Crop Diseases Research Institute, National Agricultural Research Center, Park Road Islamabad, Pakistan
Anjum Munir, Khalil Ahmed Khanzad, Javed Iqbal Mirza, Shahzad Asad, Atiq ur Rehman Rattu, Muahmmad Imtiaz
Evaluation of candidate lines to develop resistant varieties at multiplications in Pakistan is a regular activity which has been successfully done for many years. This approach assists in generation of future resistant cultivars around appropriate genes combinations thereby providing durable resistance outputs for wheat productivity. This year, National Uniform Wheat Yield Trial (NUWYT) comprised of 60 candidate lines. Among these 15 lines were also present in the last years NUWYT. The two years data revealed that there was only one line V-12066 resistant to all three rusts during the two consecutive seasons 2015-16 and 2016-17. Four candidate lines NR-487, V-122557, PR-115 and NRL-1123 were found resistant to yellow and leaf rust during 2015-16 and 2016-17. A candidate line DN-111 was found resistant to leaf and stem rust. There were three lines NW-1-8183-8, NW-5-20-1 and MSH which were found resistant to leaf rust only during two consecutive seasons. Similarly, two candidate lines V-122559 and QS-3 were found resistant to stem rust only, while one line NR-443 was resistant to yellow rust only. The present study provide the screening and evaluation system of Pakistan for promoting and releasing the resistant wheat varieties.
Instituto Nacional de Tecnologia Agropecuaria (INIA), Estaci?n La Estanzuela, Ruta 50, Km 11, Colonia, Uruguay
Vanesa,Domeniguini, N?stor, Gonz?lez, Richard, Garcia, Carolina, Saint-Pierre, Pawan, Singh, Mart?n, Quincke, Silvia, Pereyra, Silvia, Germ?n, , , , , , , , , , , , , ,
Since 2014 CGIAR-WHEAT Program has promoted the establishment of a network of field-based Precision Wheat Phenotyping Platforms (PWPP) to expand the existing collaborations between CIMMYT, ICARDA and National Agricultural Research System partners. The main goals are improving the quality of data collected and shared among institutions to enhance and accelerate the international wheat breeding, and promote synergism with the private sector and nongovernmental organizations. In 2015, the PWPP-Uruguay was established to test genotypes for multiple diseases: leaf rust, Fusarium head blight and Septoria tritici blotch. These diseases are phenotyped each year in separate field trials artificially inoculated with pathogen isolates identified as representatives of the pathogen regional population. Wheat material is sowed in plots with susceptible checks every 50 entries. Disease severity and other variables related to the disease development are measured using standard international scales at dates when the expression of plant resistance is optimal. In the first three years of the platform, more than 1500 genotypes were screened per year. These materials had diverse origins (more than eight institutions, public and private, from eight countries) and diverse types: from recent commercialized to ancient cultivars, advanced lines, International CIMMYT nurseries, mapping populations or panels. Highly resistant genotypes to multiple diseases could be selected. At the present time, we are developing and adopting advanced phenotyping methods, combining remote sensing and image analysis, and exploring their adaptation to breeding constraints. Also, extension activities as internships, training courses and student projects are being developed. Major future prospects are the enhancement of data and germplasm exchange between platform partners and the PWPP network and the involvement in collaborative phenotyping/genotyping breeding projects.
Khaoula El Hassouni, Priyanka Gupta, Hafssa Kabbaj, Meryam Zaim, Amadou Tidiane Sall, Bouchra Belkadi, Ayed Al-Abdallat, Ahmed Amri, Rodomiro Ortiz, Michael Baum
Durum wheat is the tenth most important crop in the world, but its cultivation is mostly limited to harsh, arid, and heat prone marginal lands. Breeding for tolerance to these conditions is often considered the most strategic approach to ensure adaptation, especially when paired with best agronomical practices. The word 'adaptation' summarizes all the research efforts conducted to identify the many traits controlling the mechanisms for withstanding or escaping the traceries of the environment. It can be summarized as "GGE vs E". The durum wheat breeding program of ICARDA deploys targeted phenotyping methods in combination with genomic scans to dissect these 'adaptive' traits into simple loci. These loci can then be pyramided via a combination of international field testing, markers assisted selection, genetically-driven crossing schemes, and genomic selection to derive climate-ready cultivars. Here, several examples of this approach are presented and their implications for 'adaptation' are discussed.
