ICAR-IARI, New Delhi
Sudheer Kumar, Subhash Chandar Bhardwaj, Om Prakash Gangwar, Vaibhav Kumar Singh, Mukesh Kumar Pandey, Jaspal Kaur, Ashwani Kumar Basandrai, Deepshikha, Pradeep Singh Shekhawat, R.K. Devlash, V.K. Rathee
In India, wheat crop is a major contributor to the agricultural economy of India, occupying 30.7 mha area with 98.38 mt production. Stripe or yellow rust is a constraint to wheat production on about 12.0 m ha in the Northern Hills and North Western region of India. Varieties resistant at the time of release become susceptible usually within a few years due to new pathogen races. The present study conducted in 2015-16 was undertaken to identify stripe rust resistant genotypes among a set of 146 advanced breeding lines and popular cultivars. All genotypes were planted in two replications in northern India at ten locations viz., Karnal, Hisar (Haryana), Ludhiana, Gurdaspur (Punjab), Malan, Bajoura, Dhaulakuan (Himachal Pradesh), Pantnagar (Uttarakhand), Durgapura (Rajasthan), Jammu (J & K) and Delhi. After every 20 genotypes, infector (susceptible cultivar to both pathotypes) was planted. All genotypes were inoculated with mixture of prevalent Pst races 78S84 (Yr 27 virulence) and 46S119 (Yr 9 virulence) at Karnal. Out of 58 released cultivars grown in different zones of the country, fifteen lines (HS 507, DBW 90, HD 3086, WH 1080, WH 1124, WH 1142, HD 4728, HI 8498, HI 8737, MPO 1215 (D), NIDW 295 (d), UAS 428 (D), UAS 446 (D), DBW 71, KRL 210) showed stripe rust ACI < 10.00 (average coefficient of infection). But among advance 88 wheat lines, there was good level of resistance in 50 lines (ACI <10.00). Lines having AUDPC values <20% of those of the susceptible checks (maximum AUDPC value 2500 on susceptible check) were considered to be slow rusters. In present study, some of the wheat varieties (DBW 93, HS 490, PBW 723, PBW 644, VL 829, VL 892, WH 1105, WR 544 ) grown at present in northern India were identified as slow ruster lines. The information generated can be utilized in improving the stripe rust resistance of popular cultivars.
Turkey-ICARDA Regional Cereal Rust Research Center (RCRRC), ICARDA, Menemen, Izmir, Turkey
Muhammad Massub Tehseen, Ezgi Kurtulus, Maha Al Ahmed, Ahmed Amri, Mariana Yazbek, Ali Shehadeh
In 2016 the bread wheat (BW) and durum wheat (DW) landrace accessions were evaluated against PstS2 and in 2017 against a mixture of PstS2 and warrior race in field inoculations at Izmir precision stripe rust phenotyping platform. Inoculation was carried out three times during seedling, tillering and booting stages using mixture of fresh spore and talcum powder. Adult-plant responses of tested accessions were recorded according to 0-9 scale once the flag leaf of the susceptible cultivar became fully susceptible. During 2016, out of 3319 BW accessions, 1135 (36%), 871 (28%) and 1133 (36%) were found resistant (1-3 scale), moderately resistant (4-6), and susceptible (7-9) to PstS2, respectively. Amongst the resistant accessions in 2016, 1043 (33%) remained resistant while 786 (25%) showed moderate resistant and 1310 (42%) became susceptible. In 2017, 43% of moderately resistant accessions showed susceptibility to warrior race and 57% remained resistant to moderately resistant. Within the susceptible accessions to PstS2 race in 2016, 22% showed resistance to the warrior race and the remaining were susceptible. In case of DW in 2016, 76% (553) of the accessions were resistant to PstS2, 23% (163) were moderately resistant and only 1% (7) were found susceptible. In 2017, 329 (46%) of the resistant accessions were found resistant, whereas 289 (40%) and 105 (15%) showed moderately resistance and susceptible reaction to Warrior race, respectively. The present data indicated that BW landraces were generally more susceptible to stripe rust than DWs. Susceptibility of both BW and DW accessions to Warrior race indicated that most likely some of the uncharacterized resistance genes which conferred resistance to PstS2 were ineffective against the warrior race. Sources of resistance to both races were identified in both BW and DW. Genetic architecture of identified sources of resistance in present study requires further investigations.
