[Objective] studying the influences of different UV-B radiation treatments in short time on some physiological characteristics of winter wheat seedlings was to provide reference for the mechanism of plant response to ...[Objective] studying the influences of different UV-B radiation treatments in short time on some physiological characteristics of winter wheat seedlings was to provide reference for the mechanism of plant response to ultraviolet irradiation in short time. [Method] The winter wheat taken as materials were treated with 15 and 30 pW/cm^2 UV-B radiation, then the physiological indexes such as pigment content and photosynthetic rate were determined. [ Results] The UV-B treatment caused the declines of chlorophyll content, soluble protein content and water content of leaves, besides, dose-effect was existed. The decline of 30 pW/cm^2 treatment was bigger than that of 15 μW/cm^2 treatment. The influences of UV-B radiation on carotenoid content and anthocyanidin content were similar; the change trends were declined firstly then increased. The UVB treatment with two doses restrained the electron transport of PSⅡ, particularly; the inhibitory effect was biggest after treated 2 h, and then this effect was declined in 4, 6 and 8 h, so the dose-effect was existed. The UV-B radiation with two doses restricted photosynthetic rate and the inhibitory effect increased with the increase of treatment time. The high dose treatment caused huge damage to membrane system, while the result of low dose treatment was not obvious. [ Conclusion] UV-B radiation treatment had dose-effect on winter wheat seedlings in short time and the influence of high dose was bigger than that of low dose. With the increase of treatment time, the damage was alleviated; besides, the result was not similar to that of UV-B radiation in long time.展开更多
[ Objective] The study aimed to reveal the effects of hypergravity on salt tolerance of wheat seedlings. [ Method ] The seed germination rate (Gr) and germination index (Gi) of wheat seedlings were measured under ...[ Objective] The study aimed to reveal the effects of hypergravity on salt tolerance of wheat seedlings. [ Method ] The seed germination rate (Gr) and germination index (Gi) of wheat seedlings were measured under hypergravity of 600 × g or 1 000 × g for 4 h and under the stress of 0.4% or 0.9% salt solution. The catalase (CAT) activity and malondialdehyde (MDA) content of wheat seedlings were also measured under 0.4% salt stress. [Result] Compared with seedlings in CK group (no hypergravity or salt stress), the Gr and Gi of the seedlings in salt stress treatment decreased to different extents; while the Gr and Gi of the seedlings in treatment group (hypergravity and salt stress) increased compared with that in salt stress group. CAT in seedlings of hypergravity treatment was higher than that of CK group and 0.4% salt treatment group, meanwhile the MDA showed an opposite result. [ Conclusion] Hypergravity could enhance the salt resistance of wheat in specific range, and hypergravity of 600 × g for 4 h performed better than that of 1 000 ×g for 4 h.展开更多
[Objective] The aim was to explore physiological responses of Brazil banana seedlings to drought stress simulated by PEG-6000.[Method] Brazil banana (Musa AAA Cavendish subgroup cv.Brazil) was taken as test material...[Objective] The aim was to explore physiological responses of Brazil banana seedlings to drought stress simulated by PEG-6000.[Method] Brazil banana (Musa AAA Cavendish subgroup cv.Brazil) was taken as test materials to explore changes of physiological indices of banana seedlings under drought stresses simulated by PEG-6000,including three stress levels (5%,10% and 15%) and time periods (24,48 and 72 h).[Result] Relative water content and chlorophyll content both declined under different stress levels and in different times.The content of proline (Pro) in seedling leaves from high to low was PEG15%,PEG10% and PEG5%; the content of treatment of 5% stress in 24 h was of insignificant differences with that of the control and the contents in rest treatments were all remarkably higher compared with the control.POD activities of seedling leaves from high to low were as follows:PEG15%>PEG10%>PEG5%,and POD activity was of significant differences among treatments; POD activity achieved the peak in treatment group with 5% of stress,and POD activities of different groups were all higher compared with the control.The activity of root system in treatment groups with PEG at different concentrations was as follows:PEG10%>PEG15%>PEG5% and the activity increased remarkably in the group with PEG at 5% within 24,48 and 72 h,though the activity dropped significantly within 72 h and slowly in 24 and 48 h.[Conclusion] It can be concluded that relative water content,chlorophyll content,Pro content and activity and root activity can be references of banana resistance to drought.展开更多
[Objective] This study aimed to solve the problems of low seed germina- tion rate and difficult bareroot seedling transplanting in artificial cultivation of Arto- carpus nanchuanensis, a native species in China. [Meth...[Objective] This study aimed to solve the problems of low seed germina- tion rate and difficult bareroot seedling transplanting in artificial cultivation of Arto- carpus nanchuanensis, a native species in China. [Method] Under different seed treatment and seedling style, the seed germination rate and seedling emergence rate of A. nanchuanensis were investigated. [Result] tn both sand bed and direct sowing yellow soil, the seed germination rate, seedling survival rate and seedling emergence rate in the treatment II were all higher than those in the treatments I and III. The average seed germination rate, seedling survival rate and seedling emergence rate in sand beds were 1.5%, 16.27% and 13.95%, respectively higher than those in direct sowing yellow soil. The average seedling emergence rate in sand beds was 2.46% higher than that in containers. Among the 8 kinds of light matrix formulas, the growth of seedlings in the formula VIII was best. In the three treatment groups, the seedling emergence rates, seedling heights and ground diame- ters in the formula VIII were all significantly different from those in the other formu- las. The seedling growth in the formula I and III ranked second, while the seedling emergence rate, seedling height and ground diameter in the formula VII were the poorest. [Conclusion] If conditions allow, the formulas I (meadow soil:vermiculite:yel- low soi1=5:3:2), III (meadow soil:perlite:yellow soi1=5:3:2) and VIII (peat:forest top soi1=6:4) should be promoted in seedling with light matrixes.展开更多
