بررسی کارایی نشانگرهای issr و scot در مطالعه‌ی تنوع ژنتیکی برخی جمعیت‌های گشنیز (.coriandrum sativum l)

گشنیز یکی از چهار گیاه دارویی اصلی ایران است. ایران چهارمین تولیدکننده و هشتمین صادرکننده‌ی گشنیز در جهان است. در این مطالعه، تنوع ژنتیکی، 16 جمعیت گشنیز از سه استان خراسان‌جنوبی، یزد و کرمان با استفاده از 10 آغازگر issr و 15 آغازگر scot مورد بررسی قرار گرفت. نتایج این مطالعه نشان داد که، در مجموع، آغازگرهای issr، 95.91 و آغازگرهای scot، 97.67 درصد چندشکلی نشان دادند و به‌ترتیب 49 و 86 باند با وضوح بالا تکثیر گردید. آغازگرهای is1 و sc11، sc13 بیشترین تعداد باند (8 و 9 باند) و آغازگرهای is2، is7 و sc4 کمترین تعداد باند (3 باند) را تکثیر نمودند. مقدار شاخص‌های pic، mi، emr و rp برای نشانگر issr، به ترتیب 0.43، 2.07، 4.55 و 3.56 و برای نشانگر scot، به ترتیب 0.38، 2.09، 5.49 و 3.38 برآورد گردید. بر اساس داده‌های نشانگر issr، بیشترین شباهت‌ ژنتیکی بین جمعیت‌های بافت-راور، بافت-ماهان و یزد-تفت و بر اساس نشانگر scot، بیشترین شباهت‌ ژنتیکی بین بافت-راور و کرمان – بافت مشاهده شد. بر اساس داده‌های نشانگر issr، کمترین شباهت‌ ژنتیکی بین جمعیت‌های خوسف – زرند، نهبندان-زرند و بیرجند-زرند و بر اساس نشانگر scot، کمترین شباهت‌ ژنتیکی بین بیرجند-بهاباد، خوسف-زرند و بیرجند-یزد به‌دست آمد. تجزیه خوشه‌ای بر اساس داده‌های نشانگر issr و scot، جمعیت‌ها را به‌ترتیب در چهار و سه خوشه گروه‌بندی نمود. درصد بالای چندشکلی در داده‌های به‌دست آمده از نشانگرهای issr و scot نشان داد که این نشانگرها برای تجزیه تنوع ژنتیکی در جمعیت‌های گشنیز کارآمد است. توجیه درصد کمی از تغییرات کل داده‌ها توسط مولفه‌های اصلی نشان داد که آغازگرها پراکندگی مناسبی بر روی ژنوم داشتند. نتایج این مطالعه نشان داد که درون جمعیت‌های هر استان تشابه ژنتیکی نسبتاً بالا و بین جمعیت‌های استان‌های مختلف، تشابه ژنتیکی کمتری وجود داشت. به منظور ایجاد حداکثر هتروزیس، تلاقی خوسف × زرند پیشنهاد می‌گردد.

investigating the efficiency of issr and scot markers in studying the genetic diversity of some coriander (coriandrum sativum l.) populations

