scholarly journals Germination phenology determines the propensity for facilitation and competition

Ecology ◽  
2017 ◽  
Vol 98 (9) ◽  
pp. 2437-2446 ◽  
Author(s):  
Lindsay D. Leverett
Keyword(s):  
Germination Phenology

Seeds and seasons: interpreting germination timing in the field

2005 ◽  
Vol 15 (3) ◽  
pp. 175-187 ◽  
Author(s):  
Kathleen Donohue
Keyword(s):  
Environmental Factors ◽  
Genetic Basis ◽  
Genetic Material ◽  
Field Studies ◽  
Seed Maturation ◽  
Genetic Pathways ◽  
Ecological Conditions ◽  
Germination Phenology ◽  
Transgenic Lines ◽  
Germination Timing

This paper discusses how field and laboratory experiments, using a variety of genetic material, can be combined to investigate the genetic basis of germination under realistic ecological conditions, and it reviews some of our recent work on germination phenology ofArabidopsis thalianain the field. Our results indicate that the genetic basis of germination depends on the environment. In particular, the conditions during seed maturation interact with post-dispersal environmental factors to determine germination phenology, and these interactions have a genetic basis. Therefore genetic studies of germination need to consider carefully the environment – both during seed maturation and after dispersal – in which the experiments are conducted in order to characterize genetic pathways involved with germination in the field. Laboratory studies that explicitly manipulate ecologically relevant environmental factors can be combined with manipulative field studies. These studies can identify the particular environmental cues to which seeds respond in the field and characterize the genetic basis of germination responses to those cues. In addition, a variety of genetic material – including mutant and transgenic lines, intact natural genotypes, recombinant genotypes, and near isogenic lines – can be used in field studies as tools to characterize genetic pathways involved in germination schedules under natural ecological conditions.

Intermediate morphophysiological dormancy allows for life-cycle diversity in the annual weed, Turgenia latifolia (Apiaceae)

2014 ◽  
Vol 62 (8) ◽  
pp. 630 ◽  
Author(s):  
Miregul Nurulla ◽  
Carol C. Baskin ◽  
Juan J. Lu ◽  
Dun Y. Tan ◽  
Jerry M. Baskin
Keyword(s):  
Life Cycle ◽  
Low Temperatures ◽  
Western China ◽  
Intermediate Complex ◽  
Dormancy Breaking ◽  
Morphophysiological Dormancy ◽  
Temperature Regimes ◽  
Germination Phenology ◽  
Physiological Dormancy ◽  
Winter Annual

Our aim was to determine the seed dormancy-breaking requirements and type of life cycle of Turgenia latifolia in north-western China. At dispersal in July, only 0–9% of the seeds germinated at 5/2°C, 15/2°C, 20/10°C and 25/15°C; thus, 91% of the seeds exhibited physiological dormancy (PD) and 9% were non-dormant. Also, the embryo was underdeveloped and embryo length : seed length ratio increased from 0.38 in fresh seeds to 0.79 at germination. Seeds buried in dry soil at the four temperature regimes for 12 weeks germinated to ≥50% when tested in darkness at 5/2°C, and those buried at 15/2°C and 20/10°C germinated to ≥50% when tested at 15/2°C. Seeds have intermediate complex morphophysiological dormancy (MPD). PD was broken at high and/or low temperatures, but embryo growth was completed only at low temperatures; gibberellic acid (GA3) promoted germination. Seeds buried under natural conditions during summer germinated to ~70% and ~55% at 5/2°C and 15/2°C, respectively, in darkness in autumn. In a germination-phenology study, cumulative germination was ~20% and ~80% in autumn and spring, respectively. Intermediate complex MPD allows the species to behave as a winter annual and as a short-lived summer annual.