[Objective] With a rice variety "Long Rice 11" as a test cultivar,an experiment of raising rice seedlings with the new substrata prepared from biochar,and maize stalks,rice husks,organic fertilizer,turf,zeolite,fine...[Objective] With a rice variety "Long Rice 11" as a test cultivar,an experiment of raising rice seedlings with the new substrata prepared from biochar,and maize stalks,rice husks,organic fertilizer,turf,zeolite,fine river sand and arable layer soil by mixing according to certain volume proportions was caried out,in order to investigate the physical and chemical properties of different organic-material seedling-raising substrata and the effects of these substrata on seedling growth.[Method] The experiment raised seedlings in greenhouses and adopted randomized block arrangement.[Result] The substratum of biochar mixed with maize stalks and rice husks could increase the maximum water-holding capacity of the substratum,reduce the volume weight of the substratum and improve the buffering effect of the substratum.It also had great effects on the contents of alkali-hydrolyzale nitrogen and rapidly available potassium in the substratum,and could improve the root number and substantial degree of rice seedlings.[Conclusion] Biochar with maize stalks and rice husks(the treament HC) is the optimal substratum in this study.展开更多
[Objective]The study was conducted to investigate the effects of shading treatments on growth of Asimina triloba (L) Dunal seedlings and provided the theoretical basis for seedling production. [Method]70 day-old A. ...[Objective]The study was conducted to investigate the effects of shading treatments on growth of Asimina triloba (L) Dunal seedlings and provided the theoretical basis for seedling production. [Method]70 day-old A. triloba seedlings had similar stem diameter and plant height and good growth vigour were taken as tested materials in 2005. 4 light gradient treatments which were the natural light with 100% light intensity, one-layer, two-layer and three-layer black shading network with the light transmittance rate of 50%, 25% and 12.5% were set up to study the effects of different shading treatments on growth of A. triloba. [ Result] With the shading treatments of one-layer and two-layer net, the plants of A. triloba seedlings grew rapidly. As the intensity of illumination decreased, the cetents of chlorophyll a ( Chl. a), chlorophyll b ( Chl. b) and total chlorophyll increased at first and then reduced. At the same time the chlorophyll a/b value became smaller. Under natural light, the plants tended to consume more water and the soil temperature at 15:00 p. m was higher. There was a smaller difference among various treatments. [ Conclusion]The suitable shading treatment to the growth of A. triloba seedlings was under the light transmittance rate of 50% and height and stem diameter of trees increased fast. Chlorophyll a ( Chl. a), chlorophyll b ( Chl. b) content in leaves of A. triloba seedlings were highest comparing with those in other conditions.展开更多
A procedure for cutting Prunus humilis(Bge). Sok was comprehensively studied in this paper. It was found that the key factors involved in this procession were medium, rooting accelerator, concentration of rooting ac...A procedure for cutting Prunus humilis(Bge). Sok was comprehensively studied in this paper. It was found that the key factors involved in this procession were medium, rooting accelerator, concentration of rooting accelerator and type of shoot. The results showed that send was used as mediums; Treatment with 1 000 mg/L AST rooting powder No. 2 and semi-woody shoots were the optimal materials for cutting, and the rooting rate reached 88.1%. Anatomical study on rooting of Prunus hum#is(Bge). Sok cutting has been carded out by the paraffin section method. The observation result shows that the adventitious root primordium of Prunus humili$(Bge). Sok cutting belongs to the type of induced root primordium. The adventitiousroot primordium originates from the cross region of vascular cambium and pith rays.展开更多
Cultivating strong seedlings is an important guarantee for the production of high-quality flue-cured tobacco, while there are many disadvantages in tobacco floating system that is commonly adopted in China. To improve...Cultivating strong seedlings is an important guarantee for the production of high-quality flue-cured tobacco, while there are many disadvantages in tobacco floating system that is commonly adopted in China. To improve the tobacco floating system, with Xiangyan No.3 as experimental material, the effects of water control before transplanting and rooting powder treatment on tobacco seedling quality and physiological properties at green stage were investigated. The results showed that: (1) water control showed small influence on tobacco seedling quality, while rooting powder treatment and water control + rooting powder treatment showed great influence on tobacco seedling quality, mainly represented by reduced plant height, thickened stem and increased dry matter accumulative amount; (2) water control before transplanting and rooting powder treatment all improved leaf chlorophyll content and root vigor of tobacco seedlings, and the effect of water control + rooting powder treatment was best, followed by rooting powder treatment and water control; (3) all treatments increased the nitrate reductase and invertase activity, and reduced the MDA content of tobacco seedlings, and the effect of water control + rooting powder treatment was best, followed by rooting powder treatment and water control. Mean- while, the treatment effect 10 d before the transplanting was better than that 5 d before the transplanting. In overall, the improvement effects of water control 10 d before transplanting + rooting powder treatment on tobacco seedling quality and physiological properties at green stage were the best.展开更多
