[Objectives]To study the differences of growth rate,morphology,ultrastructure,pigment content and antioxidant enzyme activity of free-living conchocelis of cultivated type of Neopyropia yezoensis under different light...[Objectives]To study the differences of growth rate,morphology,ultrastructure,pigment content and antioxidant enzyme activity of free-living conchocelis of cultivated type of Neopyropia yezoensis under different light qualities(white,red,blue,and green light).[Methods]The study was carried out through light quality design and culture,growth rate determination,microstructure and ultrastructure observation,chlorophyll a content and carotenoid content determination,phycobiliprotein content determination,malondialdehyde(MDA)content determination,superoxide dismutase(SOD)activity determination.[Results]After 21 d of culture,the specific growth rate(SGR)and chlorophyll a content of free-living conchocelis of N.yezoensis were significantly increased by white light(WL),followed by red light(RL)and green light(GL),and they were the lowest under blue light(BL).Compared with the WL group,the BL group had the highest content of phycoerythrin(PE),and the RL and GL groups had the highest content of phycocyanin(PC).The algal body of WL group was normal black brown,and the cell wall was the thickest.In RL and GL groups,the algal bodies were green,and their diameters and cell wall thicknesses were similar to those in WL group.In BL group,the algal body was bright red,the diameter was the smallest,the cell wall was the thinnest,and the ultrastructure showed that the number of plastoglobulus on the thylakoid was the largest.After BL irradiation,the highest MDA content and the lowest SOD activity were observed.The results revealed that WL is the most beneficial to the growth of free-living conchocelis,followed by RL and GL,while BL has adverse effects.[Conclusions]This study explored the most suitable light quality conditions for the propagation of free-living conchocelis.It is expected to provide germplasm guarantee for the production and seedling of N.yezoensis.展开更多
[Ohjective] The aim of the study is to investigate the productivity and light quality in two high density M26 dwarf rootstock apple orchards in central China so as to provide some management guidance for close plantin...[Ohjective] The aim of the study is to investigate the productivity and light quality in two high density M26 dwarf rootstock apple orchards in central China so as to provide some management guidance for close planting of dwarf rootstock apples.[Method] The technical parameters of individual trees and group parameters as shoot number and composition and canopy coverage were determined, and the light quality in the canopy, fruit production and quality were investigated. [Result] Slender spindle （SS） orchard has 54 thousands shoots per 667 m^2. Coverage rate is 76%. Leaf area index is 1.9. The ratio of long, medium and spur shoots is 1：1：8. Fruit yield is 3 263 kg/667 m^2 with 85% first grade fruit. Light interception in the canopy is 58% while the ratio of canopy with good light is 65%. Modified slender spindle （MSS） orchard has 93 thousands shoots per 667 m^2 and the coverage is 77%. Leaf area index is 3.3. The ratio cf long, medium and spur shoots is 1：2：7. Fruit yield is 3 931 kg/667 m^2 with 85% first grade fruit. The light interception in the canopy is 73% while the ratio of canopy with good light is 35%. [Conclusion] Apple orchard with M26 dwarf rootstock trained as SS and MSS tree form in medium planting density may be useful to the management of the similar orchards in Central China.展开更多
Phytochemicals（including proteins, lipids, carbohydrates, vitamins, minerals,phenolic compounds and so on） are one of the most important groups of the bioactive compounds in vegetables and fruits, benefit for human ...Phytochemicals（including proteins, lipids, carbohydrates, vitamins, minerals,phenolic compounds and so on） are one of the most important groups of the bioactive compounds in vegetables and fruits, benefit for human health. The phytochemicals biosynthesis is affected by environmental factors, and light in particular. Light effects can be categorized in photoperiod, intensity and quality. While it is widely known that light intensity can positively affect phytochemicals accumulation, the effects of light quality are more complex and often reported with mixed results. So this review focuses on the currently knowledge about different light quality on the control of phytochemicals biosynthesis. A better knowledge on these regulatory mechanisms will be useful for modifying phytochemicals biosynthesis in vegetables and fruits.展开更多
