bluuebunny/crossref_metadata_2025_split huggingface dataset:
Correlation of modified water sorption properties with the decline of storage stability of osmotically-primed seeds ofVigna radiata(L.) Wilczek
Authors: Sun Wendell Q. , Koh Dora C. Y. , Ong Choong-Moi 
Published: September 2008

AbstractOsmotic priming in a polyethylene glycol solution (300 g/kg water) for 48 h resulted in a partial loss of desiccation tolerance for seeds ofVigna radiata(L.) Wilczek (mung bean). The percentage of germination began to decrease after primed seeds were dried down to water contents less than 0.06 g/g DW. As compared with control seeds, primed mung bean seeds also had poorer storage stability. The decline of storage stability after osmotic priming was correlated with the modifications of seed water sorption properties. Priming significantly increased the amount of water associated with the weak water-binding sites, and reduced the amount of water associated with the strong binding sites and multi-molecular binding sites in seed tissues. The enhancement of molecular mobility in seeds, as a result of such water redistribution, probably accelerates seed deterioration and decreases storage stability.
The effect of soaking injury in seeds ofPhaseolus vulgarisL. on germination, respiration and adenylate energy charge
Authors: Pretorius Johan C. , Small J. G. Chris , Fagerstedt Kurt V. 
Published: September 2008

AbstractSubmergingPhaseolus vulgariscv. Top Crop seed in air-saturated water for 16 h markedly depresses subsequent germination. This is termed soaking injury. The postulate by Norton (1986) that soak-injured seeds merely run out of available energy was investigated. Soaking in air-saturated water reduced the total respiration (VT; in terms of O2uptake) of excised axes and cotyledons resulting in lower ATP levels. The contribution of both the mitochondrial cytochrome respiratory pathway (VCYT) and the alternative respiratory pathway (VALT) to the total respiration (VT) was significantly lower in these axes. However, the adenylate energy charge (AEC) values for both axes and cotyledons excised from soak-injured seeds did not drop below 0.6, the threshold value indicating death of plant material. Differences between the ultrastructure of mitochondria in the radicle tips of axes from unsoaked and water-soaked seeds were observed. However, the capacity to operate the Krebs cycle was similar in all axes and soak-injured seeds were still capable of germinating when the testas were removed or the seeds dried. This means that axes contained a sufficient amount of carbohydrates and potential energy to germinate after soaking. Moreover, soak-injured seeds produced ethanol at a rate which was five times higher than that of unsoaked control seeds, both during the soaking and post-soaking periods. Together with the low rate of oxygen consumption by soak-injured seeds during the same soaking and incubation time, it appears that soak-injured seeds lack the potential to switch from an anaerobic to an aerobic respiration pattern causing low ATP levels in these axes. It is speculated that the latter seems to be the result of limited pyruvate supply, probably due to accelerated and prolonged fermentation or futile combustion through other pathways or both.
Variation in seed dormancy among mother plants, populations and years of seed collection
Authors: Andersson L. , Milberg P. 
Published: September 2008

AbstractVariation in dormancy level was tested in seeds of four species, each collected from three populations in 1994 and 1995 (experiment 1). Germination was tested in light and darkness on recently-harvested seeds and on those after-ripened in dry storage for one year. In addition, seeds from each of eight individual plants within each of eight populations were tested for germination when recently harvested and after warm stratification or cold stratification followed by a drying period (experiment 2). Seeds from the two years differed in dormancy level in Silene noctiflora, Sinapis arvensis and Spergula arvensis. Germination percentage differed significantly among populations in Sinapis arvensis and Spergula arvensis in both experiments and in Thlaspi arvense in experiment 2. Furthermore, dormancy level in seeds from different mother plants also varied in the three species tested in experiment 2. Variations at the three levels tested (year, population and mother plant) indicate that these species have a random pattern of variation in dormancy level. It is concluded that variation in seed dormancy among mother plants, populations and years must be taken into account when testing the germination characteristics of a species and also when attempting to model weed seed bank dynamics.
The applicability of a seed ecological database (SEED) in botanical research
Authors: Csontos Péter 
Published: September 2008

AbstractThis is the first report on the SEed Ecological Database (SEED) being developed under the co-ordination of the author. In its first version the database will cover physical characteristics of seeds, such as: slenderness (length/width), flatness (thickness/width) and thousand-seed weight. The list of species encompasses all seed plants (gymnosperms and angiosperms) native or naturalized in Hungary (about 2450 species). Two examples to demonstrate the power of SEED are included. The significantly lower slenderness values of Hungarian C4 grasses (compared with C3 types), shown in the first example, is a new contribution to understanding the ecology of C4 grasses. In the second example heavier seed weights of shade plants are statistically demonstrated, compared to their heliophilous congeners with the same life forms. The 113 congeneric species pairs considered are derived from a wide range of plant families.
A comparative study of the seed germination biology of a narrow endemic and two geographically-widespread species ofSolidago(Asteraceae). 6. Seed bank
Authors: Walck Jeffrey L. , Baskin Jerry M. , Baskin Carol C. 
Published: September 2008

