Longevity of Cantaloupe Seed1
Louis N. Bass
Seeds of 27 cantaloupe cultivars were stored 23½ years at 10, 21, and 32 C. At 32 C seed of only three cultivars showed any signs of life. Seeds of only two and three cultivars gave 0% germination after storage at 10 and 21 C, respectively. At 21 C seeds of two cultivars germinated over 50% in 10 days. Seeds of numerous cultivars showed dormancy and germinated later. At 10 C seeds of four cultivars germinated better than 75%. Differences in seed longevity among cultivars were variable.
Additional index words: Cucumis melo, seed storage, viability, germination.
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Germination Response of Loblolly Pine to Temperature Differentials on a Two-Way Thermogradient Plate
F. T. Bonner1
A two-way thermogradient plate (TGP) was used to test temperature response of two lots of loblolly pine (Pinus taeda L. ), one dormant and the other nondormant. Both stratified and unstratified seeds were tested on 144 alternating or constant temperature regimes which ranged 14 to 33 C.
Additional index words: Pinus taeda (L)., Stratification, Seed testing, Germination rate.
Proteolytic Activities in Germinating Seeds of Curcurbita moschata1
Reiner H. Kloth and Walter E. Splittstoesser2
Enzymatic activity capable of cleaving the peptide bond of Nα-benzoyl-DL-arginine-p-nitroaniline (BAPAse activity) and Nα-benzoyl-DL-arginine-β-naphthalinide ( BANAse activity) was found in cotyledons of germinating seeds of Cucurbita moshata Poir. 'Waltham Butternut'. Removal of the embryonic axis did not influence the maximum level of enzyme activity.
Additional index words: arginine, BAPAse, BANAse, Nα-benzoyl-DL-arginine-P-nitroaniline, Nα-benzoyl-DL-arginine-α-naphthalamide, globulin.
Effects of Embryo Removal Upon Reserve Protein Degradation in Curcurbita moschata1
Walter E. Splittstoesser2
Reserve protein degradation began the second day of germination in cotyledons of Cucurbita moschata Poir. 'Walthan Butternut', and was complete by the sixth day of germination. The original salt soluble, heat stable protein was converted into water soluble, heat stable protein and finally into free amino acids. Removal of the embryo tissue had no effect upon the degradation rate or pattern.
Additional index words: Cyclohexamide, cotyledon expansion, globulin.
Achieving Maximum Germination Potential in Germination Tests of Soybean1
Q. E. Schultz and P. D. Evenson
Prehydration of soybean seed resulted in an average 3.6% increase in germination for 100 soybean lots. The prehydration treatment resulted in an increase in moisture ranging from 2.2% to 8.3% with a similar response to prehydration occurring at all moisture levels. The response to prehydration decreased as mechanical damage levels increased.
Additional index words: Glycine max (L.) Merr., Prehydration, imbibition, imbibition injury.
The Effect of Growth Promoting Substances and Gels on the Emergence and Dry Weight of Tomato and Pepper1
M. D. Orzolek2
Addition of ascorbic acid (250 ppm), phosphoric acid (250 ppm) and gibberellic acid (GA3, 200 ppm) to germinated seed-gel mixtures of tomato and pepper prior to planting affected the emergence and growth of the seedlings. Ascorbic plus gibberellic acid significantly increased the emergence rate, but not dry weight of pepper; while gibberellic acid in combination with either phosphoric or ascorbic acid significantly increased the emergence, but not dry weight of tomato.
Additional index words: Ascorbic acid, phosphoric acid, gibberellic acid, pre-germination.
Pyrrolizidine Alkaloid Levels in Tall Fescue Seed as Influenced by Seed Age, Location, and Variety1
T. A. Jones, R. C. Buckner, and P. B. Burrus II2
Tall fescue (Festuca arundinacea Schreb.) long has had a reputation as a poor-quality forage because of an assortment of toxicological problems experienced by animals grazing this species. Summer syndrome toxicity is associated with a seed-transmitted endophytic fungus (Epichloe typhina (Fr . ) Tul., Acremonium coenophialum Morgan-Jones and W. Gams) which, in turn, is associated with pyrrolizidine alkaloid accumulation, especially N-formyl and N-acetyl loline. The objectives of this study were 1) to assay the major seed-producing areas and varieties in the U. S. for loline alkaloids and 2) to investigate the effect of age of seed at planting on loline alkaloid levels of seed harvested from these stands.
Additional index words: Festuca arundinacea Schreb., N-formyl loline and N-acetyl loline alkaloids, Acremonium coenophialum Morgan-Jones and W. Gams, Epichloe typhina (Fr. ) Tul., Tall fescue endophyte, summer syndrome, Tall fescue toxicity.
Seed Vigor Testing - 19821
Dennis M. TeKrony2
The status of seed vigor testing was determined by surveying seed testing laboratories in the Association of Official Seed Analysts (AOSA) and the Society of Commercial Seed Technologists ( SCST ) . The survey indicated that 61% of the 102 laboratories responding were testing for seed vigor, which was 10 percentage points higher than in 1976.