Wheat Research Institute, Faisalabad, Pakistan
Ghulam Mahboob Subhani, Javed Ahmad, Abid Mahmood
Global warming affects the environmental parameters of agro-based countries like temperature increase, melting of glaciers, floods, erratic rains, low temperature, frost and high temperature. As a result agriculture is becoming more vulnerable to global environmental shifts. In case of wheat, erratic or low rains badly affect the wheat crop of rainfed areas of the country along with high temperature at seedling or juvenile stage. Similarly, frost affects the early sown wheat crop in irrigated areas of Punjab. Lesser availability of irrigation water from water reservoirs also reduces the wheat crop productivity. Sudden increase in temperature (>30?C) during the month of March adversely affect the grain filling. High temperature during grain filling stage interferes with the photosynthetic activities of the plant due to enhanced maturity, grain become shriveled and results in low grain yield. The threat of these environmental changes can only be overcome through breeding with specific objectives which is cost effective once obtained.
Hence development of wheat varieties for frost, drought and heat tolerance is the only feasible solution to combat these stresses which is being used at Wheat Program of Ayub Agricultural Research Institute, Faisalabad, Pakistan. New emphasis is also being given to develop frost resistant wheat varieties due to changing scenario of last few years. The institute is actively involved for the development of heat, drought and frost tolerant wheat varieties. During working for tolerance against any of these stresses plant types to be breed are physiologically and morphologically modeled in such a way that they should be capable of tolerating respective stress. In addition to breeding work an extensive research is also being done at Wheat Research Institute, AARI., Faisalabad to investigate best agronomic strategies to make wheat crop best adapted to environmental stress conditions.
Scuola Superiore Sant'Anna
Yosef G.,Kidane, Cherinet, Alem, Bogale, Nigir, Dejene, Mengistu, Carlo, Fadda, , , , , , , , , , , , , , , , , , , ,
The Ethiopian plateau hosts thousands of durum wheat landraces cultivated in low input agriculture conducted by an estimated 70 million smallholder farmers. Having thoroughly characterized the phenotypic and molecular uniqueness of Ethiopian durum wheat landraces, we produced a large nested association mapping (NAM) population harnessing their mostly untapped diversity in a set of recombinant inbred lines (RIL). The NAM founders are 50 landraces providing valuable traits such as drought tolerance and resistance to pests, and maximizing molecular diversity. Each selected landrace was crossed to a durum wheat line with an international background (Asassa), establishing independent interconnected bi-parental families, for a total of 6,280 RILs currently in F8. The Ethiopian NAM is at once i) a powerful QTL mapping tool that will side the increasing availability of genomic tools in wheat towards high-throughput candidate genes identification, and ii) a large pre-breeding panel closing the gap between local and international materials. Here we discuss the molecular and phenotypic characterization of twelve NAM families, represented by 100 RILs each. The 1,200 NAM RIL showed elevated allelic variation and a genetic structure reminiscent of the breeding design followed. The NAM RILs were phenotyped for ten agronomic and five disease traits in multiple locations in the Ethiopian highlands. A quantitative method eliciting smallholder farmers traditional knowledge was used to record local farmers appreciation of NAM RILs in all phenotyping locations. We report that the superior genetic properties of the NAM can be used to map QTL for both agronomic and farmer traits with unprecedented precision. The most promising NAM RILs can be identified combining farmers appreciation and agronomic measures, and prioritized for introgression of Ethiopian landraces traits in breeding pipelines aiming at higher uptake and productivity in local agriculture.
