تاثیر خشکی بر واکنش لاین‌های گرده‌افشان چغندرقند (.beta vulgaris l) از نظر عملکرد قند

خشکی یکی از اصلی‌ترین تنش‌های غیر زیستی است که باعث کاهش عملکرد محصولات زراعی می‌شود. بهبود عملکرد گیاهان تحت تنش خشکی هدف اصلی برنامه‌های اصلاحی است، زیرا برای امنیت غذایی بسیار مهم هستند. مطالعه حاضر به‌منظور ارزیابی لاین‌های گرده‌افشان چغندرقند نسبت به تنش خشکی و شناسایی لاین‌های متحمل به خشکی انجام شد. به این منظور 20 لاین چغندرقند در دو شرایط آبیاری نرمال و تنش خشکی در قالب طرح بلوک‌های کامل تصادفی با سه تکرار در سال 1394-1393 در ایستگاه تحقیقات چغندرقند مهندس مطهری کرج کشت گردیدند و عملکرد قند آن‌ها تحت شرایط نرمال ( yp) و تنش خشکی ( ys) برآورد شد. شاخص‌های تحمل و حساسیت بر مبنای دو عملکرد یادشده محاسبه شدند. تجزیه واریانس مرکب نشان داد که اثرات محیط، ژنوتیپ و برهمکنش میان آن‌ها معنی‌دار بود. بر اساس نتایج شاخص‌های mp، gmp، sti، hm، yi، rei و mrp لاین‌های s1- 9501116 و s1- 950123، شاخص di لاین s1- 9501116، شاخص ati لاین s1- 950123 و شاخص‌های rdi، tol، ssi و sspi لاین s1- 950079 به‌عنوان لاین‌های متحمل شناخته شدند. شاخص siig از بین لاین‌های معرفی‌شده توسط شاخص‌ها، لاین s1- 950116 را به دلیل کم‌ترین فاصله از لاین ایده‌آل (0/56)، بیشترین فاصله از لاین غیر ایده‌آل (1/12) و بیش‌ترین مقدار siig (0/66)، متحمل‌ترین لاین عنوان نهاد. پس از آن، لاین‌های s1- 950123، s1- 950077 و s1- 950119 به ترتیب با داشتن مقدار siig برابر با 0/57، 0/56 و 0/56 در رتبه‌های بعدی قرار گرفتند. لذا می‌توان این ‌لاین‌ها را به‌عنوان والد پدری برای تولید هیبریدهای متحمل به خشکی پیشنهاد کرد.

drought impacts on the reaction of sugar beet (beta vulgaris l.) pollinator lines in terms of sugar

introduction: drought is one of the most significant abiotic stresses that reduce crop yield. the primary objective of breeding programs is to increase the yield of plants under drought stress, as these plants are vital to food security. this study was conducted to evaluate the drought tolerance of sugar beet pollinator lines and to identify drought tolerant lines.materials and methods: 20 sugar beet lines were planted in two conditions of normal irrigation and drought stress in the randomized complete block design with three replications in the 2014 crop year in motahhari sugar beet research station, karaj, alborz, iran. these lines were produced by crossing a drought tolerant fodder beet (7221) with an o-type monogerm variety over the course of several years in order to produce a pollinator parent for the development of drought tolerant sugar beet hybrids. sugar yield under normal conditions (yp) and drought stress (ys) were estimated.  on the basis of these two yields, tolerance and sustainability indices were subsequently calculated.results and discussion: results revealed that the effects of environment, genotype, and their interaction were statistically significant. the mp, gmp, sti, hm, yi, rei, and mrp indices of lines s1- 9501116 and s1- 950123, the di index of line s1- 9501116, the ati index of line s1- 950123, and the rdi, tol, ssi, and sspi line indices s1- 950079 were introduced as drought tolerant lines. among the lines introduced by the aforementioned indices, the siig index designated line s1- 950116 as the most tolerant pollinator line due to its short distance from the ideal line (0.56), its greatest distance from the non-ideal line (1.12), and the highest value of siig (0.66),  after the mentioned line, the lines s1- 950123, s1- 950077, and s1- 950119 followed with siig values of 0.57, 0.56, and 0.56, respectively. cluster analysis showed, 20 pollinator lines and three controls were categorized into five main groups, while sugar yield under normal conditions, sugar yield under drought stress conditions, and 16 estimated indices were categorized into four main groups. the s1-950116 line was placed in the first group alone due to its superior sugar yield under both normal irrigation and drought stress conditions, as well as its superior mp, gmp, sti, hm, yi, di, rei, and mrp indices. so, this pollinator line can be used to produce drought-tolerant hybrids for cultivation in various regions where water scarcity stress is a possibility. in the second group, s1-950077, s1-950118, s1-950074 and s1-950119 pollinator lines and ir7 tolerant control were present. this group exhibited relatively high values in both conditions and stress tolerance indices, indicating that they are drought-tolerant and capable of producing hybrids with a high sugar yield.conclusion: mp, gmp, hm, sti, yi, di, rei and mrp indices were found to be the most suitable indices for selecting lines with high sugar yield potential and tolerance to drought stress environment based on the results of correlation analysis of the studied indices. among 20 pollinator lines, according to these indices, lines s1-9501116 and s1-950123 had the highest tolerance compared to other lines in terms of drought stress. additionally, the aforementioned lines with siig values close to one were identified as tolerant lines. under both normal and stress conditions, the aforementioned lines had the highest sugar production potential and yield, which may be due to the transfer of drought tolerance genes from their tolerant maternal parent; consequently, these lines can be suggested as the parent for the production of drought-tolerant hybrids.