Drying is a prerequisite to maintaining maize (zea mays L.) seed quality. New technologies are available and a dryer prototype has been developed that has the unique feature of taking the moisture out of the air stream before it is heated and passed through the seed. The heat that is generated when the water is removed is reintroduced into and raises the temperature of the air stream. In contrast to the 45°C temperature typical of conventional dryers, the temperature of the air stream in the new method does not exceed 35°C. No detrimental effects were observed on various parameters of maize seed physiological quality due to the drying conditions provided by the heat pipe technology. The time required for drying was reduced significantly compared to the traditional system of heated ambient air. The heat pipe system is a promising technology to be used for drying shelled seed.

Crop ScienceVolume 40, Issue 4 p. 1186-1187 Book Review Forage Seed Production, Volume 2: Tropical and Subtropical Species S.H. West, S.H. West Department of Agronomy, University of Florida, Gainesville, FL, 32611Search for more papers by this author S.H. West, S.H. West Department of Agronomy, University of Florida, Gainesville, FL, 32611Search for more papers by this author First published: 01 July 2000 https://doi.org/10.2135/cropsci2000.0019brRead the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume40, Issue4July–August 2000Pages 1186-1187 RelatedInformation

Effects of drying conditions during seed priming on muskmelon seed quality were investigated either immediately after seed priming or after twelve months of storage. Seeds of muskmelon, cv. Top Net SR were primed for 6 days in darkness at 25°C in KNO 3 (0.35 M) aerated solution. Seeds were rinsed in running tap water and redried at 18, 28, and 38°C during 24, 48, and 72 hours. Seeds were stored at 10°C, 45% RH for 12 months. The beneficial effects of seed priming were maintained after dehydration. Drying temperature did not affect seed germination after priming. An interaction effect on germination between temperature and drying duration was observed at low temperature. Seed germination and vigour of primed seeds decreased after 12 months of storage. Both temperature and duration of drying affected seed vigour after storage period. A better management of drying conditions during muskmelon seed priming should be focused in order to achieve the benefits of seed priming and to maintain seed quality, especially if primed seeds are to be stored.

Dimorphandra mollis Benth. is a multipurpose tree species providing important subsistence and economic benefits to rural communities of the Brazilian cerrado. Seeds of D. mollis were collected to test for germination following one of 24 pretreatments intended to overcome seed coat impermeability. The tests were conducted for 21 days at 28 degreesC under a 24-hour constant light regime. Seeds without a pretreatment resulted in only 4% germination while immersion in sulfuric acid for 45 min to 1 1/2 hours and mechanically scarifying the seeds with a file improved germination to over 90%. A sulfuric acid treatment for 1 1/2 hours followed by a 2 hour water soak was the most efficient method of accelerating germination rate. Seeds exposed to sulfuric acid for longer than 1 1/2 hours showed marked decreases in viability. Though several heat pretreatments with boiling water provided germination responses of over 50%, fire was not successful in eliciting germination significantly higher than the control. These results provide viable pretreatment options for both large and small-scale reforestation efforts.

ABSTRACTSeed dormancy and aging affect maintenance of germination in storage and ultimately seedling establishment. The effects that year of harvest, heat vs. air drying seed at harvest, storage environment, and aging had on germination of ‘Suerte’ atra paspalum (Paspalum atratum Swallen) were studied. Across 5 yr, average germination of fresh seed at harvest was 0% during 0 to 7 d and 5% during 8 to 14 d of a 28‐d germination period. Total germination depended on year of harvest and ranged from 9 to 46%. Oven drying (40°C for 24 h) at harvest increased germination in 2 of 5 yr. Storing seed for 6 mo in a building with no environmental control (ambient condition) increased germination to 69% (3‐yr average) and shifted most of the germination to the first 7 d, but germination was nil after 1 yr. Germination averaged 55% at 28 d after harvest for seed stored at 3°C and changed little for up to 4 yr. Oven drying seed at harvest delayed the break in dormancy ≈1 mo compared with air drying seed. Chilling air‐dried, ambient stored seed at 3°C for 48 h before testing reduced germination at 84 d after harvest (compared with 28 d and 6 mo). Neither chilling oven‐dried seed nor heat (40°C for 24 h before testing) treatment of oven‐ and air‐dried seed affected germination. Removal of the lemma and palea at harvest resulted in 96% germination compared with 26% for intact seed. Treatment of freshly harvested seed with H2SO4 for 6 min and accelerated aging (48 h at 41°C, 100% relative humidity) increased germination from 29 to 68% and 30 to 48%, respectively. Dormancy in atra paspalum is short‐lived and should be of minor agronomic importance with fall seed harvest and spring sowing. Consideration must be given to seed storage conditions to assure viability beyond 1 yr.