ICAR-Indian Institute of Wheat and Barley Research
Sudheer Kumar, P.L. Kashyap, Gyanendra Pratap Singh
Yellow rust of wheat caused by Puccinia striiformis Westend. is one of the important diseases of wheat in India. In north Indian states it spreads quite fast due to favourable temperature and moisture prevailing in these states during major part of crop growth (November-mid March). In spite of favourable weather, proactive survey and surveillance and advisories issued in time resulted successful management of yellow rust in India during past four decades. Even large scale cultivation of varieties like HD 2967 in about 12 million ha past two years did not result any losses. Three spots of initial foci near foot hills in Punjab have been identified and are monitored regularly. Any sign of yellow rust is controlled effectively with the foliar sprays of fungicides like propiconazole @ 0.1%. Use of mobiles phones and internet services is regularly done for transfer of information on wheat crop health and suggestions for proper management. Strategic planting and sowing of wheat in which newly released high yielding yellow rust varieties helped in reducing the yellow rust inculum build up. Regular monitoring of wheat health via weather forecasts take place after every fortnight from December to March. During 2016-17 crop season, yellow rust was effectively managed and its occurrence was delayed in Punjab, Haryana and Uttarakhand states. Two new pathotypes, 110S 119 and 110S 84 developed recently were used for evaluation of entries of wheat yield trials during 2016-17 at hot spot locations. The new varieties in pipe line of identification and release are tested against yellow rust. The most critical period for yellow rust management remained from December till mid February.
University of Eldoret
Julius Ochuodho, Ruth Wanyera, Sridhar Bhavani, Les Szabo
Stem rust Ug99 and related race group are one of the major constraints of wheat production in Kenya. The challenge has been largely due to rapid evolution of races within lineage defeating resistance genes resulting in boom and burst cycles. Understanding of the pathogen population structure in major wheat growing regions in Kenya gives comprehensive information of the predominant races as well as capturing new races which may have potential of causing epidemics. Such information can have significant impact on effective gene stewardship in breeding resistant varieties. Using 11 Pgt Simple Sequence Repeats (SSR) markers we analyzed 104 single uredinial-pustule samples. Allele frequency distribution ranged from 2 to 6 per locus with an average of 3.27 per locus. Observed heterozygosity ranging from 0.297-1.000 (mean HO=?0.809) was significantly different (P< 0.001) than the expected heterozygosity (0.264 to 0.507; mean HE=?0.407) indicating that the population is asexual. Analysis of molecular variance (AMOVA) showed that the majority of the variation occurred within the samples (98%) rather than between regions (2%). Analysis of 104 samples identified 21 multiple locus genotypes (MLGs). MLG.19 was observed across the three region analyzed that is Central Rift, North Rift and Mount Kenya while MLG.18 was predominant in Mount Kenya. Based on SSR genotypes of reference isolates, Pgt clade IV (race TKTTF) was associated with MLG.16 in Central Rift Kenya while clade I (race TTKSK) had a unique MLG.10. These results indicated two main groups corresponding to Clade I (Ug99 race group) and Clade IV (race TKTTF race group). This minimum spanning network analysis pattern points to the Pgt population being asexual due to mutation. These preliminary results suggest that Pgt population in Kenya is asexual in nature. Further analysis is being conducted to ascertain geographical structure as well as compare the results with the 2011 data.
CIMMYT International, South Asia, Regional Office, Kathmandu
Gurbinder Gill, Madan Bhatta, Andrew McDonald, Arun Joshi
The experience of seed system development works in Nepal shows that lack of business orientation is one of the key challenges for the growth of Nepalese seed enterprises (SEs). We implemented a business mentorship activity focusing on SEs in the project - Cereal System Initiative for South Asia. The business mentoring (BM) was implemented covering 10 SEs during 2014 to 2017 using discovery sensitization and facilitation mode. The key actions were, SWOT analysis, mentorship to develop strategic business plan, technical facilitation for seed quality improvement through maintenance breeding and on-farm farmer participatory trials as well as large plot demonstrations of recently released and pre-released wheat varieties. This resulted in 45% average increase in the volume of seed sold by individual SEs in three years. Five SEs started maintenance breeding in wheat and by third year, over 50% of the seed sold by the enterprises consisted of newly released varieties compared to 20% before mentoring. The improved performance of SEs prompted seed quality control authority of Nepal to issue a license to two of these private seed companies for maintenance breeding cum foundation seed production. As a consequence, foundation seed production of these entities increased by 60% in three years, and two of them have also started maintenance breeding in rice from 2017. The facilitation in developing business plan by SEs helped them to attract financial resources from different sources in upgrading seed processing, storage and laboratory facilities. Moreover, the National Wheat Research Program of Nepal has proposed the release of a new wheat variety BL 4341 through integration of on-farm trials and seed production data of these SEs. This new variety is resistant to major diseases, yields 7% higher than the popular cultivar NL 297 which was released 32 years ago and needed replacement due to susceptibility to wheat rusts
P. triticina has a biotrophic relationship with wheat and needs certain elements from the wheat host for a successful life cycle. In recent years, several long lasting, minor resistance genes have been cloned, and their function suggests that the resistance is not due to a classic NB-LRR gene, but a gene that functions in a biotrophic pathway. The hypothesis was proposed that modification of a susceptibility gene can provide broad, long lasting resistance. To test this hypothesis, Thatcher was treated with EMS and screened for changes in susceptibility. M5 lines were evaluated in the greenhouse with BBBD Race 1 and 5 lines were identified. Also, M5 lines were planted in the field to verify the resistance and test the resistance effectiveness to natural infections of P. triticina. The same five lines were resistant in the field. Resistance ranged from few pustules, a race specific-like reaction, lesion mimics with few or no pustules, and near immunity. These lines were backcrossed to Thatcher, and resistant F2 plants were bulked and sequenced. Gene candidates will be identified and discussed.
