Feb 4, 2015: Preliminary report for Puccinia striifromis race analysis 2014 published by Global Rust Reference Center (GRRC), Aarhus University, Denmark.

Posted on by April 27, 2015

GRRC-Logonew3 smallFollowing the recent release of the 2013 stripe rust report, the Global Rust Reference Center in Denmark has now just published the latest report detailing the results of race analysis for  Puccinia striifromis samples submitted during the period January – December 2014. A total of 250 yellow rust infected leaf samples from 12 countries entered the recovery process using susceptible seedlings of Cartago and Morocco. A total of 83 isolates were recovered and multiplied whereas 5 isolates from Pakistan were avirulent on both Cartago and Morocco. A subset of 52 isolates from 2014 and 10 additional isolates collected in 2013 were pathotyped using an extended set of wheat differential lines carrying resistance genes to P. striiformis.

Key highlights from the report are:

  • Races of the aggressive strain (likely PstS2) were common across many sampling areas in East Africa and Asia
  • Aggressive strain PstS2 was detected frequently in Ethiopia, Kenya, Tanzania and Rwanda, often with additional virulence to Yr1 or Yr10
  • Another group of Yr27-virulent races were observed in East Africa, e.g., Rwanda and Ethiopia
  • The races in Central Asia often combined multiple virulences and many isolates produced huge amounts of telia, which may suggest a recent evolutionary origin from a sexual population
  • ‘Warrior’ race was detected in Morocco and Algeria (exhibits same characteristics as above)
  • Very similar races to ‘Warrior’ have been observed in Bhutan (2012) and in 2014 also in Nepal. However, these Warrior-like races from South Asia differed from the Warrior race in Europe by DNA markers and in response to additional, non-standard differentials.

A copy of the report – Hovmøller & Rodriguez-Algaba 2015: Global Rust Reference Center: Research funded by: Aarhus University,Denmark; CIMMYT; ICARDA – can be found on Wheatrust.org

Jan 21, 2015: First reports of stripe rust appearing in India

Posted on by January 21, 2015
stripe rust

Photo: Dave Hodson, CIMMYT

Indian media sources are reporting the first appearance of stripe rust in Punjab. According to a report in the Hindustan Times (read report here), stripe rust was detected on Jan 9th in Kharod village, Nawanshahr district.  Stripe rust is also reported to be present in Ropar district. These reports are in-line with reports from previous years, both in terms of location and timing of the first reports of stripe rust in India. As in previous years, Indian authorities are responding to these initial outbreaks in a rapid, effective and well organized way.

Alert – Jan 9, 2015: Summary of Ethiopia 2014/15 rust situation. Re-current, localized stem rust epidemics caused by race TKTTF (“Digalu” race) in Ethiopia. Extreme caution and vigilance needed in East Africa

Posted on by January 20, 2015
stem rust banner

Photo Credit: Dave Hodson, CIMMYT

Following the localized stem rust epidemics in Ethiopia on the cultivar “Digalu” in 2013/14 (see report 23rd Dec 2013); continued, severe stem rust outbreaks have been observed in the 2014/15 main season. Once again the popular cultivar “Digalu” has been seriously affected in several areas. Overall, at least 20 districts were considered to be affected to some extent by the Digalu epidemic. Complete crop loss has occurred in the worst affected areas.  Race TKTTF (known as the “Digalu” race in Ethiopia) has been identified as the causal race for the 2014/15 outbreaks (the same as in 2013/14). Virtually all samples analyzed from 2014/15 have proven to be race TKTTF and this race now totally dominates the stem rust population in Ethiopia. This race is NOT related to the Ug99 race group; it was first detected in Ethiopia in Aug 2012 (1 sample only, trace levels) but then went undetected until it caused severe localized epidemics during Nov 2013 to Jan 2014. The same race is known from several countries in the Middle East and that region is a presumed likely origin. Virulence on the resistance gene SrTmp is considered the main factor behind the complete susceptibility of the cultivar “Digalu”.

