首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 31 毫秒
1.
Arvind BHATT 《干旱区科学》2020,12(6):1071-1082
Germination timing is highly regulated in short-lived plant species since it strongly influences recruitment success of vegetation. In deserts, the spatiotemporal distribution of plant-available water is highly episodic and unpredictable, making winter months more favorable for seed germination when other abiotic conditions co-occur. We hypothesized that changes in photoperiod and thermoperiod would impact germination more in seeds that had undergone in situ storage. We assessed 21 annual and short-lived perennial species in the Arabian Desert to find (1) if seeds were dormant at maturity, (2) if in situ seed storage increased germination percentage compared with no storage, (3) if photoperiod and thermoperiod germination requirements were influenced by in situ storage, and (4) if a phylogenetic association in seed germination could be observed. Seeds of each species collected in early 2017 were divided into two batches. One was tested for germination within one week (fresh seeds). The other was stored in situ at the maternal location (stored seeds) until October 2017 and tested for seed germination in the first week of November. Seed germination was conducted in incubators at two thermoperiods (15°C/20°C and 20°C/30°C; 12 h/12 h), and two photoperiods (12 and 0 h light per day). Results indicated that seed germination percentages of 13 species were significantly enhanced by in situ storage. A thermoperiod response was exhibited by stored, but not fresh seeds. Light exposure increased germination of fresh seeds but had only a minimal effect on stored seeds. Germination traits exhibited no phylogenetic correlation. This result indicated that selection pressure for germination strategy was stronger than that for taxonomic traits of these desert species.  相似文献   

2.
Seed germination is a key transitional stage in plant life cycle and is strongly regulated by temperature and light. Therefore, research on the effects of temperature and light on seed germination is extremely meaningful for vegetation restoration, especially in desert ecosystems. Seeds of 28 ephemeral plants collected from the Gurbantunggut Desert of China were incubated at different temperatures (5°C/1°C, 15°C/5°C, 20°C/5°C, 25°C/10°C and 30°C/15°C) in 12-h light/12-h darkness or continuous darkness regimes, and the responses of seed germination to temperature and light and the germination speed were studied in 2016. Results showed that seed germination percentage of the 28 ephemeral plants significantly differed to temperature and light. We classified the studied plants as the following groups based on their responses to temperature: 1 low temperature responsed plants, 12 moderate temperature responsed plants, 7 high temperature responsed plants, 4 non-responsed plants and 5 plants of no germination. It should be noted that Corispermum lehmannianum Bunge is sensitive to both moderate and high temperatures. There were 4 groups of plant in response to light, i.e., 7 light responsed plants, 10 dark responsed plants, 6 light non-responsed plants and 5 plants of no germination. Based on seed germination speed of the 28 ephemeral plants, we divided them into 4 patterns of germination, i.e., very rapid, moderately rapid, moderate and slow. Combining variations of temperature, precipitation and sand dune types in the study area, we suggested that very rapid and moderately rapid germinated plants could be used to moving sand dunes in early spring during vegetation restoration, moderate germinated plants could be used to semi-fixed sand dunes in late autumn, and slow germinated plants could be used to sand plain in summer. Thus, seedling establishment and vegetation restoration would be improved by considering seed germination characteristics of these ephemeral plants in the Gurbantunggut Desert, China.  相似文献   

3.
Shrubby seablite or lani(Suaeda fruticosa Forssk)is a perennial euhalophyte with succulent leaves,which could be planted on arid-saline lands for restoration and cultivated as a non-conventional edible or cash crop.Knowledge about the impacts of maternal saline environment on seed attributes of this important euhalophyte is lacking.This study investigated the effects of maternal salinity on yield,size and stress tolerance of S.fruticosa seeds.Seedlings of S.fruticosa were grown in a green net house under increasing maternal salinity levels(0,300,600 and 900 mM NaCl)until seed production.Total yield,size,stress tolerance and germination of the descended seeds under different maternal saline conditions were examined.Plants grown under saline conditions(300,600 and 900 mM NaCl)produce a substantially higher quantity of seeds than plants grown under non-saline condition(0 mM NaCl).Low maternal salinity(300 mM NaCl)improves seed size.Seeds produced under all maternal salinity levels display a higher tolerance to low temperature(night/day thermoperiod of 10℃/20℃),whereas seeds produced under 300 mM NaCl maternal saline condition show a better tolerance to high temperature(night/day thermoperiod of 25℃/35℃)during germination.Seeds from all maternal saline conditions germinate better in the 12 h photoperiod(12 h light/12 h dark)than in the dark(24 h dark);however,seeds produced from low and moderate maternal saline conditions(300 and 600 mM NaCl)show a higher germination in the dark than those from control and high maternal saline conditions(0 and 900 mM NaCl).In general,maternal salinity is found to improve yield,size and stress tolerance of S.fruticosa seeds.  相似文献   

