ABSTRACT
Stomata are probably a viable taxonomy distinguishing feature. The study of stomata characteristics of synthetic banana hybrids and their parentage has been carried out. Ploidy determination is essential in banana breeding programs to understand the genetic makeup of hybrid plants. The purpose of this study was to determine the ploidy level of hybrids in contrast with the properties of plant stomata in synthetic banana hybrids with those of their parent plants. Therefore, by examining components such as stomata location, number of epidermal cells, number of stomata cells, stomata length, width, area, intensity and density, as well as chloroplast count, it is possible to compare and contrast the traits of synthetic banana hybrids and their parentage which have different genomes. The entire mount approach was used to make an incision for the purpose of observing stomata. By characterising the stomata traits of the synthetic hybrids and their parentage, the results were then descriptively and qualitatively assessed. Three different locations on the abaxial of the leaf were taken for the determination. The samples were collected from close to the petiole (R1), middle (R2), and distal end (R3), stomata were observed using the replica method. Results showed that more number of stomata was observed in R2of leaf abaxial. The chloroplast count in pairs of stomatal guard cells from the accessions was also measured. The chloroplast density was determined in pairs of stomatal guard cells from the accessions. Based on morphological descriptions, it was observed that 16.66% of the accessions were diploid, 50% were triploid and 33.33% were tetraploid. When considering the chloroplast count, the accessions were categorized into groups, certain accessions classified as tetraploids, others as triploids, and diploids.
ABSTRACT
Leaves of P. sativum the double mutant genotype tendril-less (tl) leaflet-development (lld), due to the action of lld mutation, produce many leaflets that are aborted at different stages of development. Morphological, vein pattern and histological observations showed that aborted leaflets became cup/bell/trumpet (cup) shaped because of segmental differentiation in the leaflet primordium. Cup’s inside lamina surface was adaxial and outer surfaces of cup and its stem were abaxial. The lld cups were phenotypically homologous to aborted leaves described in Arabidopsis thaliana mutants, angustifolia and those which underexpressed the HD-ZIP III proteins. Leaflet primordium was found to grow and establish three dimensional polarities apex-downwards. Primordium produced lateral outgrowth on one side of midvein. Differentiation, in the outgrowth, of secondary veins, whose xylem tissues faced each other, established the adaxial-abaxial polarity. Lateral outgrowth then developed a cavity which got bounded by future adaxial epidermis. Further growth, veinlet formation, differentiation of palisade parenchyma and spongy parenchyma followed. Opening of lateral outgrowth at its outer midline produced a flat leaflet with lateral lamina spans. The structural and functional correspondence between leaflet and simple leaves suggested commonality between leaf and leaflet development mechanisms. A molecular model for the lld led leaflet abortion was also provided.