The present work dealt with sexual reproduction capacity of three relic species of the genus Sternbergia （family AmaryUidaceae） distributed in the Caucasus, i.e., Sternbergia lutea （L.） Ker Gawl. ex Spreng., Stern...The present work dealt with sexual reproduction capacity of three relic species of the genus Sternbergia （family AmaryUidaceae） distributed in the Caucasus, i.e., Sternbergia lutea （L.） Ker Gawl. ex Spreng., Sternbergiafischeriana （Herb.） Roem and Sternbergia colchiciflora Waldst. ＆ Kit.. Under this study, the natural populations of species, which possess valuable medicinal and ornamental properties, have been assessed by experts as vulnerable, and S. colchiciflora is included in the red list of endemic plants of the Caucasus, as having status of the critically endangered species. The situation is aggravated by the poor self-regeneration capacity of these species, which is one of the main factors responsible for the sustainability of the population of this or that species in the wild. Self-regeneration capacity for sexual reproduction was investigated in the listed species of the genus Sternbergia using common methods of embryology and reproduction biology. In conditions of the National Botanical Garden of Georgia （NBGG）, the species S. lutea and S. fischeriana prove to be completely infertile and propagate vegetatively by bulblets, while S. colchiciflora revealed the ability for propagation by seed. Long-term conservation of seeds of the studied species S. colchiciflora in the Caucasus Regional Seed Bank （CRSB） and establishing of living collections of this species at the experimental plot were chosen as the method for safeguarding this critically endangered species.展开更多
Ten cold-pressed oil from 6 herb plant seeds （sesame, fax, saffower, pumpkin, tomato and hemp） and 4 woody plant seeds （camellia, almond, walnut and peony） were analyzed to determine bioactive compounds content, i...Ten cold-pressed oil from 6 herb plant seeds （sesame, fax, saffower, pumpkin, tomato and hemp） and 4 woody plant seeds （camellia, almond, walnut and peony） were analyzed to determine bioactive compounds content, including tocopherols, phytosterols and phenolics, as well as their antioxidant activities. Total tocopherols content ranged from 161.11 mg/kg in camellia seed oil to 1,072.51 mg/kg in tomato seed oil. Tomato seed oil had the highest total phytosterols （708.89 mg/100 g） and phenolics content （20.27 mg SAE/100 g）,whereas, saffower seed oil has the lowest total phytosterols （173.75 mg/100g） and walnut kernel oil contained the lowest phenolics （2.32 mg SAE/100 g）, respectively. Tomato seed oil exhibited the strongest ferric-reducing antioxidant power （FARP, 311.36 μmol/100 g） and 2,2-diphenyl-1-picrylhydrazyl （DPPH） radical scavenging activity （56.40 μmol/100 g）, while camellia seed oil had the lowest FRAP value （34.83 μmol/100 g） and fax seed oil had the lowest DPPH value （2.75 μmol/100 g）. Correlation coeffcient was determined as 0.647 and 0.863 between FRAP value and total tocopherols and phenolics, and 0.673 and 0.711 between DPPH value and total tocopherols and phenolics （p 〈 0.05）, respectively. This result indicated the antioxidant activities （FRAP and DPPH） were highly correlated with total tocopherols and phenolics content of oil. This study will be very useful for comprehensive utilization of all 10 cold-press oils.展开更多
Aims In dry tropical forests,herbaceous species may have dormancy mechanisms and form persistent and transient seed banks in the soil.Evolutionarily acquired,these mechanisms are efficient for the establishment and su...Aims In dry tropical forests,herbaceous species may have dormancy mechanisms and form persistent and transient seed banks in the soil.Evolutionarily acquired,these mechanisms are efficient for the establishment and survival of these herbs,especially in forests with unpredictable climates,such as the Caatinga.Thus,our objective was to verify whether the studied herbaceous species adopt the physical dormancy mechanism and how these natural barriers are overcome,to understand the temporal dynamics existing in the soil seed bank from a Brazilian dry tropical forest.Methods Seeds of five native herbaceous species from the Caatinga forests were selected and submitted to pre-germinative treatments for verifying the presence of physical dormancy.We collected soil samples in the rainy and dry seasons for four consecutive