A cantaloupe (Cucumis melo L.) Seed sample with 20% of infested seeds was treated with fungicide Captan 50 WP (3 g/kg seeds) and primed for six days in darkness at 25 degrees C in a KNO3 + KH2PO4 (1.5 + 1.5%) aerated solution. Half of the seed sample was primed without fungicide treatment. In nonprimed seeds, fungicide treatment eliminated microorganism incidence. During priming, captan did not give good control of microorganisms. Seed priming increased the microorganism incidence to 60% on fungicide-treated seeds and 94% on nontreated seeds. The conditions established by seed priming contributed to seed fungal proliferation, and a high incidence of fungi may have contributed to the decrease of seed germination.

The effects of seed priming and seed orientation on seedcoat adherence and seedling development of containerized muskmelon transplants were investigated. Seeds of muskmelon `Top Net SR' were primed for 6 days in darkness at 25 °C in an aerated solution of KNO 3 (0.35 M). Primed and nonprimed seeds were individually planted in Styrofoam trays in the greenhouse. Seeds were carefully oriented with the radicle down, up, or in the horizontal position, and covered with 0.5 cm of the growing mix. Seed priming and seed orientation affected both seedcoat adherence and seedling development, and interaction between priming and orientation was significant for seedcoat adherence. Our data indicate that seed priming can minimize seedcoat adherence during emergence of muskmelon seeds.

Crop ScienceVolume 38, Issue 3 cropsci1998.0011183X003800030045x p. 879-880 Book Reviews Basic and Applied Aspects of Seed Biology Proceedings of the V International Workshop on Seeds, University of Reading, UK, September 10–15, 1995. Edited by R. H. Ellis, M. Black, A. J. Murdoch AND T. D. Hong. Kluwer Academic Publishers, PO Box 989, 3300 AZ Dordrecht, The Netherlands. 1997. Hardback, 823 pp., $396.50. ISBN 0-792-34363-8 S. H. West, S. H. West Agronomy Seed Laboratory, University of Florida, Gainsville, FL, 32611Search for more papers by this author S. H. West, S. H. West Agronomy Seed Laboratory, University of Florida, Gainsville, FL, 32611Search for more papers by this author First published: 01 May 1998 https://doi.org/10.2135/cropsci1998.0011183X003800030045xAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume38, Issue3May–June 1998Pages 879-880 RelatedInformation

The establishment rate of warm‐season turf and forage grasses propagated by sprigs or cuttings is of economic importance by determining not only how quickly an area may be utilized but also by influencing the extent of weed invasion. We monitored ‘Tifton 85’ bermudagrass [Cynodon dactylon (L.) Pers.] vegetative growth response to the application of ethephon (2‐chloroethylphosphonic acid), an ethylene‐producing compound, and how this treatment affected subsequent vegetative establishment. Responses of established Tifton 85 plants to ethephon treatment when compared with untreated plants included a 22% reduction in plant height, node swelling, bud swelling at the crown, terminal leaf necrosis, chlorotic striping of young developing leaves, and a 118% and 101% increase in leaf/stem fresh and dry weight ratios, respectively. Swelling of ethephon‐induced buds appeared to be due to a transient arrest in sprouting. Swelled buds finally sprouted 9 d following ethephon treatment. In glasshouse experiments, vegetative cuttings taken from ethephon treated plants produced 112% more roots under a range of water stress conditions 8 d after cutting removal, and produced 10‐fold higher number of tillers at 6 d after planting in soil than untreated cuttings. Tiller production in the soil establishment study was not statistically different between ethephon treated and untreated plants after 21 d. These glasshouse results indicated that it may be feasible to develop ethephon treatments that improve establishment rate and subsequent stand quality of Tifton 85 bermudagrass in field/commercial applications.

