To study non-structural carbohydrate character-istics and nutrient utilization strategies of Pinus yunnanen-sis under continuous drought conditions,2-year-old seed-lings were planted in pots with appropriate water,lig...To study non-structural carbohydrate character-istics and nutrient utilization strategies of Pinus yunnanen-sis under continuous drought conditions,2-year-old seed-lings were planted in pots with appropriate water,light and moderate and severe drought treatments[(80±5),(65±5),(50±5),and(35±5)%of field water-holding capacity].Non-structural carbohydrates,carbon(C),nitrogen(N),and phosphorus(P)concentrations were measured in each plant component.The results show that:(1)With increasing drought,non-structural carbohydrates gradually increased in leaves,stems,and coarse roots,while gradually decreased in fine roots;(2)C concentrations of all were relatively stable under different stress levels.Phosphorous utilization of each component increased under light and moderate drought conditions,while N and P utilization efficiency of each plant component decreased under severe drought.Growth was mainly restricted by N,first decreasing and then increasing with increased drought;(3)There was a correlation between the levels of non-structural carbohydrates and C,N,and P in each component.Changes in N concentration affected the interconversion between soluble sugar and starch,which play a regulatory role in the fluctuation of the concentration of non-structural carbohydrates;and,(4)Plasticity analysis showed that P.yunnanensis seedlings responded to drought mainly by altering starch concentration,the ratio of soluble sugar to starch in leaves and stems,and further by alter-ing N and P utilization efficiencies.Overall,these results suggest that the physiological activities of all organs of P.yunnanensis seedlings are restricted under drought and that trade-offs exist between different physiological indicators and organs.Our findings are helpful in understanding non-structural carbohydrate and nutrient adaptation mechanisms under drought in P.yunnanensis seedlings.展开更多
Seedling characteristics such as leaf emergency, chlorophyll content, and height are important for early growth and also associated with seed size. Quantitative trait loci (QTLs) for rice (Oryza sativa L.) seedling ch...Seedling characteristics such as leaf emergency, chlorophyll content, and height are important for early growth and also associated with seed size. Quantitative trait loci (QTLs) for rice (Oryza sativa L.) seedling characteristics (leaf length, chlorophyll content, seedling height) and seed size were identified with an attempt to explore the relationship between seedling characteristics and seed size, using a recombinant inbred population derived from a cross between Zhenshan 97A and Minghui 63. Two, one, five, four, four, and nine QTLs were detected for chlorophyll a content, total chlorophyll, length of the second seedling leaf, length of the third seedling leaf, seedling height, and seed size, respectively. The results indicated that four QTLs for seed size and four QTLs for seedling characteristics shared several similar regions (G359-RG532, C567-RG236, RZ403-R19, C371-C405a), respectively, suggesting a close association between seedling characteristics and seed size. Several chromosomal regions influencing seed size, however, had no effects on seedling characteristics, suggesting that it was possible to improve seedling vigor without increasing grain size.展开更多
We investigated the combined effects of soil moisture and light intensity on the growth, development and ecophysiological characteristics of one-year old Amorpha fruticosa seedlings. Soil moisture and light intensity ...We investigated the combined effects of soil moisture and light intensity on the growth, development and ecophysiological characteristics of one-year old Amorpha fruticosa seedlings. Soil moisture and light intensity influenced the ecophysiological characteristics of Amorpha fruticosa seedlings. Soil moisture resulted in the decreases of growth rate, individual size, net photosynthetic rate, transpiration rate, leaf water loss rate (WLR), and biomass accumulation of plant parts, and led to increased leaf water saturation deficit (WSD). Under water stress, more photosynthetic products were allocated to root growth. With decreasing light intensity, net photosynthetic rate, transpiration rate, chla/b, water saturation deficit, water use efficiency, water loss rate and biomass accumulation declined, while Chla, Chlb, Chla+b and carotenoids (Car) increased and more photosynthetic products were allocated to stem and leaf growth. Maximum growth vigor, net photosynthetic rate and total biomass accumulation in Amorpha fruticosa seedlings was recorded at 75 80% soil water-holding capacity and 100% light density in greenhouse environments.展开更多
