The effectiveness of three pre-germination treatments in breaking dormancy of the seeds of Dialum guineense and effects of three watering regimes on the growth performance of the seedlings were investigated. The pre-g...The effectiveness of three pre-germination treatments in breaking dormancy of the seeds of Dialum guineense and effects of three watering regimes on the growth performance of the seedlings were investigated. The pre-germination treatments were: soaking in hot water for 10 seconds and cooling down in cold water (T1), soaking in cold water for 24 hours (T2), soaking in running water for 48 hours (T3) and control (T4), while watering regimes include: watering once daily in the morning (W1), watering once every two days in the morning (W2) and watering once every three days in the morning (W3). The results showed that germination occurred first at 5 days after sowing (5 DAS) among the seeds soaked in cold water for 24 hours before sowing (T2), while the untreated seeds (control) took the longest period of 12 days before germination occurred. T1 had the highest germination value of 49.6% while T3 had the least of 31.2%. The effects of watering regimes were found to be significantly different on stem-collar diameter, leaf area and total dry weight (P < 0.05). The least significant difference (LSD) test showed that W2 and W3 supported the best growth performance. It is concluded from the results that T2 should be adopted for breaking the dormancy of Dialium guineense seeds and watering interval of three days would not dispose the seedlings to water-stress.展开更多
Seed morphology,germination and seedlings growth of Acacia auriculiformis were studied.The experiment was conducted in the nursery of Forestry and Wood Technology Discipline,Khulna University,Bangladesh.Matured seeds ...Seed morphology,germination and seedlings growth of Acacia auriculiformis were studied.The experiment was conducted in the nursery of Forestry and Wood Technology Discipline,Khulna University,Bangladesh.Matured seeds of the species were collected from healthy trees of road side plantation from different areas of Khulna District,Bangladesh and treated with five pre-sowing treatments(control,immersion in cold water,immersion in hot water,scarification with sand paper and immersion in concentrated H2SO4).The average length,breadth and thickness were found to be(0.58±0.017) cm,(0.44±0.007) cm and(0.20±0.089) cm,respectively.Germination was conducted in polybags with a mixture of top soil,coconut husk,coarse sand,and fine sand in a ratio of 3:4:1:1.Results reveal that pre-sowing treatments influences the germination rates of seeds that significantly increase the percentage germination compared with those in control(43%) and cold water treatment(52%).The highest germination success rate was found 83% in hot water treatment followed by 78% in scarification with sand paper,and 75% with immersion in H2SO4.Germination started from 7 to 12 days and completed between 28 and 35 days period in all treatments.ANOVA showed the significant difference(p0.05) among the treatments in seed germination,but no significant difference among treatment with regard to starting day,closing day and total germination period.In case of height and diameter growth,seedlings originated from the seeds with hot water treatment shows significantly higher in wet season(from May to July).Hot water treatment can be recommended on seed germination of the species in rural Bangladesh.展开更多
Experiments on temperature-accelerated germination. seeding quantity, and optimum density of seedlings were made for Kalopanax septemlobus. The experimental results indicated that the seeds of kalopananx septemlobus h...Experiments on temperature-accelerated germination. seeding quantity, and optimum density of seedlings were made for Kalopanax septemlobus. The experimental results indicated that the seeds of kalopananx septemlobus had physiological dormancy because of unmature embryo and existence of inhibitory matter in the seed. Temperature-accelerated germination was a preferable and essential way to assure the germination. Seed dormancy could be overcome through accelerating germination. Firstly, warm treatment should be done, morphological maturity occurred, then, followed by lower temperature treatment, reaching physiological maturity, Seeding quantity, optimum density and the relations between density of seedlings and yield were studied.展开更多