AbstractSeeds of the geographically-widespreadSolidago altissimaandS. nemoralisand the narrow-endemicS. shortiiwere buried in pots of soil and placed in a glasshouse without temperature control. After 0.3–4.3 years of burial, some seeds (21–60%) of all three species were viable and they germinated to 75–100% during 2 weeks of incubation in light at 30/15°C. Soil samples collected from several population sites ofS. altissima, S. nemoralisandS. shortiiwere placed in the glasshouse and monitored for seedling emergence. During the first, second, third, fourth, fifth and sixth springs, the number ofS. altissimaseedlings m−2emerging was 108–1080, 8–494, 0–520, 0–69, 0–6 and 3, respectively, ofS. nemoraliswas 108–1122, 17–667, 0–42, 0–6, 0, 0 and 0, respectively, and ofS. shortiiwas 61–1753, 0–25, 0–6, 0, 0 and 0, respectively. More seedlings emerged from disturbed than from non-disturbed soil, but the differences were not significant. Thus, although some seeds of all three species buried in pots remained viable in soil throughout the 4.3-year burial period, longevity was greater and size of seed bank larger in field-collected soil samples containing seeds of the geographically-widespread species than in those containing seeds of the narrow endemic. Although 34 studies have reported seeds of 17 species ofSolidagopresent in soil seed banks, the present study is the first to show, conclusively thatSolidagocan form a persistent seed bank.
The regulation of secondary dormancy. The membrane hypothesis revisite
Authors: Hilhorst Henk W. M. 
Published: September 2008

AbstractSecondary dormancy is predominantly associated with seed behaviour in soil seed banks. Periodic changes in secondary dormancy may explain seasonal emergence of weedy species. Temperature and possibly soil water potential appear to be the predominant factors that determine the annual cycling of dormancy. Dormancy cycling is paralleled by modulations of germination responsiveness to germination stimulants, such as light and nitrate and to the width of the germination temperature window. Membranes have been proposed to be the primary target for the perception of temperature. It is hypothesized that alterations in properties of cellular membranes are involved in the regulation of dormancy. Possible mechanisms are discussed.
Ecological aspects of seed dormancy loss
Authors: Allen Phil S. , Meyer Susan E. 
Published: September 2008

AbstractAdvances in seed biology include progress in understanding the ecological significance of seed dormancy mechanisms. This knowledge is being used to make more accurate predictions of germination timing in the field. For several wild species whose seedlings establish in spring, seed populations show relevant variation that can be correlated with habitat conditions. Populations from severe winter sites, where the major risk to seedlings is frost, tend to have long chilling requirements or to germinate very slowly at low temperatures. Populations from warmer sites, where the major risk is drought, are non-dormant and germinate very rapidly under these same conditions. Seed populations from intermediate sites exhibit variation in dormancy levels, both among and within plants, which spreads germination across a considerable time period. For grasses that undergo dry after-ripening, seed dormancy loss can be successfully modelled using hydrothermal time. Dormancy loss for a seed population is associated with a progressive downward shift in the mean base water potential, i.e., the water potential below which half of the seeds will not germinate. Other parameters (hydrothermal time requirement, base temperature and standard deviation of base water potentials) tend to be constant through time. Simulation models for predicting dormancy loss in the field can be created by combining measurements of seed zone temperatures with equations that describe changes in mean base water potential as a function of temperature. Successful validation of these and other models demonstrates that equations based on laboratory data can be used to predict dormancy loss under widely fluctuating field conditions. Future progress may allow prediction of germination timing based on knowledge of intrinsic dormancy characteristics of a seed population and long-term weather patterns in the field.
Methods for dehydration-tolerance: Depression of the phase transition temperature in dry membranes and carbohydrate vitrification
Authors: Oliver Ann E. , Crowe Lois M. , Crowe John H. 
Published: September 2008

