تغییرهای آللی، تجزیه ارتباط و تنوع هاپلوتایپی برای نشانگرهای ریزماهواره‌ی پیوسته به qtlهای مرتبط با تحمل به خشکی در جو

تنش خشکی ناشی از کم آبی و گرمای آخر دوره رشد، از مشکل‌های مهم در کشاورزی به شمار رفته و یکی از مهم‌ترین عوامل کا هش عملکرد گیاهان زراعی می باشد. از همین‌رو به منظور بررسی آلل‌های مرتبط با تحمل به خشکی در گیاه جو و همچنین گروه‌های هاپلوتایپ اثر‌گذار بر آن این پژوهش به انجام رسید. برای این منظور، آزمایش جهت تعیین فنوتیپ در ایستگاه تحقیقات گنبد‌کاووس و در قالب طرح اگمنت با 96 ژنوتیپ و 4 شاهد اجرا شد و 18 صفت بر روی بوته‌ها مورد ارزیابی قرار گرفت. سپس برای بررسی تنوع آللی و هاپلوتایپی، ژنوتیپ‌های مورد آزمایش به وسیله 5 نشانگر ریزماهواره مرتبط با تحمل به خشکی آزمون گردیدند. بررسی تنوع آللی میانگین تعداد آلل، محتوی اطلاعات چند شکل و تنوع ژنی را به ترتیب 5.2، 0.6267 و 0.6807 نشان داد که در هر سه بخش آلل gbms180 دارای بیشترین و آلل bmag0782 دارای کمترین مقدار بود. همچنین نتایج بررسی هاپلوتایپی 58 گروه هاپلوتایپ را نشان داد. گروه نوزده که شامل ژنوتیپ صد و سی و پنج بود با عملکرد 5183.333 کیلوگرم در هکتار بیشترین عملکرد و مقاومت در برابر خشکی را داشت. تجزیه ارتباط بین داده‌های مولکولی و فنوتیپی بیان‌گر این موضوع بود که از میان 16 آلل موثر بر صفت‌های مورد ارزیابی آلل gmbs183d با اثر‌گذاری بر روی سه صفت تعداد دانه در سنبله، تعداد سنبله (در هکتار) و عملکرد (در هکتار) دارای بیشترین اثر‌گذاری بر روی عملکرد و اجزای آن بود. آلل gmbs183c نیز با r2 برابر با 23.3 برای صفت تعداد سنبله (در هکتار) بالاترین مقدار ضریب تبیین را در بین آلل‌های دخیل در صفت‌های مربوط به عملکرد و اجزا عملکرد دارا بود. در صورت تایید نتایج می‌توان از نشانگر‌ها و ژنوتیپ‌های حاضر در تحقیقات و برنامه‌های به‌نژادی استفاده نمود.

Allelic variation, association analysis and haplotype diversity of microsatellite markers related to drought tolerance QTLs in barely

BackgroundBarley (Hordeum vulgare L.) is one of the most important cereals in the world. Drought is one of the most important abiotic stress and severely limits the production of barley around the world. Diversity is the basis of all screenings and genotypic selection also needs diversity. The use of haplotypes in the study of genetic relationships is important. This is more important when there is little indication of the power of the individual’s markers, or when there are several genetic markers in the selected QTLs. Association analysis and study of the relationship between molecular markers and agronomic traits have several applications, including the possibility of studying the genetic potential of specific genotypes before phenotyping, identifying alleles related to traits in the germplasm, facilitating locating QTLs and validation of candidate genes responsible for quantitative traits. The aim of this experiment was to investigate the allelic variation, association analysis and haplotypes of continuous microsatellite markers to drought tolerance genes in the barley. Materials and methodsThe experiments were carried out as an augmented design with 96 barley genotypes along with four controls. 18 traits were evaluated on the plants. Then, to evaluate the allelic and haplotypic diversity, the genotypes were tested using five microsatellite markers related to drought tolerance. In the end, phenotypic information was compared with genotypic information, and the relationship between them was determined by linear forward regression. FindingsThe analysis of the data obtained from the markers revealed that there were 26 multivariate alleles and also an average of 3.429 alleles for each marker, with the highest number of GBMS180, GMBS183 and EBmac0755 markers with 6 alleles. The results of the PIC show the highest value of the GBMS180 marker and the lowest value of the Bmag0782 marker; the mean of PIC was also 0.6267. The genetic diversity was also between 0.7117 and 0.7602 with an average of 0.6807. The GBMS180 has the highest value and the Bmag0782 has the lowest value. Haplotype evaluation of microsatellite markers on 96 genotypes studied genotypes in fiftyeight haplotype groups, among which the third haplotype group had the most sub cluster with three genotypes. The nineteen group, which included genotype 134, with the highest yield and drought tolerant, with 5183.333 kg ha1. The results of the coupling analysis indicated that the GMBS183D allele was involved in controlling four traits of the number of spikes, spike weight, number of seeds per spike and yield, and had the greatest effect among other alleles on the increase or decrease in yield and its components. DiscussionLinear regression and haplotype studies did not overlap, although the forward linear regression of alleles was studied individually and the allelic groups were able to interact with each other, but the obtained data did not have two match methods. But a comparison of the results of allelic variation was similar to linear regression and showed GMBS183, which had the highest PIC, among four attributes related to yield and its components in controlling the three traits of the number of spikes, number of seeds per spike and yield. This marker was also present in control of days to physiological reppining, which plays an important role in plant escape from the stresses, especially drought stress, and R2 is equivalent to 15.4%. This suggests that the results of linear regression match the results of the allele variation and overlap each other.