Germination of common bean under constant and alternating cool temperatures

2005 ◽  
Vol 85 (3) ◽  
pp. 577-585 ◽  
Author(s):  
T. Nleya ◽  
R. A. Ball ◽  
A. Vandenberg
Keyword(s):  
Common Bean ◽  
Germination Rate ◽  
Base Temperature ◽  
Moisture Availability ◽  
Temperature Regimes ◽  
Moisture Regimes ◽  
Cold Tolerant ◽  
Parental Material ◽  
Petri Dishes ◽  
Cool Conditions

In western Canada, common bean is often sown in cool soils, which causes poor germination and uneven stand establishment. A major goal in bean breeding is to find and assess cold-tolerant parental material. Seed germination and emergence of 12 diverse common bean genotypes, which included adapted Prairie cultivars, were evaluated in petri dishes under 15 alternating and five constant temperature regimes. Cumulative heat hours to maximum germination were calculated for all 12 genotypes using a base temperature of 9°C. Six genotypes were tested for emergence in soil in growth chambers at two temperature and three soil moisture regimes. In petri tests, optimal temperatures for bean germination were 16/16°C (day/night temperature) or higher. G8823, G9345 and AC Polaris germinated below 10°C, and all genotypes germinated at 12°C or higher. Rapid germinating genotypes with >0.09 cumulative heat hours per percentage germination were G8823, G9345 and AC Polaris, which took the least number of cumulative heat hours to germinate (<1100 heat hours). CDC Pinnacle was the highest representative of the medium germination rate group, having 1170 heat hours to germination. Emergence and plant development in soil were decreased by low moisture availability or cooler temperatures. Genotypes with >80% emergence in soil were CDC Crocus, CDC Nighthawk, CDC Pinnacle and CDC Polar Bear. Differing genotype rankings in soil versus petri dishes demonstrated that germination in controlled cool conditions may still be complicated by dormancy, moisture availability, seed coat thickness, imbibition rate and differing viabilities of seed lots. G8823, G9345 and AC Polaris are promising genotypes for developing cultivars that can germinate under cool temperatures (<10°C) at the highest rate. Key words: Phaseolus vulgaris, common bean, germination, temperature

Variability in temperature-dependent germination in eastern black nightshade (Solanum ptycanthum)

1991 ◽  
Vol 69 (7) ◽  
pp. 1463-1470 ◽  
Author(s):  
L. A. Hermanutz ◽  
S. E. Weaver
Keyword(s):  
Genetic Variability ◽  
Cultural Practices ◽  
Germination Rate ◽  
Base Temperature ◽  
Range Limit ◽  
Temperature Dependent ◽  
Marginal Populations ◽  
Solanum Ptycanthum ◽  
Temperature Regimes ◽  
Response To Temperature

The colonization potential of the northwardly migrating weed Solanum ptycanthum was evaluated by comparing germination profiles of southern agrestal populations with northern marginal populations sampled from both ruderal and agrestal habitats. Under laboratory conditions, the seed from five maternal families from each population was subjected to six light:dark temperature regimes from 18:8 to 40:30 °C and germination rate (time to 50% germination) and final percent germination were monitored. The base temperature and thermal time (degree-days) required for 50% germination were calculated. Seeds from southern agrestal populations germinated over a broader temperature range than northern agrestal populations but had similar rates of germination, base temperatures, and thermal times. At the northern range limit, ruderal populations germinated faster and had smaller thermal times than agrestal populations but had similar base temperatures. Delayed emergence in agrestal habitats may be a response to cultural practices. Seeds from northern populations were heavier than southern populations. Plasticity of germination response to temperature did not differ between populations. The observed levels of genetic variability in all germination parameters suggest that future range expansion would be possible. Key words: temperature-dependent germination, agrestal, ruderal, marginal populations, genetic variability, plasticity.

scholarly journals Using hydrothermal time concepts to model seed germination response to temperature, dormancy loss, and priming effects in Elymus elymoides