Under natural conditions, plants constantly encounter various biotic and abiotic factors, which can potentially restrict plant growth and development and even limit crop productivity. Among various abiotic factors aff...Under natural conditions, plants constantly encounter various biotic and abiotic factors, which can potentially restrict plant growth and development and even limit crop productivity. Among various abiotic factors affecting plant photosynthesis, light serves as an important factor that drives carbon metabolism in plants and supports life on earth. The two components of light(light quality and light intensity) greatly affect plant photosynthesis and other plant's morphological, physiological and biochemical parameters. The response of plants to different spectral radiations and intensities differs in various species and also depends on growing conditions. To date, much research has been conducted regarding how different spectral radiations of varying intensity can affect plant growth and development. This review is an effort to briefly summarize the available information on the effects of light components on various plant parameters such as stem and leaf morphology and anatomy, stomatal development, photosynthetic apparatus, pigment composition, reactive oxygen species(ROS) production, antioxidants, and hormone production.展开更多
The photosynthetic characteristics of strawberry (Fragariaananassa Duch. cv. Toyonoka)leaves under illumination of identical light intensity(55-57% natural light) withdifferent light quality were studied. It was showe...The photosynthetic characteristics of strawberry (Fragariaananassa Duch. cv. Toyonoka)leaves under illumination of identical light intensity(55-57% natural light) withdifferent light quality were studied. It was showed that the chlorophyll content,maximal photochemical efficiency of PSⅡ(Fv/Fm), Fm/Fo, amount of inactive PSⅡreactioncenters (Fi-Fo) and rate of QA reduction were positively correlated with the red-light/blue-light ratios, but the chlorophyll (a/b) ratios were negatively correlated withthem. Carotenoid content of the leaves was maximum under the blue film, than under greenfilm, red film, white film and yellow film, and negatively correlated with the red/far-red ratios. The apparent quantum yield (AQY), photorespiratory rate (Pr) and carboxylationefficiency (CE) were also strongly affected by light quality. The photosynthetic rate(Pn) in strawberry leaves under green film was significantly lower than under all otherfilm. Our results suggested that light quality is an essential factor regulating thedevelopment of PSⅡ, and phytochrome and an independent blue light photoreceptor,possibly a cryptochrome, can regulate photosynthetic performance.展开更多
An experiment was carried out to examine the effects of light quality on the growth and development of antirrhinum under three different temperatures 19℃, 24℃ and 27℃ in glasshouses. Five different colour filters (...An experiment was carried out to examine the effects of light quality on the growth and development of antirrhinum under three different temperatures 19℃, 24℃ and 27℃ in glasshouses. Five different colour filters (i.e. 'Red absorbing', 'Blue absorbing', 'Blue and Red absorbing' and two 'partially Blue absorbing' materials) were tested, with one clear polythene as a control. Plant height, internode length and leaf area were significantly affected by the spectral filters as well as the temperature.Analysis of color filter's effect on presumed photoreceptors to exist indicated that antirrhinum plant height was regulated by the action of a blue acting photoreceptor (BAP) and not the phytochrome. There was no evidence for an effect ofphytochrome or BAP on time to flowering, however, increasing temperature levels effectively decreased the time to flowering. To predict the effects of different spectral qualities and temperature, simple models were created from data on plant height, internode length and time to flowering. These models were then applied to simulate the potential benefits of spectral filters and temperature in manipulation of growth control and flowering in antirrhinum.展开更多
[Objective] This study was conducted to provide theoretical and data reference for high-quality high-yield production of Shangqie 1 under controlled light quality environment and light quality control of other eggplan...