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%).
Department of Plant Sciences, University of the Free State, South Africa
Marcel Meyer, Robert Park, Christopher Gilligan, Laura Burgin, Matthew Hort, David Hodson, Zacharias Pretorius
Despite being 10,000 km apart, the current study emphasizes the potential vulnerability of Australia to wind-borne Puccinia graminis f. sp. tritici (Pgt) spore introductions from southern Africa. Of four Pgt introductions into Australia since 1925, at least two (races 326-1,2,3,5,6 and 194-1,2,3,5,6) are thought to have originated from southern Africa. Microsatellite analysis of 29 Australian and South African Pgt races confirmed close genetic relationships between the majority of races in these two geographically separated populations, thus supporting previously reported phenotypic similarities. Using Lagrangian Particle Dispersion Model simulations with finely-resolved global meteorological data over a 14-year period and a three-day urediniospore survival time, the study showed that long distance dispersal of Pgt from southern Africa to Australia is possible, albeit rare. Transmission events occurred most frequently from central South Africa, but were also possible from southern South Africa and Zimbabwe; while none occurred from a representative source-location in Tanzania. Direct dispersal incursions into both the western and eastern Australian wheat belts were feasible. Together, the genetic and simulation data strongly support the hypothesis that earlier introductions of Pgt into Australia occurred through long-distance wind-dispersal across the Indian Ocean. The study thus acts as a warning of possible future Pgt dispersal events to Australia which could include members of the Ug99 race group. This emphasizes the continued need for Pgt surveillance on both continents.
Faculty of Agriculture, The University of Jordan
Moneer Mansour, Nasab Rawashdah, Rabei Sayaydeh
Durum wheat (Triticum turgidum subsp. durum) landraces are rapidly disappearing from the main wheat production areas in the Fertile Crescent. Such local landraces are most likely contain geographically specific, ectopically adapted alleles or gene complexes for their harsh environments. A panel of 156 durum wheat landraces and released varieties were assembled from historical collections deposited in national and international gene banks and from a recent active collection mission from selected areas across Jordan. The panel were evaluated under field conditions in two different locations for one growing season. Data for days to heading, plant height, peduncle length, number of spikes spike length, spike weight, grains number, grains weight, number of kernels per spike and thousand-kernel weight were recorded. Results indicate the existence of a wide variation between the tested genotypes for all tested agronomical traits. For heading date, the Jordanian landrace "JDu103" was the earliest under dry environment conditions. Regarding grains weight and spike weight, the Jordanian landrace "JDu105" produced the highest mean value under humid conditions. Another landrace "JDu46" produced the longest spikes and the highest TKW mean value, while the Jordanian landrace "JDu105" produced the heaviest spikes weight mean value, while "JDu100" produced the highest grains number. For molecular analysis, total genomic DNA was extracted from each genotype and then used for SNP genotyping using Illumina iSelect wheat 90k SNP chip. Structure analysis showed that the analyzed durum wheat panel can be divided into three genetically distinct subgroups. The GWAS analysis identified 93 significant markers-traits associations for multiple traits with two QTLs located at 7A and 7B, which seems important for TKW in durum wheat under dry environments. In conclusion, the Jordanian landraces used in this study showed wide genotypic and phenotypic variability, which can be considered by plant breeders for their future use in breeding programs.
AgriLife Research, Texas A&M University
Monsanto, through the MBBIScholars Program, has invested $13 million over an 8 year period for training rice and wheat breeders from around the World. The Judging Panel for MBBISP selected 89 Scholars from 432 applicants. The selected scholars were from 30 different countries. Scholars selected included 35 young ladies and 54 young men, 37 are in rice breeding and 52 in wheat breeding. Currently 28 Scholars are still completing their PhD programs (As of 8/8/2017). This past year Monsanto established the "Ted Crosbie Monsanto Beachell-Borlaug International Scholars Impact Award" to begin recognizing Scholar contributions. To be eligible for the "Ted Crosbie MBBIScholars Impact Award," scholars must have received their PhD and must apply for the award. Bhoja Basnet, selected as an MBBIScholar in 2009 who is now in charge of CIMMYT's Hybrid Wheat Breeding program, was selected to receive the "Ted Crosbie Monsanto Beachell-Borlaug Scholars Program Impact Award" this year. Scholar contributions are in wheat and rice breeding as well as in other crops. Hopefully the Ted Crosbie MBBIScholars Impact Award will continue to recognize accomplishments of Scholars into the future. MBBIScholars are making an impact and we look forward to recognize their career contributions. Employment of Scholars post PhD will be reviewed.
