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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.
Short season, high latitude spring wheat is grown on 7 million ha in Western Siberia and 10 million ha in Northern Kazakhstan. Despite relatively low wheat yields (1.5 t/ha), the region is extremely important for regional and global food security. Leaf rust dominates, occurring three years out of five, especially in favorable years with higher rainfall. Since 2010, stem rust has been observed at an increasing number of sites. The first large-scale stem rust outbreak occurred in 2015 and affected about 0.5-1 million ha in Omsk, Western Siberia. In 2016, 2 million ha were affected in the Omsk and Altay regions, while 1 million ha in the Kostanay and Northern Kazakhstan regions were affected in 2017. Estimated yield losses reached 25-35% each year. Factors associated with the outbreaks included: higher rainfall in late June and July; cultivation of susceptible varieties; and an increased area planted to winter wheat, which serves as a source of inoculum. Sampling and race analysis revealed a diverse pathogen population, indicative of a sexual recombination. A total of 51 races were identified from 31 samples taken in 2015 and 2016. All races were avirulent on Sr31. The majority of varieties released and cultivated in the region are susceptible to stem rust and require replacing. A recent study of 150 local resistant varieties and breeding lines indicated that the genetic basis of resistance was limited to Sr25, Sr31, Sr36, Sr6Ai, Sr6Ai#2, and additional unknown major genes. Adult-plant resistance to stem rust was observed in less than 20% of the germplasm. The potential impact of these large stem rust outbreaks on other wheat growing regions is being investigated by analyzing spore wind dispersal patterns. Further research is required to understand and mitigate the sudden appearance of stem rust as a disease of economic importance.
Study at Omsk State Agrarian University was supported by the Russian Science Foundation (project No. 16-16-10005).
Genomic selection facilitates rapid cycling through a breeding cycle by eliminating the need to phenotype prior to selecting superior parents and crossing among them. In winter wheat we can now complete a cycle of GS in about 12 months and two greenhouse seasons. Season consists of planting F1s from the previous cycle and selfing to obtain F2 seed. The second season involves planting and genotyping the F2s, predicting their value with GS, selecting and crossing the best, and harvesting the F1 seed. Our breeding program has completed five cycles of GS in one population primarily for grain yield, over the past five years. We have completed three cycles of GS for resistance to Fusarium Head Blight in a second population. Genotyping was done using genotyping-by-sequencing. This provides an opportunity to assess the changes in the population that have occurred as a result of this rapid cycling. These include 1) changes in genomic estimated breeding values for grain yield and FHB resistance, 2) effect of selection and drift on allele frequencies including fixation, 3) effect of selection on diversity and genetic relationships, and 4) changes in linkage disequilibrium. We are conducting these analyses and will present the results.
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.
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.
Malnutrition affects more than 2 billion people across the globe, particularly zinc and iron deficiency causes major health problem in developing world. The biofortified staple food crops such as wheat, is an important channel to contribute to the hidden hunger problem in low income countries. Breeding for enhanced zinc concentration in wheat was initiated by crossing high zinc sources identified among synthetic wheats, T. dicoccum, T. spelta and landraces. These crosses have resulted in wheat varieties with competitive yields and enhanced grain zinc were adapted by farmers in South Asia. CIMMYT-derived early-maturity wheat cultivar 'Zinc-Shakti' with about 40% increased zinc (+14 ppm), is now grown in eastern India through public-private partners. The two CIMMYT-derived biofortified varieties: 'WB2' and 'HPBW01' released in 2016 for northwestern plains zone of India. In Pakistan, 'Zincol' was released in 2016. The first high zinc wheat variety (Bari-Gom 33) with better resistance to wheat blast have been released in Bangladesh for commercial cultivation in 2017. Targeted crosses with increased population sizes were used to obtain superior progeny lines that have high zinc levels in combination with other essential traits. This has resulted in the incorporation of several novel alleles for grain zinc and iron in elite, high-yielding germplasm. High zinc and iron are under quantitative genetic control and further progress is possible as multiple QTL are pyramided in high yielding wheats. High-throughput, non-destructive phenotyping for grain zinc and iron using the X-ray fluorescence (XRF) analysis has facilitated the selection dramatically. Gene discovery and mapping studies leading to the utilization of markers to further improve the breeding efficiency. Rapid adoption of high zinc wheat varieties in South Asia and beyond is expected with the second wave of high zinc wheat lines with superior yield, heat and drought tolerance and resistance to rusts and other foliar diseases.
In the Czech Republic all three rust species on wheat occur. Leaf rust (Puccinia triticina) can be found almost everywhere, and it can cause yield losses up to 40% mainly in warmer parts of the country in South Moravia.
Yellow rust, typical for cooler climate, occurred in relatively long time intervals. However in 2013 new pathotypes tolerating higher temperatures occurred and caused yield losses. In 2016 yellow rust incidence was lower, being still important in Moravia, where yellow rust occurred already in previous years.
Stem rust incidence was very rare in the last years. However in Germany, outbreaks and new pathotypes (e.g. Digalu) of stem rust in 2013 were recorded and comeback of stem rust to Central Europe can be expected.
Rust control consists of chemical control and especially of breeding for resistance, that aims at combined resistance to all three rusts. On the scale 9 high resistance, 1 high susceptibility average 4 year rating (2013-2016) of the tested cultivars was 6.4 for yellow rust, 5.7 for leaf rust and 6.2 for stem rust.
"Triple rust resistance" was recorded in spring wheat LOTTE and winter wheat line SG-S 1684 13, high resistance to yellow rust and stem rust in the cultivar Steffi. Resistance to all three rusts of 14 winter wheat cultivars and 12 breeding lines from the Plant Breeding Station-Stupice is summarized on separate tables and described in the text.
High-temperature adult-plant (HTAP) resistance to stripe rust in wheat has proven to be durable. Molecular markers tightly linked to HTAP resistance offer an alternative to phenotypic selection and are useful for pyramiding HTAP resistance genes with other types of resistance. This study assessed HTAP resistance in six diverse mapping populations derived from four types of crosses: 1. Resistant × Susceptible, IDO444 × Rio Blanco (winter wheat RILs) and UI Silver × Shaan 89150 (winter wheat DH lines); 2. Moderately Resistant × Resistant, UI Platinum × SY Capstone (spring wheat DH lines) and UI Stone × IDO686 (spring wheat RILs); 3. Moderately Resistant × Moderately Resistant, UI Stone × Alturas (spring wheat RILs); and 4. Moderately Susceptible × Moderately Susceptible, IDO835 × Moreland (winter wheat, DHLs). Eight QTL significantly associated with HTAP resistance were earlier identified in the IDO444 x Rio Blanco RIL population, including three major QTL (QYrid.ui-2B.1, QYrid.ui-2B.2, and QYrid.ui-4A) and five minor QTL (QYrid.ui-1A, QYrid.ui-3B.1, QYrid.ui-3B.2, QYrid.ui-4B, and QYrid.ui-5B) (Chen et al. 2012, Mol Breeding 29:791–800). These QTL are being validated and novel QTL are being identified in the other five populations. The current study used elite × elite crosses; therefore, the identified QTL may have application in selecting lines with combinations of stripe rust resistance and other superior agronomic traits and perhaps for release as new cultivars.