The first stem rust outbreaks in Ethiopia were recorded in West Shewa (about 100 km to the west of Addis Ababa) in early September 2014. Digalu exhibited very high stem rust incidence and severity (both up to 100%) and severe losses resulted on unsprayed fields. Two districts were initially affected, but over time the outbreak spread to cover 5-7 districts in this area. Subsequent outbreaks were recorded in October to December 2014 and these have continued into Jan 2015, with the Arsi Robe area and Bale zone (notably Sinana district) experiencing severe outbreaks with complete crop loss in many fields.

Ethiopia Overview Map

Map 1: Overview of Rust Situation Ethiopia 2014/15

yellow rust also caused localized problems during the 2014/15 season. In Amhara region, 4 zones (East Gojam, South Gonder, North and South Wollo) were affected, with South Wollo experiencing the worst outbreaks. Local triticale’s and the known susceptible variety Kubsa were the most badly affected. Aggressive yellow rust outbreaks also occurred in Bale zone, with some newly released varieties showing susceptibility.  Analysis is on-going to determine the causal race.

An overview of the stem and yellow rust outbreaks in Ethiopia during 2014/15 is given in Map 1.

A broad spectrum of different agencies, both national and international, worked tirelessly to control and mitigate the rust outbreaks in Ethiopia in 2014/15. These efforts were successful in many areas and  very good crop performance was observed. However, in some areas no, or limited, control was achieved and serious losses resulted (see photos). The 2014/15 situation in Ethiopia is a stark reminder of the extreme difficulties in trying to successfully control stem rust when large areas are planted to highly susceptible cultivars, a virulent pathogen is present and environmental conditions are suitable. Replacement of the highly susceptible cultivars is now the highest priority for Ethiopia.

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Photo Credit: Wubishet Alemu (Sinana Agricultural Research Centre)

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Photo Credit: Wubishet Alemu (Sinana Agricultural Research Centre)

 

 

 

 

 

 

The huge stem rust  inoculum load generated in Ethiopia during 2014/15 is a threat and concern for neighbouring countries and also for future seasons in Ethiopia. Spore dispersal modelling undertaken by the Epidemiological Modelling Group at Cambridge University, UK indicated that most spores were likely to be distributed in a south-westerly direction towards Kenya, Uganda and possibly Rwanda. These countries should be vigilant for the incursion of race TKTTF and any varieties protected by the SrTmp gene should be closely monitored.

Jan 9th, 2015: Latest version of Mehtaensis newsletter published by DWR, Flowerdale, Shimla: Comprehensive updated information on rusts in India and South Asia

Posted on by January 13, 2015

The latest version of the Mehtaensis newsletter (a 6 monthly newsletter named after Prof. K.C. Mehta) has just been published by the DWR, Regional Station, Flowerdale, Shimla. Compiled and edited by Dr. S.C. Bhardwaj, O.P. Gangwar, Pramod Prasad and Hanif Khan with technical assistance from S.B. Singh and Subodh Kumar. Mehtaensis contains a detailed summary of all the rust activities and race analysis results from India and neighbouring South Asian countries during the period July – Dec 2014. The executive summary is reproduced here:
“During the off season/summer crop (2013-14) all the rusts of wheat were observed at Wellington (Tamil Nadu), Dalang (Himachal Pradesh) and Ladakh (Jammu & Kashmir). Yellow and brown rusts were first observed on 12th of September and 6th of October, respectively on wheat disease monitoring nursery (WDMN) at Shimla. Scientists from PAU, Ludhiana have observed (19.12.2014) the occurrence of yellow rust of wheat in a farmer’s field in village Daroli Upper near Anandpur Sahib in Punjab. The spot has been chemically treated to eradicate the focus of infection. During the period about 135 samples of wheat rusts were collected/received. So far 38 samples of all three rusts of wheat have been analysed.
Only two pathotypes each of black {34-1 (10G13) and 40A (62G29)} as well as yellow rust {46S119 and 46S117 (new pathotype)} of wheat were observed till date. Brown rust, pathotypes 77-5 (121R63-1), 77-11 (125R28), 104-4 (93R57) and 162-1 (93R47) were identified in Himachal Pradesh samples. In samples from Tamil Nadu only 77-9 (121R60-1) and 77-10 (377R60-1) were observed.
Seedling resistance test (SRT) of more than 1070 lines of wheat and barley, including AVT, NBDSN and EBDSN entries have been done against different pathotypes of three rusts of wheat and barley. Analysis of polymorphism among brown rust pathotypes based on SSR marker analysis and their infection types on brown rust differential sets and the clustering in the same was done in the form of dendrogram.
Forty five different crosses were attempted for inheritance studies and gene transfer for rust resistance. More than fifty populations/selections were analyzed for seedling resistance against suitable rust pathotypes and were transplanted in the field for advancement of generations for genetic analysis and gene pyramiding studies.
Repository of pathotypes of different rust pathogens of wheat, barley, oat and linseed was maintained and inoculum of wheat and barley rusts was supplied to 39 centers/Scientists.
For monitoring the occurrence/spread of different diseases of wheat, WDMN and SAARC-WDMN were planted at different locations”. Mehtaensis Vol. 35 (1). ICAR. Indian Inst of Wheat and Barley Research, Regional Station, Flowerdale, Shimla 171 002 H.P. India