2000 ◽  
Vol 10 (3) ◽  
pp. 213-223 ◽  
Author(s):  
Susan E. Meyer ◽  
Susan B. Debaene-Gill ◽  
Phil S. Allen
Keyword(s):  
Seed Germination ◽  
Water Potential ◽  
Time Course ◽  
Germination Rate ◽  
Base Temperature ◽  
Hydrothermal Time ◽  
Time Model ◽  
Priming Effects ◽  
Elymus Elymoides ◽  
Temperature Regimes

AbstractHydrothermal time (HTT) describes progress toward seed germination under various combinations of incubation water potential ( ) and temperature (T). To examine changes in HTT parameters during dormancy loss, seeds from two populations of the bunchgrass Elymus elymoides were incubated under seven temperature regimes following dry storage at 10, 20 and 30°C for intervals from 0 to 16 weeks. Fully after-ripened seeds were primed for 1 week at a range of s. Data on germination rate during priming were used to obtain a HTT equation for each seed population, while data obtained following transfer to water were used to calculate HTT accumulation during priming. HTT equations accurately predicted germination time course curves if mean base water potential, b(50), was allowed to vary with temperature. b(50) values increased linearly with temperature, explaining why germination rate does not increase with temperature in this species. b(50) showed a linear decrease as a function of thermal time in storage. Slopes for the T × b(50) relationship did not change during after-ripening. This thermal after-ripening time model was characterized by a single base temperature and a constant slope across temperatures for each collection. Because the difference between initial and final b(50)s was uniform across tempera-tures, the thermal after-ripening requirement was also a constant. When seeds were primed for 1 week at −4 to −20 MPa, accumulation of HTT was a uniform 20% of the total HTT requirement. When primed at 0 to −4 MPa, HTT accumulation decreased linearly with decreasing priming potential, and a hydrothermal priming time model using a constant minimum priming potential adequately described priming effects. Use of these simple HTT relationships will facilitate modelling of germination phenology in the field.

Influence of Heat on Seed Germination of Cistus Laurifolius and Cistus Ladanifer

1992 ◽  
Vol 2 (1) ◽  
pp. 15 ◽  
Author(s):  
L Valbuena ◽  
R Tarrega ◽  
E Luis
Keyword(s):  
Seed Germination ◽  
High Temperatures ◽  
Exposure Time ◽  
Germination Rate ◽  
Heat Exposure ◽  
Cistus Ladanifer ◽  
Different Temperatures ◽  
Petri Dishes ◽  
Germinated Seeds

The influence of high temperatures on germination of Cistus laurifolius and Cistus ladanifer seeds was analyzed. Seeds were subjected to different temperatures for different times, afterwards they were sowed in plastic petri dishes and monitored for germinated seeds over two months.The germination rate observed in Cistus ldanifer was greater than in Cistus laurifolius. In both species, heat increased germination percentages. For Cistus laurifolius higher temperatures or longer exposure times were needed. Germination percentages of Cistus ladanifer were lower when heat exposure time was 15 minutes.It must be emphasized that germination occurred when seeds were not treated, while seeds exposed to 150�C for 5 minutes or more did not germinate.

Monitoring Agricultural Drought in the Near East

2005 ◽  
Author(s):  
Eddy De Pauw
Keyword(s):  
Near East ◽  
Potential Evapotranspiration ◽  
Groundwater Resources ◽  
Winter Season ◽  
Aridity Index ◽  
Agricultural Drought ◽  
Moisture Regime ◽  
Temperature Regimes ◽  
Moisture Regimes ◽  
Dry Climates