Agriculture Botany Division, Nepal Agricultural Research Council
Baidya Nath,Mahto, Sarala, Sharma, Madan Raj, Bhatta, Mahesh, Subedi, Deepak, Pandey, Nutan Raj, Gautam, Suraj, Baidya, Roshan, Basnet, Rudra, Bhattarai, Ajaya, Karkee, Suk Bahadur, Gurung, Prem Bahadur, Magar, Sunita, Adhikari, Bhagarathi, Shahi, Basistha, Acharya
A total of 41 bread wheat (Triticum aestivum L.) varieties have been released so far in Nepal since 1960. Farmers have been gradually adopting newly released varieties due to disease and lodging resistance, better yield performance and good taste. In Nepal, wheat area coverage, production and productivity have been increased by almost seven, sixteen and two folds, respectively in the last 56 years. Performance of varieties varies from one region to another. Yellow rust is the major problems in hills while leaf rust is the primary issue on the plains. Stem rust is sporadic in localized areas of Nepal. Wheat research program in Nepal has released 9 wheat varieties resistant to Ug99 namely Vijaya, Tilottama, Banganga, Gaura, Dhaulagiri, Danphe, Sworgadwari, Munal and Chyakhura. Vijay, Tilottama and Banganga are also resistant to leaf rust while, Dhaulagiri, Danphe, Sworgadwari, Munal and Chyakhura are resistant to yellow rust. Since the release of Vijay, the first Ug99 resistant variety in Nepal during 2010, source seed production of rust resistant varieties has been increasing significantly each year with present coverage under these varieties being around 40%. WK 1204 has been occupied 35% area in hills of Nepal. Seed production and distribution of such high yielding disease resistant varieties through public-private partnership is leading to quality seed supply for varietal diversity and better food security in the country.
International Maize and Wheat Improvement Center (CIMMYT), P.K. 39 Emek 06511 Ankara, Turkey
Nilufer,Akci, Sridhar, Bhavani, Mesut, Keser, Fatih, Ozdemir, Ruth, Wanyera, Alexey, Morgounov, , , , , , , , , , , , , , , , , ,
A diverse set of winter wheat germplasm was screened for resistance to stem rust in large-scale trials in Kenya and Turkey during 2009-16. The study aimed to select resistant material and characterize types of resistance and possible genes, as well as evaluate agronomic traits and resistance to other diseases to select superior variety candidates and parental lines. The study material was comprised of various Facultative and Winter Wheat Observation Nurseries (FAWWON), which are developed and distributed by the International Winter Wheat Improvement Program (www.iwwip.org) in Turkey. More than 1600 global accessions were screened, with most evaluated for two years. Based on stem rust data from Kenya, more than 400 genotypes were identified exhibiting adequate levels of resistance to the Ug99 race group. The highest number of resistant lines originated from IWWIP (~170), USA (~100), Russia (~40), Iran (~30), Romania (~20), and South Africa (~20). Material was also tested at two sites in Turkey: Haymana (artificial inoculation) and Kastamonu (natural infection). There was no significant correlation between stem rust severities in Kenya and in Turkey, due to differences in stem rust pathotypes. However, a set of germplasm (more than 100 entries) has been identified as resistant in both countries. This set represents promising material as variety candidates and parental lines; another study is currently identifying the genes controlling the stem rust resistance in this population. IWWIP distributed stem rust resistant germplasm to its global collaborators during 2010-2015, in response to the threat from the Ug99 race group. New resistant germplasm combining broad adaptation, high yields, and resistance to other diseases is available on request.
Rosemary,Shrestha, Kate, Dreher, Victor, Jun Ulat, Luis A., Pubela Luna, Susanne, Dresigacker, , , , , , , , , , , , , , , , , , , ,
The Global Wheat Program of CIMMYT is one of the largest public breeding programs in the world consisting of millions of lines/ genotypes derived from thousands of crosses evaluated under using a shuttle breeding cycle and multi-environment testing. The germplasm is phenotyped for conventional (such as yield and grain quality) as well as non-conventional traits (physiological traits) in field and greenhouse conditions. The breeding germplasm is also screened with genome-wide markers (using Illumina SNP array, genotyping-by-sequencing, or DArTseq platforms) and/or multiple gene/QTL region-specific molecular markers (using KASP platform). All genotyped samples are registered in the "DNA SampleTracker," a software system for tracking DNA samples developed at CIMMYT. In collaboration with High Throughput Genotyping Platform project, the plant sample and data collection methods are optimized. Meanwhile, the extensive wheat genealogies and phenotypic information have been maintained in the International Wheat Information System and will be transferred to a new Enterprise Breeding System. Furthermore, several bioinformatics/statistical genetics methods with the objectives of gene discovery and genomic prediction have been developed and utilized for optimizing genomics-assisted selection. The wheat team is a member of "Genomic Open-source Breeding Informatics Initiative (GOBII)" which aims to develop and implement genomic data management systems to enhance the capacity of breeding programs. Under this initiative, a new genomics database has been built and a pilot wheat version is being tested at CIMMYT. Several decision support tools are also under collaborative development, such as a Genomic Selection Pipeline based on Galaxy, Flapjack-based F1/line verification, and marker assisted backcrossing tools. Additional tools are envisioned for the future including a Cross-Assistor and Selection-Assistor. The ultimate aim is to seamlessly connect the genomic database, phenotypic database, and decision support tools to support the breeding selection process and to lead to the development of cultivars with increased rates of genetic gain.