4.
For a plant species to complete its life cycle in arid and saline environments, each stage of the life cycle must be tolerant to the harsh environmental conditions. The aim of the study was to determine the effects of water stress (water potentials of -0.05, -0.16, -0.33, -0.56, -0.85 and -1.21 MPa) and NaCl stress (50, 100, 200, 300, 400, 500 and 600 mmol/L NaCl) on seed germination percentage, seedling survival and growth, juvenile growth and plant reproduction of Lachnoloma lehmannii Bunge (Brassicaceae), an cold desert annual that grows in the Junggar Basin of Xinjiang, China in 2010. Results indicated that low water stress (-0.05 and -0.16 MPa) had no significant effect on seed germination percentage. With a decrease in water potential, germination percentage decreased, and no seeds germinated at -0.85 and -1.21 MPa water stresses. Germination percentage of seeds was significantly affected by NaCl stress, and higher germination percentages were observed under non-saline than saline conditions. An increase in NaCl concentrations progressively inhibited seed germination percentage, and no seeds germinated at ≥400 mmol/L NaCl concentration. Non-germinated seeds were transferred from both PEG (polyethylene glycol-6000) and NaCl solutions to distilled water for seed germination recovery. The number of surviving seedlings and their heights and root lengths significantly decreased as NaCl stress increased. About 30% of the plants survived and produced fruits/seeds at 200 mmol/L NaCl concentration. Thus, seed germination, seedling establishment and reproductive stage in the life cycle of L. lehmannii are water- and salt-tolerant, with seedlings being the least tolerant. These tolerances help explain why this species can survive and produce seeds in arid and saline habitats.  相似文献   

5.
Cyanus segetum is an iconic, colourful weed in arable fields that provides ecological and societal services. To understand better both the infestation dynamics of C. segetum as an abundant, harmful weed and maintain sustainable populations where it provides beneficial services, we compared information on seed dormancy, seed longevity and germination conditions in two populations. Persistence of seeds buried in the soil was low, with <10% viable after 3 years. Periodic dormancy cycling was observed over the 4 years in the soil, with a maximum of dormant seeds in the spring and a minimum in the autumn; however, 20% of the seeds were non‐dormant all the time. Seeds of C. segetum were positive photosensitive, but light requirement varied among populations. Base water potential for germination was ?1 MPa. Base temperature ranged from 1 to 2°C. Optimum temperature for germination was about 10 to 15°C, but the mean thermal time varied greatly between populations, from 80 to 134 day °C. Photoperiod and temperature combinations had no effect on germination percentage, but both reduced the germination rate. Burial deeper than 2 cm greatly reduced germination and seedling emergence strongly decreased at depths >0.5 cm. No seeds buried deeper than 8 cm emerged. Low seed longevity and a wide range of germination conditions could partly explain the rapid disappearance of C. segetum populations after herbicide application began in western Europe. However, yearly sowing in restoration areas does not seem to be essential.  相似文献   

6.
Most ecological studies in North Africa reveal a process of continuous degradation of rangeland ecosystems as a result of overgrazing. This degradation appears across the decreasing of perennial grass diversity. Indeed, the majority of steppe ecosystems are characterized by a low density of perennial grass species at present. This study evaluated the effects of temperature and water limitation on the seed germination of Stipagrostis ciliata(Desf.) de Winter, a perennial grass species. The seeds were collected from the Bou Hedma Park, Sidi Bouzid Governorate, Central Tunisia. The thermal time and hydrothermal time models were used to describe the seed germination of S. ciliata under different water potentials and temperatures. The germination response of S. ciliata seeds in darkness was evaluated over a range of temperatures(15°C, 20°C, 25°C, 30°C and 35°C) and across a wide range of osmotic potentials(0.0, –0.2, –0.6, –1.2, –1.6 and –2.0 MPa) of the polyethylene glycol(PEG6000) solutions at each temperature level. Among the tested temperatures, 25°C was found to be the optimal temperature to the germination of S. ciliata seeds. The final germination percentage(75.2%) was obtained with distilled water. The progressive decrease of osmotic potential of the PEG6000 solutions inhibited the seed germination. However, the number of days to first germination was increased with a reduction of osmotic potential. A significant positive relationship was identified between final germination percentage of S. ciliata seeds and osmotic potential of the PEG6000 solutions, with R~2 ranging from 0.5678 to 0.8761. Furthermore, a high degree of congruency between predicted and observed germination time course curves was observed. In general, S. ciliata exhibits a significant adaptation capacity for water limitation and high temperature in arid ecosystems.  相似文献   