AbstractAnhydrobiosis, or life without water, is the remarkable ability of certain types of plants and animals to survive almost total dehydration. This phenomenon requires a coordinated series of events within the cells of anhydrobiotes that protect their cellular components, particularly proteins and lipid membranes, from damage caused by the removal of water. Much of what is now understood about preserving biological samples during drying was learned by studying naturally desiccation-tolerant organisms and extended using model systems such as phospholipid vesicles. Most anhydrobiotic organisms accumulate disaccharides in their cells and tissues during the dehydration process. These carbohydrates, usually sucrose or trehalose, satisfy two criteria that appear to be necessary for protecting membranes during desiccation and during storage in the dry state. These requirements include: (1) depression of the gel-to-liquid crystalline phase transition temperature (Tm) in the dehydrated lipid to a temperature at or near that of the hydrated lipid, a process that appears to require a direct interaction between the carbohydrates and the lipid molecules of the membrane; and (2) formation of a carbohydrate glass with a relatively high glass transition temperature, leading to inhibition of fusion between the vesicles.
Genetic engineering with α-amylase inhibitors makes seeds resistant to bruchids
Authors: Chrispeels Maarten J. , Fatima Grossi de Sa M. , Higgins T. J. V. 
Published: September 2008

AbstractSeeds of the common bean,Phaseolus vulgaris, contain two inhibitors of mammalian and insect α-amylases (αAls) that show specificity towards the amylases of different insect species. Expression in pea (Pisum sativum) and azuki bean (Vigna angularis) of a chimeric gene consisting of the cDNA of bean αAl-1 and a seed-specific promoter makes the seeds of these legumes resistant to three species of Old World bruchids whose amylases are inhibited by αAl-1. This was the first successful genetic engineering of insect resistance in seeds. To understand the basis of the specificity between amylases and inhibitors we cloned a second bean inhibitor (αAl-2) with different specificity, and we cloned the cDNA of the New World bruchid,Zabrotes subfasciatus. The amylase of this bruchid is inhibited by αAl-2, but not by αAl-1. Knowledge of the amino acid sequences and of the three-dimensional structure of the pancreatic α-amylase–αAl-1 complex allows us to predict the peptide domains and amino acids of the proteins that are important for protein–protein recognition and inhibition of enzyme activity.
Seed quality assessment
Authors: McDonald Miller B. 
Published: September 2008

AbstractGrowers expect high-quality, genetically pure seed. As a result, seed companies maintain quality control programmes that monitor seed from harvest to purchase. An array of ‘traditional’ seed quality tests, including mechanical tests and tests of genetic purity, seed germination and vigour, and seed health tests, is used, and seed quality assessment techniques continue to evolve. Advances in molecular genetics are allowing the release of new varieties differing essentially in one gene. New molecular biology approaches offer the potential to identify these subtle genetic differences. Advances in seed enhancements, such as pelleting, priming and pregermination, require increased scrutiny of seed quality before and after the enhancement process. New developments in computer imaging for improved purity and germination/vigour analyses are being developed. These novel approaches to seed quality assessment become important as new genetic improvements are conveyed in the seed at increased cost to the grower.
Implications of new technologies for seed health testing and the worldwide movement of seed
Authors: Maddox Darrell A. 
Published: September 2008

AbstractNew techniques for the accurate and feasible detection of many seedborne pathogens have been developed over the last 25 years. These include conducive environmental incubation and identification (many seedborne fungi), liquid plating assay (seedborne bacteria), enzyme-linked immunosorbent assay (seedborne viruses) and polymerase chain reaction (PCR) technology. Regardless of the detection methodology, the specificity, sensitivity, reliability, efficiency of the assay and an understanding of pathogen tolerance in a seedlot need to be considered before a technique is an acceptable clinical seed health test. Acceptable seed health tests are tools for disease risk-management and routinely used in seed quality assessment. Seed health issues are increasingly important in international seed trade. With the advent of free trade, many countries are redefining their phytosanitary requirements with the goal of preventing introduction of a devastating pathogen into their country. However, many phytosanitary regulations are implemented without fully understanding the economic threat of a pathogen or a complete scientific analysis of a pathogen's presence in that country. This has led to confusing regulations, unnecessary tests or inspection requirements and unjustified trade barriers. To provide a means to answer scientifically the problems encountered in the worldwide movement of seed, an international movement has emerged to standardize seed health tests and inspection practices for international seed trade. The impact of standardization on the free trade of seed and the goals of the International Seed Health Initiative (ISHI) will be discussed.
Genetic purity and testing technologies for seed quality: a company perspective
Authors: Smith J. S. C. , Register III J. C. 
Published: September 2008