ICAR Indian Institute of Wheat and Barley Research, Karnal
Satish Kumar, Rekha Malik, Garima Singhroha, Vinod Tiwari, Gyanendra Pratap Singh
Breeding rust resistant cultivars using conventional methods is time-consuming, complex and slow, but molecular markers offer a rapid alternative for developing cultivars with improved disease resistance. Three wheat cultivars, DBW88, DBW107, and DBW110, from different production zones were used as recipients for incorporation of resistance genes using a marker-assisted backcross (MAB) breeding approach. Leaf rust resistance gene Lr32 is being incorporated into all the three varieties, stripe rust resistance gene Yr15 is being incorporated into DBW88 and DBW107, and stem rust resistance gene Sr26 is being added to variety DBW110. Lines PBW703 (Yr15), FLW15 (Lr32) and Avocet (Sr26) were used as donors. Six cross combinations viz., DBW88/PBW703, DBW107/PBW703, DBW88/FLW15, DBW107/FLW15, DBW110/FLW15 and DBW110/Sr26 were made at Karnal during 2015-16 and the crosses were grown at IIWBR-RS, Dalang Maidan for backcrossing. BC1F1 plants were raised at Karnal during 2016-17. Both foreground and background selections were practiced in each combination. SSR markers gwm264 and barc135 were used for foreground selection of Lr32, marker barc8 was used for selection of Yr15, and markers Sr26#43 and BE518379 were used to detect presence and absence of Sr26. From 90 to 127 polymorphic SSR markers chosen for each cross from an initial set of 800 screened on the parents are being used for background selection.
Muhammad,Noor, Makhdoom, Hussain, Majid, Nadeem, Monsif, ur Rehman, Jesse, Poland, Ravi, Prakash Singh, Matthew, Reynolds,, , , , , , , , , , , , , , , ,
Drought and heat along with rusts are the most common biotic and abiotic stresses that affect growth, development and yield of wheat crop in Pakistan. CIMMYT in partnership with Wheat Research Institute Faisalabad (WRI-Fsd), USDA, and Kansas State University initiated an effort to develop heat tolerant, high yielding, and farmer-accepted rusts resistant wheat varieties for Pakistan. A set of 1656 wheat lines received in the form of EPCBW and SABWGPYT nurseries were tested in 2013-14 and 2014-15 wheat season, respectively. Testing of the materials at (WRI-Fsd), Pakistan under normal and late planting conditions resulted in the selection of 55 lines with higher grain yield and resistant to both leaf (LR) and yellow (YR) rusts. Among these lines, the line no. 1027 produced maximum yield (5.78 ton/ha) under normal and line no. 5030 produced maximum yield (3.38t/ha) under late planting conditions with resistance to both LR and YR. Further evaluation of the selected 55 lines as HYT-60 in 2015-16 showed the average grain yield ranged from 4.98 to 2.51 ton/ha under normal and 1.74 to 0.73 t/ha under late planting. Three lines HYT-60-57, HYT-60-7 and HYT-60-5 were included in the first year advanced yield trials to test for their potential as commercial cultivars while another seventeen lines were distributed as HYT-20 to six national wheat breeding programs for yield testing at key location which will enable national partners to combine yield potential with resistance to biotic and abiotic stresses.