Wheat Research Institute, Ayub Agricultural Research Institute,Faisalabad,Pakistan
Mehvish,Makhdoom, Javed, Ahmad, Makhdoom, Hussain, Iqra, Ghafoor, , , , , , , , , , , , , , , , , , , , , ,
Wheat crop is facing immense losses each year owing to climate change, eventually being major threat to global food security. So, the objective of the present study was to screening of advance lines under drought and heat stress conditions. In following study, 30 advance lines of wheat along with four checks(Faislabad-08, Millat-11, Galaxy-13 and ujala16) with three treatments (heat, drought, normal) were tested for different morphological (days to heading, plant height, days to maturity, biomass,1000 grain weight and grain yield) and physiological (canopy temperature at vegetative & reproductive stage, NDVI vegetative & reproductive), parameters. Biplot analysis depicted that V2, V3, V8, V14, V19, V25, and V30 showed the highest OP vector for grain yield in drought environment. Whereas, under heat conditions, V3, V4, V5, V10, V11, and V12 displayed their maximum longest vector for grain yield. Correlation analysis depicted that grain yield had non-significant correlation with canopy temperature (vegetative stage), normalized difference vegetation index (vegetative stage) canopy temperature (reproductive stage), plant height, days to heading and days to maturity under heat stress environment, while it had significant association with biomass and thousand grain weight. Under drought environment, grain yield had positive and significant correlation with biomass while on the other hand it had negative but significant association with normalized difference vegetation index (reproductive stage) and canopy temperature (reproductive stage). Best performing lines could be efficiently exploited in research programs to evade the perilous impact of climate change.
Dryland Agricultural Research Institute, Sararood branch, AREEO, Kermanshah, Iran
Ehsan,Lorestani, Reza, Haghparast, Mohammad Reza, Jalal Kamali, Ahmed, Amri, , , , , , , , , , , , , , , , , , , , , ,
Yellow rust (Puccinia striiformis Westendorf f. sp. tritici) is an important disease on wheat worldwide and especially in the highlands of West and Central Asia. Wheat landraces are composed of complex, variable, genetically dynamic and diverse populations, in equilibrium with both biotic and abiotic stresses prevailing in their environment. A germplasm collection consisting of 380 durum wheat accessions conserved at National Plant Gene Bank (Seed and Plant Improvement Institute, Iran) with worldwide origins, along with four check varieties were screened for resistance to yellow rust, and were also evaluated for several drought adaptative traits under rainfed conditions during 2009-10 cropping season at Sararood agricultural research station, Kermanshah, Iran. The study was conducted to quantify the phenotypic diversity and exploring durum accessions for yellow rust resistance, and to characterize the agronomic profile of different subsets of accessions for reaction to local yellow rust races. High natural infection, caused by the predominant virulent races of 6E8A+ and Yr27+, was experienced as shown by the 100 S reaction of the check bread wheat ?Sardari? and several highly susceptible accessions. The tested accessions exhibited significant variation in yellow rust severity, ranging from highly resistant to highly susceptible. Approximately 12.1% of accessions were found to be resistant to yellow rust, 9.5% were moderately resistant, 10.5% were moderately susceptible and 67.9% were susceptible. The germplasm showed a relatively modest response to yellow rust as expressed by a decrease in 1000-kernel weight (TKW) and a lower yield of the susceptible vs. resistant subsets by 11.4% and 19.9%, respectively. A comparison of foreign vs. Iranian resistant accessions, revealed higher yield productivity, higher TKW, and shorter plant height for the foreign accessions. Durum germplasm may constitute valuable genetic material for breeding new durum varieties characterized by high yield productivity under rainfed conditions and with adequate resistance to yellow rust.
Plant Pathology Research Institute
,, , , , , , , , , , , , , , , , , , , , , , , , , , , ,
Leaf rust resistance genes Lr9 and Lr19 were previously highly effective against the most predominant races of Puccinia triticina in Egypt. In 2015/2016 growing season, susceptible field reaction was recorded on these two genes where rust severity reached about 40S for Lr9 and 5S for Lr19 under Egyptian field conditions at four locations i.e. El-Behira, El-Minufiya, El-Qalubiya and El-Fayom governorates. Eight leaf rust field samples were collected from these governorates (four from each of Lr9 and Lr19). Forty single isolates were derived from the collected samples of Lr9 and Lr19 (each with 20 isolates). Eight pathotypes were identified from Lr9 and only two pathotypes were identified from Lr19. The most frequent pathotypes virulent to Lr9 were KTSPT (30%) followed by TTTMS (25%). Moreover, the other pathotypes ranged from 5 to 10%. Whereas, the most frequent pathotype virulent to Lr19 was CTTTT (85%) and the lowest PKTST was 15%. Pathotypes i.e. PRSTT, NTKTS and TTTMS identified from Lr9 were more aggressive on most of the tested leaf rust monogenic lines, as they were virulent to 36, 35 and 35 lines, respectively from a total of 39 lines. The two pathotypes; PKTST and CTTTT identified from Lr19 were virulent to 36 and 35 lines, respectively. Moreover, leaf rust pathotypes i.e. NPTNK and PRSTT from Lr9 and PKTST from Lr19 were the most aggressive on the tested wheat cultivars at seedling stage. The Lr2a was the most effective leaf rust resistance genes against the tested pathotypes at adult plant stage. Wheat cultivars Misr 1, Misr 2 and Nubariya 1 were the most resistant cultivars against the tested pathotypes at adult plant stage.
