Physiological Predetermination of the Order of Hardseededness Breakdown in Subterranean Clover (Trifolium subterraneum L.)

Hardseededness breakdown in the burr of subterranean clover(Trifolium subterraneum L.) was found to be non-random in occurrencewith respect to the relative position of seed in the burr. Thissuggests the presence of a predeterminative mechanism of theorder of hardseededness breakdown. While seed moisture content did not exhibit a pattern of variationconsistent with that for hardseededness breakdown, seed weightvariation appeared to conform closely with the pattern of breakdown. It is postulated that, either differences in seed size per sewithin the burr may determine the order of hardseededness breakdown,or that such differences may reflect a disproportionate supplyof translocate, and hence promotors or inhibitors, of hardseedednessbreakdown to the seeds of the burr. The implications of this finding to the assessment of genotypesfor differences in level of hardseededness level have been outlined.