Seed heteromorphy influences seed longevity in Aegilops

2018 ◽  
Vol 28 (4) ◽  
pp. 277-285 ◽  
Author(s):  
Filippo Guzzon ◽  
Simone Orsenigo ◽  
Maraeva Gianella ◽  
Jonas V. Müller ◽  
Ilda Vagge ◽  
...  
Keyword(s):  
Seed Germination ◽  
Field Experiments ◽  
Soil Seed Bank ◽  
Seedling Emergence ◽  
Seed Longevity ◽  
Ex Situ ◽  
Bet Hedging ◽  
Hedging Strategy ◽  
Seed Conservation ◽  
Germination Phenology

AbstractThe genus Aegilops belongs to the secondary gene pool of wheat and has great importance for wheat cultivar improvement. As a genus with only annual species, regeneration from seeds in Aegilops is crucial. In several species in Aegilops, spikes produce different seed morphs, both in size and germination patterns. However, little is known about the ecology of seed germination, nor about the seed longevity in this genus. Here we investigated the germination phenology of Ae. neglecta under laboratory and field conditions and assessed longevity of different seed morphs of five additional Aegilops species using controlled ageing tests. Large seeds were short-lived and germinated faster than small seeds in most of the species. Field experiments with Ae. neglecta showed that large seeds of the dimorphic pair germinated 3 months after dispersal in contrast to 14 months for smaller seeds. Differences in longevity were detected not only in dimorphic seed pairs, but also among seeds from different positions on the spike. Our results indicate that different longevities in seed morphs of Aegilops may reflect a different soil seed bank persistence, with smaller seeds able to maintain a higher viability after dispersal than larger ones, thereby spreading seedling emergence over two years. Differences of seed germination and longevities between seed morphs in Aegilops may have important implications for ex situ seed conservation and reinforce the hypothesis of a bet-hedging strategy in the germination ecology of this genus.

A comparative study of the seed germination biology of a narrow endemic and two geographically-widespread species ofSolidago(Asteraceae). 1. Germination phenology and effect of cold stratification on germination

1997 ◽  
Vol 7 (1) ◽  
pp. 47-58 ◽  
Author(s):  
Jeffrey L. Walck ◽  
Jerry M. Baskin ◽  
Carol C. Baskin
Keyword(s):  
Small Area ◽  
Geographic Range ◽  
The Other ◽  
Cold Stratification ◽  
Dormancy Breaking ◽  
Widespread Species ◽  
Narrow Endemic ◽  
Germination Phenology ◽  
Primary Difference ◽  
Germination Requirements

AbstractSolidago shortiiis endemic to a small area in northcentral Kentucky (USA), whereas two of its sympatric congeners,S. altissimaandS. nemoralis, are geographically widespread. Seeds (achenes) ofS. shortii(0.370 mg) are significantly larger (PLSD,P=0.05) than those ofS. altissima(0.070 mg) andS. nemoralis(0.068 mg). Germination percentages of freshly-matured seeds of the threeSolidagospecies collected in November 1991, 1992 and 1994 were 0–2% in light at 15/6°C, 1–37% at 20/10°C, 9–56% at 25/15°C and 10–85% at 30/15 and 35/20°C. Stratification increased the percentage and rate of germination and decreased the time to the onset of germination (measured by Timson's index only at 20/10°C in light) in the three species. Following 12 weeks of cold stratification in light, seeds of the three species germinated to 72–100% in the light and to 22–100% in darkness over the range of thermoperiods; those cold-stratified in darkness germinated to 39–100% in light. Freshly-matured seeds ofS. altissimaand ofS. nemoralisgerminated to 0–4% in darkness, whereas those cold-stratified for 12 weeks in darkness germinated to 0–28% in darkness. On the other hand, freshly-matured and cold-stratified (in darkness) seeds ofS. shortiigerminated to 0–13 and 13–73%, respectively, in darkness. Under near-natural temperatures in a glasshouse without temperature control, germination of the three species peaked in March. Thus, the primary difference in dormancy-breaking and germination requirements of the three species is that the endemic germinates to a much higher percentage in darkness than its two congeners. Seeds ofS. shortiido not have any special dormancy-breaking or germination requirements that could not be fulfilled outside its present-day geographic range.

