different PST races and determine whether PST genotypes identified early in the season are predictive of dominant genotypes found later in the season. Understanding PST dynamics within a field is key to build an epidemiological model that can predict how this disease behaves. This would improve disease management, targeting of chemical sprays and optimize pathogen surveillance.
Sathguru Management Consultants
Kanan,Vijayaraghavan, Vijay, Paranjape, Richa, Kapur, Vignesh, Vilayanur Jayaraman, , , , , , , , , , , , , , , , , , , , , ,
Wheat is one of the most important food crops of the world. India is the second largest producer of wheat, currently producing 95 million tons from about 30 million hectares. Looking ahead to 2050, India needs to constantly increase production to about 150 million tons, to meet the rising population and demand. With area under cultivation having no room for growth, productivity will be the main pillar for growing production. Currently India?s yield of 3.1 t/ha has plenty room for growth as compared to the world leaders such as France (7.5 t/ha), Germany (7.3 t/ha) and UK (6.6 t/ha). Wheat productivity depends on multiple factors, seed being one of the most important.
The current operating environment is characterized by wheat R&D in the country conducted by public institutes, but there are clear signs of an emerging private sector involvement. The government promoting Inter-institutional linkages by way of associating private players in research and seed production.
This study evaluates and reflects on the current situation of the wheat seed sector in India - from research, variety/hybrid development, seed production, indent to distribution, the players involved, the challenges therein, upcoming technologies and the way forward.
Wheat Research Centre, Bangladesh Agricultural Research Institute
,, , , , , , , , , , , , , , , , , , , , , , , , , , , ,
The soils of the entire Sylhet region of Bangladesh are strongly acidic where lands remain fallow during winter season due to scarcity of irrigation water required for rice cultivation. There is a scope of wheat expansion in this region as the water requirement of wheat is less than Boro rice. Field experimens were carried out at South-Surma, Sylhet, in 2012-13 and at FSRD site Jalalpur, Sylhet in 2013-14, in collaboration of WRC and OFRD. BARI examined the response of seven wheat varieties at two levels of lime in split-plot design where lime was applied in main plots and different wheat varieties were grown in sub-plots. The seeds were sown on December 05, 2012 and November 30, 2013 for the growing season of 2012-13 and 2013-14, respectively. The wheat varieties used in this study were Shatabdi, Sufi, Sourav, Bijoy, Prodip, BARI GOM 25 and BARI GOM 26. The index of relative performance of each variety in comparison to mean yield of all varieties under the contrast conditions of liming and non-liming was estimated to determine relative adaptability of wheat variety under experimental soil conditions. The result indicated that most of the yield components viz. spikes/m2, thousand grain weight and grain yield of wheat were significantly improved by liming for both the years and locations. There were variations in lime response among the wheat varieties. The index of relative adaptability (IRA%) for yield of BARI GOM 26 and Bijoy was more than 100% for both the years. The result indicated that these two wheat varieties are relatively tolerant to low pH and could be adapted in acidic soil of Sylhet.
Institute of Plant Protection, Chinese Academy of Agricultural Sciences
Jing Feng, Ruiming Lin, Fengtao Wang, Qiang Yao, Qingyun Guo, Shichang Xu
Wheat stripe rust is an important air borne disease caused by Puccinia striiformis f. sp. tritici, and seriously threatens the safety of wheat production. Breeding and utilization of resistant varieties is the most economical, safe and effective measure to control wheat stripe rust. Sifangmai is a landrace from the state of Guangxi, China, and maintains good resistance to the current epidemic species CYR34, CYR33, CYR32 and CYR29 in China. Sifangmai was crossed with Taichung 29 to obtain F1, F2 and F2:3 to analyze its character of inheritance. In the adult stage, the cross of Sifangmai /Taichung 29 was inoculated by CYR32. The genetic analysis showed that the resistance of Sifangmai to CYR32 was controlled by a dominant gene, named as YrSF. A mapping population of F2 was genotyped with simple sequence repeat (SSR) markers. SSR loci Xgpw8015, Xgpw4098, Xwmc73, Xgpw8092, Xgpw7309 and Xbarc89 on 5B chromosome showed polymorphic between Taichung 29, Sifangmai, and resistant and susceptible pools, indicating that the resistant gene in Sifangmai was located on the 5B chromosome. The linkage map of these SSR markers was constructed and the nearest SSR to the gene is Xgpw8015. A set of Chinese Spring nulli-tetrasomic lines was used to confirm YrSF on chromosome 5B. YrSF is different from known genes in chromosome 5B. Xgpw8015 can be used as a marker for detection of YrSF.
