共查询到20条相似文献，搜索用时 31 毫秒
1.
Wild asparagus (Asparagus acutifolius L.) is a widespread species found in all the Mediterranean areas. The spears are highly valued by consumers and owing to its frugality, this species is a feasible new crop with high income potential, especially for Mediterranean marginal areas. Currently, the cultivation of this species is limited because of its low and erratic seed germination that makes difficult the production of seedlings for plant propagation. In this research, non-after-ripened (1 month-old) and after-ripened seeds (dry stored at room temperature for 13 months) were exposed for 30 days in the dark to three moist stratification treatments: cold (5 °C), warm (23 °C) or no stratification; subsequently they were soaked for 12 h in warm water (35 °C) or not soaked. The effect of these pre-germination treatments on three germination parameters (germination percentage, time to 50% of final germination – T50 – and germination pattern) was studied, as well as some possible seed dormancy forms involved therein. The 1-year dry storage period proved to be effective in after-ripened seeds by enhancing seed sensitivity to the subsequent pre-germination treatments. After-ripened seeds exhibited higher and more rapid germination compared to non-after-ripened seeds. Soaking, cold or warm moist stratification had similar single effect on non-after-ripened seeds (27% germination). With after-ripened seeds, only soaking or warm stratification were effective (47% germination) when singularly applied, while cold stratification did not improve germination. By combining stratification and soaking treatments, a higher germination for both non-after-ripened and after-ripened seed-lots was achieved. The highest germination was obtained when after-ripened seeds were stratified and soaked (76%), without any significant difference between cold or warm stratification. Single or combined application of moist stratification (regardless of the temperature used) and soaking resulted always in a faster germination compared to that of no-treated seeds and especially with after-ripened seeds (T50 = 6 days). A non-deep type 1 physiological dormancy can be hypothesized for the seeds of this species. Low stratification temperature induce secondary dormancy in after-ripened seeds that can be removed by soaking them at 35 °C for 12 h. 相似文献
2.
Seeds of wild asparagus (Asparagus acutifolius L.) were treated and compared in this research to investigate seed dormancy class and level involved in this species. Four seed lots were compared: (i) freshly harvested seeds in 2007 (07Fr); (ii) freshly harvested seeds in 2008 (08Fr); (iii) after-ripened (AR) 2007 seeds dry stored in glass jars (ARg); (iv) AR 2007 seeds dry stored in paper bags (ARp). The 07Fr seeds were exposed to (1) chemical scarification combined with gibberellic acid (GA3) levels (0, 200, 400, and 600 mg L−1) and to (2) 28-day moist stratification at 5 and 23 °C, and two sequences of 5/23 °C combined with 0 and 400 GA3 mg L−1 levels, and (3) together to the 08Fr and AR seeds were exposed to 56-day moist stratification at 5, 23, or 5/23 °C. With the 08Fr and AR seed lots this last stratification treatment was combined with 0 or 800 GA3 mg L−1 levels. The dormancy depth of 08Fr (32% germination) was less than 07Fr seeds (2%). The latter after-ripened during dry storage and when stored in glass germinated more (47.5%) than in paper (12%). Stratification for 4 weeks was ineffective in improving germination of 07Fr seeds; when chemically scarified they did not germinate at all. The highest (nearly 70%) and the most rapid and uniform germination were observed for all the lots when they were warm stratified for 56 days. Warm stratification improved germination more than alternate temperature stratification, while cold stratification inhibited germination especially for the 08Fr and ARg lots, thus seeds seem not to have a morphological component to their dormancy. GA3 only improved germination of 07Fr seeds, at a low rate. A. acutifolius seeds fit the characteristics of a non-deep physiological dormancy. 相似文献
3.
