روابط سيتوژنتيكي گندم هاي Triticum monococcum subsp. aegilopoides و Aegilops cylindrica

چكيده انگليسي :

Cytogenetic Relationships BetweenTriticummonococcumsubsp aegilopoides and Aegilopscylindrica FatemehGhorbaniSini f ghorbani @gmail com Department of Agronomy and Plant Breeding Isfahan University of Technology Isfahan Iran Degree M Sc Language Farsi Supervisor Ahmad Arzania arzani@cc iut ac ir Abstract Cytogenetic analysis is one of the first steps of breeding studies Understanding chromosomes and their behavior is effective in successful hybridization This study was carried out on Triticummonococcumsubsp aegilopoidesand Aegilopscylindricato study theirkaryotypic characteristics and meiotic behavior Eight genotypes of T m subsp aegilooidesand eight genotypes of Ae cylindrica collected from west of Iran were planted in two autumn planting dates To study karyotypic characteristics root tips of seedlings were pretreated with bromonaphtalene fixed in Lewitsky solution hydrolyzed in N sodium hydroxide stained with hematoxilin and squashed To study meiotic behavior when the spikes were at suitable stage of meiotic division immature spikes were harvested fixed in Carnoy solution stained with hematoxilin In karyotypic study results of analysis of variance showed statistically significant variation in long and short arm lengths total chromosomal length but they did not have any significant variation for other karyotypic characteristics Variation in chromosomal length could be occurred by sample preparation method or sampling at different mitotic stages Loss of significant variation in mostkaryotypic variation is reasonable because of investigating one species All of genotypes of Ae cylindrica classified in A class of Stebbin s classification The most frequent type of chromosomes weresubmetacentric and subtelocentricwhile A A A and A genotypes were presented metacentric chromosomes Total form percentage was approximately varied in genotypes A genotype possessed highest value of TF The highest and least value of symmetry index belonged to A and A genotypes respectively Also highest and least value of interchromosomal asymmetry index belonged to A and A genotypes A and A genotype had the highest value and least value of intrachromosomal asymmetry indx T m subsp aegilopoides genotypes belonged to A class of Stebbin s classification T m subsp aegilopoidesis a primary species because of its metacentric chromosomes Thehighest and least value of TF belonged to T and T genotypes respectively Also highest and least value of symmetry index belonged to T and T genotypes T and T possessed the highest and least value of interchromosomal asymmetry index The highest and least value of intrachromosomal asymmetry index belonged to T T and T respectively All of karyotypic symmetry indices revealed that Ae cylindricawas more advance than T m subsp aegilopoides Results of meiotic investigation of Ae cylindricaindicated some meiotic abnormalities including laggard chromosome stickiness and bridge B chromosomes chromosomal unequal distribiution asynchrony micronuclei abnormal localization of daughter nucleus n gametes formation by different mechanisms and absence of spindle fibers This species with meiotic index wasapproximately unstable This meiotic index was caused by interaction between genetic and environment Meiotic abnormalities of T m subsp aegilopoideswere including laggard chromosome stickiness and bridge abnormal localization of daughter nucleus n gametes formation the species presented a meiotic index of suggesting its meiotic stability Key words Karyotype laggardchromosome chromosome stickiness and bridge B chromosome asynchrony micronuclei meiotic index PDF created with pdfFactory trial version www pdffactory com

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روابط سيتوژنتيكي گندم هاي Triticum monococcum subsp. aegilopoides و Aegilops cylindrica

كاريوتيپ , كروموزوم تاخيردار , چسبندگي و پل كروموزومي , كروموزوم B , عدم همزماني , ميكرونوكلئي , شاخص ميوزي