7.
The seed germination behaviour of four populations each of Diplotaxis erucoides (L.) DC. and D. virgata (Cav.) DC, two weedy Brassicaceae species widely distributed in the Mediterranean region, was studied under controlled light, temperature and moisture conditions. Germination rates in D. virgata were generally higher at alternating (25/15^C) and low (15^C) temperatures, whereas in D. erucoides optimal germination rates were achieved at higher temperatures (25^C). No correlation between seed weight and germination was found in either species. In D. virgata, the geographic origin of the seed had an important effect on germination percentage. Great germination variability was found among the populations and even among seeds belonging to the same population. In this species, the application of gibberellic acid stimulated germination, especially in the populations with higher dormancy levels. Dormancy was found in mature D. virgata seeds but not in those of D. erucoides. In both species, germination percentages decreased after a certain period of storage at low temperatures. This period varied depending on the species and the population considered.  相似文献   

8.
Seed germination profoundly impacts plant community composition within the plant life cycle. Snow is an important source of water for seed germination in the temperate deserts of Central Asia. Understanding how seed germination responds to variations in snow cover in relation to seed traits and plant ecological characteristics can help predict plant community sustainability and stability in Central Asia under a scenario climate change. This study investigated the seed germination of 35 plant species common to the Gurbantunggut Desert in Central Asia under the three snow treatments: (1) snow addition; (2) ambient snow; and (3) snow removal. Two-way analysis of variance (ANOVA) tests were performed to assess interactions among the impacts of snow treatments, seed traits and plant ecological characteristics on seed germination. Phylogenetic generalized least-squares (PGLS) model was used to test the relationships between seed traits and seed germination. The results demonstrated that snow variations had no significant impacts on seed germination overall. Seed germination under the snow addition treatment was similar with that under the ambient snow treatment, irrespective of seed traits and plant ecological characteristics. Snow removal only had negative impacts on seed germination for certain groups of seed traits and plant ecological characteristics. Seed mass positively affected seed germination, showing a linear increase of arcsin square root-transformed seed germination with log-transformed seed mass. Seed shape also profoundly impacted seed germination, with a higher germination percentage for elongated and flat seeds. Seed germination differed under different plant life forms, with semi-shrub species showing a significantly higher germination percentage. Most importantly, although snow treatments, seed traits and plant ecological characteristics had no interactive effects on seed germination overall, some negative impacts from the snow removal treatment were detected when seeds were categorized on the basis of seed mass and shape. This result suggests that variations of snow cover may change plant community composition in this temperate desert due to their impacts on seed germination.  相似文献   

9.
Caucalis platycarpos is a weed species in irrigated and dry land farming systems in East Azerbaijan and Kermanshah provinces of Iran. Experiments were undertaken to compare C. platycarpos seed germination and emergence of a population from each province over a range of environmental factors, burial depth and crop residue treatments. The Azerbaijan population required lower temperatures (20/10°C day/night temperature) for its highest (90%) germination, compared with the Kermanshah population (88% germination at 25/15°C day/night temperature). In both populations, germination was 84–90% over a wide range of light/dark periods (10–24 h light), but considerable reduction (up to 42%) occurred under continuous darkness. The osmotic potential required for 50% inhibition of germination was ?0.54 and ?0.40 MPa for Azerbaijan and Kermanshah populations respectively. The NaCl concentration of 8.83 and 5.71 dS m?1 caused 50% inhibition of germination in Azerbaijan and Kermanshah populations respectively. The X50 parameter (the burial depth at which emergence is reduced by 50%) for Azerbaijan and Kermanshah population was 2.18 and 2.86 cm respectively. Crop residues had more inhibitory effects on the Azerbaijan than Kermanshah population. Adaptive differentiation of C. platycarpos populations has also resulted in smaller seeds of the Azerbaijan compared with the Kermanshah population and resulted in higher emergence for Kermanshah population seedlings from greater soil depths. These results suggest that differences in germination requirements, drought and salinity tolerance of C. platycarpos populations are correlated with environmental conditions of the habitats of the studied populations.  相似文献   