We present an overview of previous research results on the molecular phylogenetic analyses in Agaricales and its higher ranks (Agaricomycetes/Agaricomycotina/Basidiomycota) along with the most recent treatments of tax...We present an overview of previous research results on the molecular phylogenetic analyses in Agaricales and its higher ranks (Agaricomycetes/Agaricomycotina/Basidiomycota) along with the most recent treatments of taxonomic systems in these taxa. Establishing phylogenetic hypotheses using DNA sequences, from which an understanding of the natural evolutionary relationships amongst clades may be derived, requires a robust dataset. It has been recognized that single-gene phylogenies may not truly represent organismal phylogenies, but the concordant phylogenetic genealogies from multiple-gene datasets can resolve this problem. The genes commonly used in mushroom phylogenetic research are summarized.展开更多
The paper aimed to investigate the growth of seedlings of three species of Cassia (C tora, C. sophera and C occidentalis) at different concentrations of salinity (NaC1) and pH treatments. All the species showed th...The paper aimed to investigate the growth of seedlings of three species of Cassia (C tora, C. sophera and C occidentalis) at different concentrations of salinity (NaC1) and pH treatments. All the species showed the highest seedling length under control condition, and with the increase of salinity, C occidentalis showed the highest sensitivity. The seedling length of C tora at 0.05 M NaCI significantly (P = 0.05) decreased to 5.71 cm, and further increase of salinity to 0.1 M, the seedling length was decreased to less than the value of 0.05 M NaC1 treatment and one-third (2.15 cm) of that of control (6.92 cm). Seeds of all the species failed to germinate at 0.5 M NaC1. Scarified seeds of C. sophera and C occidentalis increased seedling length. The highest seedling length was in C. sophera, followed by C. tora and C. occidentalis. All the species showed significant decrease (P 〈 0.05) of fresh weight with the increase of salinity; scarification of seeds in C. occidentalis and C. sophera showed higher fresh weight than those of without scarification. Experiments at different pH levels did not show any significant (P = 0.05) change in seedling length, except C. sophera, while at acidic pH, both seedling length and dry weight were significantly (P 〈 0.05) decreased.展开更多
Albizia saman (Jacq.) F. Muell. commonly known as rain tree seeds were treated with five pre-sowing treatments to study the effect of pre-sowing treatments on germination and initial seedling development in the nurs...Albizia saman (Jacq.) F. Muell. commonly known as rain tree seeds were treated with five pre-sowing treatments to study the effect of pre-sowing treatments on germination and initial seedling development in the nursery.The experiment was established in the nursery of the Institute of Forestry and Environmental Sciences.University of Chittagong, Chittagong, Bangladesh. Results revealed that Nail clipping in one side of the seed (at the distal end of the seed) (T4) provides the highest (50%) seed germination. The second highest germination (42%) was obtained for the seeds treated with immersion in cold water for 24 h (T1). Germination was completely inhibited when the seeds immersed in boiled water for 30 s followed in cold water soaking for 24 h. Other germination parameter and initial morphological growth and biomass production of the seedlings was also higher for the treatments T4and Ti in comparison to the control (Ta)treatment. Pre-sowing treatments of T4 e.g. Nail clipping in one side of the seed (at the distal end of the seed) and T1 (Seeds immersed in cold water for 24 h) may be recommended for maximum germination and initial vigorous seedlings growth of Albizia sarnan in the nursery.展开更多
AIM: To investigate the expression of several important molecules involved in major histocompatibility complex (MHC) class I presentation pathway in primary hepatocellular carcinoma (HCC), and to determine whether cyt...AIM: To investigate the expression of several important molecules involved in major histocompatibility complex (MHC) class I presentation pathway in primary hepatocellular carcinoma (HCC), and to determine whether cytotoxic T lymphocyte (CTL) vaccine therapy was suitable for HCC. METHODS: Labeled streptavidin biotin(LSAB) method of immunohisto-chemistry was used to study 33 HCC tissue specimens. RESULTS: Most HCC tissues and adjacent histological normal hepatocytes expressed HLA-I antigens,TAP,and B7, expression of B7 was especially strong,and there was no significant difference between them (P>0.05). CONCLUSION: The MHC class I presentation pathway in primary hepatocellular carcinoma may not be abnormal or dysfunctional,and CTL could kill these tumor cells. Thus, it is suitable and practicable to design and construct CTL vaccine against HCC.展开更多
Fifty cultivated Catharanthus roseus seedlings were selected for tip-pruning treatment and the effects of tip-pruning on seedling growth and source-sink regulation were investigated for revealing physiological mechani...Fifty cultivated Catharanthus roseus seedlings were selected for tip-pruning treatment and the effects of tip-pruning on seedling growth and source-sink regulation were investigated for revealing physiological mechanisms of plants. The results showed that tip-pruning treatment resulted in obvious inhibition of apical dominance and enhancement of branching numbers. The contents of soluble sugars, acid sucrose invertase activity (AI) had a great change in differently positional leaves of the seedling. The sink strength in tip leaves of seedlings dramatically declined after tip-pruning treatment, while that in the leaves at the middle and bottom of seedlings had no obvious changes. The inhibition of apical dominance of tip leaves of seedlings was caused by the diminished sink strength due to tip-pruning treatment,展开更多
