بررسی تنوع ویژگی‌های ریشه در لاین‌های نخود (cicer arietinum l.)

نخود یکی از مهم‌ترین حبوبات در ایران و در مناطق خشک و نیمه‌خشک جهان است. بخش مهمی از موفقیت تولید در مناطق دارای تنش خشکی به جذب موثر آب و عناصر غذایی توسط سیستم ریشه‌ای کارآمد وابسته است. مطالب زیادی در ارتباط با تیپ مطلوب گیاهی و ساختار هندسی گیاه به رشته تحریر در‌آمده است، امّا اطلاعات در مورد رشد و نمو ریشه بسیار اندک است. به‌منظور ارزیابی صفات ریشه 39 لاین نخود، آزمایشی در قالب طرح کاملاً تصادفی با چهار تکرار در گلخانه دانشکده کشاورزی دانشگاه ایلام انجام شد. پس از گذشت 30 روز از سبز شدن بذور، 16 ویژگی ریشه اندازه‌گیری شد. یافته‌های این مطالعه نشان داد که ویژگی‌های ریشه دارای دامنه تنوع بالایی در بین لاین‌های نخود مورد مطالعه بودند. نتایج نشان داد که تفاوت زیادی بین بیشترین و کمترین حجم ریشه وجود دارد (19و 4.43 سانتی‌مترمکعب). در میان لاین‌های مورد مطالعه، لاینflip07-20c  بیشترین طول ریشه، تراکم طول ریشه و محتوای آب ریشه را دارا بود. لذا، می‌تواند ضمن استفاده از آب موجود در حجم وسیع‌تری از نیم‌رخ خاک، از عناصر غذایی بیشتری نیز در طول دوره رشد بهره‌مند گردد و در برابر شرایط تنش خشکی تحمل بهتری از خود بروز می‌دهد. از‌ آنجا‌ که حجم ریشه نیز از مهم‌ترین ویژگی‎های گیاه به‌منظور جذب آب و مواد غذایی است و نسبت حجم ریشه به اندام‌های هوایی می‌تواند یکی از مهم‌ترین شاخص‌های پیش‌بینی‌شده برای میزان تنفس و جذب آب باشد، لاین flip07-31c با دارا بودن بیشترین حجم ریشه می‌تواند تحمل خوبی در برابر شرایط تنش خشکی داشته باشد. از داده‌های به‌دست‌آمده در مورد ویژگی های ریشه لاین های مورد مطالعه می‌ توان به‌منظور اصلاح لاین‌های مقاوم به خشکی نخود استفاده کرد.

investigation of diversity of root traits of chickpea lines

introductionchickpea is the third most important grain legume and its seeds contain protein that is an important energy source for human. drought diminishes crop yields and carries the potential to result in total crop failure. however, chickpeas are renowned for their superior drought tolerance compared to many other cool-season legumes. given that water availability is the primary constraint on growth in arid conditions, optimal yields and crop production occur when plants efficiently absorb the limited soil moisture available. this feature will only be achieved through the compatibility mechanisms associated with the root system. chickpea have a direct and deep root system that helps the plant absorb moisture from the lower layers of the soil. therefore it has led to the prosperity of its cultivation in rainfed areas. water absorption by the plant depends on the size of the root, its activity and distribution in the soil. therefore, it seems that the understanding of plant root traits is necessary to further understand the mechanisms of drought resistance. in general, few studies have been done on the diversity of legume roots. therefore, this research was carried out with the aim of investigating the diversity of root morphological traits of chickpea lines in order to use these traits to select drought-tolerant chickpea lines. materials and methodsthe plant materials of this experiment included 39 chickpea lines of icarda origin, which were taken from the kurdistan research center. the experiment was conducted as a completely randomized design with four replications in the research greenhouse of ilam university. seeds were implanted in pvc tubes with a diameter of 10 cm and a length of 60 cm. a drip irrigation system was designed in such a way that an emitter was located inside each tube. with this method, the test tubes were in favorable conditions. in the greenhouse the temperature was under control and had a temperature of 25 degrees celsius and an average humidity of 70% and the plants used natural light without any additional light. after 35 days of seed germination traits were measured. for this purpose, first the aerial parts of the plant were separated by scissors. after separating the roots from the pvc tubes, they were placed in ethanol with a concentration of 98% and after being transferred to the laboratory, they were stored in the refrigerator, then the traits were measured. variance analysis of traits and average comparison of data was done with duncans multi-range test using sas software version 9.1. results and discussionall the measured traits had a good variation range among the studied chickpea lines that these results are consistent with previous studies. none of the lines showed superiority for all root traits. line flip07-20c having the longest root length, can benefit from the water available in a larger volume of the soil profile. in the examination of rooting depth in grain legumes, such as chickpeas, it was observed that root length remains relatively stable across a broad spectrum of soil moisture levels. root length is considered a crucial parameter in plant growth, as researchers posit that the length of roots per unit of soil volume is the most effective characteristic for assessing water and nutrient absorption by plants. in our current investigation, a significant disparity was noted between the highest and lowest root volumes. root volume stands out as one of the plant’s key attributes for absorbing water and nutrients. in this research, line flip 82-150c had the highest and line flip97-706c had the lowest specific root length. the specific root length is one of the important traits in showing the efficiency of the root in absorbing water and resistance to drought. when faced with drought stress, the plant assigns more dry matter to the root system in order to increase the absorption ability of the roots; as a result, there are changes in the morphological characteristics of the roots, such as an increase in the specific length of the root. the highest root density was observed in line flip09-149c. root density is a trait that is affected by root weight and volume. in the condition of drought stress, the decrease in root volume caused an increase in root density and at the end of the growth period, the decrease in root dry weight was more than the decrease in its volume, which ultimately led to a decrease in root density. studies have indicated that as humidity decreases and soil depth increases, there is a notable decrease in root density. overall, the findings from this research offer foundational insights for advancing efforts to enhance root characteristics, thereby mitigating drought and enhancing the resilience of chickpea varieties to drought stress. conclusionsthe results showed that line flip07-20c had the highest root length, root length density and root water content compared to other lines, but none of the lines were superior in terms of all root traits. the obtained information about the characteristics of the roots of the studied lines can be used to improve drought-resistant chickpea lines.