October 27, 2014: Kenya 2014 Rust Surveys- High Level of stem rust; Yellow rust and Leaf rust at low levels

Posted on by November 19, 2014

Ken2014StemrustRust surveys were carried out in all the four key wheat growing regions of Kenya: South Rift, Mount Kenya region, Central Rift and North Rift. The surveys were conducted by experts from the Kenyan Agricultural Research Institution (KARI). A total of 296 farms were sampled. stem rust was detected in 196(66.2.0%), yellow rust in thirty-one (10.4%) and leaf rust in eight(2.7%) of the farms with disease severity ranging from trace to 80S, 50S and 40S respectively. The rusts were detected in all the wheat growing regions. Stem rust infection ranged from TR to 80S with infection in South Rift (69.6%) North Rift (55.8%), and maximum infection in Central Rift (92.2%) and Mount Kenya region (57.7%). Yellow rust infection ranged TR to 60S with minimum infection in North Rift (7.4%) ,South Rift (8.9%) and maximum infection in Mt. Kenya region (15.5% and Central Rift (11.8%). Leaf rust infection ranged from trace to 50S with minimum infection in Mount Kenya region (1.4%, Central Rift (3.9% and maximum infection in North Rift was (5.3%).

Commonly grown varieties :Robin, NJRBWII, KSMwamba and Kwale . Robin was popular in Central Rift( 47.1%), Mt.Kenya region(43.7%), South Rift (41.8%) and North Rift (12.6%) of the sampled fields.Variety NJRBWII occupied the largest area in North Rift (63.2%).

The area planted with NJRBWII increased in 2014 the North Rift compared to 2013 in the same region and the area under Robin increased in the other three regions. Variety Eagle 10 still occupied a very small area in all the regions except in the South Rift(19.5%) of the sampled fields.

The general observation was that the adoption of Robin was coming up very fast, but unfortunately the variety has broken down to apparently new race of stem rust yet to be defined. Only those farmers who sprayed following the right recommendations harvested/will harvest the crop. Those who did not spray or sprayed without following the proper recommendations lost the crop to the disease.

Secondly, the disease pressure was very high in all the regions but the majority of the farmers sprayed to keep the inoculum load low( South Rift,North Rift,Central and Mt.Kenya region).

Aug 11th, 2014: Latest version of Mehtaensis newsletter published by DWR, Flowerdale, Shimla: Comprehensive updated information on rusts in India and South Asia

