Giemsa C-banding Karyotype and Detection of Polymorphic Constitutive Heterochromatin in <i>Nigella sativa</i> L.

Abstract

Karyomorphology, distribution of constitutive heterochromatin, and intrapopulation polymorphism of C-bands in a cross-pollinated population of Nigella sativa L. were studied. Enzymatic digestion of the cell wall allows cytoplasm-free chromosome preparation and enhances the stain resolution, thereby promoting accurate chromosome measurements and identification of chromosomal landmarks. The diploid chromosome number is 2n= 12, of which five pairs are moderately long and have median centromere, whereas one small pair has a subterminal centromere. Secondary constriction has been observed in two pairs of long chromosomes. Polymorphism of the C-band size in individuals of the same population and even between two homologous chromosomes of a single individual has been detected by the C-banding technique. Further, the absence of any DAPI-bands indicated that the DNA of C-band region is not AT-rich. The heterogeneity of C-bands in homologous pairs of a single individual is a consequence of cross-pollination where chromosomes come from two different parents. The pattern of heterochromatin distribution can serve as a unique marker that can enrich the karyosystematic database and prove useful in the breeding program of N. sativa.

Chromosomal characterization mediated by karyomorphological analysis and differential banding pattern in fenugreek (Trigonella foenum-graecum L.): a neglected legume

“…The growing roots from germinated seeds of T. foenum-graecum were taken for chromosome preparation. Chromosomes were prepared following Santra et al (2020) with minor modifications. Roots were pretreated with 0.5 g L -1 8-hydroxyquinoline solution at 16 °C for 6 h and then fixed in acetic acid:methanol solution (1:3) overnight.…”

EMA-based chromosome characterization and karyotype analysis in two wild spiny medicinally and nutritionally important Solanaceaous species ̶ <i>Solanum sisymbriifolium</i> Lam. and <i>Solanum virginianum</i> L.

“…The seeds were subjected to germination in seed beds, and the growing roots from germinated seeds of S. sisymbriifolium and S. virginianum were collected for chromosome preparation. Chromosome preparation has been done following Santra et al (2020) with minor modifications. For pretreatment of root tips, 2 mM 8-hydroxyquinoline solution was used at 18 C for 6 h and the fixation was done in acetic acid: methanol solution (1 : 3) overnight.…”

Pollen Mitosis is a Good Choice for Gametophytic Chromosome Study in Higher Plants—Investigation with <i>Allium cepa</i> L. and <i>Aloe vera</i> L.

“…On the way to exploring the genetic structure of any organism, accurate information about its karyotype is necessary (Santra et al 2020). The karyotype data are established based on morphological features of chromosomes such as total length, arm ratio, and the position of primary and secondary constriction (Alam et al 2018).…”