AbstractThe developmental pattern of biotinylated proteins (BP) during embryogenesis and maturation of soybean seed was characterized. Detection of these BP was compared with the development of desiccation tolerance in seeds. Three groups of BP were detected in soybean seeds using a biotin-streptavidin detection method: the first group consisted of a set of three bands with a mean apparent MW of 85 kDa (called BP85), detected in crude extracts of embryonic axes (EA) from non-dehydrated seeds (NDS) and from artificially slow-dehydrated seeds (DS); the second one, BP75, was a single protein with an apparent MW of 75 kDa and was expressed in cotyledons (COT) and EA tissues of NDS and DS; the third group with a mean apparent MW of 35 kDa (BP35), was expressed at high levels only in COT of NDS. BP35 concentration was highest in the early stages of seed development (21 days after flowering — DAF) and decreased as seeds developed, being almost imperceptible after 47 DAF. Conversely, only traces of BP75 and BP85 extracted from EA and COT were detected at early stages of seed development (21–33 DAF). Maximum levels of accumulation of these proteins were expressed at 42–47 DAF and remained constant until harvest maturity. Desiccation-tolerant stage of the seeds was initiated at 47 DAF, which coincided with the stage of maximum accumulation of BP75 and BP85 in the seeds, however, appearance of these proteins could be stimulated by desiccation of immature seeds that had not achieved desiccation tolerance. Therefore changes in biotinylated proteins are coincident with, but not sufficient for, the development of desiccation tolerance.

AbstractBiotin is an important vitamin. It is biologically active as a protein prosthetic group, where it functions in enzymatically catalysed carboxylation reactions. It has previously been shown that the ability to synthesize biotin is not necessary for germination of Arabidopsis thaliana seeds, but that this process is required for early seedling growth. This research was conducted to determine if changes in the detection of biotinylated proteins could be observed that reflect changes in the need for biotin-mediated enzyme reactions observed during early soybean seedling growth. A seed specific 75-kDa biotinylated protein present in the embryonic axes and the cotyledons was lost during the first 3 d of germination. Seed specificity, and pattern of expression during germination suggest that this protein is a homologue of the seed specific 65-kDa biotinylated protein previously identified in pea (Pisum sativum). If samples were not treated with 2-mercaptoethanol, three equally spaced proteins at approx. 85 kDa were visible. In the presence of 2-ME these proteins appeared as a single 85-kDa band. This triplet was distinct only in the embryonic axes of dry seeds and not in imbibed seeds or in other plant parts. This demonstrates that imbibitional changes do occur in the pool of biotinylated proteins present in dry soybean seeds, and that 2-ME treatment can inhibit complete identification of the biotinylated proteins present in seed tissues.

Biotin is an important vitamin. It is biologically active as a protein prosthetic group, where it functions in enzymatically catalysed carboxylation reactions. It has previously been shown that the ability to synthesize biotin is not necessary for germination of Arabidopsis thaliana seeds, but that this process is required for early seedling growth. This research was conducted to determine if changes in the detection of biotinylated proteins could be observed that reflect changes in the need for biotin-mediated enzyme reactions observed during early soybean seedling growth. A seed specific 75-kDa biotinylated protein present in the embryonic axes and the cotyledons was lost during the first 3 d of germination. Seed specificity, and pattern of expression during germination suggest that this protein is a homologue of the seed specific 65-kDa biotinylated protein previously identified in pea (Pisum sativum). If samples were not treated with 2-mercaptoethanol, three equally spaced proteins at approx. 85 kDa were visible. In the presence of 2-ME these proteins appeared as a single 85-kDa band. This triplet was distinct only in the embryonic axes of dry seeds and not in imbibed seeds or in other plant parts. This demonstrates that imbibitional changes do occur in the pool of biotinylated proteins present in dry soybean seeds, and that 2-ME treatment can inhibit complete identification of the biotinylated proteins present in seed tissues.

The influence of accelerated aging (AA-48h @ 41 degrees C/100% humidity) and simulated drought on the germination of Argentine and Tifton 9 bahiagrass (Paspalum notatum Flugge.) was studied. Seeds were subjected to AA and germinated in 0, -0.23, -0.32, -0.38, -0.43, -0.50, and -0.52-MPa water solutions of polyethylene glycol to simulate variations in available soil moisture. Tifton 9 seeds had higher germination than Argentine seeds, especially with the AA treatment. Higher (P < 0.01) total germination occurred with AA seeds compared to the check for Argentine (38.1% vs 30.0%) and Tifton 9 (72.3% vs 34.8%). For total germination, both grasses responded quadratically to increasing moisture stress. Accelerated aging also increased the rate of germination for both grasses compared to the check seed. Highest predicted rare of germination for treated Tifton 9 seed was 5.1 d at an osmotic pressure of -0.06 MPa. The Tifton cultivar appeared less sensitive to simulated drought than did the Argentine cultivar. Earlier, more uniform germination could be expected under field conditions for AA treated bahiagrass seed. More favorable germination of treated seed in dry soil conditions may allow an increase in the period of the year for which bahiagrass planting could be recommended.