Northwest A&F University
Yanping,Fu, kang, Wang, Yingbin, Hao, Zhensheng, Kang, , , , , , , , , , , , , , , , , , , , , ,
Wheat adult plant resistance (APR) to stripe rust, a non-race-specific and durable resistance, is ideal for breeding. However, the knowledge concerning APR mechanism is largely limited. In order to further investigate the molecular basics of APR to provide guidance for wheat breeding, we conducted the transcriptome sequencing of wheat XZ9104 infected by Puccinia striiformis f. sp. tritici (Pst) at seeding and adult stages, respectively. Comparative analysis revealed that many WRKY transcription factors (TFs) may participate in the APR to stripe rust, of which, TaWRKY79 transcript levels were sharply elevated at the early infection stage in seedling plants. To dissect the relationship between TaWRKY79 and APR, we further studied the function of TaWRKY79. Subcellular localization showed that TaWRKY79 is located in the nuclear, and TaWRKY79 protein contains a separated region for mediating transcriptional activation at the C-terminus (246-328 aa) by yeast one-hybrid analysis. When TaWRKY79 was silenced by virus-induced gene silencing (VIGS) in seedling plants, the Pst growth was attenuated, with shortened hyphae, reduced hyphal branches and colony size. Meanwhile, the expression of TaWRKY79 was highly suppressed by salicylic acid (SA) but induced by jasmonic acid (JA) in seedling of wheat, and the transcription levels of LOX2 and PDF2.2 were significantly reduced, but the expression of PR1.1 was enhanced in TaWRKY79 knocking-down seedlings of wheat. Hence, these findings suggested that TaWRKY79, as a SA/JA cross talk, might play a negative role in resistance defence response to Pst infection at seeding stage by simultaneously activating the JA-dependent pathway and suppressing the SA-dependent pathway.
National Agronomic Institute of Tunisia
FATMA,BEN JEMAA, HAJER, SLIM-AMARA, , , , , , , , , , , , , , , , , , , , , , , , , ,
Wild species with valuable genetic heritage was used long time ago in interspecific crosses to improve cultivated plants adaptation to environmental constraints. The objective of this study is to transfer the salinity tolerance of Hordeum marinum, a wild barley species, to three durum wheat varieties (Karim, Razzek and Nasr) by intergeneric crosses. In order to skip the incompatibility between these species, in vitro immature embryo rescue was performed using B5 medium (Gamborg et al., 1968). The results showed that the genotype has an important effect on the success of the crosses and the rate of regenerated plants. We have found that 34.21% of the embryos derived from hybridization Razzek x Hordeum marinum has regenerated haploid plantlets, 5.88% for Karim x Hordeum marinum cross, and 2.78% for Nasr x Hordeum marinum.
The obtained chromosomal stock of the hybrid haploid plants was doubled by colchicine treatment concentrated at 0.05%. The rate of doubled haploid plants were reduced after colchicine treatment to 26.32% for Razzek x Hordeum marinum cross, 0% for Karim crossed with Hordeum marinum and remained unchanged for Nasr x Hordeum marinum.
The doubled haploids obtained are subjected to salt stress (6-12 g/l) in order to evaluate their tolerance to salinity.
