| چکیده انگلیسی مقاله |
Extended Abstract
Introduction and Objectives: Wheat is a plant that is cultivated in different environments around the world and provides approximately 20% of the energy and 25% of the protein needs of the world population. Durum wheat (Triticum turgidum L.var durum) is an industrial product that is mainly used in the pasta production industry. In addition, the difference in the price of durum wheat in the world markets compared to bread wheat has prompted some countries to increase the area under cultivation and production of this product and start exporting it and to supply the bread wheat they need through imports and thus save large sums of foreign currency. Although it is often believed that durum wheat produces less yield than bread wheat, the results of national uniformity tests conducted in recent years showed that not only the yield of durum wheat is not lower than that of bread wheat, but also the promising lines of durum wheat has an increase in performance in the conditions of the tests carried out, and if we consider the 20% increase in the price of its grain, the development and promotion of its cultivation in tense areas can provide more economic benefits for the producers and the country. The production of crop cultivars with appropriate characteristics, high performance and stable production is one of the main goals of wheat breeding programs. Therefore, identification of suitable lines and cultivars for cultivation in each geographical region is of special importance. By evaluating the set of new lines of each plant in each region, it is possible to achieve such a goal. According to the special program of the Seed and Plant Improvement Institute (SPII) in the plan to increase the self-reliance coefficient of wheat for the introduction of new varieties, this study was also carried out to obtain more productive and promising durum wheat genotypes in the northern region of Khuzestan province.
Material and Methods: For this purpose and identify the best durum wheat lines in terms of yield and other agricultural traits, an experiment was carried out during the two crop years of 2020-2021 and 2021-2022 in the research farm of Safiabad Agricultural and Natural Resources Research Center, Dezful. 76 new durum wheat lines were evaluated observationally along with 3 control varieties Aran, Hana and Mehregan, in the first year and 37 best lines of the first year were evaluated in the form of an alpha lattice design along with 3 control varieties, in the second year. In addition to seed yield, other important agricultural traits including heading date, physiological maturity date, length of seed filling period, lodging rate, plant height and 1000 kernel weight were calculated and considered in the final selection. For the results of each year, statistical parameters (indices of central tendency) were measured using Excel software. Also, the correlation between traits was measured using SPSS software. In addition, MetaR software was used to analyze the variance of Alphalatis design. Also, in order to group the tested lines, a dendogram was drawn using the Ward method and SPSS software.
Results: The results of the trait analysis in the first year showed that the tested lines had a very high variety, so that their yield ranged from 5883 kg/ha for the weakest line to 8350 kg/ha for the best line and the average yield of all tested lines was equal to 7231 kg per hectare. In addition the average yield of 37 selected lines in the second year was about 6423 kg per hectare, which was about one ton less than the yield of the same lines in the first year (7397 kg per hectare). One of the main reasons for this decrease in yield can be attributed to the increase in the temperature of March in the second year (20 degrees Celsius) compared to the first year (16 degrees Celsius), which caused the average grain filling period from 49.3 days in the first year to reach 45.1 days in the second year. Finally, according to the total measured traits of each line during two crop years and cluster analysis, lines No. 6, 38, 57, 58, 59 and 73 were selected as the best lines. The yield of these lines in the first year was 8350, 8303, 7917, 7537, 8000 and 8130 kg per hectare and in the second year it was 6933, 6917, 6775, 7045, 7178 and 6815 kg per hectare respectively. While the average yield of Aran, Hana, and Mehregan controls was 7207, 7148, and 7109 kg per hectare in the first year, and 5698, 6208, and 5927 kg per hectare in the second year, respectively. The dendogram drawn using the total of the measured traits placed the 40 studied lines in three different groups, that each of this groups has two subgroups. The important thing about the cluster analysis is that, the selected top lines (lines no. 6, 38, 57, 58, 59 and 73) are placed in one group and only line no. 61 added to them.
Conclusion: Pedigree study of the top lines, it was found that in the pedigree of the 4 lines, there is a common parent named PLATA, which probably made these lines superior to the other tested lines. According to these results, it is possible to propose and implement the use of this line to improve the wheat breeding program in the hot and dry areas of the south.
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