A wheat rust survey was conducted in Iraq in 2019 and collected 27 stem rust (caused by Puccinia graminis Pers.:Pers. f. sp. tritici Erikks. & E. Henn.) samples. Seven samples were viable, and they were tested for races of P. graminis f. sp. tritici at the Regional Cereal Rust Research Center (RCRRC) in Izmir, Turkey under strict quarantine procedures. Two 0.5 cm segments of each infected stem sheath were incubated in a petri dish at 20°C for three hours for re-hydration of urediniospores, which were multiplied on 10-day old seedlings of susceptible cultivar Morocco grown in a spore free growth chamber at 18°C and 16 hours light. Inoculated seedlings underwent a dew period at 18°C for 16 hours dark and 8 hours fluorescent light and 95% relative humidity. Three days after moving the pots to a growth chamber with eight hours dark at 18°C and 16 hours light (300 µmol m-2s-1), each pot was covered using a cellophane bag. Bulk urediniospores of each collection were collected 14 days post-inoculation from a cellophane bag using a mini cyclone spore collector connected to a gelatin capsule. One ml of 3M Novec™ oil was added to each capsule, and spores were inoculated onto 20 North American stem rust differential lines using the standard procedures (Jin et al. 2008). Pre-inoculation, inoculation, incubation, and post-inoculation conditions were the same as above. Seedling infection types (ITs) were recorded 14 days post-inoculation using 0 to 4 scale (Stakman et al. 1962). Race designation followed the five- letter code nomenclature described by Jin et al. (2008). Out of the seven samples, four were typed as TKKTF, two as TKTTF, and one collected from an advanced breeding bread wheat line “Shahoo 2” (Inqalab 91*2/Tukuru) in a trial site at Halabja governorate showed mixed ITs of 11+ and 3+ for lines carrying Sr11, Sr24, Sr36, and Sr31. Three single pustule (SP) isolates were developed from the IT of 3+ pustules collected from the Sr31 tester line, and one SP isolate was developed from the IT 11+ pustule collected from the Sr11 source. After spore multiplication, the SP-derived isolates were inoculated on the 20 North American differential lines. To confirm virulence/avirulence on Sr24, Sr31, and Sr36, cultivars Siouxland (PI 483469, Sr24+Sr31) and Sisson (PI 617053, Sr36+Sr31) were also inoculated. All seedling assays were repeated three times. The three SP isolates virulent on Sr31 were designated as race TTKTT, and the SP isolate virulent on Sr11 was designated as TKTTF. Seedling ITs of 3+ and 0; were recorded for Siouxland and Sisson against TTKTT, respectively, and both cultivars showed IT of 1+ against TKTTF. Race TKTTF was similar to TKKTF except for additional virulence on Sr36, and TTKTT differed from the other two races being virulent on Sr24 and Sr31. DNA analysis of three TTKTT isolates from Kenya and the TTKTT isolate from Iraq using a diagnostic qPCR assay developed by the USDA-ARS Cereals Disease Laboratory (Ug99 RG stage 1, Szabo unpublished) confirmed that all tested isolates belonged to the Ug99 lineage. Race TTKTT was first reported from Kenya in 2014 (Patpour et al. 2016), and in 2018 from Ethiopia (Hei et al. 2020). We report the first detection of TTKTT in Iraq and the Middle East region. This represents only the third instance of a member of the Ug99 race group outside of Africa since first detection of race TTKSK in Yemen in 2006, and Iran in 2007 (Nazari et al. 2009). The continued spread of stem rust races with complex virulence and the increasing frequency and early onset of stem rust infections in the Middle East is a cause for concern. Continuous support for rust surveillance and race typing in this region remains crucial. References: Hei, N. B., et al. 2020. Plant Dis. 104:982. Jin, Y., et al. 2008. Plant Dis. 92:923-926. Nazari, K., et al. 2009. Plant Dis. 93:317. Patpour, M., et al. 2016. Plant Dis. 100:522. Stakman, E. C., et al. 1962. Identification of physiological races of Puccinia graminis var. tritici. U. S. Dep. Agric. ARS E-617.
In this study, a total of 209 individuals of leeches were collected from Al-Hindyia River / Babil Province. 116 individuals were identified as Erpobdella octaculata (Linnaeus, 1758), 50 individuals as Erpobdella punctata (Leidy,1870) and 43 individuals as Hemiclepsis marginata (Müller, 1774). Four samples were collected monthly during a period from February to June 2018. Some physical and chemical water properties were also examined, including air and water temperature, potential of hydrogen pH, Electrical Conductivity EC, Total Dissolved Solid TDS, Dissolved Oxygen DO, and the Biological Oxygen Demand BOD₅. Air and water temperature were ranged 19.5-29, & 14.6-23.2 °C respectively. The values of pH ranged 6.2-7.6. EC ranged 1104-1581 μs/cm². The TDS recorded 669-767 mg/l, while the DO reached 1.3-8.5 mg / l, the BOD₅ ranged 3.5-5.7 mg/l.
Common bunt of wheat is one of the most important diseases of wheat in Al-Jezera and northern parts of Iraq. Yield losses up to 70% were recorded in most wheat fields sown with untreated seeds. Recently an epidemic form of the disease was observed in the central and southern parts of Iraq for the first time. High disease incidence was detected in most wheat fields in the region. This caused potential hazard to wheat production in the country. A systematic survey was conducted to detect the importance and geographical distribution of the disease in Iraq and to identify the causal agents. Results revealed that the disease is distributed in most of wheat fields in the northern and central parts of the country. The high level of wheat grain contamination with bunt balls was about 1.3% (w/w) in Diyala province and the low percent was about 0.04% (w/w) in Wasit. The disease was also detected for the first time in two locations in the south. These levels of contamination caused 50-100% superficial contamination of wheat seeds with teliospores of the causal agents in all wheat samples. Tilletia tritici, T. laevis, T. intermedia and Tilletia sp. were identified in all infected samples collected from wheat fields. The frequency of T. tritici was high (38.4%) in the north, while both T. laevis and T. intermedia were more frequent in the south (34.5 and 8.9%, respectively) followed by Tilletia sp. (25.5%) in the middle zones.
SUMMARYCommon bunt disease incited by Tilletia tritici and T. laevis, is one of the most important disease of wheat in Iraqi Kurdistan region. The disease can cause severe yield losses when the susceptible cultivars are grown without chemical treatment. This study was carried out to search for resistance sources to common bunt disease in wheat and also to determine the efficiency of Bt genes against the pathogen to be introduced in the future breeding program to improve disease resistance. Seeds of different wheat genotypes including the released cultivars and the differential varieties set were artificially inoculated with a mixture of the pathogen teliospores and planted at Bakrajo, Sulaimania for three successive generations. Disease scoring for each genotype was conducted at maturity stage. Results revealed that most of the tested wheat cultivars showed susceptible and intermediate reaction to the disease while the local wheat cultivars Ashor, Acsad, Farris1, Hasad, Waha, Simmetto and the promising advance lines Shaho, Hamada and Charmo2 showed high resistance level to the disease. The international resistance sources Nadro, carbidit, Togano, tillet and Firsal were highly resistant to the local pathogen population. The known resistant genes Bt 1, Bt 3 , Bt 5 , Bt 9 , Bt 11 and Bt 12 were highly effective against the races of Tilletia tritici and T. laevis under Sulaimania conditions.
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