B-chromosomes in Iranian pomegranate (Punica granatum L.) cultivars
2007
Sheidai, M. (Shahid Beheshti Univ., Tehran (Iran). Dept. of Biology) | Khandan, M. (Islamic Azad Univ., Tehran (Iran). Genetics Dept.) | Esfahani, S.N. (Islamic Azad Univ., Tehran (Iran). Genetics Dept.)
Programs for screening the genetic and cytogenetic diversity among Punica granatum L., cultivars of Iran are in hand, therefore cytogenetical study of 22 Punica granatum cultivars was carried out for the occurrence and effect of B-chromosomes in genetic recombination of the cultivars possessing them. The study revealed the presence of 0-5 B- chromosomes in 17 cultivars out of 22. These accessory chromosomes were smaller than the A-chromosomes and did not pair with them or among themselves. B-chromosomes could arrange themselves on the equatorial plane and move to the anaphase poles however they lagged in some cases controlling their accumulation in the daughter nuclei. Statistical analysis showed a significant increase in the mean number of chiasmata when B- chromosomes are present in some of the cultivars leading to a change in genetic recombination.
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