Orchids are important ornamental, food, and medicinal plants. Orchid germplasm preservation is important because some species are endangered due to loss of habitat and human predation. Very few of the world's genebanks are involved in orchid preservation. Orchid germplasm preservation is a priority for the USDA Ornamental Plant Germplasm Center in Columbus, Ohio. Brassia and Phalaenopsis seeds were harvested at different stages of development and stored at –196 °C (liquid nitrogen), –80, –18, 4, and 25 °C for 6, 12, 18, and 24 months to determine the optimum conditions for long-term seed storage. Phalaenopsis and Brassia seeds adjusted to 45.5% RH over chromium dichromate were able to survive 10-d storage. Seeds frozen in liquid nitrogen for 30 min were able to germinate and produce protocorms 19 d after sowing, just a day longer than control seeds. Liquid nitrogen storage also improved germination of some Phalaenopsis seed lots from 0 (control) to 38%. Storing Phalaenopsis seeds at –80 and 4 °C also improved germination similarly, suggesting dormancy was broken by low-temperature seed treatments. On the other hand, seeds stored at 25 °C did not germinate. Preliminary results suggest that orchid seeds tolerate freezing even in liquid nitrogen and that cryopreservation may be a viable long-term strategy for orchid germplasm preservation.
seed storage on seedling emergence percentage. The results will inform management decisions for conservation nurseries. Materials and Methods Separate experiments were conducted for each of the species, and individual shade structures were constructed
Interconversions of seed storage reserves during osmoconditioning (controlled imbibition of water) may influence seed performance under suboptimal conditions. Sweet corn (Zen mays L. cv. Florida Staysweet) storage reserve changes were examined during osmoconditioning in relation to seed germination performance. Seeds were osmoconditioned in two experiments using distilled water (duration 3, 6, 9, 12, and 24 h) and polyethylene glycol 8000 solutions (0, .5, and 1.0 MPa for 12, 24, 48, 72 and 96 h). Germination performance was evaluated at 10 and 25C, and seed moisture, carbohydrate, and protein concentrations were quantified at each water potential x duration combination. Germination performance was not significantly improved by any treatment at 25C. Germination percentage at 10C was increased 10% for seeds osmoconditioned for 24 h in distilled water, and time to germination was decreased 50%. For seeds osmoconditioned 12 and 48 h at .5 and 1.0 MPa, respectively, germination percentage at 10C was increased 15%. Time to germination was reduced 50% for seeds osmoconditioned at .5 and 1.0 MPa after 48 and 96 h, respectively. Starch levels increased for seeds osmoconditioned at higher water potentials, but remained the same or decreased at lower water potentials.
continuous dark in comparison with both continuous and alternating light conditions in which no germination was recorded ( Fig. 3A ). However, the inhibitory effect of white light was significantly reduced after 12 months of seed storage, exhibiting 65.2 ± 0
important over the next 5 years. Only 4.4% foresaw little or no need for local FNW production. A majority indicated that the nine areas of research listed were important or very important. Of these areas, respondents gave seed germination (85.4%), seed
dry seed storage to provide dormancy relief and viability maintenance. The other salts used in this research (calcium nitrate and sodium chloride) are required to absorb less moisture (to impose higher RH levels of 50% and 75%) from the chambers
Common persimmon, Diospyros virginiana, a medium to large, attractive native tree of narrow habit, is potentially a valuable landscape tree due to its tolerance of diverse environmental conditions. Previous work by the authors demonstrated that seed stored in perlite or peat moss had a higher percent germination following cold storage than seed stored without media. Seeds were prepared for cold storage by two methods: 1) moist seed—cleaned (cap, skin, and the easily removed pulp discarded), and (2) dry seed—cleaned, dried for three days, and the remaining pulp removed. The media were either dried or moistened, but not saturated. The treatments were: 1) moist seeds; 2) dry seeds; 3) moist seeds in dry perlite; 4) moist seeds in moist perlite; 5) dry seeds in dry perlite; 6) dry seeds in moist perlite; 7) moist seeds in dry peat moss; 8) moist seeds in moist peat moss; 9) dry seeds in dry peat moss; 10) dry seeds in moist peat moss. Seed was stored at 4.4° for 142 days. Germination of seed stored in dry perlite was not significantly different from that stored in moist perlite or peat moss, but dry peat moss significantly limited germination regardless of seed preparation.
Abstract
Seed of papaya stored at 10°C and 50% relative humidity in cloth bags, and at 5° in sealed, moistureproof packages, retained their viability reasonably well during 6 years' storage.
The effects of incorporating plant growth regulators into the priming solution on low temperature germination and emergence percentage performance of sweet pepper (Capsicum annuum `Demre') seeds before and after seed storage were investigated. Seeds were primed in 3% KNO3 solution for 6 days at 25 °C in darkness containing one of the following: 1, 3, 5, or 10 μm methyl jasmonate (MeJA) or 0.05, 0.1, 0.5, or 1 mm acetyl salicylic acid (ASA). Following priming, seeds were either immediately subjected to germination and emergence tests at 15 °C or stored at 4 °C for 1 month after which they were subjected to germination test at 15 °C. Priming pepper seeds in the presence or absence of plant growth regulators in general improved final germination percentage (FGP), germination rate (G50) and germination synchrony (G10-90) at 15 °C compared to nonprimed seeds which had an FGP of 44%, G50 of 7.3 days and G10-90 of 7.3 days. Priming seeds in KNO3 solution containing 0.1 mm of ASA resulted in the highest germination percentage (91%), fastest germination rate (G50 = 2.2 days) and the most synchronous germination (G10-90 = 6.1 days). Emergence percentages were the highest for the seeds primed in the presence of 0.1 mm ASA (85%) and 3 μm MeJA (84%) while nonprimed seeds had an emergence percentage of 40%. Fastest emergence rates (E50) were also obtained from seeds primed in KNO3 supplemented with 3 μm MeJA (E50 = 15.2 days) and 0.1 mm ASA (E50 = 15.2 days). Shoot fresh and dry weights of pepper seedlings were significantly affected by priming treatments and priming in the presence of 0.1 mm ASA resulted in highest seedling shoot fresh and dry weights. Although all priming treatments improved germination performance of pepper seeds at 15 °C following 1 month of storage, inclusion of 0.1 mm ASA into the priming solution resulted in the highest germination percentage (84%) and germination rate (G50 = 3.8 days). These results indicate that priming seeds in 0.1 mm of ASA or 3 μm MeJA incorporated into the KNO3 solution can be used as an effective method to improve low temperature performance of sweet pepper seeds and that these seeds can be stored for 1 month at 4 °C and still exhibit improved germination performance at 15 °C.