Chromosome count improvement and digitalization of Neolamarckia cadamba

Abstract

Background: Chromosome count is the only direct way to determine the number of chromosome of a species. This study is often considered trivial that seldom described and discussed in detail. Therefore, it is evitable that chromosome count protocol should be revised and revisited before it becomes obliterated. Our chromosome counts in N. cadamba root tips have encountered challenges that prevent us from obtaining clear micrograph with the correct chromosome number. Several obstacles were determined through micrograph observation such as existing unwanted particles in cells, poor chromosome staining and chromosome crumping. Results: The chromosome counts of Neolamarckia cadamba under optimized procedure yielded 44 chromosomes per nucleus. To overcome these, root tip types, stain types, squashing methods were among factors assessed to obtain clear micrograph. We also apply digital technology in term of online database and graphic software that are open source and freely accessible to the public. Conclusions: Throughout the study, we used a few basic laboratory equipment and chemicals, thus making this study economical and applicable in a basic laboratory. The availability of online digital software and databases provide open-source platforms that will ease the efforts in chromosome count.

Peer Review #2 of "In vitro induction and identification of polyploid Neolamarckia cadamba plants by colchicine treatment (v0.1)"

“…The staining process was carried out at room temperature. Feulgen stain was applied on the root tips for 30 min in dark condition before squashing with a metal bar in a drop of aceto-orcein 1% stain followed by thumb squash (Eng et al, 2020).…”