years and monitored the emergence of the selected herbaceous in the greenhouse.We verified the differences in germination and seed bank emergence in the soil by generalized linear models.Important Findings The presence and absence of physical dormancy were observed in seeds from Caatinga herbaceous species.We found intraspecific and interspecific differences in the herbaceous emergence from soil seed banks between years and climatic seasons.In perennial herbs,consecutive lack of emergence between seasons and years was frequent,which suggests a direct relationship with the mechanism of physical dormancy and the environmental conditions necessary to overcome integument barriers.In these species,seed dimorphism and dormancy may confer additional advantages to their survival.Moreover,presenting intermediate levels of physical dormancy in an annual species may be an evolutionary adjustment to rainfall unpredictability.In contrast,we found that the annual herb without dormancy is more sensitive to seasonal and interannual climate changes,as evidenced by the increase and significant reduction of its emergence in the soil seed bank.These differences acquired evolutionarily are advantageous for the establishment of herbaceous populations,mainly in semiarid regions with an unpredictable climate.展开更多
The vast majority of herbaceous plants engage into arbuscular mycorrhizal (AM) symbioses and consideration of their mycorrhizal status should be embodied in studies of plant-microbe interactions. To establish reliable...The vast majority of herbaceous plants engage into arbuscular mycorrhizal (AM) symbioses and consideration of their mycorrhizal status should be embodied in studies of plant-microbe interactions. To establish reliable AM contrasts, however, a sterilized re-inoculation procedure is commonly adopted. It was questioned whether the specific approach is sufficient for the studies targeting the bacterial domain, specifically nitrifiers, a group of autotrophic, slow growing microbes. In a controlled experiment mycorrhizal and non-mycorrhizal Plantago lanceolata were grown up in compartmentalized pots to study the AM effect on nitrification rates in the plant rhizosphere. Nitrification rates were assayed following an extensive 3-week bacterial equilibration step of the re-inoculated soil and a 13-week plant growth period in a controlled environment. Under these specific conditions, the nitrification potential levels at harvest were exceptionally low, and actual nitrification rates of the root compartment of non-mycorrhizal P. lanceolata were significantly lower than those of any other compartment. It is then argued that the specific effects should be attributed to the alleged higher growth rates of non-mycorrhizal plants that are known to occur early in the AM experiment. It is concluded that the specific experimental approach is not suitable for the study of microbes with slow growth rates.展开更多
文摘The present work dealt with sexual reproduction capacity of three relic species of the genus Sternbergia （family AmaryUidaceae） distributed in the Caucasus, i.e., Sternbergia lutea （L.） Ker Gawl. ex Spreng., Sternbergiafischeriana （Herb.） Roem and Sternbergia colchiciflora Waldst. ＆ Kit.. Under this study, the natural populations of species, which possess valuable medicinal and ornamental properties, have been assessed by experts as vulnerable, and S. colchiciflora is included in the red list of endemic plants of the Caucasus, as having status of the critically endangered species. The situation is aggravated by the poor self-regeneration capacity of these species, which is one of the main factors responsible for the sustainability of the population of this or that species in the wild. Self-regeneration capacity for sexual reproduction was investigated in the listed species of the genus Sternbergia using common methods of embryology and reproduction biology. In conditions of the National Botanical Garden of Georgia （NBGG）, the species S. lutea and S. fischeriana prove to be completely infertile and propagate vegetatively by bulblets, while S. colchiciflora revealed the ability for propagation by seed. Long-term conservation of seeds of the studied species S. colchiciflora in the Caucasus Regional Seed Bank （CRSB） and establishing of living collections of this species at the experimental plot were chosen as the method for safeguarding this critically endangered species.
