Electron microscopic studies in cultivated plants. I. Green pods of Phaseolus vulgaris var. nanus L.

Scanning (SEM) and transmission (TEM) electron microscopic studies in the legumen of Phaseolus vulgaris var. nanus L. (kidney beans) were carried out. In this work emphasis was laid on the analysis of the morphological structure of the parenchyma tissue, being the chief component of the pod at edible maturity. The leaf character of the pod becomes especially evident by the occurence of stomata, trichomes, and typical cuticle structures on the outside of the pod (SEM). The cells of the mesophyll-like parenchyma tissue are distinguished by a great range of variation of their plastids (chloroplasts--chloroamyloplasts--amyloplasts) and some special cytological features such as a strongly developed rough ER, big nuclei, and numerous plasmodesmata (TEM).