[Objective] This study was conducted to provide theoretical and data reference for high-quality high-yield production of Shangqie 1 under controlled light quality environment and light quality control of other eggplant varieties. [Method] With Shangqie1 as an experiment material, the effects of red light, blue light, red-blue light, red-blue light and white light(control) on the carbon-nitrogen metabolism and root vitality of eggplant were investigated. [Result] Different light quality significantly affected sugar and starch contents in leaves of eggplant. Under the red-blue light(5∶1) treatment, the sucrose, total sugar and starch contents were the highest, and the values were higher than those under the white light treatment by 3.47%, 13.61% and 33.49%,respectively. The fructose content was the highest under white light. Under red-blue light(3∶1) and red-blue light(5∶1), the nitrate nitrogen contents were higher than that under white light, indicating that compound light affects nitrate content not only by simple superposition of light quality, but also by other type of interaction effect. The free amino acid and soluble protein contents under blue, red-blue(3∶1), red-blue(5∶1) and red light treatments were all higher than those under the white light treatment, and the blue light treatment exhibited the highest values, which were higher than those under white light by 24.89% and 46.62%, respectively, with significant differences. The red-blue light(5 ∶1) treatment exhibited the highest root vitality of eggplant, which was higher than that under the white light treatment by 31.85%. The red light treatment had the second highest root vitality, which was higher than that under the white light treatment by 19.30%, followed by the red-blue light(5∶1) treatment, and the blue light treatment showed the lowest value. [Conclusion] Under red-blue light(5 ∶1) treatment, eggplant had vigorous carbon-nitrogen metabolism and the highest root vitality.展开更多
The possibility of associative learning in plants is a topic of ongoing controversy.In one published study,growing pea plants were reported to associate two stimuli(airflow and light)and thereafter use one(airflow)as ...The possibility of associative learning in plants is a topic of ongoing controversy.In one published study,growing pea plants were reported to associate two stimuli(airflow and light)and thereafter use one(airflow)as an indicator for the other(light),similar to dogs in Pavlov’s famous experiments.However,this observation could not be independently repeated.Here we examine a possible reason for the failure of a published reproduction attempt,which used substantially different light quality during plant cultivation prior to experimental treatments than in the original study.This could have resulted in dramatically different growth characteristics.While the relevance of the original report of plant associative learning remains questionable,greater attention should be paid to good documenting and standardizing the light conditions,in particular spectral quality,not only in studies of plant learning and memory,but also in other areas of experimental plant biology.展开更多
Proper timing of flowering under different environmental conditions is critical for plant propagation.Light quality is a pivotal environmental cue that plays a critical role in flowering regulation.Plants tend to flow...Proper timing of flowering under different environmental conditions is critical for plant propagation.Light quality is a pivotal environmental cue that plays a critical role in flowering regulation.Plants tend to flower late under light with a high red(R)/far-red(FR)light ratio but early under light with a low R/FR light ratio.However,how plants fine-tune flowering in response to changes in light quality is not well understood.Here,we demonstrate that F-box of Flowering 2(FOF2),an autonomous pathway–related regulator,physically interacts with VASCULAR PLANT ONE-ZINC FINGER 1 and 2(VOZ1 and VOZ2),which are direct downstream factors of the R/FR light receptor phytochrome B(PHYB).We show that PHYB physically interacts with FOF2,mediates stabilization of the FOF2 protein under FR light and end-of-day FR light,and enhances FOF2 binding to VOZ2,which leads to degradation of VOZ2 by SCF^(FOF2) E3 ligase.By contrast,PHYB mediates degradation of FOF2 protein under R light and end-of-day R light.Genetic interaction studies demonstrated that FOF2 functions downstream of PHYB to promote FLC expression and inhibit flowering under both high R/FR light and simulated shade conditions,processes that are partially dependent on VOZ proteins.Taken together,our findings suggest a novel mechanism whereby plants fine-tune flowering time through a PHYB–FOF2–VOZ2 module that modulates FLC expression in response to changes in light quality.展开更多