Byrsonima intermedia A. Juss. is a species from the Brazilian Cerrado that produces edible fruits and, in common with other species from the Byrsonima genus, has pharmacological potential. Previous attempts to propaga...Byrsonima intermedia A. Juss. is a species from the Brazilian Cerrado that produces edible fruits and, in common with other species from the Byrsonima genus, has pharmacological potential. Previous attempts to propagate the species through conventional methods showed difficulties. Thus, the purpose of this work was to characterize pro-embryogenic masses of Byrsonima intermedia callus, aiming for their in vitro propagation through somatic embryogenesis. Leaf segments from in vitro germinated seedlings were employed as explants for callus production. The calli were then subcultured and exposed to dyes to fulfill their embryogenic potential. Digitalizations of the cytological preparations were made in order to measure the area that was stained by both Aceto-Carmine and Evans-Blue, using image tool software. Somatic embryos were induced after treatments with l-naphthaleneacetic acid (NAA). The percentages of double-colored areas (by Aceto-Carmine and Evans-Blue) were calculated and the data were analyzed by using the Skott-Knott test (P ≤ 0.05) and, the embryogenic callus, as well as the formation of somatic embryos were analyzed by using the Krsuskal-Wallis rank test (P ≤0.05). The results show that double coloration is effective at identifying cells showing embryogenic potential. Early callus subculture phases show a larger percentage ofembryogenic area (83%) Somatic embryos were induced by using high auxin level.展开更多
The aim of this work was to study the reactions of wheat (T. aestivum L.) and its wild congeners under salt stress. Physiological mechanisms that underlie traits for salt tolerance plantlets have been used to test s...The aim of this work was to study the reactions of wheat (T. aestivum L.) and its wild congeners under salt stress. Physiological mechanisms that underlie traits for salt tolerance plantlets have been used to test some wheat species and to identify sources of salty tolerance. Stress conditions were founded by means of exposure of the plantlets in NaCI water solution, 1.68% that demonstrably differentiates the samples by growth parameters. Under laboratory conditions the ability of seedlings to bear a significant shortage of water, their ability to accumulate biomass, changing the parameters of linear growth processes and changes in water content in leaves and roots of seedlings under stress was determined. Interest is also the rate of growth of root fibrils in saline conditions. These experiments allowed to provide a comprehensive diagnosis of studied forms of wheat and make an initial opinion on their salt tolerance. Different features of abiotic stress responses of some wheat species at the early stages of development were shown that testifies necessi~ of great number of approaches at selection of genetic material for improvement of modern wheat eultivars. This work is the first phase of research for practical breeding.展开更多
Understanding the embryo physiology of Hizikia fusiformis(Harvey) Okamura will promote the development of artificial seedlings. In this study, H. fusiformis embryos were cultured under different environmental condit...Understanding the embryo physiology of Hizikia fusiformis(Harvey) Okamura will promote the development of artificial seedlings. In this study, H. fusiformis embryos were cultured under different environmental conditions, including different temperatures(15℃, 20℃, and 25℃), sunlight intensities(100%, 50%, and 25% of full solar radiation) and types of UVR(UV-A and UV-B). Then, we determined the lengths, maximal quantum yields( Fv/Fm), and survival rates of the embryos. The results showed that the embryos had the highest lengths, Fv/Fm values and survival percentages when cultured under a temperature of 20℃ and 25% sunlight intensity. The full level of solar radiation severely reduced the growth and survival ratios of the embryos. Hizikia embryos recovered within 2 h from the damage caused by short-term(30 min) high radiation(about 70% of full solar radiation) and UVR exposure. However, the viabilities of the embryos were significantly decreased after 4 h exposure to UVR. According to these results, we propose that culture conditions with indoor natural light and room temperature would be favorable for the growth, development and physiology of H izikia embryos.展开更多
Studies were conducted to detennine the effects of hot water (50 ℃) and fungicide (contizeb ‘5') treatments on avocado seeds in terms of seed health, germination and seedling growth before side-grafting. The le...Studies were conducted to detennine the effects of hot water (50 ℃) and fungicide (contizeb ‘5') treatments on avocado seeds in terms of seed health, germination and seedling growth before side-grafting. The leathery coverings or seed coat were removed and either 1 cm or 1.5 cm of the narrow top of the seeds was removed before sowing. There were six treatments arranged in a randomized complete block and rephcated three times. In a six week period after germination when side grafting could be done, it was found out that the earliest germination came from the 'no hot water or fungicide-treated" seeds cut at 1 cm but most seeds germinated from the fungicide-treated seeds at 1 cm cut. Most fungi including Fusarium andAspergillus spp found to either delay germination or reduce seedling vigour were minimized in number through the fungicide treatment compared to the hot water-treated seeds. Seedlings performance in terms of shoot extension and canopy development was significantly better in the fungicide-treated seeds than from either the hot water or the non-treated seeds. The study concluded that avocado seed treatment prior to sowing enhanced germination.展开更多
