Morphological Note on Sweet Orange at Different Developmental Stages

Background: Citrus sinensis (L.Osbeck) is commonly known as sweet orange and widely distributed as an excellent source of antioxidants and vitamin C, which play a pivotal role in strengthening the immune system.The peel of sweet orange is a major source of various bioactive compounds that are utilized in different medicines.Objective: This study aimed to explore the anatomical changes occurring at different developmental stages of sweet orange fruit.Methodology: Orange fruits at different developmental stages were collected from the Botanical Garden of the University of Agriculture, Faisalabad.For this purpose, 16 developmental stages of sweet orange were selected on the basis of their size, growth, and development.Data were obtained for stomatal density, number of cells, and cell size.Furthermore, the thickness of albedo and flavedo was also recorded at each developmental stage.Results: Results revealed that fruit diameter, cell size, stomatal number, number of hesperidia, and the thickness of albedo and flavedo increased progressively with fruit development and maturation.The maximum increase in all the recorded parameters was noted at stage 16, followed by stage 15.Moreover, significant variations in anatomical structures were observed across different developmental stages. Conclusion:This study highlights the growth dynamics and structural modifications of sweet orange across different developmental stages and explores the progressive enlargement of cell size, albedo, and flavedo thickness with developmental stages.