We have previously identified four major α-glucan Phosphorylase (GP) enzymes in crude leaf extracts from pangolagrass (Digitaria eriantha Stent.). One co-isolates with the chloroplasts (cGP) while the other three are non-chloroplastic (nGP). In this report we present further characterization and leaf cell-type localization of the non-chloroplastic enzymes. In contrast to observations in maize, all of the pangolagrass GP enzymes were present in both isolated bundle sheath strands and mesophyll cells. Ion exchange column chromatography separated the leaf GPs into three peaks: A, B and C. Peak A was the most active and contained three non-chloroplastic GP (nGP), active bands separable by native Polyacrylamide gel electrophoresis (NPGE). Peak B GP enzymes migrated identically to peak A enzymes during NPGE. Peak C contained a single chloroplastic GP (cGP). The two major nGPs in the peak A fraction co-purified and migrated as a single band during SDS-PAGE, but they could be separated by IEF-column chromatography. Kinetic properties of these peak A nGP enzymes were similar to those of other plant nGP enzymes, with the exception that the pangolagrass nGP is not inhibited by dinucleotide sugars. The co-localization of the leaf GP enzymes in both bundle sheath and mesophyll cells, and the separation of the non-chloroplastic GPs into two pools (peaks A and B) during ion exchange chromatography are unique characteristics not previously described for plant leaf GPs.

Experiments were performed to analyze how chilling temperatures present during the night period affect leaf carbohydrate metabolism in pangolagrass (Digitaria decumbens Stent.), a warm‐season forage grass. Plants were exposed to three consecutive 14‐h night periods of either 25 or 10°C. Control plants (25°C nights) displayed an average 75% decline in leaf glucose levels during the night. This decline was more than 50% smaller in chilled plants (10°C nights) during all three nights. In control plants, leaf sucrose levels declined 78% during the night period. In chilled plants, this decline was inhibited to less than 2% of the available sucrose during the first night, and 47 and 44%, respectively, during two subsequent chilling nights. Greater than 90% of leaf starch was mobilized in control plants during the night, whereas 52, 46, and 16% of leaf starch was mobilized during three consecutive chilling nights, respectively. Chilling did not cause observable alterations in the ex planta activity of specific amylase enzymes; however, two diurnally regulated extrachloroplastic amylolytic enzymes were identified. Total leaf α‐1,4‐glucan phosphorylase (GP) activity was diurnally regulated with highest activity at the end of the night period, and activity increased in chilled plants after two consecutive chilling nights. Therefore, during three consecutive chilling nights the diurnal fluctuations in neither leaf carbohydrate levels nor GP activity remained constant. This dynamic response indicates that previous chilling night exposure influenced subsequent night‐period carbohydrate metabolism despite each night period being separated with a warm (25–33°C) 10‐h d period.

Experiments were performed to determine if RAPD profiles developed using total DNA isolated from soybean seed could be affected by the physiological state or the quality of the seed. RAPD profiles were developed using template DNA isolated from a single seed lot of soybean (Glycine max L. cv. Kirby). High quality seeds were used to produce four populations varying in either quality or physiological state: untreated control seed ambient temperature and humidity storage for 12 months, accelerated aging at 41 degrees C and 100% relative humidity for 48 h, and controlled hydration (seed priming). One hundred and eighty-eight primers were used to create separate RAPD profiles from total DNA isolated from each set of seed and from soybean leaf tissue. Sixteen polymorphisms from 14 primers were identified as a result of seed treatments. Six primers showed nine polymorphisms in RAPD profiles of ambient-stored seed DNA, while four and two primers produced polymorphisms in reactions using accelerated aged or primed-seed template DNA, respectively. Two primers showed a polymorphic fragment in vegetative DNA not observed in any of the seed DNA samples. Ten of the observed polymorphisms were due to the appearance of a DNA fragment in response to a specific seed treatment while six were the result of the treatment-induced loss of a DNA fragment. The six polymorphisms resulting from the loss of a major fragment were all due to ambient-temperature seed storage. Results were reproducibly obtained from multiple DNA isolations using three separate DNA isolation procedures involving either multiple seed or a single seed as the template source. Therefore, genetically identical seed can consistently display RAPD polymorphisms as a response to the environmental exposure.