Sweet clover studies on habit of growth, seed pigmentation and permeability of the seed coat.
AbstractData are presented on the inheritance of mottled seed, dwarf branching growth habit and on permeable seeds in white-flowered sweet clover (Melilotus alba Desr.)
The non-mottled condition of the seed is recessive to the mottled and the pigment which is located in the lower parts of the Malphigian cells has the general properties of anthocyanin. The dwarf branched habit is dependent on a single factor difference and it is recessive to the common type.
Less than one per cent of the seeds of the sweet clover plants tested were naturally permeable and able to germinate after scarification or other treatment. The region of impermeability of the seed coat coincides with the " light-line." This region was not readily stained and showed great resistance to the action of sulfuric acid.
Selection within inbred lines increased the proportion of seeds having permeable seed coats. The areas which are permeable are scattered at random on the seed coat. Hard seeds from permeable lines were rendered permeable by treatment with sulfuric acid, but only a small proportion of hard seed from impermeable lines was affected by this treatment. Pseudo-hard and hard seed examined histologically showed no recognizable differences. A high proportion of the pseudo-hard seeds from permeable lines germinated without treatment when sown in moist soil.-A.R.B.