10.
短毛柽柳(Tamarix karelinii)是分布于盐渍化沙地和重盐碱地的灌木。为了阐明短毛柽柳种子的萌发特性,设置不同的温周期、储藏时间和盐分梯度,采用室内控制实验研究这些因子对种子萌发的影响。结果表明:1短毛柽柳种子在4个温周期中均具有高的萌发率,并且温周期温度越高,种子的萌发速率越快。2室温贮藏1个月显著提高种子的萌发速率,在贮藏6个月内,种子的最终萌发率都能达到100%。3≤0.8 mol·L~(-1)的Na Cl溶液对种子的最终萌发率无显著影响,而≥1.0 mol·L~(-1)的溶液则抑制种子的萌发,且随着浓度的增加,种子的最终萌发率呈下降趋势,直至为0。将1.0~4.0 mol·L~(-1)溶液中没有萌发的种子,转移至蒸馏水继续培养后,仍有71.67%~28.00%的种子恢复萌发率,表明种子具有较强的耐盐性。对短毛柽柳种子萌发特性的研究,为短毛柽柳的种苗培育提供基础资料。  相似文献   

11.
It is important to understand the effects of dew events on non-mucilaginous seed germination of annual desert plant species during dry seasons, which is critical to maintaining long-term soil seed banks in a harsh desert environment. We hypothesize that dew deposition also assists in the non-mucilaginous seed germination of annual desert species. A common field dew treatment experiment was conducted in the Linze Inland River Basin Research Station to investigate the effects of dew deposition on the seed germination of four annual species, including Agriophyllum squarrosum, Corispermum mongolicum, Bassia dasyphylla and Halogeton arachnoideus. The results showed that the presence of dew significantly increased seed germination percentages and decreased the nonviable seed percentages of B. dasyphylla and H. arachnoideus, whereas there was no such trend for the seeds of C. mongolicum and A. squarrosum. The ecological effects of dew on the seed germination and viability of the annual desert plants were species specific. Although dew wetting is insufficient to cause seed germination, it may help in priming the seeds.  相似文献   

12.
长叶红砂和红砂种子萌发对光照、温度和水分的响应   总被引：1，自引：0，他引：1  
长叶红砂(Reaumuria trigyna)和红砂(Reaumuria soongorica)均为荒漠地区超旱生小灌木,长叶红砂为红砂属珍稀种,而红砂为广布种。通过种子萌发对光、温和土壤水分需求的研究表明,长叶红砂对光照不敏感,而黑暗有利于红砂的萌发。种子萌发的适宜温度均为恒温20-25℃或15/25℃变温。25℃后,随着温度升高萌发率下降。土壤含水量在3%以上时,有利于两物种的萌发,萌发适宜的含水量都在12%。在各种条件下,珍稀种长叶红砂的萌发均高于广布种红砂,说明种子质量和萌发并没有造成长叶红砂的珍稀濒危。但长叶红砂高萌发率却不利于应对荒漠地区极端和不可预测的环境变化,增加了生存的风险性,可能是其濒危原因之一。  相似文献   

13.
The effects of maternal salinity and light incubation on the salinity tolerance of the facultative halophyte Anabasis setifera during their germination stages were assessed. Seeds were collected from non-saline habitats in Egypt and saline habitats in the United Arab Emirates(UAE). The seeds of the two populations were germinated in 0, 100, 200, 400, 600 and 800 m M Na Cl, and incubated at 25°C/15°C in both 12-h light and 12-h darkness regimes and continuous darkness. Significantly more seeds germinated in the Egyptian population than in the UAE population. Salinity tolerance was significantly greater with the Egyptian population than with the UAE population, especially under the conditions of higher salinities. The difference in salinity tolerance between the seeds of two populations was attributed to their seed mass. In addition, germination was significantly faster for the Egyptian population than for the UAE population. Most of the saline treated seeds were able to recover their germination when transferred to distilled water, but this depended on their maternal salinity and light incubation. Recovery from higher salinities was significantly better for the seeds under darkness than for those under light in the UAE population, but the reverse was true for the seeds in the Egyptian population. The higher salinity tolerance for the A. setifera seeds from the non-saline Egyptian population and the lower salinity tolerance for the seeds from the saline UAE population cannot explain their natural distribution. Further studies about other possible roles, such as levels of different promoting and inhibiting phytohormones, are needed to understand the importance of salinity as an environmentally induced maternal effect.  相似文献   