The role of mycorrhizal symbiosis in the alleviation of salinity stress induced by sodium chloride (NaCI) was investigated. Three artichoke hybrids, Madrigal F1, Opal FI, and Concerto FI (Nunhems company), were gr...The role of mycorrhizal symbiosis in the alleviation of salinity stress induced by sodium chloride (NaCI) was investigated. Three artichoke hybrids, Madrigal F1, Opal FI, and Concerto FI (Nunhems company), were grown in pot in controlled environment with two different mycorrhizal treatments (with or without Glomus viscosum). Two months after inoculation, the fungus established well on roots of the Madrigal and Opal plants with higher colonization and dependency values, instead the Concerto plants showed lower mycorrhizal dependency and colonization rate. Mycorrhizal symbiosis generally improved plant vegetative growth and sustained plant physiology increasing stomatal conductance and SPAD values. The root systems of two months old artichoke plantlets, both inoculated and non inoculated, were placed in distilled water enriched with different salt concentrations (0, 100, 150, 200, 250 mM NaCI) to study the wilting response. A visual rating system was developed defining various wilting indexes (TO, no wilting; T1, foliar damage on less than 50% of vegetal tissues of basal leaves; T2, initial wilting and foliar damage on more than 50% of vegetal tissues of basal leaves; T3, foliar damage on the apical leaves; and T4, total wilting). Mycorrhizal plants reached later the wilting indexes than non-mycorrhizal plants. Electrolyte leakage by leaves after salinity imposition was higher in non-mycorrhizal plants and the vegetal tissues were severely damaged especially in the basal leaves. The greater tolerance observed in the mycorrhizal plants could be in agreement with the improvement in growth stimulated by mycorrhizal symbiosis, which leads to the dilution of toxic ions.展开更多
基金Supported by Natural Science Foundation of China(Grant:30771156)Student Technology New Ideas Project of Liaocheng University(Grant:SRT08111SM2)~~
文摘[Objective] studying the influences of different UV-B radiation treatments in short time on some physiological characteristics of winter wheat seedlings was to provide reference for the mechanism of plant response to ultraviolet irradiation in short time. [Method] The winter wheat taken as materials were treated with 15 and 30 pW/cm^2 UV-B radiation, then the physiological indexes such as pigment content and photosynthetic rate were determined. [ Results] The UV-B treatment caused the declines of chlorophyll content, soluble protein content and water content of leaves, besides, dose-effect was existed. The decline of 30 pW/cm^2 treatment was bigger than that of 15 μW/cm^2 treatment. The influences of UV-B radiation on carotenoid content and anthocyanidin content were similar; the change trends were declined firstly then increased. The UVB treatment with two doses restrained the electron transport of PSⅡ, particularly; the inhibitory effect was biggest after treated 2 h, and then this effect was declined in 4, 6 and 8 h, so the dose-effect was existed. The UV-B radiation with two doses restricted photosynthetic rate and the inhibitory effect increased with the increase of treatment time. The high dose treatment caused huge damage to membrane system, while the result of low dose treatment was not obvious. [ Conclusion] UV-B radiation treatment had dose-effect on winter wheat seedlings in short time and the influence of high dose was bigger than that of low dose. With the increase of treatment time, the damage was alleviated; besides, the result was not similar to that of UV-B radiation in long time.
基金the Start-up Research Grant of Excellent Talent in ZhongKai University of Agriculture and Engineering (G2360250)Shanxi Natural Science Foundation (20031067)~~
文摘[ Objective] The study aimed to reveal the effects of hypergravity on salt tolerance of wheat seedlings. [ Method ] The seed germination rate (Gr) and germination index (Gi) of wheat seedlings were measured under hypergravity of 600 × g or 1 000 × g for 4 h and under the stress of 0.4% or 0.9% salt solution. The catalase (CAT) activity and malondialdehyde (MDA) content of wheat seedlings were also measured under 0.4% salt stress. [Result] Compared with seedlings in CK group (no hypergravity or salt stress), the Gr and Gi of the seedlings in salt stress treatment decreased to different extents; while the Gr and Gi of the seedlings in treatment group (hypergravity and salt stress) increased compared with that in salt stress group. CAT in seedlings of hypergravity treatment was higher than that of CK group and 0.4% salt treatment group, meanwhile the MDA showed an opposite result. [ Conclusion] Hypergravity could enhance the salt resistance of wheat in specific range, and hypergravity of 600 × g for 4 h performed better than that of 1 000 ×g for 4 h.
文摘[Objective] The aim was to explore physiological responses of Brazil banana seedlings to drought stress simulated by PEG-6000.[Method] Brazil banana (Musa AAA Cavendish subgroup cv.Brazil) was taken as test materials to explore changes of physiological indices of banana seedlings under drought stresses simulated by PEG-6000,including three stress levels (5%,10% and 15%) and time periods (24,48 and 72 h).[Result] Relative water content and chlorophyll content both declined under different stress levels and in different times.The content of proline (Pro) in seedling leaves from high to low was PEG15%,PEG10% and PEG5%; the content of treatment of 5% stress in 24 h was of insignificant differences with that of the control and the contents in rest treatments were all remarkably higher compared with the control.POD activities of seedling leaves from high to low were as follows:PEG15%>PEG10%>PEG5%,and POD activity was of significant differences among treatments; POD activity achieved the peak in treatment group with 5% of stress,and POD activities of different groups were all higher compared with the control.The activity of root system in treatment groups with PEG at different concentrations was as follows:PEG10%>PEG15%>PEG5% and the activity increased remarkably in the group with PEG at 5% within 24,48 and 72 h,though the activity dropped significantly within 72 h and slowly in 24 and 48 h.[Conclusion] It can be concluded that relative water content,chlorophyll content,Pro content and activity and root activity can be references of banana resistance to drought.
