Relation Between the Anatomy of the Testa, Water Permeability and the Presence of Phenolics in the Genus Pisum

The seed coats of Pisum elatius, P. fulvum and P. humile are impermeable to water while those of P. sativum and P. humile × P. sativum are permeable. The anatomical structure of the seed coats and the location of phenolics and quinones in the cells is described. The barriers to permeation of water in the impermeable seeds are the continuous, very hard, pectinaceous layer of the caps of the palisade cells and the presence of quinones in either the palisade or osteosclereid cells, in a continuous layer of these cells. In water permeable seeds the caps are looser and quinones discontinuous or absent in palisade or osteosclereid cells.