Fermentation and other seed pregermination treatments of Mayhaw [Crataegus opaca (1.) Hook and Arn-Series Aestivales] (Vines,; Phipps, 1988) were evaluated as potential requirements to increase germination percentages. Low seed germinability and arratic seedling emergence are major problems in Crataegus breeding. Freshly harvested fermented open-pollinated seed from 5 different Mayhaw selections averaged 93.4% at 8 days fermentation and 92.8% at 4 days fermentation. Frozen fruit stored from these 5 selections and later fermented 12 days showed the following higher percentages of germination: frozen storage for 10 days - 87.2% (<4 days fermentation (df); frozen storage for 20 days - 83.8% (<4 days df; frozen storage for 30 days - 74.4% (<8 df; frozen storage for 40 days - 72.6% (<4 df; frozen storage for 60 days - 70.2% (<4 df and frozen storage for 90 days - 60.8% (< 8 df. Positive responses to short fermentation durations (<8 days) were observed, but longer fermentation durations were deleterious. Embryo dormancy requiring acid treatment or stratification and problems with germination inhibiting substances were minimized by fermenting fresh ripened fruit containing large embryos. The fruits and seed were not allowed to dry and they were either prepared immediately or frozen for later use.
Thomas H. Boyle
Binomial probability distributions were used to determine the effects of percent seed germination and number of seeds sown per cell on expected numbers of seedlings in plug trays. Expected numbers of empty cells in five types of plug trays (128, 273, 338, 406, and 512 cells/tray) were calculated for cases where one to seven seeds were sown per cell and seed germination ranged from 50% to 95%. Generally, one additional seed was required per plug cell for each 10% decrease in the germination percentage in order to attain the same number of filled cells per plug tray. Expected frequencies were calculated for the number of seedlings in plug trays when one to five seeds were sown per cell and seed germination ranged from 50% to 95%. When the number of seeds sown per cell remained constant, uniformity in seedling number per cell increased as the germination percentage increased. When percent seed germination remained constant and the number of seeds sown per cell was increased, the percentage of cells with at least one seedling increased, whereas the uniformity in seedling number per cell decreased. Additional examples are presented in the article on the utility of binomial distributions in determining expected number of seedlings.
Menahem Edelstein and Haim Nerson
by analysis of variance and Duncan's multiple range test. The data of germination percentages were arcsin-transformed before calculating. The variation of germination under low temperature was expressed as mean days to germination ± sd . The
). In different populations of the dimorphic Tragopogon pratensis subsp. pratensis , larger seeds yield higher germination percentage, yet no relationship has been found between seed size and seedling growth ( Mölken et al., 2005 ). Previous studies
K.G.V. Davidson, F.D. Moore III, and E.E. Roos
Multiple electroconductivity readings (μAmps) of leachates from individual seeds during the first 6 hr of imbibition was examined as a possible predictor of seed quality. Readings from each sample of 100 seeds were formed into frequency distributions and the mean, median. and internal slope were calculated using an automated computer retrieval system. Internal slope is a non-central tendency measure based on the slope of a line tangent to the inflection point of the S-shaped cumulative frequency distribution (CFD) of μAmps. Radicle lengths (3 days) and germination (7 days) percentages were regressed on each of the two measures of central tendency and also the CFD shape indicator, internal slope. None of the three predictors were satisfactory for estimating seed vigor (root lengths) of maize (Zea mays L.) or wheat (Triticum aestivum L.) or germination of wheat seed lots. Internal slope was useful in estimating viability of artificially aged maize seeds (r2= 0.91), which compared favorably with our previous results using naturally aged red clover (Trifolium pratense L.) seed lots. Overall the seed quality of the unaged wheat lots was fairly high and the electrolyte leakage test was not sensitive enough to detect differences within these lots.
James A. Schrader and William R. Graves
Genotypic variation and horticultural potential of Alnus maritima [Marsh.] Nutt. (seaside alder), a large shrub or small tree found naturally in only three small, disjunct populations, have not been studied. We examined effects of population of origin and environment on seed germination and growth and morphology of seedlings. The first experiment showed that 6 weeks of cold stratification optimized germination of half-sibling seeds from Oklahoma at 73.2%. When this treatment was applied to multiple groups of half-siblings from all populations in a second experiment, seeds from Oklahoma had a higher germination percentage (55.0%) than seeds from Georgia (31.4%) and the Delmarva Peninsula (14.7%). In a third experiment, morphology and growth of multiple groups of half-siblings from all three populations were compared in one environment. Leaves of seedlings from Oklahoma were longer (12.8 cm) and more narrow (2.15 length to width ratio) than leaves of seedlings from Georgia (12.0 cm long; ratio = 1.76) and the Delmarva Peninsula (11.6 cm long; ratio = 1.86). Seedlings from Oklahoma and Georgia accumulated dry weight at higher rates (181 and 160 mg·d-1, respectively) than seedlings from Delmarva (130 mg·d-1), while seedlings from Oklahoma and Delmarva were more densely foliated (0.72 and 0.64 leaves and lateral shoots per centimeter of primary stem, respectively) than those from Georgia (0.46 per cm). These differences indicate genetic divergence among the three disjunct populations and the potential to exploit genetic variation to select horticulturally superior A. maritima for use in managed landscapes.
Alireza Talaie* and Rasoul Akrami
The objective of this study was the identification of existing olive trees in eight regions of Kermanshah province and investigation of their fruit, seed, and leaf characteristics in order to be used in the olive production industry of Iran. The germination ability of olive seed in field and nursery were also studied. In this research, 61 genotypes were identified and their characteristics were studied. It was found out that the present genotypes of Kermanshah showed different vegetative and reproductive growth based on the climatic and topographic conditions. This was verified by cluster analysis of the genotypes of different regions, which showed clearly their far and close relations. It was found out that some of the genotypes in the region spite of their appearance differences have same origin and most probably should be considered as the same genotype. The results also showed that favorable seed bed, planting depth and scarification of the seeds have positive effects on their germination while scarification of the seeds without other treatments had no significant effect on the seed germination.
Kathryn L. McDavid, David L. Sanford, and Robert D. Berghage
the highest day 21 germination percentages at 92%, 78%, and 89%, respectively ( Table 1 ). Table 1. Final germination percentage at 21 d and time to 50% germination (T50) of goldmoss sedum after different durations of storage grown in a 70 or 90 °F (21
Sang In Shim, Jun-Cheol Moon, Cheol Seong Jang, Paul Raymer, and Wook Kim
seed was considered germinated. Germination was checked daily and calculated as a percentage (germination percentage) and as a weighted germination percentage. The weighted germination percentage (WGP) was calculated as follows: where t i
Omar A. Lopez, Danny L. Barney, Bahman Shafii, and William J. Price
V. membranaceum at a constant 20 °C, some Vaccinium sp. need temperature fluctuations to germinate ( Baskin et al., 2000 ; Minore et al., 1979 ; Stushnoff and Hough, 1968 ; Vander Kloet, 1983 ). Relatively low germination percentages and a slow