Institute of Agricultural Sciences, Banaras Hindu University, India-221005
Punam Singh,Yadav, Naveen Kumar, Umesh Chandra, Dubey, Ramesh Chand, Sundeep Kumar, Arun Kumar Joshi
Four leaf rust adult plant resistance genes (Lr34, Lr46, Lr67 and Lr68) are known to be associated with leaf tip necrosis (LTN). LTN caused by these genes is different from each other at phenotypic level. LTN associated with APR genes Lr34, Lr46 and Lr67 has been designated as Ltn1, Ltn2 and Ltn3. Seventy-seven CIMMYT genotypes were selected to find out the association between genotypic and phenotypic variability for LTN and its association with yield traits; 1000 grain weight, grain yield, leaf area and percentage of leaf tip necrosis in the flag leaf of main tiller. All the genotypes were screened for the presence of 3 APR genes with linked markers, csLV34 for Lr34; Xwmc44 and Xgwm259 for Lr46 and Xcfd71 for Lr67. The genotypes were grouped into 5 classes; only Lr34, only Lr46, only Lr67, Lr34+L46+Lr67 and genotypes lacking all three genes. Molecular analysis revealed that 7 genotype with Lr34 only, 6 with Lr46 only, 7 with Lr67 only, 13 with all the 3 genes, and 28 without any Lr gene. Phenotypic data of LTN percentage was compared and it was noted that maximum LTN % was observed for Lr67 (7.811%) followed by Lr46 (7.348%) and Lr34 (6.47%). Surprisingly, presence of all three genes reduced the LTN% (4.7055%) as compared with absence of all three genes (6.011%). It was also observed that the three genes simultaneously reduced 1000 grain weight and plot yield. All three genes increased leaf area highly significantly both when they are alone or together (34.7 to 44.7 cm2) in comparison to those genotypes (24.7 cm2) which lacks these Lr genes and also reduced 1000-grain weight and plot yield but non-significantly.
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.
Cereal Crops Research Institute (CCRI), Pirsabak Nowshera Khyber Pakhtunkhwa-Pakistan
Gulzar,Ahmad, Imtiaz, Muhammad, Khilwat, Afridi, , , , , , , , , , , , , , , , , , , , , , , ,
In the current scenario of climatic change, exploration and development of new stable genotypes performing better under stressed and non stressed environmental conditions is the priority of wheat breeders for exploiting genetic variability to improve stress tolerant cultivars. Late planting is one of the major abiotic stresses, seriously influencing wheat production. In the current study, twenty eight bread wheat genotypes were evaluated independently under normal (optimal) and late (stress) planting conditions at Cereal Crops Research Institute (CCRI), Pirsabak Nowshera Khyber Pakhtunkhwa Pakistan during 2013-14. Analysis of variance revealed highly significant (P < 0.01) differences among the genotypes, planting (sowing dates), and genotype ? sowing dates interactions effects for the studied traits. Generally, reduction in plant height (0.41 to 10.91%) and grain yield (0.36 to 53.35%) was observed among the tested genotypes under late planting as compared to normal (optimal) planting. Least % reduction in grain yield was recorded for genotypes BWL-23 (0.36%), BWL-4(0.76%), BWL-16(1.22%) and BWL-13 (1.78%) and were found tolerant to late planting stress as compared to check (Pirsabak-2008). Eight stress selection indices i.e. Mean productivity (MP), Tolerance (TOL), Geometric Mean Productivity (GMP), Harmonic mean (HM), Stress selection Indices(SSI), Stress Tolerance Index (STI), Yield Index (YI) and Yield Stability Index (YSI) were determined based on mean performance of genotypes evaluated under normal and late planting conditions. Analysis of correlation revealed that plant height and grain yield under normal and late planting conditions, had significant positive correlation with stress selection indices i.e. GM, HM, SSI and YI. These selection indices could be effective in identification of lines/ genotypes to late planting stress tolerant conditions. Based on MP, GMP, HM, STI and YI genotypes i.e. Pirsabak-2008, BWL-23 and BWL-27 were found late planting stress tolerant and could be recommended for sowing in both normal and late planting.
