نوع مقاله : مقاله کامل علمی پژوهشی
نویسندگان
1 گروه مهندسی تولید و ژنتیک گیاهی، دانشکده کشاورزی، دانشگاه مراغه، مراغه، ایران
2 عضو هیئت علمی، گروه مهندسی تولید و ژنتیک گیاهی، دانشکده کشاورزی، دانشگاه مراغه
چکیده
کلیدواژه‌ها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Background and Objective: Barley is the fourth most important cereal crop in the world. Today, this plant is used as animal feed, malt production, and human food. The quality of its seeds, like other crop seeds, decreases under unfavorable environmental conditions. Seed aging or aging is usually an irreversible, cumulative, and irreparable process that causes cellular damage, leading to delayed germination, reduced ability to resist stress, and ultimately loss of vitality. The use of biological treatments or their derivatives is considered one of the strategies for controlling the rate of seed aging, among which the use of fungi of the genus Trichoderma is of great importance. The aim of this research is to investigate the effect of fungal extracts of Trichoderma koningii, T. virens, and T. harzianum on improving germination and seedling quality of 'Jolgeh' barley seeds under induced aging conditions.
Materials and Methods: In this experiment, the effects of seed treatment with T. koningii, T. virens, and T. harzianum extracts on germination indices and seedling vigor of spent and unspent seeds of plain barley cultivar Jolgeh were investigated under laboratory and greenhouse conditions as factorial experiments in completely randomized plots with three replications. For seed exhaustion, accelerated exhaustion method was used for 24, 48, 72, 96, 144, and 120 hours at 44±1°C and 95±5% relative humidity. Extraction of fungal extracts was performed using Trichoderma-TSM specific culture medium. Germination traits were examined using ISTA method under standard laboratory conditions and greenhouse experiment was adjusted based on the results. In the greenhouse experiment, two exhaustion levels of 120 and 144 (hours) were excluded from the exhaustion treatment levels due to complete exhaustion of seeds. At this stage, all seedling traits were examined, including seed reserve utilization efficiency, seed discharge percentage, material mobility amount, and seedling vigor.
Result: The results showed that all the studied parameters including germination percentage, germination rate, germination percentage, germination rate, abnormal seedling percentage, stem length, leaf length, root length, seedling length, root to stem length ratio, stem dry weight, root dry weight, seedling dry weight, seed reserve utilization efficiency, seed discharge percentage, material mobility amount, and seedling vigor were significantly (p≤0.01) affected by the interaction between seed exhaustion and fungal extracts. Seed exhaustion caused a decrease in germination percentage, which was proportional to the intensity of stress. However, the positive effect of fungal extracts of T. koningii, T. virens and T. harzianum on improving germination percentage in treatments with exhaustion longer than 72 hours was more pronounced than in the control treatment (p≤0.05). Seed exhaustion for 48 hours significantly increased germination rate, after which this trait decreased significantly under exhaustion (p≤0.05). The greenhouse results indicated positive effects of fungal extracts on important seedling traits. T. virens and T. harzianum extracts reduced the percentage of abnormal seedling compared to the control treatment. Also, these treatments performed better than the control treatment in most of the seedling weight and length traits under exhaustion conditions. The highest efficiency of using reserves from T. virens and T. harzianum was achieved at 72 hours and 24 hours of exhaustion, respectively, while the conversion efficiency of T. koningii was lower than the control at all exhaustion levels.
Conclusion: The effect of fungal extracts on seed and seedling vigor recovery was not significant up to exhaustion levels of 48 hours compared to the control, but at higher levels, a significant effect on seed and seedling vigor recovery was observed, especially with extracts of T. virens and T. harzianum fungi, which was due to the increase in the mobility of seed reserves and their efficiency of use.
کلیدواژه‌ها [English]
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