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Deterioration of soybean [Glycine max (L.) Merr. cv. Essex] seeds during accelerated aging at 41°C and 100% relative humidity predisposes the embryonic axis to injury during the initial period of imbibition. This injury was prevented or greatly reduced in severity when excised axes were imbibed on blotters containing 30% polyethylene glycol which slowed the rate of water uptake and when axes were pre‐equilibrated to a high moisture level. Rates of water uptake by “high”(no treatment) and “low vigor”(accelerated aged) excised axes were identical. However, high vigor axes tolerated rapid water uptake during early imbition, whereas low vigor axes did not. Leakage of electrolytes during early imbibition was nearly six times greater in low than in high vigor axes. Polyethylene glycol significantly reduced the leakage of electrolytes from both low and high vigor axes. The data are in agreement with the hypothesis that seed deterioration in soybeans involves membrane changes which may predispose embryonic tissues to injury during imbibition. Reduction of the rate of water uptake during the initial period of imbibition would allow extra time for membrane repair or rearrangement, thus permitting the tissues to develop in a more orderly manner. The data indicate that deterioration in soybean seeds involves, at least in part, a decrease in ability of seed axes to tolerate rapid water uptake at the start of imbibition and that this weakness may be compensated by osmotic control of water uptake.

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Gene banks around the world have had difficulty detecting changes in the genetic composition of germplasm accessions after seed storage and regeneration. The large number of accessions requires a rapid and easy test. This study was conducted to develop such a test for wheat (Triticum spp.) accessions. A phenol test modified by soaking seeds in 40 °C water for 30 rain and then exposing them to 130 mM phenol solution vapor on a wire screen can differentiate among genetic types by staining in up to five colors: dark brown, brown, light brown, fawn, and ivory. The test is nondestructive. Phenol test results from gene‐bank accessions indicate that there was no significant change in the population composition after regeneration in homogeneous accessions such as bread wheat (T. aestivum L.) cultivars Sprint Aquileja, and Adria, and durum cultivars (T. turgidum L., durum group) Appulo, Capeiti, and Creso. Several heterogeneous durum wheat accessions showed significant changes, however. In the Italian durum wheat accession MG 8001, the dark brown phenol‐stained seeds increased from 11% to 95% after eight regeneration cycles. Gliadin polyacrylamide gel electrophoresis and root tip chromosome counting, conducted on the same seed, indicated that the dark‐brown phenol‐stained seeds were bread wheat instead of durum wheat. Thus, the modified phenol test could be a useful test for gene banks to detect changes in the composition of heterogeneous germplasm accessions after regeneration and storag.

Two types of soil varying in water holding capacity (WHC) were used for the cold test. The same seed lot of ‘Wells’ soybean (Glycine max (L.) Merr.) showed 71% emergence in a muck soil (WHC 78% w/w) in contrast to 2% in a silt loam (WHC 25% w/w). Soil sterilization slightly increased the emergence percentage in both soils. Modifying the WHC of the muck soil with the addition of sand showed a significant decrease in the emergence percentage at a level of 42% but not at 52%. Seedling length also varied among soils of different WHC. Similar emergence percentages were obtained in the silt loam soil and the muck soil after the WHC of both soils had been adjusted to approximately 50% w/w by the addition of sand. However, other additives tested caused a decrease in germination. Results of the cold test using a soil with WHC of 52% showed high correlation with the field emergence of five seed lots of three cultivars in two different plantings under stress conditions (r ‐ 0.91 and 0.96). Evidence, however, indicated that cold tests failed to predict seed vigor in ‘Evans’ soybeans.