Wheat Disease Research Department, Plant Pathology Research Institute, Agricultural Research Center, Giza, Egypt
Stripe rust (Puccinia striiformis f. sp tritici) (Pst) infected wheat samples collected from three Egyptian Governorates (Alexandria, Beheira and Kafr-El Sheikh) were processed for race analysis to determine the race identity among the current populations of the stripe rust fungus. Single uredinial isolates were inoculated to a core set of the 17 World/European differential hosts along with wheat lines with Yr17, Yr25, Yr32. Based on virulence phenotyping, the data revealed that the current populations of Pst belong to three races: Triticale aggressive (virulent to Yr2, Yr6, Yr7, Yr8, Yr10); PstS3 (virulent to Yr2, Yr6, Yr7, Yr8, Yr25); and PstS2 (virulent to Yr2, Yr6, Yr7, Yr8, Yr9, Yr25, Yr27). No collections were found with the Warrior race, that has virulence to Yr1, Yr2, Yr3, Yr4, Yr6, Yr7, Yr9, Yr17, Yr25, Yr32, YrSp).
All Russian Research Institute of Biological Plant Protection
Irina Petrovna Matveeva
Yellow rust caused by Puccinia striiformis West. is a harmful and dangerous disease in the south of Russia. Yield losses under optimum conditions on highly susceptible varieties can vary from 10 to 100%. During the growing season of 2017, cool weather with constant precipitation from the third decade of April to the first decade of June contributed to the intensive development of the pathogen. Surveys of the main winter wheat production areas in five agroclimatic zones of the region revealed that yellow rust was prevalent in all areas. The maximum development of P.striiformis was observed in southern submontane and western Priazovsky agroclimatic zones. Some varieties such as Grom, Yuka, Tanya, Anka had losses to yellow rust of up to 30-40 %. In the central and northern agroclimatic zones, the losses averaged 5%, whereas in the dry eastern steppe zone losses were only up to 1%. The build up of yellow rust inoculum in the region raises concerns that in 2018, under favorable weather conditions in spring, winter wheat crops could be infected with the disease, especially in the wetter agroclimatic zones.
Sulaimani University,IKR, Iraq
Rusts continue to cause significant losses in grain yield of wheat in Iraq. Substitution of susceptible cultivars with resistant ones is an important step in reducing the vulnerability of the wheat crop. The present study represents a breeding program to develop high yielding bread wheat cultivars with resistance to brown rust and yellow rust. The performance of 265 spring wheat genotypes representing an international bread wheat-screening nursery from CIMMYT were evaluated in different agro-ecological zones in comparison with local commercial cultivars. Adult plant stage screening of the materials for brown rust and yellow rust reaction under inoculated conditions for three successive seasons identified 29 resistant and 59 moderately resistant genotypes, and 79 genotypes out-yielded the local cultivars. The selected lines were comprehensively evaluated for grain yield potential and disease response in different locations and agro-systems. Among 13 genotypes line 172 was selected for higher grain yield than local commercial cultivars in the presence and absence of both diseases. Mean coefficients of infection on line 172 were 0.57 and 5.35 to brown rust and yellow rust, respectively. It was also moderately resistant to common bunt. Yield potential of the new cv. Alaa was 9-20% higher than the commercial local cultivars Araz, Tamuz 2 and Adana. Alaa was registered and released by the National Committee for Registration and Release of Agricultural Cultivars according to order no. 39, 30/10/2017 as a new cultivar with high yield potential and resistance to brown rust and yellow rust. Great emphasis was made on multiplication and delivery of seeds to farmers. Grain yield potential of Alaa on a farm scale is 3,372 Kg/ha under rain-fed conditions and 5,024 Kg/ha under irrigated conditions.