An artificial seed bank study was conducted at Pendleton, SC, USA, to investigate the persistence of Palmer amaranth seeds buried uniformly across a 10-cm depth in soil inside polyvinyl chloride (PVC) cylindrical pipe...An artificial seed bank study was conducted at Pendleton, SC, USA, to investigate the persistence of Palmer amaranth seeds buried uniformly across a 10-cm depth in soil inside polyvinyl chloride (PVC) cylindrical pipes over 4 years. The experiment was conducted using a split-plot design, with year as the main plot factor and with or without soil disturbance (shallow tillage to a depth of 10 cm) as the subplot factor. Annual soil disturbance through tillage in the spring stimulated emergence during the first and second year after burial. A total of 0.5% to 0.8% of the seed bank emerged during the 4-yr burial period, and 99% or more of the 4-yr total emergence occurred during the first two years of burial. Seeds retrieved from 0 to 5 cm and 5 to 10 cm depths did not differ in viability. Soil disturbance influenced the decline of the artificial seed bank at least in the first year, with fewer viable seeds remaining in annually-disturbed plots. Regardless of soil disturbance, a small fraction of seeds (0.01% to 0.03% of original seed bank) remained viable in the soil after four years of burial. In conclusion, Palmer amaranth seeds buried across a 10 cm soil depth in the artificial seed bank had low persistence, which implies that burial may aid management of the weed seed bank.展开更多
Aims Seed dormancy and the soil seed bank are crucial to plant regeneration strategy,especially in semiarid ecosystems with unpredictable precipi-tation.the aim of this study was to investigate how seed dormancy is co...Aims Seed dormancy and the soil seed bank are crucial to plant regeneration strategy,especially in semiarid ecosystems with unpredictable precipi-tation.the aim of this study was to investigate how seed dormancy is controlled by environmental factors and how it is correlated with the soil seed bank and regeneration of the perennial legume Oxytropis race-mosa,a dominant perennial herb in Mu Us Sandland of semiarid China.Methods Germination and imbibition experiments on fresh intact and scarified seeds of O.racemosa were used to identify physical dormancy(PY)in seeds of this species.Soil seed bank dynamics,timing of seedling emer-gence and the fate of buried seeds in the natural habitat were investigated.Important Findings PY was broken by mechanical scarification or wet heat/ice water cycles but not solely by dry heat or wet heat treatment.the soil seed bank exhibited seasonal changes in the number of seeds,which was highest in September and lowest in July.Seeds buried at different sand depths gradually lost dormancy;20-42%of the seeds remained dormant after 20 months of burial.Dormancy break occurs grad-ually throughout the year.Our results indicate that O.racemosa exhibits hardcoatedness heterogeneity that spreads germination of a seed cohort between seasons and years in the semiarid environ-ment,where the amount of precipitation during the growing season is highly variable.展开更多
文摘The effectiveness of three pre-germination treatments in breaking dormancy of the seeds of Dialum guineense and effects of three watering regimes on the growth performance of the seedlings were investigated. The pre-germination treatments were: soaking in hot water for 10 seconds and cooling down in cold water (T1), soaking in cold water for 24 hours (T2), soaking in running water for 48 hours (T3) and control (T4), while watering regimes include: watering once daily in the morning (W1), watering once every two days in the morning (W2) and watering once every three days in the morning (W3). The results showed that germination occurred first at 5 days after sowing (5 DAS) among the seeds soaked in cold water for 24 hours before sowing (T2), while the untreated seeds (control) took the longest period of 12 days before germination occurred. T1 had the highest germination value of 49.6% while T3 had the least of 31.2%. The effects of watering regimes were found to be significantly different on stem-collar diameter, leaf area and total dry weight (P < 0.05). The least significant difference (LSD) test showed that W2 and W3 supported the best growth performance. It is concluded from the results that T2 should be adopted for breaking the dormancy of Dialium guineense seeds and watering interval of three days would not dispose the seedlings to water-stress.