Seed collections of the wild relatives of cultivated blackberry and raspberry (Rubus species) are maintained at the National Clonal Germplasm Repository, Corvallis, OR. Information on wild species germination requirements is rarely available, and germination may be poor or slow, making it difficult for scientists to use them for breeding improved cultivars. Eight diverse Rubus species in 6 of the 12 Rubus subgenera from seed stored at −20 °C for 1–23 years were studied. Seed weight, seed-coat thickness and hardness varied widely. Scarification with sulfuric acid (98% H2SO4) or sodium hypochlorite (14% NaOCl) was followed by germination treatments of deionized water (DI), smoke gas or a combination of gibberellic acid (2.03 mg/L GA3) and potassium nitrate (34 mg/L KNO3) during stratification. The commonly used scarification protocols were not effective for many species; but effective scarification exposure was established based on the amount of embryo damage seen with 2,3,5 triphenyl tetrazolium chloride (TZ) viability testing. H2SO4 scarification followed by a treatment with KNO3 and GA3 during stratification was highly effective for the most species. Two species in subgenus Anoplobatus had a hilar-end hole that allowed rapid germination of unscarified seed. Some species with extremely hard seed coats had little or no germination, and longer scarification times are suggested based on seed size, seed-coat thickness and hardness and viability testing. 相似文献
4.
Most of the achenes produced by Rosa multibracteata Hemsl. & E. H Wilson are dormant on maturity and require pretreatment to stimulate germination. To investigate the mechanism of dormancy and to develop effective methods of improving germination, roles of the pericarp, testa, and embryo of R. multibracteata in regulating dormancy were studied by investigating the effect of different pretreatments on germination. The effects of temperature and water stress were also tested with achenes treated by warm plus cold stratification. In freshly harvested achenes, pericarps are permeable and the embryo fully developed, which eliminates the possibility of physical, morphological, or morphophysiological dormancy. Germination percentage remained low (<5%) despite softening the pericarp or even removing it fully. However, fully removing the testa improved germination significantly (39%), indicating the possible presence of germination inhibitors in the testa. Dry storage, scarification with sulphuric acid (H2SO4), and warm stratification proved ineffective by themselves but when combined with cold stratification, improved germination and shortened the cold stratification period needed to break dormancy. Dry storage for 68 weeks followed by cold stratification for 16 or 24 weeks resulted in maximum germination (72–79%) among all the treatments. In achenes scarified with H2SO4, germination increased with an increase in the duration of cold stratification. Neither gibberellic acid (GA3) nor ‘smoke water’ (water through which smoke had been bubbled for 2 h) had any positive effect on germination even on seeds that had been mechanically scarified or stratified. Both high temperature and water stress lowered germination in achenes treated with warm plus cold stratification. Our results suggest that R. multibracteata achenes have an intermediate physiological dormancy, and that dry storage for 68 weeks followed by cold stratification for 16 or 24 weeks is the best method for propagating R. multibracteata from seed. 相似文献
5.
6.
Low seed germination is a major problem in commercial rose propagation and breeding and is species-dependent. The present work selected four rose species previously un-examined to explore effective methods for improving seed germination and the relevant dormancy mechanism and its levels in seven experiments. The results showed that both pulp and achenes from the four rose shrubs had chemical substances that significantly inhibited seed germination with the inhibitory effect was more pronounced in pulp extract than of achenes. Single treatments of H2SO4 scarification, short-term cold stratification (<16 weeks) or warm stratification were less effective in breaking dormancy as indicated by lower germination index than their combinations. Comprehensive comparisons showed that among the six treatments the most effective for breaking dormancy was H2SO4 scarification followed by warm plus cold stratification, then H2SO4 scarification followed by cold stratification and finally warm plus cold stratification. Scarification with H2SO4 for 2–4 h ordinal followed by warm stratification at 20 °C for 4 weeks and cold stratification at 5 °C for 8 weeks was the best pretreatment for increasing seed germination percentage for Rosa multibracteata (81.4 ± 2.9%), Rosa hugonis (13.1 ± 6.0%), and Rosa filipes (62.7 ± 5.7%); and H2SO4 scarification for 4 h followed by cold stratification at 5 °C for 12 weeks was the best pretreatment for Rosa sericea (46.7 ± 8.7%). Our results suggest that these four species have only physiological dormancy caused by integrative roles of pulp, pericarp and embryo. The level of physiological dormancy was ranked as R. hugonis > R. sericea > R. filipes > R. multibracteata. 相似文献
7.
8.