In this study, we investigated the effect of exogenous sodium benzoate on wheat seedlings(Yangmai 16) grown under heavy metal stress. The results showed that 2.4 mmol kg-1 of heavy metals significantly inhibited growt...In this study, we investigated the effect of exogenous sodium benzoate on wheat seedlings(Yangmai 16) grown under heavy metal stress. The results showed that 2.4 mmol kg-1 of heavy metals significantly inhibited growth and delayed emergence of wheat seedlings. Under compound heavy metal stress, application of 2-4 g L^-1 sodium benzoate significantly increased(P<0.01) chlorophyll content and chlorophyll fluorescence parameters Fv/Fm and Fv/Fo of wheat, compared to the control(water treatment). Further analysis showed that application of 2-4 g L^-1 sodium benzoate alleviated osmotic stress by promoting the accumulation of osmolytes such as soluble proteins and free proline, increased the activity of superoxide dismutase(SOD) and reduced malondialdehyde content(MDA). In contrast, higher concentrations of sodium benzoate solution(>6 g L^-1) inhibited the growth of wheat seedlings and even caused damage to seedlings. Correlation analysis showed that when the sodium benzoate concentration was in the range of 1.97-3.12 g L^-1(2016) and 1.58-3.27 g L^-1(2017), values of chlorophyll and its components, root activity, SOD activity, soluble protein, and free proline content were the highest. When the sodium benzoate concentration was raised to 2.59 g L^-1(2016) or 3.02 g L^-1(2017), MDA content was the lowest. Ultimately, exogenous sodium benzoate(2-4 g L^-1) facilitates root development and improves the root activity of wheat seedlings grown under compound heavy metals stress, thereby effectively alleviating the damage of compound heavy metal stress in wheat seedlings.展开更多
The physiological and biochemical characteristics of Glycine max seedlings were changed under the high concentration of Pb stress, in which the malony dialdehyde (MDA) content, plasmalemma, activities of catalase (CAT...The physiological and biochemical characteristics of Glycine max seedlings were changed under the high concentration of Pb stress, in which the malony dialdehyde (MDA) content, plasmalemma, activities of catalase (CAT) and peroxidase (POD) were increased drastically. The damage effects of Pb were reduced when 15 mg . L-1 La-Gly was used to spray Glycine max seedlings. The results of La-Gly treatment show that the effects are related to the decrease of Pb content in plants, the increase of photosynthetic rate and nitrate reductase (NR) activity, decrease of MDA content and cell membrane permeability, and maintenance of activities of CAT and POD.展开更多
[Objective] The aim was to explore growth performance of Phoebe bournei in seedling stage.[Method] Based on 17 superior plus trees of Phoebe bournei,a seedling cultivation test was conducted in Jindong Forest Farm in ...[Objective] The aim was to explore growth performance of Phoebe bournei in seedling stage.[Method] Based on 17 superior plus trees of Phoebe bournei,a seedling cultivation test was conducted in Jindong Forest Farm in Yongzhou,Hunan Province,exploring growth indices and analyzing seedling height and ground diameter.[Result] As per the selection rate at 20%,PB17,PB9 and PB12 were selected from the 17 species.Specifically,the seedling height averaged 36.52 cm of the selected three seedlings,which was higher by 16.1% compared with average of 17 species (31.45%).As for ground diameter,the selected species averaged 2.6 mm,which was higher (13.0%) compared with the average level (2.3 mm).[Conclusion]Both of seedling height and ground diameter reached extremely significant differences,which indicated that half-sib families of Phoebe bournei have rich variations,with selection and breeding potential.展开更多
The classification of seedlings is important to ensure the viability of seedlings after transplantation and is acknowledged as a key factor in forestation and environmental improvement. Based on numerous papers on aut...The classification of seedlings is important to ensure the viability of seedlings after transplantation and is acknowledged as a key factor in forestation and environmental improvement. Based on numerous papers on automatic seedling classification (ASC), the seedling grading theory, traditional grading methods, the background and the proceeding of ASC techniques are described. The automation of the measurement of seedling morphological characteristics by photoelectric meters and computer vision is studied, and the automatic methods of the current grading systems are described respectively. And the further researches on ASC by computer vision are proposed.展开更多
The aim of this study was to evaluate the growth of rape (Brassica napus L.) seedlings under different light intensities to select appropriate conditions for cultivation in an indoor system. Seedlings were grown und...The aim of this study was to evaluate the growth of rape (Brassica napus L.) seedlings under different light intensities to select appropriate conditions for cultivation in an indoor system. Seedlings were grown under different light intensities of red and blue light provided by light-emitting diodes (LEDs) and their self-adjustment ability and changes in leaf microstructure were evaluated. Light was supplied by red LEDs with peak wavelengths of 630 (R1) and 660 nm (R2) and by blue LEDs (B) with a peak wavelength of 445 nm (the light intensity ratio of R1:R2:B was 3:3:2), at intensities of 400 (R1R2B400), 300 (R1R2B300), and 200 μmol m-2 s-1 (R1R2B200). Natural solar light served as the control (C). Plant height, stem diameter, root length, leaf area, and dry weight of rape seedlings gradually increased with increasing light intensity. The seedlings in the R1R2B400 treatment grew more vigorously, while those in the R1R2B200 treatment were weaker. The photosynthetic pigment contents did not differ significantly between the R1R2B400 treatment and C, but were significantly lower in the R1R2B300 and R1R2B200 treatments. The highest intercellular CO2concentration, stomatal conductance, and transpiration rate were in the R1R2B300 treatment. The highest photosynthetic rate was in the R1R2B400 treatment, and was related to more compact leaves, thicker and tidier palisade and spongy tissues, and well-developed chloroplasts. In contrast, the seedlings in the R1R2B200 treatment had disordered mesophyll cells, round chloroplasts, and fractured and fuzzy grana lamellae, all of which inhibited plant growth. In conclusion, the seedlings in the R1R2B400 treatment had well-developed leaves, which favored photosynthesis. Compared with the light intensities below 300 μmol m-2 s-1, the light intensity of 400 μmol m-2 s-1 provided by a cembination of red and blue LEDs was beneficial for cultivating strong and healthy rape seedlings in an artificial system.展开更多