基金Supported by Wildlife Conservation and Nature Reserve Construction Projects of Chongqing City in 2013~~
文摘[Objective] This study aimed to solve the problems of low seed germina- tion rate and difficult bareroot seedling transplanting in artificial cultivation of Arto- carpus nanchuanensis, a native species in China. [Method] Under different seed treatment and seedling style, the seed germination rate and seedling emergence rate of A. nanchuanensis were investigated. [Result] tn both sand bed and direct sowing yellow soil, the seed germination rate, seedling survival rate and seedling emergence rate in the treatment II were all higher than those in the treatments I and III. The average seed germination rate, seedling survival rate and seedling emergence rate in sand beds were 1.5%, 16.27% and 13.95%, respectively higher than those in direct sowing yellow soil. The average seedling emergence rate in sand beds was 2.46% higher than that in containers. Among the 8 kinds of light matrix formulas, the growth of seedlings in the formula VIII was best. In the three treatment groups, the seedling emergence rates, seedling heights and ground diame- ters in the formula VIII were all significantly different from those in the other formu- las. The seedling growth in the formula I and III ranked second, while the seedling emergence rate, seedling height and ground diameter in the formula VII were the poorest. [Conclusion] If conditions allow, the formulas I (meadow soil:vermiculite:yel- low soi1=5:3:2), III (meadow soil:perlite:yellow soi1=5:3:2) and VIII (peat:forest top soi1=6:4) should be promoted in seedling with light matrixes.
文摘[Objective] With a rice variety "Long Rice 11" as a test cultivar,an experiment of raising rice seedlings with the new substrata prepared from biochar,and maize stalks,rice husks,organic fertilizer,turf,zeolite,fine river sand and arable layer soil by mixing according to certain volume proportions was caried out,in order to investigate the physical and chemical properties of different organic-material seedling-raising substrata and the effects of these substrata on seedling growth.[Method] The experiment raised seedlings in greenhouses and adopted randomized block arrangement.[Result] The substratum of biochar mixed with maize stalks and rice husks could increase the maximum water-holding capacity of the substratum,reduce the volume weight of the substratum and improve the buffering effect of the substratum.It also had great effects on the contents of alkali-hydrolyzale nitrogen and rapidly available potassium in the substratum,and could improve the root number and substantial degree of rice seedlings.[Conclusion] Biochar with maize stalks and rice husks(the treament HC) is the optimal substratum in this study.
基金Supported by the National"948"Import Program(2001-46)~~
文摘[Objective]The study was conducted to investigate the effects of shading treatments on growth of Asimina triloba (L) Dunal seedlings and provided the theoretical basis for seedling production. [Method]70 day-old A. triloba seedlings had similar stem diameter and plant height and good growth vigour were taken as tested materials in 2005. 4 light gradient treatments which were the natural light with 100% light intensity, one-layer, two-layer and three-layer black shading network with the light transmittance rate of 50%, 25% and 12.5% were set up to study the effects of different shading treatments on growth of A. triloba. [ Result] With the shading treatments of one-layer and two-layer net, the plants of A. triloba seedlings grew rapidly. As the intensity of illumination decreased, the cetents of chlorophyll a ( Chl. a), chlorophyll b ( Chl. b) and total chlorophyll increased at first and then reduced. At the same time the chlorophyll a/b value became smaller. Under natural light, the plants tended to consume more water and the soil temperature at 15:00 p. m was higher. There was a smaller difference among various treatments. [ Conclusion]The suitable shading treatment to the growth of A. triloba seedlings was under the light transmittance rate of 50% and height and stem diameter of trees increased fast. Chlorophyll a ( Chl. a), chlorophyll b ( Chl. b) content in leaves of A. triloba seedlings were highest comparing with those in other conditions.
文摘A procedure for cutting Prunus humilis(Bge). Sok was comprehensively studied in this paper. It was found that the key factors involved in this procession were medium, rooting accelerator, concentration of rooting accelerator and type of shoot. The results showed that send was used as mediums; Treatment with 1 000 mg/L AST rooting powder No. 2 and semi-woody shoots were the optimal materials for cutting, and the rooting rate reached 88.1%. Anatomical study on rooting of Prunus hum#is(Bge). Sok cutting has been carded out by the paraffin section method. The observation result shows that the adventitious root primordium of Prunus humili$(Bge). Sok cutting belongs to the type of induced root primordium. The adventitiousroot primordium originates from the cross region of vascular cambium and pith rays.
基金Supported by Science and Technology Plan Project of Hunan Province(2013NK3036)Science and Technology Projects of Changsha Tobacco Company(12218,12231)~~
文摘Cultivating strong seedlings is an important guarantee for the production of high-quality flue-cured tobacco, while there are many disadvantages in tobacco floating system that is commonly adopted in China. To improve the tobacco floating system, with Xiangyan No.3 as experimental material, the effects of water control before transplanting and rooting powder treatment on tobacco seedling quality and physiological properties at green stage were investigated. The results showed that: (1) water control showed small influence on tobacco seedling quality, while rooting powder treatment and water control + rooting powder treatment showed great influence on tobacco seedling quality, mainly represented by reduced plant height, thickened stem and increased dry matter accumulative amount; (2) water control before transplanting and rooting powder treatment all improved leaf chlorophyll content and root vigor of tobacco seedlings, and the effect of water control + rooting powder treatment was best, followed by rooting powder treatment and water control; (3) all treatments increased the nitrate reductase and invertase activity, and reduced the MDA content of tobacco seedlings, and the effect of water control + rooting powder treatment was best, followed by rooting powder treatment and water control. Mean- while, the treatment effect 10 d before the transplanting was better than that 5 d before the transplanting. In overall, the improvement effects of water control 10 d before transplanting + rooting powder treatment on tobacco seedling quality and physiological properties at green stage were the best.