Posted on by October 17, 2014

The latest version (Vol 34, July 2014, No. 2) of the Mehtaensis newsletter (a 6 monthly newsletter named after Prof. K.C. Mehta) has just been published by the DWR, Regional Station, Flowerdale, Shimla. Compiled by Dr. S.C. Bhardwaj, O.P. Gangwar, P. Prasad and Hanif Khan with technical assistance from: S.B. Singh, Subodh Kumar (Mehtaensis July 2014 Vol.34No.2). Mehtaensis contains a detailed summary of all the rust activities and race analysis results from India and neighbouring South Asian countries during the 2013/14 season. Reported highlights are summarized as follows:
There was no major outbreak of wheat rusts in India during 2013-14. However, sporadic incidence of yellow rust of wheat was observed at some locations in Northern India. Stem (Black) rust of wheat was reported on indigenous experimental wheat material planted in Uttarakhand and barley material in Karnataka. During the year 1625 samples of different rusts of wheat and barley were received/collected for pathotype analyses. Analyses of more than 1209 samples revealed that the wheat rust population analyzed is avirulent to Yr5, Yr10, Yr11, Yr12, Yr13, Yr14, Yr15, Yr24, Yr26, YrSp and YrSk (yellow/stripe rust); to Sr26, Sr27, Sr31, Sr32, Sr35, Sr39, Sr40, Sr43, SrTt3 and SrTmp (black/stem rust); to Lr24, Lr25, Lr29, Lr32, Lr39, Lr42 and Lr45 (brown/leaf rust). Predominant pathotypes were; (i) yellow/stripe rust: 46S119 (74% of samples) and 78S84 (18.5% of samples); (ii) brown/leaf rust: 77-5 (121R63-1=THTTM) predominant, followed by 104-2 (21R55=PHTTL); (iii) black/stem rust: pathotype 11 (79G31=RRTSF) was predominant followed by pathotype 40A (62G29=PTHSC). One new pathotype each of the three wheat rusts were identified, however all were less virulent than those already described. Virulence on Sr31 (Ug99 type of pathotypes) was not identified anywhere in India, Bangladesh, Bhutan and Nepal.

June 13, 2014: Yemen 2014 Central Highland Rust Surveys – Yellow rust and stem rust present, but at generally low levels

Posted on by October 17, 2014

Rust surveys were undertaken in the central Highlands of Yemen during the period 20-25th May 2014. The surveys were undertaken by scientists from the Agricultural Research & Extension Authority (AREA), with the survey team being Musaed Eisa, Rashad Al Basha … Continue reading →

May 14, 2014: Bangladesh 2014 Rust Surveys – High leaf rust pressure and the first stem rust records in three decades

Posted on by May 20, 2014
Fig. 1. Wheat stem rust at Dinajpur, May 2014

Fig. 1. Wheat stem rust at Dinajpur, May 2014 (Photo credit: Dr P.K. Malaker WRC, Dinajpur)

Extensive annual rust surveys were undertaken throughout the wheat growing areas of Bangladesh during February-March 2014. The surveys were coordinated by Dr P.K. Malaker of the Wheat Research Centre (WRC), Dinajpur, but implemented by several collaborating stations, including; Dinajpur, Joydebpur, Jamalpur, Jessore and Rajshahi. A total of 230 different locations were covered by the survey teams. 2014 was a favourable year for wheat rusts in Bangladesh. It was exceptional in the respect that all three rusts were recorded on the survey. leaf rust was the most frequent with much higher disease pressure than in previous years. Leaf rust was very widely distributed, being present throughout the wheat growing regions of Bangladesh. Almost 90% of the sites surveyed (n=197) recorded leaf rust, and 50% of these had high or moderate severity. Highest severity was recorded in the north-west and western wheat growing areas of Bangladesh (Map 1).  The popular variety ‘Prodip’ was notably susceptible to leaf rust.

Stem rust was putatively recorded at two widely separated locations in Jamalpur and Jessore and later, clear symptom (Fig. 1) of the disease with susceptible reaction was observed at WRC, Dinajpur. Only low severity and incidence were recorded. The disease was observed on few lines in the rust trap nurseries from ICARDA, but not in any other cultivars or lines. The symptoms

Map 1. Leaf Rust Severity 2014 (red dots = high severity, orange dots = mod severity, yellow dots = low severity)

Map 1. Leaf Rust Severity 2014 (red dots = high severity, orange dots = mod severity, yellow dots = low severity)

and urediospore morphology were examined at WRC, Dinajpur and ascertained to be of stem rust. Samples were collected and are undergoing race analysis at DWR Regional Station in Shimla, India. These would probably represent the first stem rust records from Bangladesh in three decades. Yellow rust was recorded only at WRC, Dinajpur. The disease was found on the rust susceptible check variety Morocco in a trial plot. Yellow rust is infrequent in Bangladesh, but does occur sporadically.

Feb. 21, 2014: Ethiopia – Update on localized stem rust epidemic

Posted on by March 10, 2014
Overview Map: Ethiopia localized stem rust epidemic

Overview Map: Ethiopia localized stem rust epidemic

This report gives an update on the previously reported stem rust outbreak in southern Ethiopia (see http://rusttracker.cimmyt.org/?p=5473). Thanks to extensive surveillance and sampling, more details are now available regarding the areas affected and also the likely causal race.

