Seeds of Kosteletzkya virginica (Malvaceae): their structure, germination, and salt tolerance. I. Seed structure and germination

Dormancy of Kosteletzkya virginica (L.) Presl. seeds is primarily due to the impermeability of the seed coat to water. The impermeable structure is assumed to be, in other Malvaceae, the palisade layer of the seed coat. The percentage of seeds capable of imbibition and germination increased with increasing time of storage at low temperatures, but the release from dormancy was not accompanied by decreased seed coat resistance to pressure. Under natural conditions, mechanical damage to the seed coat due to changes in temperature and/or abrasion may render the seeds water permeable. It is not clear what causes water permeability during storage under laboratory conditions. During seed maturation and drying, the inner epidermis of the tegmen partly separates from the rest of the seed coat and an air space, which makes the seed buoyant, is formed around the region of the chalazal cleft. The optimal temperature for germination of K. virginica seeds is between 28 and 30 C in light or darkness. Domestication of halophytes that may serve as forage or grain plants, or for industrial purposes, has been suggested as a way of developing salt-tolerant crops (Mudie, 1974; Somers 1979a, b; Somers, Grant, and Smith, 1979; Gallagher, 1985). Kosteletzkya virginica (L.) Presl. (Malvaceae) was found to be among the suitable candidates for domestication (Somers, Grant, and Smith, 1979). This species is reasonably salt-tolerant and occurs in nature at substrate salinity levels of 50-425 mM NaCl. It has relatively large seeds with high protein and fat content (,250/o-30% protein, ,200/o-30% oil composed largely of unsaturated fatty acids), high potassium content, and a mucilage that possibly could be used in the candy industry (Somers, 1979a, b; Islam, Wilson, and Watkins, 1982).