文摘We present an overview of previous research results on the molecular phylogenetic analyses in Agaricales and its higher ranks (Agaricomycetes/Agaricomycotina/Basidiomycota) along with the most recent treatments of taxonomic systems in these taxa. Establishing phylogenetic hypotheses using DNA sequences, from which an understanding of the natural evolutionary relationships amongst clades may be derived, requires a robust dataset. It has been recognized that single-gene phylogenies may not truly represent organismal phylogenies, but the concordant phylogenetic genealogies from multiple-gene datasets can resolve this problem. The genes commonly used in mushroom phylogenetic research are summarized.
文摘The paper aimed to investigate the growth of seedlings of three species of Cassia (C tora, C. sophera and C occidentalis) at different concentrations of salinity (NaC1) and pH treatments. All the species showed the highest seedling length under control condition, and with the increase of salinity, C occidentalis showed the highest sensitivity. The seedling length of C tora at 0.05 M NaCI significantly (P = 0.05) decreased to 5.71 cm, and further increase of salinity to 0.1 M, the seedling length was decreased to less than the value of 0.05 M NaC1 treatment and one-third (2.15 cm) of that of control (6.92 cm). Seeds of all the species failed to germinate at 0.5 M NaC1. Scarified seeds of C. sophera and C occidentalis increased seedling length. The highest seedling length was in C. sophera, followed by C. tora and C. occidentalis. All the species showed significant decrease (P 〈 0.05) of fresh weight with the increase of salinity; scarification of seeds in C. occidentalis and C. sophera showed higher fresh weight than those of without scarification. Experiments at different pH levels did not show any significant (P = 0.05) change in seedling length, except C. sophera, while at acidic pH, both seedling length and dry weight were significantly (P 〈 0.05) decreased.
文摘Albizia saman (Jacq.) F. Muell. commonly known as rain tree seeds were treated with five pre-sowing treatments to study the effect of pre-sowing treatments on germination and initial seedling development in the nursery.The experiment was established in the nursery of the Institute of Forestry and Environmental Sciences.University of Chittagong, Chittagong, Bangladesh. Results revealed that Nail clipping in one side of the seed (at the distal end of the seed) (T4) provides the highest (50%) seed germination. The second highest germination (42%) was obtained for the seeds treated with immersion in cold water for 24 h (T1). Germination was completely inhibited when the seeds immersed in boiled water for 30 s followed in cold water soaking for 24 h. Other germination parameter and initial morphological growth and biomass production of the seedlings was also higher for the treatments T4and Ti in comparison to the control (Ta)treatment. Pre-sowing treatments of T4 e.g. Nail clipping in one side of the seed (at the distal end of the seed) and T1 (Seeds immersed in cold water for 24 h) may be recommended for maximum germination and initial vigorous seedlings growth of Albizia sarnan in the nursery.
基金Supported by the National Natural Science Foundation of China, No. 30070855
文摘AIM: To investigate the expression of several important molecules involved in major histocompatibility complex (MHC) class I presentation pathway in primary hepatocellular carcinoma (HCC), and to determine whether cytotoxic T lymphocyte (CTL) vaccine therapy was suitable for HCC. METHODS: Labeled streptavidin biotin(LSAB) method of immunohisto-chemistry was used to study 33 HCC tissue specimens. RESULTS: Most HCC tissues and adjacent histological normal hepatocytes expressed HLA-I antigens,TAP,and B7, expression of B7 was especially strong,and there was no significant difference between them (P>0.05). CONCLUSION: The MHC class I presentation pathway in primary hepatocellular carcinoma may not be abnormal or dysfunctional,and CTL could kill these tumor cells. Thus, it is suitable and practicable to design and construct CTL vaccine against HCC.
基金The research was Supported by the Natural Science Foundation of Heilongjiang Province (C200511)
文摘Fifty cultivated Catharanthus roseus seedlings were selected for tip-pruning treatment and the effects of tip-pruning on seedling growth and source-sink regulation were investigated for revealing physiological mechanisms of plants. The results showed that tip-pruning treatment resulted in obvious inhibition of apical dominance and enhancement of branching numbers. The contents of soluble sugars, acid sucrose invertase activity (AI) had a great change in differently positional leaves of the seedling. The sink strength in tip leaves of seedlings dramatically declined after tip-pruning treatment, while that in the leaves at the middle and bottom of seedlings had no obvious changes. The inhibition of apical dominance of tip leaves of seedlings was caused by the diminished sink strength due to tip-pruning treatment,
文摘Byrsonima intermedia A. Juss. is a species from the Brazilian Cerrado that produces edible fruits and, in common with other species from the Byrsonima genus, has pharmacological potential. Previous attempts to propagate the species through conventional methods showed difficulties. Thus, the purpose of this work was to characterize pro-embryogenic masses of Byrsonima intermedia callus, aiming for their in vitro propagation through somatic embryogenesis. Leaf segments from in vitro germinated seedlings were employed as explants for callus production. The calli were then subcultured and exposed to dyes to fulfill their embryogenic potential. Digitalizations of the cytological preparations were made in order to measure the area that was stained by both Aceto-Carmine and Evans-Blue, using image tool software. Somatic embryos were induced after treatments with l-naphthaleneacetic acid (NAA). The percentages of double-colored areas (by Aceto-Carmine and Evans-Blue) were calculated and the data were analyzed by using the Skott-Knott test (P ≤ 0.05) and, the embryogenic callus, as well as the formation of somatic embryos were analyzed by using the Krsuskal-Wallis rank test (P ≤0.05). The results show that double coloration is effective at identifying cells showing embryogenic potential. Early callus subculture phases show a larger percentage ofembryogenic area (83%) Somatic embryos were induced by using high auxin level.