Cyclocarya paliurus is native to China and is the sole species in its genus. However, the seeds remain deeply dormant for 2 years in their natural environment. We tested different pretreatments of chemical scarification and exogenous application of gibberellic acid (GA3) for efficacy in breaking dormancy and speeding germination. In contrast to scarified seeds, non-scarified seed did not germinate, indicating that C. paliurus seeds have hard, impermeable seed coat dormancy. Exogenous application of GA3 significantly enhanced germination of scarified seeds. Compared with seeds stratified in sand with water, the germination of seeds stratified in sand moistened with 400 ppm GA3 for 60 days was significantly increased and germination rate was over 90% after 120 days. Analysis of variance indicated that both GA3 concentration and stratification medium had significant effects on seed germination and final germination percentage. Germination was higher for longer stratification periods, but no significant difference in germination was observed after 90 days. These results suggested that C. paliurus seeds exhibit both exogenous and endogenous dormancy. A combination of chemical scarification and exogenous application of GA3 alleviated seed dormancy in a relatively short period of time. 相似文献
9.
影响野生杏种子萌发的相关因素研究初报 总被引：2，自引：0，他引：2
试验以新疆野生杏的单株种子为材料,通过低温层积、机械去壳、去种皮及赤霉素处理等方法,研究不同处理对野生杏种子休眠及萌发的影响.结果表明:野生杏种子经过低温层积处理后,在一定时间内,随着层积时间的延长,发芽率也随之提高;低温层积处理40 d后野生杏种子开始萌发,100 d后发芽率可达90%;野生杏种子的种壳和种皮不同程度的抑制了种子萌发,去除种壳可使种子萌发提前,同时提高其发芽率;未层积的种子在去除种皮后用清水处理24 h,在25℃条件下,种子的萌发率达到80%以上,说明去除种皮能基本解除种子的休眠;一定浓度的GA3对野生杏种子的萌发具有促进作用.6号带壳种子与去壳种子的最适GA3浓度均为100mg/L,发芽率分别为86.7%、100%.而7号带壳种子的最适GA3浓度为300 mg/L,发芽率为70%. 相似文献
10.
11.
The bitter gourd seed has a thick, hard seed coat. Mildew often occurs during germination and causes uneven and low rates of seed germination. However, the problems caused by mildew can be overcome by treating seeds with hot water, by soaking in water, or by using microorganisms. Seeds of the ‘Ching Pi’ bitter gourd were treated in a water bath at 60 °C for 10 min and then soaked in tap water at 25 °C for 24 h. The resulting germination percentage was 86.7%, and the resulting percentage of mildewed seeds was 10%. The biocontrol potential of three commercially available Bacillus subtilis solutions was examined. For seeds primed with Huodijun B. subtilis solution, the germination percentage was 73.3% and the mildewed percentage 6%. In dual cultures, the antibiotic content in the Huodijun B. subtilis solution was significantly greater than in Yunghsing and Huolibao, the other B. subtilis solutions examined. B. subtilis effectively inhibited the growth of Rhizoctonia solani mycelium and caused abnormal mycelial growth. 相似文献
12.
Michelia yunnanensis Franch. is a Chinese endemic ornamental shrub with potential for greater utilization as a landscape and medicinal plant if propagation was less difficult. Seed development and breaking of seed dormancy were investigated to improve propagation of M. yunnanensis. No fresh seeds germinated when tested at the time of dispersal. Newly matured seeds of M. yunnanensis contained differentiated linear underdeveloped embryos that were physiologically dormant. The embryo/seed length ratio of M. yunnanensis was 0.15. Warm stratification did not break seed dormancy. Dormancy was broken by cold stratification at 4 °C but not by flowing water or nitrate. Embryos developed grew inside seeds during cold stratification at 4 °C. In newly harvested dormant seeds, embryos were 0.94 mm long and increased in length 139% before radicle emergence (germination). GA3 substituted for cold stratification to break dormancy in seeds of M. yunnanensis incubated at 25 °C or 20/25 °C. Mature M. yunnanensis seeds exhibited intermediate complex morphophysiological dormancy. Optimal germination of non-dormant seed in terms of both germination percentage and rate occurred at 20/25 °C. 相似文献
13.
The germination period of seeds can be predicted for any soil temperature with the use of a heat sum (S) and a minimum temperature for germination (Tmin). Experiments with vegetable seeds were carried out to establish whether S and Tmin are affected by diurnal soil temperature variation, depth of sowing, variation in seed size (of radish) and whether great differences are to be expected between cultivars (of lettuce). In general the above mentioned variables do not affect Tmin and S to a great extent. For practical purposes, an optimum temperature range for germination has been established. 相似文献
14.