Saccharina japonica gametophytes can survive a long period under unfavorable environmental conditions,while they also delay in growth and/or reproduction.Although the reproduction in delayed gametophyte of S.japonica ...Saccharina japonica gametophytes can survive a long period under unfavorable environmental conditions,while they also delay in growth and/or reproduction.Although the reproduction in delayed gametophyte of S.japonica was known to be strongly influenced by light intensity,light quality,and photoperiod,no previous studies have evaluated their interactive effects on gametogenesis.To evaluate these effects,we used an orthogonal experiment to expose delayed gametophytes of S.japonica to different light intensities,light qualities,and photoperiods for 12 days.The results showed that changes in light intensity rather than light quality and photoperiod significantly affected the relative growth rates of the delayed gametophytes.Blue light had the greatest promotion on reproduction rate.The optimal light conditions in the early vegetative growth phase in gametogenesis induction for the delayed gametophytes were at 60–80μmol photons m^(−2) s^(−1) with daylength of 12 or 16 hours under white or blue light.When the delayed gametophytes were maintained in a constant light condition from delayed state to gametogenesis,the beneficial photoperiods for vegetative growth and reproductive rate were both 16L(16 hours of light):8D(8 hours of dark).However,when the delayed S.japonica gametophytes achieve the optimal growth state during the first 6 days and then they were cultured at different light conditions for the following 6 days,the reproduction rate increased as the daylength decreased and attained a peak value in group of 8L:16D photoperiod,indicating that photoperiod adjustment at the transition period is crucial in the gametogenesis induction process of delayed gametophyte of S.japonica.展开更多
Previous studies have shown that high light intensity can induce anthocyanin synthesis(AS)in petunia plants.To identifywhich kind of light quality plays a role in inducing such metabolic process,and what transcripts p...Previous studies have shown that high light intensity can induce anthocyanin synthesis(AS)in petunia plants.To identifywhich kind of light quality plays a role in inducing such metabolic process,and what transcripts participate in controlling it,we carried out whole-transcriptome sequencing and analysis of petunia petals treated with different light-quality conditions.Among the red and white light treatments,a total of 2205 differentially expressed genes and 15,22,and 20 differentially expressed circRNAs,miRNAs,and lncRNAs,were identified respectively.The AS-related genes,including the structural genes CHSj,F3H,F35H,DFR,and ANS,and the regulatory genes AN4,DPL,PHZ and MYBx were found to be downregulated under red light condition compared with their levels under white light condition.Furthermore,the light photoreceptor Cryptochrome 3(CRY3)and a series of light-dependent genes,such as PIF,HY5,andBBXs,were also determined to respond to the light treatments.The anthocyanin contents in early petunia petals under red light were significantly lower than that under white and blue light.The results of qRT-PCR further confirmed the expression pattern of some AS-related and light-response genes in response to different light quality.Yeast two-hybrid results showed that the key elements in the light signal pathway,HY5 can interact with BBX19,BBX24 and BBX25.And PHZ,the important AS regulator can induce anthocyanin synthesis in response to blue light quality fromtransient expression analysis in petunia petals.These findings presented here not only deepen our understanding of how light quality controls anthocyanin synthesis,but also allow us to explore potential target genes for improving pigment production in petunia flower petals.展开更多
The extensive environment,especially low temperature and weak lighting in winter and spring,which limits the growth of pepper(Capicum annuum L.)seedlings,the use of plant factory with artificial lighting technology ca...The extensive environment,especially low temperature and weak lighting in winter and spring,which limits the growth of pepper(Capicum annuum L.)seedlings,the use of plant factory with artificial lighting technology can effectively control the lighting environment to produce high-quality seedlings.In this study,white LED lamps with R:B ratio of 0.7(L0.7)and 1.5(L1.5)and red-blue LED lamps with R:B ratio of 3.5(L3.5)were used to cultivate seedlings of“CAU-24”pepper in the light intensity of 250μmol/m^(2)·s and photoperiod of 12 h/d,white fluorescent lamps with R:B ratio of 1.7(F1.7)was used as control.The results showed that plant height,stem diameter,hypocotyl length,biomass accumulation,light energy use efficiency(LUE)and electric energy use efficiency(EUE)of pepper seedling under L1.5 were the highest.After 36 days of sowing,the dry weight of shoot reached 302.8±45.2 mg/plant.Leaf area reached maximum value of 153.5±22.0 cm^(2) under L0.7.The contents of chlorophyll a,chlorophyll b and total chlorophyll of pepper seedling leaves under all kinds of LED light were greater than F1.7,but there was no significant difference in net photosynthetic rate.The total dry weight with lamp electric power consumption of L1.5 were 3.0 g/(kW·h)which was 1.5,2,and 3 times greater than that of L3.5,L0.7,and F1.7,respectively.Therefore,compared with fluorescent lamp and other LED lamps,the white LED light quality with R:B ratio of 1.5 is suitable for pepper seedling production in plant factory because of the high LED lighting efficiency,greater LUE and EUE.展开更多