文摘The aim of this work was to study the reactions of wheat (T. aestivum L.) and its wild congeners under salt stress. Physiological mechanisms that underlie traits for salt tolerance plantlets have been used to test some wheat species and to identify sources of salty tolerance. Stress conditions were founded by means of exposure of the plantlets in NaCI water solution, 1.68% that demonstrably differentiates the samples by growth parameters. Under laboratory conditions the ability of seedlings to bear a significant shortage of water, their ability to accumulate biomass, changing the parameters of linear growth processes and changes in water content in leaves and roots of seedlings under stress was determined. Interest is also the rate of growth of root fibrils in saline conditions. These experiments allowed to provide a comprehensive diagnosis of studied forms of wheat and make an initial opinion on their salt tolerance. Different features of abiotic stress responses of some wheat species at the early stages of development were shown that testifies necessi~ of great number of approaches at selection of genetic material for improvement of modern wheat eultivars. This work is the first phase of research for practical breeding.
基金Supported by the Science and Technology Planning Project of Guangdong,China(No.2016A020222001)
文摘Understanding the embryo physiology of Hizikia fusiformis(Harvey) Okamura will promote the development of artificial seedlings. In this study, H. fusiformis embryos were cultured under different environmental conditions, including different temperatures(15℃, 20℃, and 25℃), sunlight intensities(100%, 50%, and 25% of full solar radiation) and types of UVR(UV-A and UV-B). Then, we determined the lengths, maximal quantum yields( Fv/Fm), and survival rates of the embryos. The results showed that the embryos had the highest lengths, Fv/Fm values and survival percentages when cultured under a temperature of 20℃ and 25% sunlight intensity. The full level of solar radiation severely reduced the growth and survival ratios of the embryos. Hizikia embryos recovered within 2 h from the damage caused by short-term(30 min) high radiation(about 70% of full solar radiation) and UVR exposure. However, the viabilities of the embryos were significantly decreased after 4 h exposure to UVR. According to these results, we propose that culture conditions with indoor natural light and room temperature would be favorable for the growth, development and physiology of H izikia embryos.
文摘Studies were conducted to detennine the effects of hot water (50 ℃) and fungicide (contizeb ‘5') treatments on avocado seeds in terms of seed health, germination and seedling growth before side-grafting. The leathery coverings or seed coat were removed and either 1 cm or 1.5 cm of the narrow top of the seeds was removed before sowing. There were six treatments arranged in a randomized complete block and rephcated three times. In a six week period after germination when side grafting could be done, it was found out that the earliest germination came from the 'no hot water or fungicide-treated" seeds cut at 1 cm but most seeds germinated from the fungicide-treated seeds at 1 cm cut. Most fungi including Fusarium andAspergillus spp found to either delay germination or reduce seedling vigour were minimized in number through the fungicide treatment compared to the hot water-treated seeds. Seedlings performance in terms of shoot extension and canopy development was significantly better in the fungicide-treated seeds than from either the hot water or the non-treated seeds. The study concluded that avocado seed treatment prior to sowing enhanced germination.
文摘The role of mycorrhizal symbiosis in the alleviation of salinity stress induced by sodium chloride (NaCI) was investigated. Three artichoke hybrids, Madrigal F1, Opal FI, and Concerto FI (Nunhems company), were grown in pot in controlled environment with two different mycorrhizal treatments (with or without Glomus viscosum). Two months after inoculation, the fungus established well on roots of the Madrigal and Opal plants with higher colonization and dependency values, instead the Concerto plants showed lower mycorrhizal dependency and colonization rate. Mycorrhizal symbiosis generally improved plant vegetative growth and sustained plant physiology increasing stomatal conductance and SPAD values. The root systems of two months old artichoke plantlets, both inoculated and non inoculated, were placed in distilled water enriched with different salt concentrations (0, 100, 150, 200, 250 mM NaCI) to study the wilting response. A visual rating system was developed defining various wilting indexes (TO, no wilting; T1, foliar damage on less than 50% of vegetal tissues of basal leaves; T2, initial wilting and foliar damage on more than 50% of vegetal tissues of basal leaves; T3, foliar damage on the apical leaves; and T4, total wilting). Mycorrhizal plants reached later the wilting indexes than non-mycorrhizal plants. Electrolyte leakage by leaves after salinity imposition was higher in non-mycorrhizal plants and the vegetal tissues were severely damaged especially in the basal leaves. The greater tolerance observed in the mycorrhizal plants could be in agreement with the improvement in growth stimulated by mycorrhizal symbiosis, which leads to the dilution of toxic ions.