This paper focuses on the growth response of Caragana microphylla seedlings to changes of artificially controlled water table in Horqin Sandy Land, China. Monitoring results of soil water content shows that soil moist...This paper focuses on the growth response of Caragana microphylla seedlings to changes of artificially controlled water table in Horqin Sandy Land, China. Monitoring results of soil water content shows that soil moisture is closely correlated to groundwater depths. Soil volumetric water increased rapidly when close to water sources and finally stabilized in a saturated state. The soil moisture trend of CK (control) increased gradually at 0-50 cm of soil depth then decreased to 4% below 50 cm soil depth. C. microphylla can adapt to different soil environments by changes in ecological and physiological characteristics. By comparing the ecological characteristics of C. microphylla seedlings at various water tables, we found that a shallow water table of 40 cm depth inhibited seedling groundwater depth of 120 em was more advantageous for plant growth because of weak ecological characteristics. A height and canopy growth of C. microphylla seedlings. During the first two years, the most suitable water depth for root biomass was 120 cm, and 180 cm for root length. The growth of vertical roots is positively correlated with groundwater depth, and root thickness is the determinate factor for root biomass while the fine root is the determinate factor for root length. A thick root would grow much more in a natural drought environment while access to ground water promotes the growth of fine roots.展开更多
Biomass of seedlings at different developing stages of growth is important information for studying the response of species to site conditions.The objectives of this study was to explore the distribution characteristi...Biomass of seedlings at different developing stages of growth is important information for studying the response of species to site conditions.The objectives of this study was to explore the distribution characteristics of AGB(above-ground biomass)and BGB(below-ground biomass)of Abies georgei var.smithii seedlings of different ages,and investigate the effects of topography(slope aspect,altitude),plant community characteristics(crown density,species diversity,etc.),and soil properties(soil physical and chemical properties)on the biomass and its allocation.Seedlings in five age classes(1–2,3–4,5–6,7–8,and 9–10 years old)were collected by full excavation from 6 elevations(3800 m,3900 m,4000 m,4100 m,4200 m,4300 m)on the north and south slopes of Sejila Mountain in Tibet.15seedlings of each age class were investigated at one altitude.The individual effects of seedling age(SA)and the interaction effects of SA,slope aspect(SL),and elevation(EG),namely,SL×EG,SL×SA,EG×SA,and SL×EG×SA,had significant effects on the AGB of the seedlings(p<0.05),whereas BGB was only significantly affected by SA(p<0.001).The AGB and BGB of the seedlings showed a binomial growth trend with the increase in seedling age,and had an allometric relationship at different elevations,α(allometric exponential)varied from 0.913 to 1.046 in the northern slope,and from 1.004 to 1.268 in the southern slope.The biomass of seedlings on the northern slope was remarkably affected by stand factors,with a contribution rate of 47.8%,whereas that on the southern slope was considerably affected by soil factors with a contribution rate of 53.2%.The results showed that age was the most important factor affecting seedling biomass.The allometric pattern of seedling biomass was relatively stable,but in a highaltitude habitat,A.georgei var.smithii seedlings increased the input of BGB.Understanding seedling biomass allocation and its influencing factors is useful for evaluating plants’ability to acquire resources and survival strategies for adaptation to the environment in Tibet Plateau.展开更多
In this study, we employed a temporary immersion bioreactor(TIB)system for the micropropagation of strawberry seedlings. The TIB method and the conventional method for the micropropagation of strawberry seedlings were...In this study, we employed a temporary immersion bioreactor(TIB)system for the micropropagation of strawberry seedlings. The TIB method and the conventional method for the micropropagation of strawberry seedlings were compared in terms of explant propagation coefficient, seedling fresh weight,contents of anthocyanins and chlorophyll, and photosynthetic characteristics. The results showed that an inoculation density of 40 explants/L was suitable for the micropropagation of ’Benihope’ strawberry seedlings in the TIB. The propagation coefficient, fresh weight, photosynthetic rate, stomatal conductance, transpiration coefficient, and the contents of total anthocyanins and chlorophyll of seedlings micropropagated in the TIB were significantly higher than those of the seedlings micropropagated by the conventional method. In conclusion, the TIB method was superior to the conventional method in the micropropagation of strawberry seedlings.The negative reciprocity did not occur between anthocyanins and chlorophyll in strawberry seedlings cultured under forced ventilation such as TIB.展开更多