基金National Key R&D Program of China(2017YFD0400402)National Natural Science Foundation of China(31471620)National Science Foundation of China(31772010)for financial support
文摘Ten cold-pressed oil from 6 herb plant seeds （sesame, fax, saffower, pumpkin, tomato and hemp） and 4 woody plant seeds （camellia, almond, walnut and peony） were analyzed to determine bioactive compounds content, including tocopherols, phytosterols and phenolics, as well as their antioxidant activities. Total tocopherols content ranged from 161.11 mg/kg in camellia seed oil to 1,072.51 mg/kg in tomato seed oil. Tomato seed oil had the highest total phytosterols （708.89 mg/100 g） and phenolics content （20.27 mg SAE/100 g）,whereas, saffower seed oil has the lowest total phytosterols （173.75 mg/100g） and walnut kernel oil contained the lowest phenolics （2.32 mg SAE/100 g）, respectively. Tomato seed oil exhibited the strongest ferric-reducing antioxidant power （FARP, 311.36 μmol/100 g） and 2,2-diphenyl-1-picrylhydrazyl （DPPH） radical scavenging activity （56.40 μmol/100 g）, while camellia seed oil had the lowest FRAP value （34.83 μmol/100 g） and fax seed oil had the lowest DPPH value （2.75 μmol/100 g）. Correlation coeffcient was determined as 0.647 and 0.863 between FRAP value and total tocopherols and phenolics, and 0.673 and 0.711 between DPPH value and total tocopherols and phenolics （p 〈 0.05）, respectively. This result indicated the antioxidant activities （FRAP and DPPH） were highly correlated with total tocopherols and phenolics content of oil. This study will be very useful for comprehensive utilization of all 10 cold-press oils.
基金supported by Conselho Nacional de Desenvolvimento Científico e Tecnológico-Brazil(CNPQ 4652712914-6APQ 0083.2-05/15).
文摘Aims In dry tropical forests,herbaceous species may have dormancy mechanisms and form persistent and transient seed banks in the soil.Evolutionarily acquired,these mechanisms are efficient for the establishment and survival of these herbs,especially in forests with unpredictable climates,such as the Caatinga.Thus,our objective was to verify whether the studied herbaceous species adopt the physical dormancy mechanism and how these natural barriers are overcome,to understand the temporal dynamics existing in the soil seed bank from a Brazilian dry tropical forest.Methods Seeds of five native herbaceous species from the Caatinga forests were selected and submitted to pre-germinative treatments for verifying the presence of physical dormancy.We collected soil samples in the rainy and dry seasons for four consecutive years and monitored the emergence of the selected herbaceous in the greenhouse.We verified the differences in germination and seed bank emergence in the soil by generalized linear models.Important Findings The presence and absence of physical dormancy were observed in seeds from Caatinga herbaceous species.We found intraspecific and interspecific differences in the herbaceous emergence from soil seed banks between years and climatic seasons.In perennial herbs,consecutive lack of emergence between seasons and years was frequent,which suggests a direct relationship with the mechanism of physical dormancy and the environmental conditions necessary to overcome integument barriers.In these species,seed dimorphism and dormancy may confer additional advantages to their survival.Moreover,presenting intermediate levels of physical dormancy in an annual species may be an evolutionary adjustment to rainfall unpredictability.In contrast,we found that the annual herb without dormancy is more sensitive to seasonal and interannual climate changes,as evidenced by the increase and significant reduction of its emergence in the soil seed bank.These differences acquired evolutionarily are advantageous for the establishment of herbaceous populations,mainly in semiarid regions with an unpredictable climate.
基金Supported by a PhD fellowship from the Chloros trust
文摘The vast majority of herbaceous plants engage into arbuscular mycorrhizal (AM) symbioses and consideration of their mycorrhizal status should be embodied in studies of plant-microbe interactions. To establish reliable AM contrasts, however, a sterilized re-inoculation procedure is commonly adopted. It was questioned whether the specific approach is sufficient for the studies targeting the bacterial domain, specifically nitrifiers, a group of autotrophic, slow growing microbes. In a controlled experiment mycorrhizal and non-mycorrhizal Plantago lanceolata were grown up in compartmentalized pots to study the AM effect on nitrification rates in the plant rhizosphere. Nitrification rates were assayed following an extensive 3-week bacterial equilibration step of the re-inoculated soil and a 13-week plant growth period in a controlled environment. Under these specific conditions, the nitrification potential levels at harvest were exceptionally low, and actual nitrification rates of the root compartment of non-mycorrhizal P. lanceolata were significantly lower than those of any other compartment. It is then argued that the specific effects should be attributed to the alleged higher growth rates of non-mycorrhizal plants that are known to occur early in the AM experiment. It is concluded that the specific experimental approach is not suitable for the study of microbes with slow growth rates.