A new type of non-deep physiological dormancy: evidence from three annual Asteraceae species in the cold deserts of Central Asia

2014 ◽  
Vol 24 (4) ◽  
pp. 301-314 ◽  
Author(s):  
Mihray Nur ◽  
Carol C. Baskin ◽  
Juan J. Lu ◽  
Dun Y. Tan ◽  
Jerry M. Baskin
Keyword(s):  
Central Asia ◽  
Mechanical Resistance ◽  
Dormancy Breaking ◽  
Germination Phenology ◽  
Physiological Dormancy ◽  
Temperature Requirements ◽  
Dry Conditions ◽  
New Type ◽  
Late Stages ◽  
Germination Requirements

AbstractAlthough Asteraceae species are important in the cold deserts of Central Asia, little is known about their seed dormancy and germination. We determined dormancy breaking and germination requirements of three annual Asteraceae, Echinops gmelinii, Epilasia acrolasia and Koelpinia linearis. Achenes (seeds) were tested for germination in light and in darkness over a range of alternating temperatures after various periods of burial outdoors and of dry storage. Germination phenology was monitored for seeds sown in irrigated and non-irrigated sand, and temperature requirements for dormancy break were determined under wet and dry conditions. Effects of pericarp and phyllaries on germination of E. acrolasia and E. gmelinii, respectively, were determined. Low percentages of 20-day-old seeds of E. acrolasia and K. linearis were non-dormant and germinated to low percentages over the range of temperatures, whereas all seeds of E. gmelinii were dormant. As seeds of the three species afterripened, they germinated over the range of temperatures. Whether seeds germinated in autumn or spring depended on the amount of sand moisture. Mechanical resistance of the pericarp and phyllaries reduced germination of E. acrolasia and E. gmelinii, respectively. Temperature requirements for germination as seeds come out of dormancy do not correspond to any of the known five types of non-deep physiological dormancy (PD). Thus, a sixth type is recognized in which germination occurs over the same range of temperatures in the early and late stages of dormancy break. Type 6 allows seeds to germinate at high or at low temperatures, whenever sand moisture is non-limiting.

Germination phenology of some Great Basin native annual forb species

2010 ◽  
Vol 25 (3) ◽  
pp. 221-230 ◽  
Author(s):  
TARA A. FORBIS
Keyword(s):  
Great Basin ◽  
Germination Phenology

Life history variation in blue flax (L inum perenne : Linaceae): seed germination phenology

1994 ◽  
Vol 81 (5) ◽  
pp. 528-535 ◽  
Author(s):  
Susan E. Meyer ◽  
Stanley G. Kitchen
Keyword(s):  
Life History ◽  
Seed Germination ◽  
Life History Variation ◽  
Germination Phenology

Species-specific environmental requirements to break seed dormancy: implications for selection of regeneration niches in three Lonicera (Caprifoliaceae) species

Botany ◽  
2013 ◽  
Vol 91 (4) ◽  
pp. 225-233 ◽  
Author(s):  
Alejandro Santiago ◽  
José M. Herranz ◽  
Elena Copete ◽  
Pablo Ferrandis
Keyword(s):  
Seed Germination ◽  
Seed Dormancy ◽  
Environmental Conditions ◽  
Close Correspondence ◽  
Morphophysiological Dormancy ◽  
Germination Phenology ◽  
Environmental Requirements ◽  
Species Specific ◽  
Regeneration Niches ◽  
Selection Of

Environmental requirements for seed germination can operate as an important filter in determining the regeneration niche and ultimately the habitat preference of many plant species. We hypothesize that morphological and morphophysiological seed dormancy may play a major role in habitat selection, because underdeveloped embryos responsible for those dormancy types usually require strict species-specific environmental conditions to grow and to overcome dormancy, imposing marked constraints to recruitment and thus to species distribution. We analyzed the influence of temperature and light on embryo growth and seed germination, as well as germination phenology in three Lonicera (Caprifoliaceae) species. Lonicera xylosteum L. seeds had morphological dormancy. Those of Lonicera etrusca Santi had unusual within-species dormancy variability, with a fraction being able to show both morphological and morphophysiological dormancy. Seeds of Lonicera arborea had deep complex morphophysiological dormancy. The close correspondence between the environmental conditions that each Lonicera species requires to break seed dormancy and their altitudinal range suggests that morphological and morphophysiological dormancies act as important filters in determining the regeneration niches of species, probably because such dormancy mechanisms impose markedly specific environmental requirements during the earlier stages of recruitment.

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