A survey was conducted in 2011 in the major date growing regions of Saudi Arabia to identify and evaluate date palms with fruit characteristics preferred by the producers and consumers. The regions in the Kingdom surv...A survey was conducted in 2011 in the major date growing regions of Saudi Arabia to identify and evaluate date palms with fruit characteristics preferred by the producers and consumers. The regions in the Kingdom surveyed for this purpose were Al-Zulfi, Al-Hassa, Najran, Al-Madinah Al-Munawarah and AI-Qassim. Seventy palms from seedlings were initially identified for the study based on the following fruit characteristics, i.e., fruit length, breadth, weight, color, taste, texture, sugar content, external appearance and also the market value. Subsequently, 12 palms (Al-Afiah, Duhiba, Adbah, Aliah, Shamshula, Masifat Al-Asedy, Suwaid, Batlyah, AI-Nassar, Hussan, Sukariyat Al-Zulfi and Al-Hamat) mainly from the Zulfi and Riyadh regions were found to meet the required standards with potential for commercial date farming. Among these, fruits of Adbah had the highest total sugars of 72.9% followed by Duhiba with a total sugar content of 71.9%. Fruit length was maximum (49.1 mm) in the variety Allah, while the fruits of the variety Hussan recorded the maximum weight of 19.5 g. Furthermore, it is pertinent to mention that fruit size of the 12 selected cultivars was generally large and comparable to Majdool, a well-known date palm cultivar of North Africa. The fruits of the selected cultivars were also tasty and can be stored separately.展开更多
Stomatal characteristics and its plasticity were surveyed in leaves of four canopy species, Shoreachinensis, Pometia tomentosa, Anthocephalus chinensis, Calophyllun polyanthum and three middle-layerspecies, Barrington...Stomatal characteristics and its plasticity were surveyed in leaves of four canopy species, Shoreachinensis, Pometia tomentosa, Anthocephalus chinensis, Calophyllun polyanthum and three middle-layerspecies, Barringtonia pendula, Garcinia hanburyi, Horsfieldia tetratepala, acclimated to different lightconditions for more than one year. All plants stomata are distributed on the abaxial of leaves. Pometiatomentosa and Barringtonia pendula have higher stomatal density and the guard cell length of Anthocephaluschinensis and Calophyllun polyanthum were much greater than others. Stomatal density and stomatal index(ratio of stomatal numbers to epidermal cell number) were increased with growth irradiance increased, whilenumbers of stomata per leaf were higher in the low than the high relative PFD, and stomatal conductance ofleaves was the highest in the 50% of full light except for Anthocephalus chinensis. The relative PFD has littleeffects on the guard cell length of all seven plants. We have also found a significant negative correlationbetween stomatal density and leaf area, but the stomatal conductance was not significantly positive with thestomatal conductance. The analysis of phenotypic plasticity of stomatal characteristics showed: plasticityindex for stomatal index and numbers of stomatal per leaf were similar for canopy and middle-layer species,while the plasticity index of stomatal density and stomatal conductance were significantly greater for canopyspecies than middle-layer species. The high plasticity of canopy species was consistent with the hypothesisthat specialization in a more favorable environment increases plasticity.展开更多
In this article,we investigated effects of lead and cadmium on the biomass of ginkgo seedlings, and roles of the seedlings in accumulation characteristics of the heavy metals and remediation of the soil contaminated b...In this article,we investigated effects of lead and cadmium on the biomass of ginkgo seedlings, and roles of the seedlings in accumulation characteristics of the heavy metals and remediation of the soil contaminated by Cd<sup>2+</sup> or Pb<sup>2+</sup> as well as their combination.The results showed that both Cd<sup>2+</sup> and Pb<sup>2+</sup> significantly or very significantly reduced biomass increment of ginkgo seedlings,with Pb<sup>2+</sup> more adverse than Cd<sup>2+</sup>.The Cd<sup>2+</sup>-Pb<sup>2+</sup> compound pollution further reduced biomass increment of ginkgo seedlings.The mass fractions and enrichment coefficient of Pb<sup>2+</sup> and Cd<sup>2+</sup> in ginkgo seedlings were in an order of root】stem】leaf,which was in favor of transportation Pb<sup>2+</sup> and Cd<sup>2+</sup> from root to stem and leave.The Cd<sup>2+</sup>-Pb<sup>2+</sup> compound pollution promoted ginkgo seedling absorption to Cd<sup>2+</sup> and Pb<sup>2+</sup>.The capacity of the upward transport of Pb<sup>2+</sup> was greater than that of Cd<sup>2+</sup>,which suggested an obvious dose-effect and synergistic effect.Cd<sup>2+</sup> and Pb<sup>2+</sup> accumulations in ginkgo seedlings were relatively large.The accumulation in roots was higher than that in stems and leaves.The ability of the absorption,transportation and accumulation of ginkgo seedlings to Pb<sup>2+</sup> was relatively greater under Cd<sup>2+</sup>-Pb<sup>2+</sup> compound pollution.The phytoremediation efficiency of Cd<sup>2+</sup> and Pb<sup>2+</sup> was relatively high.展开更多
为深入了解施用氯化钠(NaCl)对椰子幼苗生理特性的影响,通过施用不同量的NaCl,30 d后测定叶绿素含量、丙二醛(MDA)含量、可溶性糖含量、脯氨酸含量、超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性。结果显示:施用100 g和1...为深入了解施用氯化钠(NaCl)对椰子幼苗生理特性的影响,通过施用不同量的NaCl,30 d后测定叶绿素含量、丙二醛(MDA)含量、可溶性糖含量、脯氨酸含量、超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性。结果显示:施用100 g和150 g NaCl时,叶绿素含量显著升高,MDA和可溶性糖含量明显降低,POD、SOD和CAT活性显著增加,脯氨酸含量少量增加;200 g NaCl处理条件下叶绿素含量显著降低,MDA和可溶性糖含量明显减少,SOD和CAT活性显著降低,脯氨酸含量显著增加。试验表明适量施用NaCl可以增强椰子幼苗光合作用,抑制膜脂过氧化,促进物质转化等。展开更多
基金This study was supported by the National Natural Science Foundation of China(31960306).