Michel E. Ghanem, Sarrah Ben M'Barek, Gustavo Azzimonti, Silvia Pereyra, Silvia Germán, Felix Marza, Amor Yahyaoui, Pawan Singh, Michael Baum, Hans-Joachim Braun
Based on a global network of wheat partners, precision field-based wheat phenotyping platforms are being developed with the support of the CGIAR Research Program on Wheat and co-investing national agricultural research institutes. This collaboration strategy aims to i) strengthen the quality of phenotypic data to fully exploit the potential of genomic data, ii) strategic prioritization of activities based on trait screening capacities and regional needs, iii) sharing knowledge and germplasm to accelerate superior germplasm development and dissemination, iv) development of capacities. Phenotyping activities are being conducted for wheat blast (Magnaporthe oryzae) in Bolivia, Septoria tritici blotch (STB) in durum wheat in Tunisia, and for multiple diseases (leaf rust, Fusarium head blight, and STB) in bread wheats in Uruguay. Subject to further funding, additional platforms will be implemented, to contribute to a faster development of broad genetic based resistant, high yielding wheat varieties, and complementing evaluations currently performed for diseases and heat, drought and yield potential (Kenya, Ethiopia, Turkey, Mexico).
The University of Agriculture, Peshawar, Pakistan
Muhammad,Khan, Sangay, Tshewang, Sarala, Lohani, David, Hodson, Muhammad, Imtiaz, Sajid, Ali, , , , , , , , , , , , , , , , , ,
The Himalayan region of Pakistan and China has been shown to be the centre of diversity of Puccinia striiformis, however, little is known about the Eastern part of the Himalayas. We studied the genetic structure of P. striiformis from Nepal and Bhutan in comparison with Pakistan through microsatellite genotyping of 66 isolates from Nepal (35 isolates) and Bhutan (31 isolates) collected during 2015 and 2016. Genetic analyses revealed a recombinant and highly diverse population structure in Bhutan and Nepal. A high level of genotypic diversity was observed for both Bhutan (0.92) and Nepal (0.67) with the detection of 53 distinct multilocus genotypes (MLGs) in the overall population; 28 for Bhutan and 27 for Nepal. Mean number of alleles per locus was higher in Bhutan (3.33) than Nepal (3.11), while the gene diversity was higher in Nepal (0.4279) than Bhutan (0.3552). A non-significant difference between the observed and the expected heterozygosity in both populations further confirmed the recombinant structure. Analyses of population subdivision revealed a low divergence between Nepal and Bhutan (FST=0.1009), along with the detection of certain common MLGs in both populations. The overall population was clearly divided into six genetic groups, with no geographical structure, confirmed by the distribution of multilocus genotypes over two countries, suggesting a potential role of migration. Comparison with the Pakistani P. striiformis population suggested a high genotypic diversity in Nepal (0.933) and Bhutan (0.959), though lower than the previously reported from Himalayan region of Pakistan (Mansehra; 0.997). The overall high diversity and recombination signature suggested the potential role of recombination in the eastern Himalayan region (Nepal and Bhutan), which needs to be considered during host resistance deployment and in the context of aerial dispersal of the pathogen.
Nepal Agricultural Research Council, National Agriculture Genetic Resources Centre, Khumaltar, Lalitpur
Baidhya Nath,Mahto, Mina Nath, Paudel, Dhruba Bahadur, Thapa, Krishnahari, Ghimire, Bal Krishna, Joshi, Suraj, Baidya, Prem Bahadur, Magar, , , , , , , , , , , , , , , ,
Naked barley (Hordeum vulgare var. nudum L.), is an important winter crop grown in the mountain region of Nepal. Stripe rust (Puccinia striiformis f.sp. hordei), is the most destructive fungal disease of barley in the hills of Nepal with losses up to 100 %, occurring in cooler regions with higher altitude (1000-2500 m). Yield components along with final rust severity (FRS), area under disease progress curve (AUDPC) and average coefficient of infection (ACI) were evaluated for 20 indigenous barley accessions collected from mountainous region of Nepal at National Agriculture Genetic Resource Centre (Genebank), Khumaltar, Nepal during winter season of 2016-2017 with three replications. Barley cultivars displayed a range of severity from 0% to 100% with immune to susceptible reaction. AUDPC values were significantly different among the tested genotypes. Barley genotypes with accession number NGRC00837 (ACI-3), NGRC02357 (ACI-7), NGRC06026 (ACI-9) and NGRC02306 (ACI-12) were found resistant with lowest diseases progress while NGRC02350 (ACI-60), NGRC06036 (ACI-80), NGRC02312 (ACI-86), NGRC04003 (ACI-83) and NGRC02318 (ACI-93) were found as highly susceptible landraces. Correlation coefficients of agronomical parameters such as grains per spike and 1000-kernels weight with epidemiological parameters such as AUDPC and ACI were found highly significant. Resistant genotypes with low values for disease progress as well as diseases reaction were identified. The results indicate that source of resistance to yellow rust in naked barley genotypes are available in Nepal and can be used for resistant breeding in future.