ارزیابی تنوع‌پذیری ژنوتیپ‌های گندم نان تحت شرایط مختلف رطوبتی با استفاده از روش‌های متنوع آماری

از بین تنش‌های محیطی، تنش خشکی مهم‌ترین عامل کاهش تولیدات گیاهان در سراسر جهان است. جهت مطالعه تنوع ژنتیکی و ارتباط بین صفات مختلف با عملکرد دانه در 17 ژنوتیپ (شامل ارقام و لاین‌های مختلف) گندم نان، آزمایشی در قالب طرح بلوک‌های کامل تصادفی با سه تکرار تحت دو شرایط عدم تنش خشکی و شرایط دیم در سال زراعی 90-1389 در مزرعه آموزشیپژوهشی دانشگاه پیام‌نور اسدآباد اجرا گردید. در این آزمایش صفات عملکرد دانه، تعداد دانه در سنبله، طول سنبله، طول برگ پرچم، عرض برگ پرچم، وزن صد دانه، ارتفاع بوته، محتوی نسبی آب برگ، میزان نسبی آب ازدست‌رفته، درصد سبزینگی برگ (میزان کلروفیل) و مساحت برگ پرچم اندازه‌گیری شدند. نتایج تجزیه واریانس ساده تنوع بالا و معنی‌داری را در هر دو شرایط رطوبتی (مکان) نشان داد. نتایج تجزیه واریانس مرکب اثر ژنوتیپ را برای اکثر صفات معنی‌دار نشان داد. نتایج تجزیه همبستگی نیز بیانگر این بود که بین عملکرد دانه و درصد سبزینگی برگ (اسپاد) در شرایط دیم و بین عملکرد دانه و میزان آب ازدست‌رفته برگ در شرایط عدم تنش خشکی همبستگی مثبت و معنی‌داری (p<0/05) مشاهده گردید. نتایج تجزیه خوشه‌ای ژنوتیپ‌های موردمطالعه را در هر دو شرایط محیطی در سه گروه مجزا و متفاوت قرار داد. به‌طوری‌که بیشترین فاصله ژنتیکی در هر دو شرایط رطوبتی بین خوشه اول و سوم مشاهده گردید. تجزیه به مولفه‌های اصلی در شرایط عدم تنش خشکی و شرایط دیم به ترتیب 71% و 76% از تنوع موجود را توجیه نمودند. با توجه به مقایسه میانگین عملکرد دانه، ژنوتیپ‌های 7 (3790 کیلوگرم در هکتار)، 8 (3525 کیلوگرم در هکتار) و 13 (3305 کیلوگرم در هکتار) در شرایط عدم تنش خشکی و ژنوتیپ‌های‌ 13 (2147 کیلوگرم در هکتار)، 14 (2440 کیلوگرم در هکتار) و 17 (2254 کیلوگرم در هکتار) در شرایط دیم بیش‌ترین عملکرد دانه را تولید کردند.

Evaluation of diversity of bread wheat genotypes under different moisture conditions using diverse statistical methods

Introduction Drought stress and water availability restrictions have always been the most important issue in agriculture in the world and Iran, and this is the most important factor in reducing plant production and Determination and identification of effective factors on wheat seed yield under water deficient condition is very important. Iran with were an average rainfall of 240 mm per year is among the arid and semiarid areas of the world, with this precipitate, the main factor influencing the plant’s performance is drought stress. In dry and semiarid regions due to peripheral dryness and available moisture constraints, the yield of wheat plants decreases dramatically. According to meteorologists, dry weather can occur when rainfall is less than the average of longterm rainfall in a long period of time. However, from the agricultural point of view, if the distribution of rainfall is so low that it causes a significant reduction in the yield of plants, then land has occurred. Considering the importance of wheat as an important and strategic product in Iran, due to the droughts that are occurring (precipitation below the normal level), The purpose of this study was to study the response of some cultivars of genotypes in Asadabad city to the end of the drought stress, identification of higher yield genotype (s) and also determining the characteristics that affect the yield of the present research. Material and method In order to This study was designed to investigate the genetic diversity and relationships between yield and related other traits (Study of irrigation and correlation of some physiomorphological traits with wheat yield) in 17 wheat genotype and were investigated at completely randomized design with three replications in 20092010 under two conditions (drought stress and nondrought stress). An experiment was conducted at the experimental field of the payame Noor University of Asadabad and the agricultural group laboratory located at the provincial lab. Each plot consisted of 5 lines 2 meters long with a distance of 20 cm and a plot distance of 50 cm. Irrigation was carried out in conditions without drought stress according to the custom of the area, However, under irrigation conditions, irrigation was not done and weed combat was carried out manually and in one step (the first stage of stemming). The harvest took place in the middle of July 2011. In order to carry out notes on the study of traits, five genotypes were randomly selected in each replicate. 14 agromorphological traits were including (Yield stress, Yield potential, Number of Seed Per Spike, Spike Length, Flag leaf Length, Width leaf Length, 100 Kernel Weight, Plant Height, Relative Water Content, Relative Water Loss, SPAD, Area flag leaf and Single Seed weight) measured. Result and discussion Analysis of variance revealed good differences among genotypes for two condition drought stress and nondrought stress. Among the traits, the highest coefficient of phenotypic variation was observed for seed yield with SPAD (drought stress condition) and seed yield with Relative Water Loss. Cluster analysis subdivided the genotypes into 3 groups. The maximum distance were observed between the genotype from groups 1 and 3. According to the comparison of mean grain yield, genotypes 7, 8 and 13 showed high yield under moisture conditions and genotype 13, 14 and 17 produced higher yields under drought stress conditions. In this study, the effects of stress have reduced the function of genotypes. However, the decreasing values in different genotypes are different, so that sensitive genotypes were with the highest yield loss and endemic genotypes with the least functional deficiency faced.