Instituto Nacional de Investigaci?n Agropecuaria (INIA) La Estanzuela
Paula Silva, Clara Pritsch, Miguel Raffo, Silvia Pereyra, Silvia German
Wheat stem rust (SR), caused by Puccinia graminis f. sp. tritici, (Pgt) is considered one of the most destructive diseases of the wheat crop. As Sr24 and Sr31 are the most widely used resistance genes in the Southern Cone of America, wheat crops in this region is under threat of SR outbreaks posed by the potential migration of virulent Pgt Ug99-lineage races (Ug99+). Efforts have to be made to develop adapted lines resistant to Ug99+. Genes Sr26, Sr32 and Sr39 are effective to both Ug99+ and local races of the pathogen. This work is aimed to pyramid two and three of the resistance genes in two locally adapted wheat cultivars (G?nesis 2375 and G?nesis 6.87). Donor lines of Sr26, Sr32 and Sr39 (developed by I. Dundas, University of Adelaide, Australia) and molecular markers Sr26#43, csSr32#1 and Sr39#22r (developed by R. Mago et al., University of Adelaide) were used. Lines with two-gene combinations were developed in two steps. First, tree-way crosses were made by crossing heterozygous F1 plants (derived from crossings donor lines) to either one of the two adapted wheat cultivars. Subsequently, tree-way F1 plants were genotyped and only those with two-gene combinations were backcrossed (BC) twice to the adapted cultivars. Among three-way F1 plants, two-genes combinations were confirmed for Sr26+Sr32 (8 out of 31), Sr26+Sr39 (2 of 115) and Sr32+Sr39 (26 out of 103). In the BC1F1 generation, Sr26+Sr32, Sr26+Sr39 and Sr32+Sr39 combinations corresponded with 9, 9 and 45 out of 99, 27 and 241 plants, respectively. In 2017, 1345 BC2F1 plants are being grown to obtain BC2F2. We plan to intercross plants with two-gene combinations to obtain lines with the three genes which will be used as sources of resistance to develop cultivars with presumably longer lasting resistance to wheat SR.
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.
ICAR- Indian Institute of Wheat & Barley Research, Karnal-132001, India
Vinod Tiwari, DP Singh, RP Gangwar, GP Singh
The changing climatic conditions are affecting wheat production in major agro-ecological zones in India, namely, north western plains(NWPZ), north eastern plains(NEPZ), central (CZ) and peninsular zone(PZ) where the reproductive phase has to endure higher temperatures. Also, the prevalence and virulence of rust pathotypes and other diseases are affected. To address such challenges, development of wheat for climate resilience was initiated following shuttle breeding approach for incorporating heat stress tolerance as well as resistance to wheat rusts. During 2010-16, a total of 583 elite lines were evaluated against prevalent pathotypes of stripe rust 78S84, 110S119, 110S84 and 46S119; leaf rust 12-2(1R5), 12-5(29R45), 77-2(109R31-1), 77-5(121R63-1), 77-9(121R60-1) and 104-2 (21R55) and stem rust 11(79G31), 40A(62G29), 42(19G35), 122(7G11) and 117-6(37G19) of which 108 promising entries were identified. These lines were evaluated for disease response in multilocational Initial Plant Pathological Screening Nursery (IPPSN) against prevalent races of all three rusts. Based on average coefficient of infection (15.0 ACI), 42 (39%), 104 (96%) and 90(83%) entries were found resistant to different races of stripe, leaf and stem rusts, respectively. Based on performance in multiplication yield trials, 29 entries were contributed in national coordinated evaluation system on Wheat & Barley which resulted in release of four wheat cultivars DBW71(Yr9+27+,Lr26+,Sr2+5+31+), DBW107(Yr9+,Lr26+3+,Sr31+), DBW110(Yr2+, Lr13+10+,Sr13+11+) and DBW93(Yr9+, Lr26+23+, Sr31+) for commercial cultivation in NWPZ, NEPZ, CZ and PZ, respectively. These cultivars are becoming popular among farmers due to their yield advantage, resistance to diseases, tolerance to high temperature and better quality traits. Also, DBW 129 was screened in multiple disease screening nursery (MDSN) and observed resistant to all rusts, leaf blight, powdery mildew, flag smut and shoot fly. The adoption of the newly developed cultivars for deployment of differential genes for resistance would lead to reduction in disease pressure and bring higher profitability to farmers in different agro-ecological zones in India.