Determination of Nuclear DNA Content and Ploidy of Hypericum perforatum L. Accessions Collected From Western Turkey

Abstract

Hypericum perforatum L. (St John's Wort) is a medicinal plant that produces pharmaceutically important compounds with antidepressive and anticancer activities. H. perforatum is a facultative apomictic species as it has the ability to reproduce with multiple reproduction mechanisms affecting genetic structure and chemical composition of the plants. The objective of this study was to determine nuclear DNA contents and ploidy levels of H. perforatum L. plants growing naturally in the flora of Turkey. The seeds of 39 Hypericum perforatum L. accessions collected from 23 different locations in Turkey were used in the study. Nuclear DNA contents of three different seedlings for each of the 39 H. perforatum accessions were determined using flow cytometry. Based on the results of flow cytometric analysis, nuclear DNA contents of the accessions varied between 0.8-2.57 pg 2C-1. Nuclear DNA content differences observed among H. perforatum accessions were statistically significant (P<0.01) and the Duncan test revealed that the accessions formed three clearly distinguishable main groups. Mean nuclear DNA contents of each group were 0.80 pg 2C-1 , 1.58 pg 2C-1 (1.36-1.73 pg 2C-1) and 2.38 pg 2C-1 (2.15-2.57 pg 2C-1). Ploidy levels were determined by correlating nuclear DNA content of accessions with the number of their mitotic chromosomes by counting chromosome number of one plant from each group. Findings suggest that H. perforatum accessions used in this study had the following three different ploidy levels: diploid, tetraploid and hexaploid. The percentages of diploid, tetraploid and hexaploid accessions were 2.2, 86.4 and 11.4% respectively.

Molecular cytogenetic characterization of common bean (Phaseolusvulgaris L.) accessions

“…In some previous studies, a positive or negative correlation was reported between the altitude and genome size. For instance, researchers have described that in Indian maize populations (Rayburn and Auger, 1990), Vicia faba (Ceccarelli et al, 1995), Dasypyrum villosum (Caceres et al, 1998), tetraploid Festuca pallens (Smarda and Bures, 2006), O. pumila and A. montbretiana (Hoffmann et al, 2010), Pinus yunnanensis (Wang et al, 2013), Hypericum perforatum (Savaş Tuna et al, 2017), Allium populations (Guo et al, 2018), Zea mays (Bilinski et al, 2018), and Crepis (İnceer et al, 2018), there was a positive correlation between the altitude and genome size, similar to the results herein. On the other hand, other studies have reported a negative correlation between the altitude and genome size (Creber et al, 1994;Bottini et al, 2000;Chia et al, 2012;Manzaneda et al, 2012;Wang et al, 2013;Akbudak et al, 2018;Savaş Tuna et al, 2019).…”

“…Knight et al (2005) found that ecological and geographic changes had an effect. In addition, it has been shown that differences in climate (especially precipitation and temperature) and geography (location, region, altitude, and latitude) are associated with genome size variations and ploidy levels (Manzadena et al, 2012;López-Alvarez et al, 2015;Bareither et al, 2017;Savaş Tuna et al, 2017Souza et al, 2019). It has also been explained that geographical isolation (Pecinka et al, 2006;Wang et al, 2013), geographic distance (Savaş Tuna et al, 2019), deletion and duplication (Vlasova et al, 2016), and ecological selection (Wang et al, 2013) were effective in genome size variations.…”

“…For Helianthus sp., H. perforatum,and B. hyridum, it was found that the location, i.e. the area where the plant was collected, had no effect on genome size variations (Sims and Price, 1985;Savaş Tuna et al, 2017. Turkey is not an origin center for Helianthus, and the common bean has been domesticated, has commercial varieties, and is cultivated by farmers for nutritional and commercial purposes.…”

“…In addition, the genome size of the accessions is also important in cytogenetic studies since the core DNA content is species-specific (Bennett and Leitch, 1995). Therefore, genome size information is an important issue in ploidy analysis, genome analysis, taxonomy, evolution, and breeding studies (Rees and Walters, 1965;Ohri, 1998;Özkan et al, 2003;Savaş Tuna et al, 2017. Today, the flow cytometry method is used to determine genome size; however, the genetic resources of the common bean have not been examined in detail using the flow cytometry method (FCM).…”

Analysis of Nuclear DNA Content and Karyotype of Phaseolus vulgaris L.

“…Several cytogenetic studies have been conducted to investigate the chromosomal structure of the common bean, which include chromosome analysis and cytogenetic maps [17][18][19][20][21][22][23][24][25][26][27][28][29][30]. Genome size information is an important issue in ploidy analysis, genome analysis, taxonomy, evolution, and breeding studies [31][32][33][34][35].…”