Genetic diversity of Iranian lettuce (Lactuca sativa. L) accessions revealed by cytological traits

Abstract

In this study, 15 different accessions of Iranian lettuce cultivars and varieties that were collected from different regions were investigated. Starting from the root apical meristem, we measured the number and size of the chromosomes. The karyotypic formula was determined. The basic chromosome number was n = 9 in all accessions, possibly due to ancient origin, also all accessions had morphological dissimilarity, and heteromorphisms between chromosomes and their chromosomal types were metacentric, submetacentric and subtelocentric. Analysis of variance showed significant differences between chromosomal characteristics. The maximum size of the estimated genome (in terms of chromosome length) was that of the Qom accession (62.45 μm). The minimum size was that of the Babol accession (19.94 μm). Symmetrical and asymmetrical karyotypes were observed between the accessions. The formula of the Ahwaz accession was 12m + 4sm + 2t with the maximum centromic index (40.93%), while the Fasa accession had a 4m + 10sm + 4st karyotypic formula and the minimum value (28.73). There were different numbers of satellites present on the chromosomes in the different accessions. Some of them had two satellites, some one and the others none. In principle component analysis two components had more than 82.75% of the data variations. Based on the first and second components the accessions separated into three groups. Cluster analysis of karyotypic traits based on the unweighted paired group method using arithmetic average (UPGMA) separated the accessions in three groups. The results of this study will be useful for accession classification and identification.

New determinations of somatic chromosome number in cultivated and wild species ofSaccharum

“…have superior levels of adaptability and higher probabilities of survival than their diploid relatives (Soltis and Soltis 2000). The presence of intraspecific differences in chromosome number in sugarcane is in accordance with the findings of Cai et al (2013), who reported high and diverse cytological variation in Plukanetia volubelis L.; whereas recent studies on different varieties of Vicia faba and 15 different accessions of Iranian lettuce collected from different regions showed cytological similarities with similar chromosome number (Mousavi et al 2013;Vandana and Chaudhari 2013). The data on cytological characterization of cultivated and wild species of Saccharum available in the global sugarcane germplasm will be useful in selecting the parents while designing crosses during hybridization.…”

Evidence of a Possible Double Hybrid Origin for Two Malagasy Species of Piper L. (Piperaceae)

“…Chromosomes images were obtained from somatic mitoses recorded from root tips of only one plant living in a pot. The procedure was the same as in Mosti et al [36] and Mousavi et al [37], with a pretreatment in 8-hydroxichinoline and fixation in Carnoy. Then the material was hydrolyzed in…”

Genome-wide screening and characterization of long noncoding RNAs involved in flowering/bolting of Lactuca sativa

“…To accredit the expression of predicted DE-lncRNAs, qPCR analysis was performed for nine DE-lncRNAs in two different lettuce genotypes, Qomi and Sefid-e-Neishabour, which were grouped by [ 33 ] as the early and late bolting genotypes, respectively. A near concordance between the expression results obtained from qPCR and RNA-Seq was observed.…”

“…To confirm the expression levels of predicted lncRNAs, the leafy lettuce genotypes Qomi (early bolting) and Sefid-e-Neishabour (late bolting) were selected according to the results of previous research [ 33 ]. To obtain these samples, permission was not necessary.…”