طه دادرضایی

Due to limited water resources in the country, irrigated wheat cultivars in cold and temperate cold regions are faced with lack of irrigation or limited irrigation at the end of the season. In these areas, most farmers who cultivate irrigated wheat due to lack of sufficient water in the spring cannot perform enough irrigation and therefore do not get the desired result from cultivating high-yielding cultivars. Development of new cultivars with high grain yield under terminal drought stress conditions is one of the major goals of wheat breeding program for cold regions of country. Heyran new bread wheat cultivar introduced from International Research Center for Maize and Wheat (CIMMYT) to Iran through an international nursery in 2010 and was evaluated in a primary trial in four research stations (Karaj, Jolge-Rokh, Ardabil and Mashhad), and due to its favorable characteristics was selected for further evaluation in preliminary yield trials in cold regions. This line showed grain yield of 8417 kgha-1 under normal irrigation compared to the check cultivars Orum, Zareh and Mihan (with average yields of 7679, 6828 and 7772 kgha-1, respectively), and under terminal drought conditions with an average seed yield of 4653 kgha-1, compared to the check cultivars Orum, Zareh and Mihan (with average yields of 4375, 3544 and 4358 kgha-1, respectively) and was selected in both conditions. Aforementioned line showed grain yield of 8340 kgha-1 in advanced yield trial of cold regions breeding program under normal conditions compared to check cultivars Orum, Zareh and Mihan (with average yields of 7518, 7613 and 8205 kgha-1, respectively) in five locations, selected for final evaluation in adaptability test. Grain yield of this line which was presented as CD-92-6 at the adaptability test was 4470 kgha-1 against 3711 and 3743 kgha-1 of Zareh and Mihan checks cultivars under water stress conditions, respectively, during two cropping seasons 2013-14 and 2014-15. This line showed overall mean grain yield, of 5143 kgha-1 under terminal drought stress conditions in extensional farmer’s fields. For these conditions checks cultivars Hydari and Mihan showed grain yields of 4808 and 4758 kgha-1, respectively. Grain yield potential of this line was recorded as 6323 kgha-1 in Khorasan Razavi farmers' field. According to the latest evaluations the response of this line to yellow rusts was resistant to semi sensitive under severe artificial infection. Wheat line CD-92-6 has considerable cold tolerance and good bread making quality and based on its good agronomic characteristics in 2019 this line was released as Heyran, for cultivation under terminal drought stress conditions in the cold agro-climatic regions.

Brown rust or leaf rust of wheat caused by Puccinia triticina Eriks. It is considered one of the most damaging diseases of wheat all over the world, including Iran. Brown rust can reduce the yield of wheat in fields by 20 to 50% in epidemic conditions. The fungus that causes brown rust disease due to having a sexual cycle and new genetic recombinations resulting from it (presence of intermediate hosts in most regions), an asexual cycle in favorable weather conditions and Also, the probability of occurrence of phenomena such as mutation, migration and selection pressure by resistance genes in the hosts has high genetic diversity (variety of physiological breeds), genetic flexibility (variability) which by producing new breeds with Completely different pest patterns can overcome the created genetic resistance. The newly created breeds can be quickly transferred from one area to another through the wind and cause an increase in racial diversity in the disease population of other areas. The most reliable and fundamental method of its control and management is the use of genetic resistance. Accurate knowledge of the genetic structure of the pathogenic population in each region is the first step and road map to achieve effective and stable genetic resistance in wheat. This is possible through the monitoring of harmful pathogenic factors on the differential genotypes of brown rust in the trap vaults.

The effectiveness of resistance genes of international differential cultivars of brown rust was investigated in Moghan region of Ardabil province as one of the important poles of Iranian wheat production in two consecutive crop years (2022-2023). To identify the sources of resistance to the existing breeds in the region, the responses of 40 commercial varieties and 40 promising lines of wheat was evaluated. Investigating the resistance response in the full plant stage under natural pollution conditions, by the parameters of pollution coefficient (CI), final disease severity (FDS) and the relative value of the area under the disease progression curve (rAUDPC) in the research station of the Research and Training Center for Agriculture and Natural Resources of Ardabil Province (Moghan) were measured.