Ethiopian Institute of Agricultural Research (EIAR)
Stripe rust caused by Puccinia striiformis f.sp.tritici, is one of the major diseases of wheat in the world. Experiments were carried out at two sites in Ethiopia (Kulumsa and Meraro) during the 2015 cropping season to evaluate the response of 198 elite bread wheat genotypes and two checks to the prevailing races of stripe rust at adult plant and seedling stage. The genetic profile of these genotypes was assessed using 13006 SNP markers and an association mapping was explored to determine marker?trait association. About 72.5% and 42.5% of the lines exhibited resistance at Kulumsa and Meraro, respectively. Out of 198 genotypes tested in the greenhouse, 31% exhibited common resistance for Kubsa and mixed stripe rust isolate. Only 8966 of the SNPs were polymorphic, only these were used for association mapping analysis. These markers spanned an average density of 3.47 cM per marker, with the poorest density on the D genome. Almost half of these markers were on known chromosomes, but had no position on the consensus map of bread wheat. Analysis of population structure revealed the existence of three clusters and the estimated genomic wide Linkage Disequilibrium (LD) decay in this study ranged from 0 to 50 cM. 53 SNPs in ten genomic regions located on wheat chromosome 1AL, 2AL, 2BL, 2DL, 3BL, 4BL, 4DL, 5AS, 7AL and 7BL were identified. Thirty nine SNP markers in five genomic regions at Kulumsa and 14 SNP markers in six genomic regions at Meraro explained more than 25.5% and 35.1% of phenotypic variability respectively. For seedling stage, 21 markers in ten genomic regions located on wheat chromosomes 1B, 2A, 2B, 3A, 3B, 4B, 4D, 5A, 6B and 7B were associated with resistant. These loci may be useful for choosing parents and incorporating new resistance genes into locally adapted cultivars.
Maize Research Institute Zemun Polje
Dragana Ranćić, Vesna Kandić, Biljana Vucelić-Radović, Jasna, Savić, Miroslav Zorć
When environmental stress develops during reproductive phases of growth, wheat plants have to rely increasingly on remobilisation of previously stored assimilates to maintain grain filling. The present study was undertaken to determine the effect of several peduncle (the uppermost stem internode) morpho-anatomical and biochemical traits on grain weight, and to assess the contribution of the peduncle water-soluble carbohydrate (WSC) reserves shortly after anthesis to its variation. In 2-year field trials, 61 wheat genotypes were used (27 F4:5 families, 17 parents used for the crosses and the 17 current best standards) comparing intact control plants (CP) with plants that were defoliated (DP) by cutting off all leaf blades 10 days after anthesis to simulate terminal stress. Estimated contributions of peduncle assimilate reserves to grain weight/spike were from 0.06 to 0.31% and from 0.11 to 0.45% in CP and DP plants, respectively. High peduncle reserve mobilization efficiency, a longer exposed part of the peduncle and larger peduncle storage capacity (through higher parenchyma and/or lower lignified area) were of specific benefit for maintaining grain weight in defoliated plants. There was a large difference in compensation of grain yield loss by dry matter remobilization within studied genotypes (in average 1.2-36.1%). Although compensation of yield loss might be improved through breeding process (our F4:5 families had slightly higher mean compensation effect than their parents under moderate stress), it does not mitigate the effect of post-anthesis drought in great extent (up to 38.4%).
All-Russian Institute of Plant Genetic Resources
Wheat varieties with single effective gene for leaf rust resistance often quickly become susceptible because of multiplication of virulent Puccinia triticina genotypes. One of the methods to elongate term of effectiveness is to combine two genes in host genotype. To note, it is impossible to distinguish phenotypically plants or families having one or two genes in hybrid populations; the only method is to use PCR producing DNA markers linked to each gene for resistance. It is not convenient when necessary to analyze thousands plants or especially families of crosses between carriers of certain genes. At inoculation of wheat seedlings having Lr 9, 19, 24, 47, 29 and Sp with rust population from North-West region of Russian Federation all of them were absolutely resistant, so these genes may be considered to be effective in this region. Rust population was multiplied on cv. Leningradka leaf segments placed on cotton wool wetted with solution of maleic acid hidrazide (10 mg/l) + potassium chloride (0.48 g/l) +monosubstituted sodium phosphate (0.66 g/l) and used to infect seedling of the lines constantly poured with the solution. Rare pustules were recorded on each line. Isolates from the line were combined, multiplied and used to infect the lines set. Interaction specificity was shown for carriers of certain genes for resistance and inoculums. We propose to infect seedlings of hybrid wheat populations with mixtures of isolates virulent to first gene and those virulent to second one at use of above-mentioned method to multiply rust and grow plants. Seedlings resistant to that inoculum have both genes for resistance. If we have F3 or later families it is possible to use original population without selection of virulent isolates; in this case the method allowed removing progenies of heterozygous plants. With this approach we developed lines possessing combinations of Lr9+Lr24 and Lr9+Lr47 genes