AbstractA high level of genetic purity in crop varieties must be achieved and maintained for agronomic performance as well as to encourage investment and innovation in plant breeding and to ensure that the improvements in productivity and quality imparted by breeders are delivered to the farmer and, ultimately, to the consumer. Traditionally, morphological comparisons have formed the basis for genetic purity evaluations. However, replicated field observations are time-consuming, expensive and unreliable. Morphology cannot provide information on the purity of specific genetic attributes that relate to grain quality or to pest or herbicide resistance bred into varieties. Biochemical assays, including isozymes, can distinguish varieties within several species. Isozymes have been routinely used in checking seed-lot purity in maize (Zea maysL.) for the past 20 years. Newer DNA-based technologies such as restriction fragment length polymorphisms and more recently developed methods that use the polymerase chain reaction can allow even more discriminative and faster identification of varieties. However, none of the DNA methods have replaced biochemical methods for seed purity assays, other than in a relatively select group of crops with very high seed value, due to their high datapoint cost. It will require further miniaturization, automation and enhanced capabilities to process numerous samples simultaneously before newly developed methods supplant biochemical methods for routine usage in purity testing. New varieties that have major genes for herbicide or insect resistance incorporated within them require purity assays during product development and following seed production of the commercial variety. Immunological or DNA sequence assays can be developed and automated systems are required to process hundreds of thousands of individuals. Ultra-high, micro-array technologies and single-molecule detection systems are now under development. These technologies offer the promise that adequate distinction and high sample throughput will be combined. New methods may eclipse the capabilities of biochemical methodologies, thereby potentially raising genetic purity standards and enabling farmers and consumers better to utilize and benefit from increasingly productive varieties that are bred from a more diverse base of genetic resources.
Vegetative plant development and seed production in cool-season perennial grasses
Authors: Chastain Thomas G. , Young William C. 
Published: September 2008

AbstractThe literature suggests that the establishment of seed yield potential in cool-season perennial grasses is based on developmental processes that take place before floral induction. The relationship between vegetative plant development to flowering and seed yield can be influenced by numerous factors, such as genotype, stand age, post-harvest regrowth environment, pests, management practices and juvenility. The objectives of our investigations and survey of literature were to identify characteristics of vegetative plant development present before floral induction (autumn regrowth period) that were related to flowering (yield potential) and seed yield (utilization of seed yield potential). The number of fertile tillers present at anthesis is a function of the number and developmental state (or biological age) of vegetative tillers present prior to floral induction. The number and size of vegetative tillers before induction was correlated with flowering and seed yield in young stands of orchardgrass (Dactylis glomerataL.) and tall fescue (Festuca arundinaceaSchreb.) (r= 0.93 and 0.95 for first-year stands of orchardgrass and tall fescue, respectively), but older stands did not exhibit this relationship. The basal diameter of vegetative tillers in autumn was related to flowering and seed yield in young stands of Kentucky bluegrass (Poa pratensisL.) and creeping red fescue (F. rubraL) As stands aged, basal diameter was not a primary indicator of subsequent flowering and seed yield. Tiller height at the end of the regrowth period was consistently related to flowering and seed yield in Kentucky bluegrass(r= −0.81,P< 0.01) and creeping red fescue (r= −0.87,P< 0.01), regardless of stand age. Increasing the rhizome:root ratio caused reduction of flowering in creeping red fescue. Vegetative characteristics were not related to flowering and seed production in perennial ryegrass (Lolium perenneL.) and dryland bentgrass (Agrostis castellanaBoiss. and Reut.). Green leaf number was a poor indicator of flowering and seed yield potential in all species tested. Ethylene production during autumn vegetative development has been implicated as a potential cause of reduced flowering in creeping red fescue. As much as 92% of the seed yield potential in several cool-season perennial grasses is set before the onset of conditions favouring vernalization of the crop. An increased understanding of developmental gateways in the formation of flowering and seed yield potential may be key to enhancing the economic and environmental sustainability of seed production enterprises.
Phytochromes and seed germination
Authors: Casal Jorge J. , Sánchez Rodolfo A. 
Published: September 2008

AbstractThe control of seed germination by red and far-red light is one of the earliest documented phytochrome-mediated processes Phytochrome is now known to be a small family of photoreceptors whose apoproteins are encoded by different genes Phytochrome B (phyB) is present in dry seeds and affects germination of dark imbibed seeds but other phytochromes could also be involved Phytochrome A (phyA) appears after several hours of imbibition and mediates very-low-fluence responses PhyB and other phytochromes different from phyA mediate the classical low-fluence responses The phytochrome involved in high-irradiance responses of seed germination (inhibition of germination under continuous far-red) has not been unequivocally established, although phyA is the most likely candidate Phytochrome can affect embryo growth capacity and/or the constraint imposed by the tissues surrounding the embryo At least in some species, gibberellins participate in the signalling process In the field, phyA has been implicated in the perception of light during soil cultivations, and phyB would be involved in the perception of red/far-red ratios associated with the presence of gaps in the canopy This review describes recent advances in phytochrome research, particularly those derived from the analysis of germination in specific mutants, and their connection with traditional observations on phytochrome control of seed germination