The population of breeds in Moghan region were different from each other in both years. The results indicated that in both years of the test, the pathogenic mushroom population had immunity to differential cultivars carrying resistance genes Lr18, Lr19, Lr20, Lr22a, and Lr29. Therefore, these genes have the necessary efficiency to create effective resistance to brown rust pathogenic races in Moghan region. The differential cultivars carrying the resistance genes Lr2a, Lr2b, Lr9, Lr17, Lr21, Lr23, Lr10/Lr27/Lr31, Lr33, and Lr34 also showed relatively acceptable resistance to the pathogenic strains of brown rust in Ardabil region. The reaction of the genotypes carrying these genes was specific to the race. In other words, in one year they had a resistance reaction and in another year they had a semi-resistant to semi-sensitive reaction with an intensity of 5-20% contamination. Commercial cultivars and promising lines of wheat, which had an effective resistance response and the lowest value for the measured traits, as sources of effective genetic resistance to the brown rust pathogenic population in Moghan region and similar regions in The hot and humid climates of the country are introduced, which include Sahar, Rakhshan, Shush, Farin, Sirvan, Araz, Meraj, Danesh, Talai, Sana, Aran, Tirgan, Taban, Hana, Mehrgan, Avan, Arman, Fallah, Tektaz cultivars. and lines N-95-6, N-98-8, S-95-3, S-96-15, S-96-16, S-97-10, S-98-11, S-98- 22, M-97-12, M-97-18, M-98-18, CD-91-12, C-97-4, CD-97-19, C-98-7, C-98-8, They were CD-98-17, MS-92-5, MS-94-5, D-97-15, and D-97-16.

Correct and conscious use of the combination of effective resistance genes identified in this research can create more stable resistance to brown rust. It is possible to use the resistance genes present in resistant genotypes identified in multi-breeding programs for the pyramiding of resistance genes in desirable wheat genotypes in terms of agricultural traits, yield and other physiological characteristics, in the production of stable resistant cultivars. Compared to the disease, he used a brown rust.

The new barley cultivar Golchin was derived from cross between  P.sto/3/Lb.iran/Una80//Lignee640/4/Bllu/5/Petunia1 and Nik cultivar as female and male parents, respectively. The initial cross between parents of this cultivar and selection among segregating generations till achieving genetic purity were done in Cereal Research Department at Seed and Plant Improvement Institute, Karaj, Iran. Observational evaluations and preliminary and advanced yield trials were performed at Ahvaz, Darab, Zabol and Gonbad agricultural research stations and the desired line was selected according to its high yield, desirable agronomic characteristics and  comparison  with yields of the check cultivars. To evaluate grain yield stability of 17 pure lines selected from advanced experiment as well as Zahak/Sahra and Nimrooz as check cultivars were studied in Ahvaz, Darab, Zabol, Gonbad and Moghan agricultural researches stations in 2015-2017 cropping seasons. Selection of lines with desirable and stable grain yield was performed using the results of grain yield mean comparisons, Lin and Binns superiority coefficient and GGE biplot analysis. Line WB-94-3 (Golchin cultivar) with an average grain yield of 4311 and 4502 kgh-1 in south and north warm regions of Iran respectively, had 9% and 8% yield superiority over Zahak and Sahra check cultivars. According to the results it was determined that line WB-94-3 in addition to desirable performance and agronomic characteristics had general adaptability to the warm regions of the Iran and therefore was released as Golchin cultivar. Golchin is a six-rowed variety and exhibits lodging resistance and non-shattering rachis. The growth type of this cultivar is spring and its protein content is 11.3%. Golchin is earlier than commercial check cultivars and has high tolerance to salinity stress and moderate tolerance to drought stress. Its reaction to powdery mildew is in the range of semi-resistant to semi-sensitive.

The new durum wheat cultivar, Sana (line DM-93-8) was initially introduced as a breeding line through 43rd International Durum Screening Nursery (IDSN) received from the International Maize and Wheat Improvement Center (CYMMIT) and was evaluated in Seed and Plant Improvement Institute (SPII) in Karaj. Sana was selected for further evaluations based on its high grain yield (7750 kgha-1) at the subsequent years. This line had average grain yield of 9675 kgha-1 in the regional preliminary yield trial in 2012-2013 cropping season. Line DM-93-8 had average grain yield of 6827 kgha-1 in the advanced yield trial, with no considerable difference with Dena check cultivar having grain yield of 6973 kgha-1 in 2013-2014, therefore this line was selected for the further evaluations. The regional elite yield trials were conducted in four stations of Isfahan, Karaj, Kermanshah and Neishabour in 2014-15 and 2015-16.  This line with 9025 kgha-1 had 16% higher grain yield than Dena check cultivar, with grain yield of 7779 kgha-1, and therefore was selected as superior line based on its grain yield and yield stability. Sana also has high quality of semolina, high protein content (12.2%) and high percentage of wet gluten (27%). The results of on-farm trials showed that this cultivar exhibited a 6% higher grain yield than newly released variety, Hana, as a local check in Kermanshah. Therefore, based on its high grain yield, yield stability, quality of semolina and its good level of resistance to yellow and leaf rusts, line DM-93-8 was released as a new durum wheat cultivar with the name of Sana for moderate agro-climate zone of Iran.