The countries of North Africa and West Asia, hereafter referred to as the “Near East,” cover a large part of the world (more than 7,200,000 km2). This region is characterized by diverse but generally dry climates, in which evaporation exceeds precipitation. The level of aridity is indicated by the aridity index, the ratio of annual precipitation to annual potential evapotranspiration, calculated by the Penman method (UNESCO, 1979). The degree of aridity is shown spatially in figure 16.1 and summarized per country in table 16.1. These data show that the region is characterized by humid, subhumid, semiarid, and arid to hyperarid moisture regimes. In addition, temperature regimes vary considerably, particularly due to the differences in altitudes and, to a lesser extent, due to the oceanic/continental influences. For most of the region, the precipitation generally occurs during the October–April period and thus is concentrated over the winter season. Table 16.1 shows that, with more than 90% of the land area in hyperarid, arid, or semiarid moisture regimes, aridity is very significant in the Near East. Turkey is better endowed with surface and groundwater resources due to the orographic capture of Atlantic cyclonal precipitation, but much of the interior is semiarid. If one excludes the hyperarid zones, which cover the driest deserts and have no potential for agricultural use, nearly 34% of the region, or about 2,460,000 km2, is dryland (i.e., the area with arid or semiarid moisture regime). These are the areas with some potential for either dryland farming (in semiarid zones) or for extensive rangeland (in arid zones). In the Near East countries, agriculture contributes about 10–20% to the gross domestic product and is therefore a major pillar of their economies. However, the indirect importance of agriculture is larger because it provides the primary goods that constitute the majority of merchandise exports and because of the relatively high number of people employed in agriculture. Because of the high degree of aridity in large parts of the region, agriculture in the Near East is particularly vulnerable to drought. Most of the agricultural systems depend on rainfall.

scholarly journals Impact of Constant Versus Fluctuating Temperatures on the Development and Life History Parameters of Aldrichina grahami (Diptera: Calliphoridae)

Insects ◽  
2019 ◽  
Vol 10 (7) ◽  
pp. 184 ◽  
Author(s):  
Wei Chen ◽  
Li Yang ◽  
Lipin Ren ◽  
Yanjie Shang ◽  
Shiwen Wang ◽  
...  
Keyword(s):  
Life History ◽  
Ambient Temperature ◽  
Developmental Rate ◽  
Threshold Temperature ◽  
Life History Parameters ◽  
Temperature Regimes ◽  
Cold Tolerant ◽  
Constant Versus ◽  
Forensic Tools ◽  
Fluctuating Temperatures

Necrophagous fly species are commonly used as forensic tools to estimate the minimum postmortem interval (PMImin). Many researchers raised necrophagous flies under constant temperature regimes to collect their developmental data. However, in most forensic cases, the ambient temperature fluctuates. In order to investigate a forensically important fly developmental mode (the Isomegalen diagram, Isomorphen diagram and Thermal summation models) and make comparisons of the developmental rate between constant temperatures and fluctuating temperatures, we used Aldrichina grahami (Diptera: Calliphoridae) to investigate the life history parameters at eight constant temperatures ranging from 8 to 36 °C. We also compared developmental rate of A. grahami in three groups of constant versus fluctuating temperatures: 8 °C vs. 6–12 °C, 12 °C vs. 10–16 °C, and 16 °C vs. 14–20 °C. Our data showed that A. grahami is cold tolerant with a mean (±SE) development threshold temperature (D0) of 3.41 ± 0.48 °C and a thermal summation constant (K) of 8125.2 ± 288.4-degree hours. The three groups subjected to fluctuating temperatures took longer to develop compared to those developing in constant temperatures when simulated in a model. These results not only provide detailed developmental data for the use of A. grahami in the estimation of the PMI, but also indicate that ambient temperature fluctuation must be taken into consideration for the use of all necrophagous fly species.

scholarly journals Effect of Environmental Factors on Seed Germination and Early Seedling Emergence of Carolina geranium (Geranium carolinianum)

2018 ◽  
Vol 36 ◽  
Author(s):  
X. LIU ◽  
T. ZONG ◽  
Y. LI ◽  
X. ZHOU ◽  
L. BAI
Keyword(s):  
Control Strategies ◽  
Germination Rate ◽  
Seedling Emergence ◽  
Burial Depth ◽  
Invasive Weed ◽  
Temperature Regimes ◽  
Dark Regime ◽  
Early Seedling ◽  
Effects Of Temperature ◽  
And Control

