Chromosome Pairing and Unreduced Gamete Formation in Nineteen Pomegranate (Punica granatum L.) Cultivars

Abstract

Summary Pomegranate (Punica granatum L.) is among important horticultural plants of Iran cultivated in several regions of the country. There is very limited cytogenetic information available for pomegranate in general. Meiotic studies were performed on 19 pomegranate cultivars of Iran considering chromosome pairing, chiasma frequency, the occurrence and effect of B-chromosomes and unreduced gamete formation. All the cultivars studied possessed 2nϭ2xϭ16 chromosome number forming mostly bivalents along with a low number of quadrivalents possibly due to the occurrence of translocations. They varied significantly in their meiotic characteristics due to their genomic differences. Some of the cultivars possessed B-chromosomes, which significantly changed their meiotic characteristics while some cultivars could produce unreduced gametes. With the use of present findings indicating genomic differences of the pomegranate cultivars studied a better hybridization and breeding program may be planned.

Cytogenetic study of Amaranthus L. species in Iran

“…Three species of A. powellii, A. spinosus and A blitum (Tabriz population) comprise the first sub-cluster, out of which the last 2 species show more similarity. Close relationship of these 2 species has been observed in protein (Sheidai et al 2006) and morphometric (unpublished data) studies too.…”

“…Close relationship of A. viridis, A. blitoides and A. graecizans has also been shown in morphometric (unpublished data) and protein studies (Sheidai et al 2006).…”

“…Various reasons have been suggested for the occurrence of diffuse stage. These are: high synthetic activity analogous to the lampbrush stage in amphibian oocyte, shedding of the lateral elements in the synaptonemal complex, the post pachytene elimination or modification of histone proteins and meiotic arrest to withstand the adverse environmental conditions (Sheidai and Inamdar 1991). As the Amaranthus species grow wild in different environmental conditiond the occurrence of diffuse stage may be considered as an adaptation to such variable conditions.…”

“…Such relative data make possible the study of the species having different chromosome number (Sheidai et al 2003).…”

Assessment of Genetic Variation within Commercial Iranian Pomegranate (Punica granatum L.) Cultivars, Using ISSR and SSR Markers

“…Morphological, cytological and DNA markers (RAPD, AFLP, SSR and ISSR) have been used to evaluate the genetic variability of Iranian pomegranates. These studies showed the occurrence of high genetic diversity among Iranian genotypes studied at both cytogenetic (Sheidai and Noormohammadi, 2005) and molecular levels including RAPD (Sarkhosh et al, 2006;Sheidai et al, 2007;Noormohammadi et al, 2010;Zamani et al 2013), AFLP (Moslemi et al, 2010) and SSR markers (KoohiDehkordi et al, 2007;Pirseyedi et al, 2010;Ebrahimi et al, 2010). The present study was performed with the aim to identify genetic diversity within four commercial pomegranate cultivars of Iran and attempt to evaluate the usefulness of the two molecular markers (ISSR and SSR) that will help breeders to recognize superior cultivars for breeding programs.…”