بررسي تنوع ژنتيكي و انحراف از تفرق در نسل هاي F2 و F6 حاصل از تلاقي بين گونه اي گلرنگ زراعي و گلرنگ وحشي با استفاده از نشانگر مولكولي ISSR

چكيده انگليسي :

Study of Genetic Diversity and Segregation Distortion of InterspecificHybridization between Carthamus tinctorius and C oxyacanthus in F2 and F6 Generations by ISSR Marker Mojgan Asadollahian mojganasadolahian@yahoo com Department of Plant Breeding IsfahanUniversity of Technology Isfahan 84156 83111 Iran Degree M Sc Language FarsiM R Sabzalian Assist Prof Supervisor Abstract Safflower Carthamus tinctorius L is a member of the family Compositae or Asteraceae Nowadays it is mainlycultivated for extract of edible oil In recent years inter specific hybridization between cultivated and wildspecies have been used to enhance genetic variation in plant populations and rendering genotypes resistant tobiotic and abiotic stress environment Breeding through inter specific hybridization coupled with markerassisted selection could accelerate the breeding programs Inter simple sequence repeats ISSR is a PCR basedmarker in which 16 25 bp long microsatellites primers in a single primer PCR reaction amplify the inter microsatellite regions This technique has been extensively used in genetic diversity studies because they needno prior DNA sequence information and development costs are low In this research ISSR marker wasemployed to study genetic variation determine parental genome contribution and segregation distortion of F2and F6 populations derived from a cross between cultivated safflower Carthamus tinctorius genotype C111 andan accession of wild species C oxyacanthus genotype ISFII The DNA from the two parents and individual F2and F6 plants was extracted following CTAB method Fifteen ISSR primers that showed polymorphism inparental genotypes were used in F2 and F6 populations whichproduced 58 polymorphic parental bands Dicesimilarity indices were subjected to cluster analysis using Complete algorithm The dendrogeram revealed twomajor groups Group 1 included genotypes similar to C111 and group 2 included genotypes similar to ISFII Theanalysis of molecular variance AMOVA also showed that genetic variance between two parental groupswithin each populations was significant P 0 001 and therefore genotypes could be discriminated based onsimilarity to parental genotypes Therefore in F2 and F6 populations the number of progenies similar to C111 wasmore than the number of progenies similar to ISFII Out of 58 parental markers the maximum minimum and theaverage of bands were 40 22 and 30 respectively in F2 generation and in F6 they were 38 19 and 29 4 bandsrespectively Results of this study showed that not all the parental markers were transmitted to F2 and F6progenies Also in both populations the average of inherited parental bands was higher from cultivatedC111genotype than wild ISFII genotype Chi square test showed a segregation distortion in both F2an F6populations from 1 1 expected ratio at 0 01 probability level Also inF2 and F6populations among 58 loci 24 41 and 27 47 of loci were significantly deviated from the expected normal segregation ratio P 0 01 respectively In both populations most of the distorted markers skewed toward the wild genotype It seems thatthetype of molecular marker differences in genome size of parents self incompatibility and natural selectionareprobably responsible for segregation distortion The presence of genetic distortion in crosses of cultivatedand wild safflower species may preclude the maximum variation to be expressed in breeding programs Key words Carthamustinctorius C oxyacanthus Inter specific hybridization ISSR Gentic diversity Segregation distortion

اسداللهيان، مژگان

بررسي تنوع ژنتيكي و انحراف از تفرق در نسل هاي F2 و F6 حاصل از تلاقي بين گونه اي گلرنگ زراعي و گلرنگ وحشي با استفاده از نشانگر مولكولي ISSR

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