14.
研究不周浓度盐溶液(NaCl、MgSO4、盐渍土壤)和PEG模拟干旱胁迫对沙米种子吸胀、萌发和幼苗生长的影响,并观察胁迫解除后种子的反应.结果表明:随着NaCl、MgSO4和PEG浓度的升高,沙米种子吸胀率先升后降,种子萌发率呈现不同程度降低,盐渍土壤溶液对萌发率没有显著影响;对沙米种子萌发和幼苗生长的胁迫效应是NaC...  相似文献   

15.
H OM  S KUMAR  & S D DHIMAN 《Weed Research》2005,45(2):140-148
Seed placement, soil temperature and soil moisture content influenced the process of after-ripening in Phalaris minor seeds. Seeds of P. minor collected from the soil just after wheat harvesting exhibited higher germination than seeds from P. minor threshed directly. There was a pronounced impact of periodic inhabitation of seed into the soil on germination after its dispersal. Germination was strongly inhibited when the seed was kept in soil at more than field capacity (FC) or in water. Maximum germination of seed incubated in soil at FC occurred at 30°C while a temperature of 40°C favoured after-ripening of seed when mixed with dry soil or kept dry without any medium. Release from conditional dormancy was quicker in the seed retrieved from the soil kept at 20°C than at 10°C. Seed release from conditional dormancy and germination increased with a rise in temperature from 30 to 40°C when the seed was retrieved from incubation in soil at FC for 70 days. The seed kept immersed in water was least responsive to a rise in temperature. Seed recovered from dry soil, or kept without any medium, responded quickly at both temperatures. Light enhanced the germination of Phalaris minor seed. The seedbank subjected to rice (Oryza sativa) field management conditions lost vigour in comparison with the seed stored in laboratory. There was significant variability in seed viability when exposed to differential water management conditions in rice.  相似文献   

16.
Redflower ragleaf (Crassocephalum crepidioides) is a weed, as well as a minor vegetable, in tropical and subtropical regions of the world. The influence of environmental factors and seed conditions on the germination and emergence of redflower ragleaf have been evaluated in order to help understand its distribution and to develop effective management strategies. The seeds germinated at a constant temperature in the range of 10–30°C and reached a maximum at 15–20°C. The highest germination rate was recorded at an alternating temperature of 20/15°C (day/night). The seeds germinated over a wide pH range (2–12), with the highest germination rate at between 4 and 10. Germination under saturated and flooded conditions was also high. The germination of seeds from opened (mature) capitula was significantly higher than from partially opened or unopened capitula. The germination of seeds without a pappus was significantly higher than for seeds with a pappus. The germination rate of 1 year old seeds decreased drastically when compared to that of freshly harvested seeds. The seedling emergence rate was ～63% for those seeds placed on the soil surface, but no seedling emerged from a depth of ≥1 cm. These results indicate that redflower ragleaf seeds can germinate in various environmental conditions, but that the percentage that germinates will be different in different environments. Regeneration could be effectively prevented by at least a 1 cm soil covering or by destroying the plant before the capitula open. In contrast, freshly harvested seeds from opened capitula should be sown on the soil surface when redflower ragleaf is to be cultivated as a vegetable.  相似文献   

17.
Phelipanche ramosa (Branched broomrape) is an obligate root parasitic plant that is a major pest of oilseed rape in France. Knowledge on seed viability and dormancy under field conditions is crucial to understand how to control P. ramosa, but is as yet unknown. Our study aimed to quantify these processes with a 2‐year seed burial experiment. Two genetically distinct populations of P. ramosa were studied, collected on winter oilseed rape (population O) and hemp (population H). Seed mortality was very low in both populations (4–7% per year). Although obligate parasitic seeds are assumed to germinate only after exposure to germination stimulants from host root exudates, a high proportion of population H seeds germinated spontaneously (up to 90%). Seeds of both populations displayed seasonal dormancy, with timing and magnitude depending on the population. Dormancy was low at the time each native host crop is usually sown. Populations differed in germination dynamics, with seeds of population H germinating faster. The difference in behaviour that we observed between populations is consistent with reported adaptations of pathovars to their preferred hosts. The results indicate that the parasitic plant management requires targeting at the populations concerned. For example, delayed sowing is more promising against population O than against population H.  相似文献   