15.
Kouakou Laurent Kouakou Irié Arsène Zoro Bi Yao Georges Abessika Tanoh Hilaire Kouakou Jean-Pierre Baudoin 《Scientia Horticulturae》2009
To develop efficient seedling production methods for Laccosperma secundiflorum and Eremospatha macrocarpa, a study was conducted to examine regeneration using offsets combined with several physical and chemical treatments of seeds. Offsets categorized into small, medium and large diameters, were planted in three conditions: shaded and open nursery, and greenhouse. We tested sucker from E. macrocarpa, and sucker and rhizome from L. secundiflorum. For both species, high viability percentage (ranging from 55% to 100%) were observed for small and medium suckers planted in shaded nursery and greenhouse, against less than 49% for sucker planted in open nursery. The mean seedling emergence times were estimated to 84, 77 and 75 days after planting (DAP) for small, medium and large sucker of L. secundiflorum, respectively under open nursery condition, and 76, 75, 95 DAP for small, medium and large suckers of the same species, respectively in shaded condition. Greenhouse has a significant positive effect on E. macrocarpa seedlings emergence time. For this species, the mean seedling emergence times were estimated to 43 DAP for small sucker and 76, 93 DAP for medium and large suckers. No seedling was obtained from rhizome planted in all the growing conditions tested. Concerning seed dormancy breaking, germination percentages and rates were determined for 13 treatments. The best treatments were pre-soaking unscarified seeds for 4 days in 1.01 g l−1 and 0.10 g l−1 KNO3, with 79% and 68% of germination, respectively and in 3.46 × 10−3 g l−1 GA3 for 68% of germination. These methods are suggested to improve germination of L. secundiflorum seeds. Successful and recommended methods for E. macrocarpa are pre-soaking scarified seeds in 3.46 × 10−3 g l−1 and 3.46 × 10−4 g l−1 GA3, 96% and 94% of germination, respectively. Dormancy, probably a combination of mechanical and chemical dormancy, is present in the two species. 相似文献
16.
Successful fruit set depends on several reproductive processes including pollen germination and tube growth processes. An experiment was conducted to determine the effects of temperature on pollen germination characteristics and to identify species/genotypic differences in Capsicum using the cumulative temperature response index (CTRI) concept. Pollen was collected from plants of seven genotypes from five Capsicum species, adapted to various parts of the world and grown outdoors in large pots. The pollen was subjected to in vitro temperatures ranging from 15 to 50 °C at 5 °C intervals. Pollen germination and tube lengths were recorded for all species after 24 h of incubation at the respective treatments. Species/genotypes differed significantly for in vitro pollen germination percentage and pollen tube length with mean values of 78% and 734 μm, respectively. The mean cardinal temperatures (Tmin, Topt, and Tmax) averaged over genotypes, were 15.2, 30.7, and 41.8 °C for pollen germination and 12.2, 31.2, and 40.4 °C for pollen tube growth. The CTRI of each species/genotype calculated as the sum of eight relative individual stress response values, such as maximum pollen germination, maximum pollen tube length; Tmin, Topt, and Tmax temperatures of pollen germination, and pollen tube lengths, identified species tolerance to high temperatures. Capsicum annum cv. Mex Serrano from Mexico was identified as tolerant, C. chacoense cv. 1312 and C. spp. cv. Cobanero from Argentina and Guatemala, respectively as intermediate and C. frutescens cv. Early Spring Giant from China, C. annum cv. Long Green from South Korea, C. spp. cv. NM89C130 and C. pubescens cv. 90002 from Guatemala as sensitive to high temperatures. The tolerant species/genotypes can be used in breeding programs to develop new genotypes that can withstand high temperature conditions both in the present climate and particularly in a future warmer climate. 相似文献
17.