文摘To study non-structural carbohydrate character-istics and nutrient utilization strategies of Pinus yunnanen-sis under continuous drought conditions,2-year-old seed-lings were planted in pots with appropriate water,light and moderate and severe drought treatments[(80±5),(65±5),(50±5),and(35±5)%of field water-holding capacity].Non-structural carbohydrates,carbon(C),nitrogen(N),and phosphorus(P)concentrations were measured in each plant component.The results show that:(1)With increasing drought,non-structural carbohydrates gradually increased in leaves,stems,and coarse roots,while gradually decreased in fine roots;(2)C concentrations of all were relatively stable under different stress levels.Phosphorous utilization of each component increased under light and moderate drought conditions,while N and P utilization efficiency of each plant component decreased under severe drought.Growth was mainly restricted by N,first decreasing and then increasing with increased drought;(3)There was a correlation between the levels of non-structural carbohydrates and C,N,and P in each component.Changes in N concentration affected the interconversion between soluble sugar and starch,which play a regulatory role in the fluctuation of the concentration of non-structural carbohydrates;and,(4)Plasticity analysis showed that P.yunnanensis seedlings responded to drought mainly by altering starch concentration,the ratio of soluble sugar to starch in leaves and stems,and further by alter-ing N and P utilization efficiencies.Overall,these results suggest that the physiological activities of all organs of P.yunnanensis seedlings are restricted under drought and that trade-offs exist between different physiological indicators and organs.Our findings are helpful in understanding non-structural carbohydrate and nutrient adaptation mechanisms under drought in P.yunnanensis seedlings.
文摘Seedling characteristics such as leaf emergency, chlorophyll content, and height are important for early growth and also associated with seed size. Quantitative trait loci (QTLs) for rice (Oryza sativa L.) seedling characteristics (leaf length, chlorophyll content, seedling height) and seed size were identified with an attempt to explore the relationship between seedling characteristics and seed size, using a recombinant inbred population derived from a cross between Zhenshan 97A and Minghui 63. Two, one, five, four, four, and nine QTLs were detected for chlorophyll a content, total chlorophyll, length of the second seedling leaf, length of the third seedling leaf, seedling height, and seed size, respectively. The results indicated that four QTLs for seed size and four QTLs for seedling characteristics shared several similar regions (G359-RG532, C567-RG236, RZ403-R19, C371-C405a), respectively, suggesting a close association between seedling characteristics and seed size. Several chromosomal regions influencing seed size, however, had no effects on seedling characteristics, suggesting that it was possible to improve seedling vigor without increasing grain size.
基金supported by National Science Foundation of China (No.31270374)Independent Innovation Foundation of Shandong University (No.2011DX008)+1 种基金Natural Science Foundation of Shandong Province,China (No.2009ZRB01875ZR2010CM062)
文摘We investigated the combined effects of soil moisture and light intensity on the growth, development and ecophysiological characteristics of one-year old Amorpha fruticosa seedlings. Soil moisture and light intensity influenced the ecophysiological characteristics of Amorpha fruticosa seedlings. Soil moisture resulted in the decreases of growth rate, individual size, net photosynthetic rate, transpiration rate, leaf water loss rate (WLR), and biomass accumulation of plant parts, and led to increased leaf water saturation deficit (WSD). Under water stress, more photosynthetic products were allocated to root growth. With decreasing light intensity, net photosynthetic rate, transpiration rate, chla/b, water saturation deficit, water use efficiency, water loss rate and biomass accumulation declined, while Chla, Chlb, Chla+b and carotenoids (Car) increased and more photosynthetic products were allocated to stem and leaf growth. Maximum growth vigor, net photosynthetic rate and total biomass accumulation in Amorpha fruticosa seedlings was recorded at 75 80% soil water-holding capacity and 100% light density in greenhouse environments.