introduction coriander (coriandrum sativum l.), is one of the four important medicinal plants in iran. iran ranks as the world’s fourth largest coriander producer and eighth largest coriander exporter. coriander seeds are considered one of iran's main export commodities, demonstrating competitive advantages comparable to cumin (cuminum cyminum l.) and saffron (crocus sativus l.) in international markets. since breeding desirable genotypes is only possible with selecting superior genetic materials, plant breeders must use appropriate genetic diversity to achieve high performance breeding lines. using markers to gain knowledge about genetic diversity can be beneficial in plant breeding programs. this study aimed to investigate genetic diversity, assess similarity and differences among coriander populations, and determine the genetic structure of different coriander populations using issr and scot markers. materials and methods to evaluate the genetic diversity of a number of coriander populations, 16 populations were collected from three provinces, including south khorasan (four populations from khusf, birjand, nehbandan and sarbishe cities), yazd (four populations from the yazd, taft, abarkoh, and bahabad cities), and kerman (eight populations from kerman, sirjan, bam, zarand, shahr babak, baft, ravar and mahan cities). this study was conducted in 2019-2020 in the molecular plant breeding laboratory, production engineering and plant genetics department, faculty of agriculture, natural resources and environment, university of birjand. ten issr (inter-simple sequence repeats) and 15 scot (start codon targeted) primers were used for molecular diversity analysis. dna was extracted from coriander leaves using the ctab method and the quantity of extracted dna was determined using a nanodrop device (thermo scientific model 2000). present and absent of bands were scored as binary data (0: absent and 1: present) and represented as a data matrix in an excel sheet. to evaluate the primers, the indices of the number of amplified alleles (na), the number of effective alleles (ne), the percentage of polymorphism (pp), the polymorphic information content (pic), the effective multiplex ratio (emr), the marker index (mi) and the resolving power (rp) were calculated. in order to cluster populations, first the genetic similarity of individuals was calculated and then cluster analysis (ward's method) was performed. data was analyzed using ntsyspc2.2, spss v26, and excel 2020 software packages. results and discussion in total, the issr and scot primers showed 95.91% and 97.67% polymorphism, respectively. the 10 issr primers and 15 scot primers produced 49 and 86 high resolution bands, respectively. among all primers analyzed, is1 and sc11/sc13 demonstrated the highest amplification efficiency, generating 8 and 9 bands, respectively. in contrast, primers is2, is7, and sc4 revealed the lowest productivity, each producing only 3 bands. the average values of the pic, mi, emr, and rp for issr and scot markers were calculated as 0.43, 2.07, 4.55, 3.56 and 0.38, 2.09, 5.49, 3.38, respectively. based on issr and scot analysis, the highest genetic similarity was observed between baft-ravar, baft-mahan, yazd-taft, and baft-ravar, kerman-baft populations, respectively. furthermore, the lowest genetic similarity was recorded between khusf-zarand, nehbandan-zarand, birjand-zarand, and birjand-bahabad, khusf-zarand, birjand-yazd populations, respectively. cluster analysis of issr and scot data categorized the populations into four and three distinct clusters, respectively. based on pcoa (principal coordinates analysis) analysis of issr data, the first four components explained 50.44% of the total variance. the 1st, 2nd, 3rd and 4th components explained the 14.25%, 12.84%, 12.45% and 10.90% of total variance. based on pcoa analysis of scot data, the first five components explained 52.97% of the total variance. the 1st, 2nd, 3rd, 4th and 5th components explained 14.16%, 11.34%, 10.85%, 8.63%, and 7.99% of the total variance, respectively. the low percentage of variation explained by the components suggests that the primers were well distributed across the coriander genome and also the choice of primers has been made correctly. conclusion high levels of polymorphism were observed for issr and scot markers, suggesting their efficacy in evaluating genetic diversity among coriander populations. in present study, the primers were effective in distinguishing the populations and exhibited a reliable performance. the issr markers had a better efficiency compared to that of scot markers. correlation analysis of two matrices obtained from the molecular data for both markers did not significantly correlate, presumably due to their different natures. this study found a general correspondence between the genetic and the geographical distances, however, in some cases certain exceptions were noted, presumably due to factors such as seed mixing, gene pool migrations between geographical regions or gene flow among different populations, or even a common ancestral origin. according to the results of this study, among different populations, khusf and zarand populations exhibited the greatest genetic divergence, while baft and rawar populations were the most genetically similar populations. consequently, crossing khusf and zarand populations is highly recommended to benefit from heterosis. future breeding studies should incorporate a broader range of molecular markers and explore the associations between genetic markers and morphological, phenological, and quantitative traits.