- Rust Issues: Leaf rust is the commonest rust on wheat.
- Ug99 Status: No Ug99 lineage races have been detected in Bangladesh.
The latest version of the Mehtaensis newsletter (a 6 monthly newsletter named after Prof. K.C. Mehta) has just been published by ICAR-Indian Institute of Wheat and Barley Research, Regional Station, Flowerdale, Shimla. Compiled and edited by Pramod Prasad, Hanif Khan, O.P. Gangwar, and S.C. Bhardwaj 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 Jan – July 2016. The executive summary is reproduced here:
“A new Lr gene was identified in local wheat LWH2. This gene confers resistance to all the pathotypes of Puccinia triticina (except pathotype 5R9-7) in India. Wheat rusts did not appear in epidemic form during 2015-16 in India. The sporadic occurrence of yellow rust was reported from few areas of North western plains and northern hills zones, but its further spread was halted through joint efforts of ICAR-IIWBR, SAUs, State Department of Agriculture and farmers. Black rust was restricted to Central and Peninsular India whereas brown rust was observed across all the zones but their severity and incidence was quite low. During 2015-16, 1028 samples of different rusts of wheat and barley were received/collected for pathotype analyses from Ravi and off season crops. About 580 samples of three rusts of wheat and yellow rust of barley were analyzed. Many of the yellow rust samples could not be revived. Yellow rust population was avirulent to resistance genes Yr5, Yr10, Yr11, Yr12, Yr13, Yr14, Yr15 & YrSp and black rust to Sr 26, Sr 27, Sr31, Sr32, Sr 35, Sr39, Sr 40, Sr 43, SrTt3 & SrTmp; and brown rust to Lr24, Lr25, Lr29, Lr32, Lr39, Lr42 and Lr45. The frequency of pathotype 46S119 (virulent on Yr2, Yr3, Yr4, Yr6, Yr7, Yr8, Yr9, Yr17, Yr18, Yr19, Yr21, Yr22, Yr23, Yr25, YrA) of yellow rust, 79G31 (virulent on Sr2, Sr5, Sr6, Sr7b Sr9a, Sr9b,Sr9c, Sr9d, Sr9f, Sr9g, Sr10, Sr13, Sr14, Sr15, Sr16, Sr17, Sr18, Sr19, Sr20, Sr21, Sr28, Sr29, Sr30, Sr34, Sr36, Sr38, SrMcN) of black rust and 121R60-1 (virulent on Lr1, Lr3, Lr10, Lr11, Lr12, Lr13, Lr14a, Lr14b,Lr14ab, Lr15, Lr16, Lr17a, Lr17b, Lr18, Lr20, Lr21, Lr22a, Lr22b, Lr23, Lr26,Lr27+31, Lr30, Lr33, Lr34, Lr35, Lr36, Lr37, Lr38, Lr44, Lr46, Lr48, Lr49) of brown rust was the maximum in their respective categories. Continue reading
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.
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
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.
Extensive rust surveys were undertaken throughout the wheat growing areas of Bangladesh during January-April 2013. The surveys were coordinated by Dr P.K. Malaker of the Wheat Research Centre, Dinajpur, but implemented by several collaborating stations, namely; Dinajpur, Joydebpur, Jamalpur, Jessore and Rajshahi. A total of 246 different locations were covered by the survey teams.
Only leaf rust, no stem or yellow rust, was observed on the 2013 surveys. Leaf rust was widespread and present in virtually all the areas surveyed. The disease was recorded at 41% (n=101) of the sites surveyed. Despite widespread incidence, severity of leaf rust was much lower than in the previous year. Only 4 sites reported high severity (>40%) of leaf rust in 2013, compared to 30 sites in 2012. Likewise only 33 sites reported moderate severity (20-40%) of leaf rust in 2013, compared to 43 sites in 2012.
Timely planted crops (15-30th November) largely escaped disease or had less disease compared to late planted crops. The cultivar Prodip was most affected by leaf rust showing low to high disease severities with a MS-S type reaction. Cultivars BARI Gom-25 and BARI Gom-26 exhibited only low disease severities with a MRMS-MSS type reaction. Five commercial cultivars; Shatabdi, Sourav,
Bijoy, BARI Gom-27 and BARI Gom-28 were free from leaf rust infection.
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 by Dr. S.C. Bhardwaj, Mehtaensis contains a detailed summary of all the rust activities and race analysis results from India and neighbouring South Asian countries during the period Aug 2012 – Jan 2013. The executive summary is reproduced here:
“All the rusts of wheat were observed in Summer Crop of Nilgiri hills (Tamil Nadu) and Leh (Jammu & Kashmir) whereas black rust was not observed in Dalang and Kinnaur areas of Himachal Pradesh. Owing to the dry weather there was no record of rusts except for mild brown rust in Karnataka.
Analysis of 213 samples of rusts of wheat and barley indicated that there was no occurrence of new pathotypes. Pathotype 40A followed by 40-1 of black rust, 46S119 followed by 78S84 of yellow rust and 77-5 followed by 104-2 of brown rust were predominant in wheat growing areas of India and neighboring countries. To identify the rust resistant lines, characterizing resistance genes, confirm the presence of resistance genes and genetics of rust resistance 1811 lines of wheat were subjected to multipathotype evaluation. National repository of 126 pathotypes of different rust pathogens was maintained, nucleus bulk inocula were supplied to 38 Scientist/centres in public and private sectors. Wheat disease monitoring nursery was a organized for planting at 45 locations. Evaluation and advancement of 34 cross combinations is being undertaken.” Mehtaensis 33(1) January, 2013