ABSTRACT: Carolina geranium (Geranium carolinianum) is an emerging invasive weed in rape and wheat fields in China. A better understanding of its germination and emergence ecology will enable the development of integrated weed control strategies. In this study, we investigated the effects of temperature, photoperiod, soil water content, salinity, and burial depth, on germination and emergence of Carolina geranium. Germination percentages were over 74% under 15/20 and 20/25 oC night/day temperature regimes. Germination rate was independent of light/dark regime. Increasing salinity reduced germination of Carolina geranium from 81.1% at 0 mM to 0% at 160 mM NaCl. Seeds germination was peaked at 50% soil moisture, but was completely inhibited at < 20% and > 90%. The seedling emergence above 82.2% was observed when seeds were placed at a depth from 0 to 1 cm, and no seedlings emerged from seeds placed at a depth of 7 cm. Current work provide the basic information to effectively prevent and control this invasive weed in Chinese rape and wheat fields.

Dormancy and Germination of Seed of Eight Populations of Themeda australis

1982 ◽  
Vol 30 (4) ◽  
pp. 373 ◽  
Author(s):  
RH Groves ◽  
MW Hagon ◽  
PS Ramakrishnan
Keyword(s):  
Population Stratification ◽  
Physiological Adaptation ◽  
Dormant Seed ◽  
Seed Formation ◽  
Fresh Seed ◽  
Temperature Regimes ◽  
Germination Characteristics ◽  
Moisture Regimes ◽  
Different Populations ◽  
Climatic Characteristics

Seed of eight populations of Themeda australis (R.Br.) Stapf from sites nith the widest range of climates in Australia and Papua New Guinea (P.N.G.) was tested for its dormancy status and germination responses to different temperature and moisture regimes. The populations were from Lae. P.N.G.. Katherine. N.T.. Mundubbera. Qld. Alice Springs. N.T.. Tantangara. N.S.W.. Adelaide Hills. S.A.. Bunbury, W.A. and Hobart. Tas. Dormancy of fresh seed was negligible in Lae and Mundubbera populations. considerable in the Alice Springs population and intermediate in populations from Katherine and all temperate sites. Addition of gibberellic acid hastened the release from dormancy of seed from Katherine and Bunbury. Exposure of plants to three different temperature regimes during seed formation had an effect on dormancy of the Katherine population. Stratification at 4°C and high alternating daily temperatures (45 20°C) hastened the loss of dormancy of fresh seeds of some populations. Germination of non-dormant seed of the different populations was relatively unaffected b) temperatures between 20 and 40°C. Germination of the Alice Springs population was the most sensitive to increasing water stress and that from Lae the least sensitive. Radicle elongation of seedlings from Alice Springs was significantly greater than that of most other populations at a water potential of - I .0 MPa. The differences reported for seed dormancy and germination characteristics of T. australis populations do not reflect a strong physiological adaptation to the climatic characteristics of the sites from which they were collected.

Hydropriming accelerates seed germination of Medicago sativa under stressful conditions: A thermal and hydrotime model approach

2017 ◽  
Author(s):  
Rong Li ◽  
Dandan Min ◽  
Lijun Chen ◽  
Chunyang Chen ◽  
Xiaowen Hu
Keyword(s):  
Water Potential ◽  
Germination Rate ◽  
High Water ◽  
Nacl Stress ◽  
Base Temperature ◽  
Severe Water Stress ◽  
Hydrotime Model ◽  
Response To Temperature ◽  
Base Water Potential ◽  
Temperature Water

This study determined the effects of priming on germination in response to temperature, water potential and NaCl. Thermal and hydrotime models were utilized to evaluate changes in parameters of the model after priming. Priming reduced the amount of thermal time in both cultivars, but slightly increased the base temperature for germination from 1.0 to 3.5°C in “Longdong”. Priming significantly increased germination rate at high water potential but had no effect at low water potential. Further, priming reduced the hydrotime constant but made the median base water potential value slightly more positive in both cultivars. Thus, priming increased germination rate in water but decrease it under severe water stress. Germination rate was significantly increased in both cultivars under salinity (NaCl) stress. Moreover, priming improved seedling growth in response to temperature, water and salinity stress in both cultivars.

Sign in / Sign up

Export Citation Format

Share Document