An improved in vitro pollen germination method was developed for avocado (Persea americana Mill.). The effect of different concentrations of sucrose, polyethylene glycol (PEG), Mg and Ca on pollen germination was evaluated in order to determine the optimal pollen germination medium, i.e. that maximizing the percentage of pollen germination and minimizing the percentage of bursted pollen grains. Once the germination medium was optimized we used it to study the effect of temperature on in vitro pollen germination and tube growth in different cultivars from the three botanical varieties of avocado, that differ in their adaptation to environmental conditions. Significant differences in percentage of pollen germination and in pollen tube growth were observed among cultivars. These results could have implications not only for optimizing pollen management in avocado but also to select the best pollinizers for a particular cultivar. 相似文献
18.
Janice M. Coons R. O. Kuehl N. F. Oebker Nancy R. Simons 《The Journal of Horticultural Science and Biotechnology》2013,88(6):705-710
SummarySeeds of seven pepper (Capsicum annuum L.) cultivars (Anaheim TMR 23, California Wonder 300, Coronado, Jalapeno M, Ma Belle, Mercury, and Yolo Wonder B) were germinated at constant day and night temperatures of 25,30,35 and 40°C or at alternating temperatures of 40/25,40/30 and 40/35°C for 14 days. Germination percentages and rates were similar at 25 and 30°C. Largest differences in cultivar responses occurred at 35°C where germination percentages ranged from 24 to 96%, and rates, calculated as summation of the number of seeds germinated on a given day divided by day number, varied from 3 to 26 (theoretical maximum value of 100). At 40°C, germination percentages were less than 5% and rates were less than one for all cultivars. Cultivars with the most heat tolerance were ‘Mercury’ and ‘Yolo Wonder B’. At alternating temperatures, germination percentages and rates were higher than those at constant 40°C. The increases were greatest when the temperature was lowered by 15°C (40/25°C) and least when temperatures were lowered by 5°C (40/35°C). Tetrazolium tests showed that a large percentage of the ungerminated seed was still viable from the highest temperature. At lower temperatures, fewer ungerminated seeds were viable with no viable ungerminated seeds from the lowest temperature. 相似文献
19.
变温及GA3 处理对辽东楤木种子解除休眠过程中代谢调控的影响 总被引：7，自引：0，他引：7
研究在变温条件下GA3对辽东楤木种子解除休眠过程和呼吸代谢途径关键酶(磷酸己糖异构酶、6-磷酸葡萄糖脱氢酶、6-磷酸葡萄糖酸脱氢酶、琥珀酸脱氢酶) 的活性变化。结果表明: GA3经200 mg·L - 1的丙酮溶液浸泡种子12 h, 其α-淀粉酶活性和可溶性糖的含量显著提高, 均在第12天达到最大值;从层积开始可溶性蛋白含量就不断降低, 在第12天降到最低点; 种子在后熟过程中主要以糖酵解和三羧酸循环作为供能形式。在GA3和层积变温处理过程中呼吸代谢途径关键酶的活性在第8天达到最大值, 表明磷酸戊糖途径的活化对解除种子休眠起到至关重要的作用。 相似文献
20.
Romero FR Delate K Hannapel DJ 《HortScience : a publication of the American Society for Horticultural Science》2005,40(6):1751-1754
Organic production of one of the most popular botanical supplements, Echinacea, continues to expand in the U.S. Echinacea seeds typically show a high degree of dormancy that can be broken by ethephon or gibberelic acid (GA), but these methods are currently disallowed in organic production. In order to determine the efficacy of non-chemical seed treatments, we evaluated the effect of varying seed source and supplying light, with and without cold-moist stratification, on seed germination of the three most important medicinal species of Echinacea, E. angustifolia DC, E. purpurea (L) Moench, and E. pallida (Nutt.) Nutt. Treatments included cold-moist stratification under 24 h light, 24 h dark, and 16/8 h light/dark to break seed dormancy. We found that germination was greater in the E. purpurea and E. pallida seeds from a commercial organic seed source compared to a public germplasm source. When seeds were not cold-moist stratified, 16-24 h light increased germination in E. angustifolia only. Echinacea angustifolia, E. purpurea, and E. pallida seeds that were cold-moist stratified under 16-24 h of light for 4 wk had a significantly greater percentage and rate of germination compared to seeds germinated in the dark. Therefore, cold-moist stratification under light conditions is recommended as a method to break seed dormancy and increase germination rates in organic production of Echinacea. 相似文献