Institute of Agricultural Environment and Resources, Yunnan Academy of Agricultural Sciences, China
Xianming Chen, Anmin Wan, Jiasheng Chen, Mingliang Ding
Wheat stripe rust (Puccinia striiformis f. sp. tritici, Pst) is the most destructive disease of wheat worldwide. Breeding and planting resistant cultivars is the most economic, effective, as well as environmental methods to control the disease. Yunnan is a severe epidemic zone in China, which provides new incursions for other parts of China. Study on virulence of the Pst population and effectiveness of resistance genes, will provide information for breeding and rational use of resistance genes. One hundred and thirty-six136 isolates collected from 9 regions of Yunnan were tested using a set of 18 Yr NILs with genes Yr1, Yr5, Yr6, Yr7, Yr8, Yr9, Yr10, Yr15, Yr17, Yr24, Yr27, Yr32, Yr43, Yr44, YrSP, YrTr1, YrExp2, YrTyTye. Stripe rust races were named by octal code. The results showed that the Pst population in Yunnan is highly variable in races and virulence. A total of 64 races were identified and the top two most frequent races were 550273 (Virulence/Avirulence formula: 1, 6, 7, 9, 27, 43, 44, SP, Exp2, Tye / 5, 8, 10, 15, 17, 24, 32, Tr1 and 550073(Virulence/Avirulence Formula: 1, 6, 7, 9, 43, 44, SP, Exp2, Tye / 5, 8, 10, 15, 17, 24, 27, 32,Tr1), with frequency of 28.68% and 11.76%, respectively. The remaining races had frequencies less than 5.0%. No virulence were found for Yr5, Yr10, Yr15, and Yr32. The frequencies of virulence to Yr24, YrTr1, Yr8, and Yr17 ranged from 0.74% to 11.76%. The frequency of virulence to Yr27 was 52.94%; and virulence to Yr1, Yr6, Yr7, Yr9, Yr43, Yr44, YrSP, YrExp2, and YrTye ranged from 79.94% to 91.91%. The results will guide the breeding and wheat production. (This study was supported by National Natural Science Foundation of China, Grant No. 31260417 and 31560490)
KENYA AGRICULTURAL AND LIVESTOCK RESEARCH ORGANIZATION (KALRO)
Godwin Macharia, Bernice Ngina
Studies have shown that women farmers are worse off than the male counterparts in terms of adoption of improved varietal technology and hence they experience low productivity. This technology adoption gender gap affects agricultural development considering that women in Kenya play a significant role in agriculture and food production. The link between gender and adoption is likely to vary across cultures and over time. The hypothesis of significant gender differences in access to and use of productive resources and adoption of improved wheat varieties was tested. Based on bivariate analysis, significant differences in access and use of productive resources between men and women farmers were observed. Men were more likely to access credit, extension services, own and cultivate more lands compared to women. Similarly, women in female-headed households were less likely to access the productive resources compared to women in male-headed households. The factors that affect adoption of improved wheat varieties among smallholder farmers were analysed with a specific focus on women. In contrast to the conventional model of using gender of the household head, gender and plot levels analyses were conducted. The results show that the gender of the field owner had a negative effect on adoption of improved wheat varieties. This indicates that, men were more likely to adopt improved wheat varieties, compared to women farmers. Moreover, the level of education of the household head, household size, and access to credit and extension services were observed to significantly increase the likelihood of farmers adopting improved wheat varieties. In the same framework, female farmers in male-headed households who had access to credit were more likely to adopt improved wheat varieties while there was greater probability of adoption of improved wheat varieties among female farmers in female-headed households who had access to agriculture extension and belonged to a farmer organization