18.
Button grass (Dactyloctenium radulans) is a native, widely spread summer grass weed species in Australia. However, limited information is available on the seed germination biology of this species. Experiments were conducted to evaluate the effect of environmental factors on the germination and emergence of two populations of D. radulans. The seeds of these populations were collected separately from Dalby, Queensland and Coleambally, NSW. Seeds were germinated at a range of constant and alternating temperatures (25/15, 30/20, 35/25 and 40/30°C day/night). The greatest seed germination was at a constant temperature of 30°C. Seed germination was reduced at the lowest alternating temperature (25/15°C). Germination of both populations was strongly stimulated by light, suggesting a great amount of emergence of D. radulans on bare ground, such as crop seedbeds. Germination of the D. radulans population collected from a northern cotton farming system (Dalby) was more tolerant to a greater range of salt stress than the population sourced from the south (Coleambally). Seeds of both populations germinated over a wide range of pH, between 4 and 10. However, germination was the greatest in a high pH buffer solution, indicating that the species prefers to germinate in alkaline soil. These results showed that D. radulans seeds possess a wide range of tolerance mechanisms to different environmental stresses. Information obtained in this study will help in developing more sustainable and effective integrated weed management strategies for the control of this weed and weeds with similar responses in summer cropping systems, such as cotton.  相似文献   

19.
The ability of plants to safely retain seeds in the mother plant is an adaptive mechanism described in many desert plants. However, research about delayed seed dispersal species in the desert of the United Arab Emirates (UAE) is lacking. This study aims to identify these delayed seed dispersal species and assess the relationships of the presence of delayed seed dispersal with plant growth form, habit, spatial dispersal, antitelechoric mechanism, and seed release time. The relationships between the presence of delayed seed dispersal and the above studied traits were assessed by using the Pearson Chi-square test and Nonlinear Principal Components Analysis (NLPCA). Results showed that a total of 46 delayed seed dispersal species were recorded (15.0% of 307 studied species) and the highest incidence occurred in the Fabaceae family (17.4%). Delayed seed dispersal species were predominantly perennial plants (73.9%) with spatial restricted dispersal (67.4%), which released seed in the dry season (45.7%). The dominant groups of delayed seed dispersal species were persistent fruits species and synaptospermy (28.3%). All graminoids showed persistent lignified fruits, while prostrate annuals were basicarpic species with myxospermy. Sandy habitats had the highest number of delayed seed dispersal species (54.3%), whereas salt flats had the lowest (23.9%). In the desert of the UAE, delayed seed dispersal species spread seeds until the end of the dry and windy season, thus breaking seed dormancy at this time and ensuring seed germination in the next arrival of the rainy season. This morphological and ecological adaptation of delayed dispersal species is essential to the survival and sustainable development of vegetation in desert environments.  相似文献   

20.
Seasonal changes in the germination of buried seeds of Monochoria vaginalis   总被引：4，自引：0，他引：4  
CHEN  & KUO 《Weed Research》1999,39(2):107-115
This study investigates the seasonal variation of germination ability of buried seeds of Monochoria vaginalis (Burm.f.) Presl var. plantaginea Solms. The field-collected seeds were buried in a flooded or an upland field and then exhumed monthly. The exhumed seeds were germinated under four temperature regimes. The seeds exhumed from the flooded soil were dormant at the beginning of burial and proceeded into a conditional dormancy/non-dormancy/conditional dormancy cycle throughout the remaining period of the experiment. The seeds exhumed monthly from the non-flooded soil exhibited an annual dormant cycle, which is dormancy/conditional dormancy/non-dormancy/conditional dormancy/dormancy. At day and night temperatures of 25/20 °C, the exhumed seeds from both the flooded and the upland soil resembled each other in terms of seasonal variation of the germination percentage. In September and October, more seeds exhumed from upland soil failed to germinate under higher temperature than from flooded soil. Strictly avoiding exposure to light during seed exhuming and seed testing prevented the seeds from germinating. A short exposure of the exhumed seeds to light during preparation promoted dark germination when the seeds were at the non-dormant stage. The potential implications of our results for weed management strategies in rice production are discussed.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号