Effect of sucrose nutrition on the histological structure of carob shoot

Abstract

Analysis of carob (Ceratonia siliqua L.) shoot cultures grown on 2 and 8 % sucrose in light and darkness (etiolation) showed marked differences in histological structure. Etiolated, dark grown shoot cultures were hypolignified on both sucrose concentrations. They had highly reduced sclerenchyma and xylem production, endodermis with Casparian bands and absence of lenticel formation. In light grown cultures shoots in transection showed nearly concentric ring of sclerenchyma (outer) and xylem (inner) ring and the absence of Casparian bands in endodermal cells. Increased sucrose nutrition promoted lignification and efficiently prevented lenticel hypertrophy characteristic for low sucrose concentration.

Keywords

• carob
• in vitro
• sucrose
• light
• etiolation
• lenticel hypertrophy