Based on surveys and information received, up to 17 woredas (districts) in Oromia and SNNPR regions may have been affected to some degree by the stem rust epidemic (see overview map). Based on Ethiopian Central Statistical Agency (CSA) data from 2001, total wheat area in these woredas is approximately 91,000 ha. Based on field observations it is not unrealistic to assume that the susceptible cultivar Digelu might occupy 20-40% of the areas planted. A very rough,  approximate, estimate of the area that may have been affected to some degree by stem rust is therefore 18,000 – 36,000 ha (i.e., approximately 1-2% of the total Ethiopian wheat area). More precise area estimates will hopefully be available in the future. Detailed crop loss assessments for the Bale zone are in progress, but no results are available yet.

Survey and sampling data currently available indicate the first outbreaks occurred in the general area of Agarfa/Gasera / Arsi Robe, most likely in late September 2013, then there appeared to be spread in a south-westerly direction into SNNPR region. Such movements would correspond to the previous predictions for spore dispersal made by the Cambridge University modelling group. The potential source of the initial outbreak is unknown.

Surveys in Arsi Robe/Diksis/Sude on 21st Jan 2014 revealed widespread  high incidence (100%)  and severity (up to 80%) of stem rust on Digelu. The situation was somewhat better than that observed in Agarfa/Gasera in Nov 2013, in the respect that no fields with 100% crop loss were observed. However, disease pressure continued to be very high in this area. The cultivar Danda’a was observed to have much lower severity of stem rust compared to Digelu.

The stem rust race implicated in the epidemic has been tentatively identified as race TKTT-, using North American nomenclature. This race is NOT part of the Ug99 race group. At present there is some uncertainty around the effectiveness of gene Sr38 in respect to this race, hence the last letter of the race code is currently blank. Further tests are on-going to resolve this issue. The race has confirmed virulence on the following resistance genes: Sr5, 21, 9e, 7b, 6, 8a, 9g, 36, 9b, 30, 17, 9a, 9d, 10, Tmp, McN. It is confirmed avirulent on: Sr11, 24, 31. The virulence on SrTmp is believed to be the key factor for the susceptibility of Digelu. Further analysis is on-going to definitively confirm this as the causal race.

This race, prior to Sep/Oct 2013, had not been detected in Ethiopia. The assumption therefore is that this is either a foreign incursion (most likely by wind) or a mutation in-country. The same (or similar) race is already known from other countries: Turkey (in 2007, 2008, 2011, 2012); Lebanon (in 2012); Egypt (in 2013); Germany (in 2013). Studies are underway to determine how related the races in different countries might be through DNA fingerprinting.

No reports of race TKTT- have yet been confirmed from any the countries neighbouring Ethiopia. However, survey and sampling activities are taking place in several countries to monitor potential spore movements.

(NB: This report was updated with new information on 10th March 2014)

Feb. 17, 2014: Rwanda – Ug99 races TTKSK and TTTSK identified from DNA samples

Posted on by February 17, 2014

rwanda_2014Following the recent surveys and sampling in Rwanda by the Rwanda Agriculture Board (RAB), wheat program and CIMMYT-Ethiopia during the period 27th Jan – 1st Feb 2014; two known Ug99 races have now been identified. Molecular diagnostic assays carried out by Dr Les Szabo at the USDA-ARS Cereals Disease Lab, Minnesota confirmed the presence of races TTKSK (original Ug99) and TTTSK (Sr36 variant of Ug99) in Rwanda. Race TTKSK was dominant, being identified in 13 samples from four dispersed locations (Kinigi RS, Rusarabuye, Rwerere RS and Sigira RS – see map). Two distinct genotypes of race TTKSK (AF-001aa and AF-001ad) were identified in the samples analysed. Race TTTSK (genotype AF-001cc) was detected in 2 samples collected at Sigira RS in the southern province. The results obtained from Rwanda make it the 12th country in which the Ug99 race group has been identified. The races and genotypes detected match those previously known from Uganda and Kenya, so are not unexpected. No evidence was found to indicate the presence of the race implicated in the recent stem rust epidemic in Ethiopia.