文摘Seed morphology,germination and seedlings growth of Acacia auriculiformis were studied.The experiment was conducted in the nursery of Forestry and Wood Technology Discipline,Khulna University,Bangladesh.Matured seeds of the species were collected from healthy trees of road side plantation from different areas of Khulna District,Bangladesh and treated with five pre-sowing treatments(control,immersion in cold water,immersion in hot water,scarification with sand paper and immersion in concentrated H2SO4).The average length,breadth and thickness were found to be(0.58±0.017) cm,(0.44±0.007) cm and(0.20±0.089) cm,respectively.Germination was conducted in polybags with a mixture of top soil,coconut husk,coarse sand,and fine sand in a ratio of 3:4:1:1.Results reveal that pre-sowing treatments influences the germination rates of seeds that significantly increase the percentage germination compared with those in control(43%) and cold water treatment(52%).The highest germination success rate was found 83% in hot water treatment followed by 78% in scarification with sand paper,and 75% with immersion in H2SO4.Germination started from 7 to 12 days and completed between 28 and 35 days period in all treatments.ANOVA showed the significant difference(p0.05) among the treatments in seed germination,but no significant difference among treatment with regard to starting day,closing day and total germination period.In case of height and diameter growth,seedlings originated from the seeds with hot water treatment shows significantly higher in wet season(from May to July).Hot water treatment can be recommended on seed germination of the species in rural Bangladesh.
文摘Experiments on temperature-accelerated germination. seeding quantity, and optimum density of seedlings were made for Kalopanax septemlobus. The experimental results indicated that the seeds of kalopananx septemlobus had physiological dormancy because of unmature embryo and existence of inhibitory matter in the seed. Temperature-accelerated germination was a preferable and essential way to assure the germination. Seed dormancy could be overcome through accelerating germination. Firstly, warm treatment should be done, morphological maturity occurred, then, followed by lower temperature treatment, reaching physiological maturity, Seeding quantity, optimum density and the relations between density of seedlings and yield were studied.
文摘An artificial seed bank study was conducted at Pendleton, SC, USA, to investigate the persistence of Palmer amaranth seeds buried uniformly across a 10-cm depth in soil inside polyvinyl chloride (PVC) cylindrical pipes over 4 years. The experiment was conducted using a split-plot design, with year as the main plot factor and with or without soil disturbance (shallow tillage to a depth of 10 cm) as the subplot factor. Annual soil disturbance through tillage in the spring stimulated emergence during the first and second year after burial. A total of 0.5% to 0.8% of the seed bank emerged during the 4-yr burial period, and 99% or more of the 4-yr total emergence occurred during the first two years of burial. Seeds retrieved from 0 to 5 cm and 5 to 10 cm depths did not differ in viability. Soil disturbance influenced the decline of the artificial seed bank at least in the first year, with fewer viable seeds remaining in annually-disturbed plots. Regardless of soil disturbance, a small fraction of seeds (0.01% to 0.03% of original seed bank) remained viable in the soil after four years of burial. In conclusion, Palmer amaranth seeds buried across a 10 cm soil depth in the artificial seed bank had low persistence, which implies that burial may aid management of the weed seed bank.
基金This research was supported by the Key Basic Research and Development Plan of P.R.China(2016YFC050080502)the National Natural Science Foundation of P.R.China(31370705,31570416).
文摘Aims Seed dormancy and the soil seed bank are crucial to plant regeneration strategy,especially in semiarid ecosystems with unpredictable precipi-tation.the aim of this study was to investigate how seed dormancy is controlled by environmental factors and how it is correlated with the soil seed bank and regeneration of the perennial legume Oxytropis race-mosa,a dominant perennial herb in Mu Us Sandland of semiarid China.Methods Germination and imbibition experiments on fresh intact and scarified seeds of O.racemosa were used to identify physical dormancy(PY)in seeds of this species.Soil seed bank dynamics,timing of seedling emer-gence and the fate of buried seeds in the natural habitat were investigated.Important Findings PY was broken by mechanical scarification or wet heat/ice water cycles but not solely by dry heat or wet heat treatment.the soil seed bank exhibited seasonal changes in the number of seeds,which was highest in September and lowest in July.Seeds buried at different sand depths gradually lost dormancy;20-42%of the seeds remained dormant after 20 months of burial.Dormancy break occurs grad-ually throughout the year.Our results indicate that O.racemosa exhibits hardcoatedness heterogeneity that spreads germination of a seed cohort between seasons and years in the semiarid environ-ment,where the amount of precipitation during the growing season is highly variable.