基金supported by the National Key Research and Development Program of China(2017YFD0201306)the National Natural Science Foundation of China(31671613,31471435)+2 种基金the Ph D Programs Foundation of Jiangsu Province,China(1601116C)the Priority Academic Program Development of Jiangsu Higher Education Institutions,Chinathe Top-Notch Academic Programs Project of Jiangsu Higher Education Institutions,China(PPZY2015A060)。
文摘In this study, we investigated the effect of exogenous sodium benzoate on wheat seedlings(Yangmai 16) grown under heavy metal stress. The results showed that 2.4 mmol kg-1 of heavy metals significantly inhibited growth and delayed emergence of wheat seedlings. Under compound heavy metal stress, application of 2-4 g L^-1 sodium benzoate significantly increased(P<0.01) chlorophyll content and chlorophyll fluorescence parameters Fv/Fm and Fv/Fo of wheat, compared to the control(water treatment). Further analysis showed that application of 2-4 g L^-1 sodium benzoate alleviated osmotic stress by promoting the accumulation of osmolytes such as soluble proteins and free proline, increased the activity of superoxide dismutase(SOD) and reduced malondialdehyde content(MDA). In contrast, higher concentrations of sodium benzoate solution(>6 g L^-1) inhibited the growth of wheat seedlings and even caused damage to seedlings. Correlation analysis showed that when the sodium benzoate concentration was in the range of 1.97-3.12 g L^-1(2016) and 1.58-3.27 g L^-1(2017), values of chlorophyll and its components, root activity, SOD activity, soluble protein, and free proline content were the highest. When the sodium benzoate concentration was raised to 2.59 g L^-1(2016) or 3.02 g L^-1(2017), MDA content was the lowest. Ultimately, exogenous sodium benzoate(2-4 g L^-1) facilitates root development and improves the root activity of wheat seedlings grown under compound heavy metals stress, thereby effectively alleviating the damage of compound heavy metal stress in wheat seedlings.
文摘The physiological and biochemical characteristics of Glycine max seedlings were changed under the high concentration of Pb stress, in which the malony dialdehyde (MDA) content, plasmalemma, activities of catalase (CAT) and peroxidase (POD) were increased drastically. The damage effects of Pb were reduced when 15 mg . L-1 La-Gly was used to spray Glycine max seedlings. The results of La-Gly treatment show that the effects are related to the decrease of Pb content in plants, the increase of photosynthetic rate and nitrate reductase (NR) activity, decrease of MDA content and cell membrane permeability, and maintenance of activities of CAT and POD.
基金Supported by Hunan Forestry Scientific Research(2010-07)~~
文摘[Objective] The aim was to explore growth performance of Phoebe bournei in seedling stage.[Method] Based on 17 superior plus trees of Phoebe bournei,a seedling cultivation test was conducted in Jindong Forest Farm in Yongzhou,Hunan Province,exploring growth indices and analyzing seedling height and ground diameter.[Result] As per the selection rate at 20%,PB17,PB9 and PB12 were selected from the 17 species.Specifically,the seedling height averaged 36.52 cm of the selected three seedlings,which was higher by 16.1% compared with average of 17 species (31.45%).As for ground diameter,the selected species averaged 2.6 mm,which was higher (13.0%) compared with the average level (2.3 mm).[Conclusion]Both of seedling height and ground diameter reached extremely significant differences,which indicated that half-sib families of Phoebe bournei have rich variations,with selection and breeding potential.
基金This paper was supported by National Natural Science Foundation of China (Grant No. 39670607).
文摘The classification of seedlings is important to ensure the viability of seedlings after transplantation and is acknowledged as a key factor in forestation and environmental improvement. Based on numerous papers on automatic seedling classification (ASC), the seedling grading theory, traditional grading methods, the background and the proceeding of ASC techniques are described. The automation of the measurement of seedling morphological characteristics by photoelectric meters and computer vision is studied, and the automatic methods of the current grading systems are described respectively. And the further researches on ASC by computer vision are proposed.
基金funded by the National High-Tech R&D Program of China (2013AA103003)the Agricultural Research Special Funds for Public Welfare Projects,China (201303108)
文摘The aim of this study was to evaluate the growth of rape (Brassica napus L.) seedlings under different light intensities to select appropriate conditions for cultivation in an indoor system. Seedlings were grown under different light intensities of red and blue light provided by light-emitting diodes (LEDs) and their self-adjustment ability and changes in leaf microstructure were evaluated. Light was supplied by red LEDs with peak wavelengths of 630 (R1) and 660 nm (R2) and by blue LEDs (B) with a peak wavelength of 445 nm (the light intensity ratio of R1:R2:B was 3:3:2), at intensities of 400 (R1R2B400), 300 (R1R2B300), and 200 μmol m-2 s-1 (R1R2B200). Natural solar light served as the control (C). Plant height, stem diameter, root length, leaf area, and dry weight of rape seedlings gradually increased with increasing light intensity. The seedlings in the R1R2B400 treatment grew more vigorously, while those in the R1R2B200 treatment were weaker. The photosynthetic pigment contents did not differ significantly between the R1R2B400 treatment and C, but were significantly lower in the R1R2B300 and R1R2B200 treatments. The highest intercellular CO2concentration, stomatal conductance, and transpiration rate were in the R1R2B300 treatment. The highest photosynthetic rate was in the R1R2B400 treatment, and was related to more compact leaves, thicker and tidier palisade and spongy tissues, and well-developed chloroplasts. In contrast, the seedlings in the R1R2B200 treatment had disordered mesophyll cells, round chloroplasts, and fractured and fuzzy grana lamellae, all of which inhibited plant growth. In conclusion, the seedlings in the R1R2B400 treatment had well-developed leaves, which favored photosynthesis. Compared with the light intensities below 300 μmol m-2 s-1, the light intensity of 400 μmol m-2 s-1 provided by a cembination of red and blue LEDs was beneficial for cultivating strong and healthy rape seedlings in an artificial system.
基金funded by the Chinese National Key Projects for Basic Scientific Research (No.2009CB421303)the Chinese National Support Projects of Science and Technology (No.2011BAC07B02)+1 种基金the Strategic Leading Science and Technology Project of Chinese Academy of Sciences (No.XDA05050201-04-01)the Chinese National Science Foundation (No.41371053)
文摘This paper focuses on the growth response of Caragana microphylla seedlings to changes of artificially controlled water table in Horqin Sandy Land, China. Monitoring results of soil water content shows that soil moisture is closely correlated to groundwater depths. Soil volumetric water increased rapidly when close to water sources and finally stabilized in a saturated state. The soil moisture trend of CK (control) increased gradually at 0-50 cm of soil depth then decreased to 4% below 50 cm soil depth. C. microphylla can adapt to different soil environments by changes in ecological and physiological characteristics. By comparing the ecological characteristics of C. microphylla seedlings at various water tables, we found that a shallow water table of 40 cm depth inhibited seedling groundwater depth of 120 em was more advantageous for plant growth because of weak ecological characteristics. A height and canopy growth of C. microphylla seedlings. During the first two years, the most suitable water depth for root biomass was 120 cm, and 180 cm for root length. The growth of vertical roots is positively correlated with groundwater depth, and root thickness is the determinate factor for root biomass while the fine root is the determinate factor for root length. A thick root would grow much more in a natural drought environment while access to ground water promotes the growth of fine roots.
基金supported by the National Natural Science Foundation of China(Grant No.31960256)Graduate Innovation Program of Key Laboratory of Forest Ecology in Tibet Plateau,Ministry of Education(XZA-JYBSYS-2021-Y13)+1 种基金the Central Government Guides Local Science and Technology Development Projects,China(XZ202101YD0016C)the Independent Research Project of Science and Technology Innovation Base in Tibet Autonomous Region(XZ2022JR0007G)。
文摘Biomass of seedlings at different developing stages of growth is important information for studying the response of species to site conditions.The objectives of this study was to explore the distribution characteristics of AGB(above-ground biomass)and BGB(below-ground biomass)of Abies georgei var.smithii seedlings of different ages,and investigate the effects of topography(slope aspect,altitude),plant community characteristics(crown density,species diversity,etc.),and soil properties(soil physical and chemical properties)on the biomass and its allocation.Seedlings in five age classes(1–2,3–4,5–6,7–8,and 9–10 years old)were collected by full excavation from 6 elevations(3800 m,3900 m,4000 m,4100 m,4200 m,4300 m)on the north and south slopes of Sejila Mountain in Tibet.15seedlings of each age class were investigated at one altitude.The individual effects of seedling age(SA)and the interaction effects of SA,slope aspect(SL),and elevation(EG),namely,SL×EG,SL×SA,EG×SA,and SL×EG×SA,had significant effects on the AGB of the seedlings(p<0.05),whereas BGB was only significantly affected by SA(p<0.001).The AGB and BGB of the seedlings showed a binomial growth trend with the increase in seedling age,and had an allometric relationship at different elevations,α(allometric exponential)varied from 0.913 to 1.046 in the northern slope,and from 1.004 to 1.268 in the southern slope.The biomass of seedlings on the northern slope was remarkably affected by stand factors,with a contribution rate of 47.8%,whereas that on the southern slope was considerably affected by soil factors with a contribution rate of 53.2%.The results showed that age was the most important factor affecting seedling biomass.The allometric pattern of seedling biomass was relatively stable,but in a highaltitude habitat,A.georgei var.smithii seedlings increased the input of BGB.Understanding seedling biomass allocation and its influencing factors is useful for evaluating plants’ability to acquire resources and survival strategies for adaptation to the environment in Tibet Plateau.
基金Supported by the Innovation Platform Open Fund of Education Department in Hunan Province (18K100)。
文摘In this study, we employed a temporary immersion bioreactor(TIB)system for the micropropagation of strawberry seedlings. The TIB method and the conventional method for the micropropagation of strawberry seedlings were compared in terms of explant propagation coefficient, seedling fresh weight,contents of anthocyanins and chlorophyll, and photosynthetic characteristics. The results showed that an inoculation density of 40 explants/L was suitable for the micropropagation of ’Benihope’ strawberry seedlings in the TIB. The propagation coefficient, fresh weight, photosynthetic rate, stomatal conductance, transpiration coefficient, and the contents of total anthocyanins and chlorophyll of seedlings micropropagated in the TIB were significantly higher than those of the seedlings micropropagated by the conventional method. In conclusion, the TIB method was superior to the conventional method in the micropropagation of strawberry seedlings.The negative reciprocity did not occur between anthocyanins and chlorophyll in strawberry seedlings cultured under forced ventilation such as TIB.
文摘A survey was conducted in 2011 in the major date growing regions of Saudi Arabia to identify and evaluate date palms with fruit characteristics preferred by the producers and consumers. The regions in the Kingdom surveyed for this purpose were Al-Zulfi, Al-Hassa, Najran, Al-Madinah Al-Munawarah and AI-Qassim. Seventy palms from seedlings were initially identified for the study based on the following fruit characteristics, i.e., fruit length, breadth, weight, color, taste, texture, sugar content, external appearance and also the market value. Subsequently, 12 palms (Al-Afiah, Duhiba, Adbah, Aliah, Shamshula, Masifat Al-Asedy, Suwaid, Batlyah, AI-Nassar, Hussan, Sukariyat Al-Zulfi and Al-Hamat) mainly from the Zulfi and Riyadh regions were found to meet the required standards with potential for commercial date farming. Among these, fruits of Adbah had the highest total sugars of 72.9% followed by Duhiba with a total sugar content of 71.9%. Fruit length was maximum (49.1 mm) in the variety Allah, while the fruits of the variety Hussan recorded the maximum weight of 19.5 g. Furthermore, it is pertinent to mention that fruit size of the 12 selected cultivars was generally large and comparable to Majdool, a well-known date palm cultivar of North Africa. The fruits of the selected cultivars were also tasty and can be stored separately.
文摘Stomatal characteristics and its plasticity were surveyed in leaves of four canopy species, Shoreachinensis, Pometia tomentosa, Anthocephalus chinensis, Calophyllun polyanthum and three middle-layerspecies, Barringtonia pendula, Garcinia hanburyi, Horsfieldia tetratepala, acclimated to different lightconditions for more than one year. All plants stomata are distributed on the abaxial of leaves. Pometiatomentosa and Barringtonia pendula have higher stomatal density and the guard cell length of Anthocephaluschinensis and Calophyllun polyanthum were much greater than others. Stomatal density and stomatal index(ratio of stomatal numbers to epidermal cell number) were increased with growth irradiance increased, whilenumbers of stomata per leaf were higher in the low than the high relative PFD, and stomatal conductance ofleaves was the highest in the 50% of full light except for Anthocephalus chinensis. The relative PFD has littleeffects on the guard cell length of all seven plants. We have also found a significant negative correlationbetween stomatal density and leaf area, but the stomatal conductance was not significantly positive with thestomatal conductance. The analysis of phenotypic plasticity of stomatal characteristics showed: plasticityindex for stomatal index and numbers of stomatal per leaf were similar for canopy and middle-layer species,while the plasticity index of stomatal density and stomatal conductance were significantly greater for canopyspecies than middle-layer species. The high plasticity of canopy species was consistent with the hypothesisthat specialization in a more favorable environment increases plasticity.
文摘In this article,we investigated effects of lead and cadmium on the biomass of ginkgo seedlings, and roles of the seedlings in accumulation characteristics of the heavy metals and remediation of the soil contaminated by Cd<sup>2+</sup> or Pb<sup>2+</sup> as well as their combination.The results showed that both Cd<sup>2+</sup> and Pb<sup>2+</sup> significantly or very significantly reduced biomass increment of ginkgo seedlings,with Pb<sup>2+</sup> more adverse than Cd<sup>2+</sup>.The Cd<sup>2+</sup>-Pb<sup>2+</sup> compound pollution further reduced biomass increment of ginkgo seedlings.The mass fractions and enrichment coefficient of Pb<sup>2+</sup> and Cd<sup>2+</sup> in ginkgo seedlings were in an order of root】stem】leaf,which was in favor of transportation Pb<sup>2+</sup> and Cd<sup>2+</sup> from root to stem and leave.The Cd<sup>2+</sup>-Pb<sup>2+</sup> compound pollution promoted ginkgo seedling absorption to Cd<sup>2+</sup> and Pb<sup>2+</sup>.The capacity of the upward transport of Pb<sup>2+</sup> was greater than that of Cd<sup>2+</sup>,which suggested an obvious dose-effect and synergistic effect.Cd<sup>2+</sup> and Pb<sup>2+</sup> accumulations in ginkgo seedlings were relatively large.The accumulation in roots was higher than that in stems and leaves.The ability of the absorption,transportation and accumulation of ginkgo seedlings to Pb<sup>2+</sup> was relatively greater under Cd<sup>2+</sup>-Pb<sup>2+</sup> compound pollution.The phytoremediation efficiency of Cd<sup>2+</sup> and Pb<sup>2+</sup> was relatively high.
文摘为深入了解施用氯化钠(NaCl)对椰子幼苗生理特性的影响,通过施用不同量的NaCl,30 d后测定叶绿素含量、丙二醛(MDA)含量、可溶性糖含量、脯氨酸含量、超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性。结果显示:施用100 g和150 g NaCl时,叶绿素含量显著升高,MDA和可溶性糖含量明显降低,POD、SOD和CAT活性显著增加,脯氨酸含量少量增加;200 g NaCl处理条件下叶绿素含量显著降低,MDA和可溶性糖含量明显减少,SOD和CAT活性显著降低,脯氨酸含量显著增加。试验表明适量施用NaCl可以增强椰子幼苗光合作用,抑制膜脂过氧化,促进物质转化等。