Objective： Light quality has effect on the accumulation of gypenosides in the medicinal plant Gynosternma pentaphyllum in the family Cucurbitaceae, while the squalene synthase （SS） and squalene epoxidase （SE） are...Objective： Light quality has effect on the accumulation of gypenosides in the medicinal plant Gynosternma pentaphyllum in the family Cucurbitaceae, while the squalene synthase （SS） and squalene epoxidase （SE） are the key enzymes for gypenoside biosynthesis, The objective of this study was to elucidate the rela- tionship between light quality and biosynthesis key enzyme involving the regulation of gypenoside accu- mulation. Methods： The content of total gypenosides was measured by colorimetric method and the expression of SS and SE gene was determined by quantitative Real-time PCR in the seedlings of G. pentaphyllum which were grown with different light quality. Results： Light quality showed remarkable impacts on the accumulation of total gypenosides. The highest content of total gypenosides in the plant under red light condition was determined, followed by blue light and white light, while the lowest content was recorded under dark condition, qRT-PCR analysis proved that the expression levels of SS and SE genes were also affected by light quality. The high-level gene expressions of SS and SE were found in the plant under red light condition, followed by blue light, with the least content in darkness. The statistical analysis revealed that the total gypenosides were significantly different in different light treatment and the content of total gypenosides was positively related to the expression of SS and SE genes. Conclusions： Light quality regulates gypenoside accumulation via altering the expression of SS and SE in G. pentaphyllum.展开更多
Pavlova sp.is not only one of the most popular microalgae in aquaculture,but also a source of high-quality biodiesel feedstock.With white light as a control(W),Pavlova sp.was cultured in this study under varying light...Pavlova sp.is not only one of the most popular microalgae in aquaculture,but also a source of high-quality biodiesel feedstock.With white light as a control(W),Pavlova sp.was cultured in this study under varying light quality,including monochromatic red light(R),blue light(B),and combinations thereof with different proportions(illuminators of m Rn B,comprised of m red light units and n blue ones,m+n=7),to examine the effects of illuminating light quality on biocomponent production and biodiesel quality.The results show that combined monochromatic light,especially 2R5B,3R4B,4R3B,and 5R2B,could improve the growth of Pavlova sp.The dry weight of harvested algae powder in the 5R2B group reached 418.03 mg/L,and was 22.65%higher than that in the control group(W).Lipid production under combined monochromatic light of 4R3B reached 107.86 mg/L,and was 25.61%higher than in the control(W).In addition,illumination using 4R3B increased the proportion of C16∶0(palmitic acid)and C16:1(palmitoleic acid)fatty acids in Pavlova sp.by 15.55%and 21.94%,respectively,which translates into improved biodiesel quality.All cetane numbers(CN)for 4R3B–6R1B were over 51,while iodine values(IV)and degrees of unsaturation(DU)were reduced,leading to more stable biodiesel suitable for longterm storage.In addition,protein production under 6R1B was as high as 31.56 mg/L,1.8 times greater than under W.Light quality is proposed as an effective tool to regulate biocomponent production by microalgae.展开更多
In the next three to five years, China’s light industry will upgrade major product quality generally to world level. This will be done by strengthening quality control and supervision and the improvement in technolog...In the next three to five years, China’s light industry will upgrade major product quality generally to world level. This will be done by strengthening quality control and supervision and the improvement in technology. The campaign was announced by Yu Zhen, president of the China National Council of Light Industry at the beginning of this year.展开更多
[Objective] The aim was to study the properties of novel ＂light fertilizer＂, photo-conversion film, in order to evaluate its effect on the environmental factors and morphogenetic process of crops in the high tunnel....[Objective] The aim was to study the properties of novel ＂light fertilizer＂, photo-conversion film, in order to evaluate its effect on the environmental factors and morphogenetic process of crops in the high tunnel. [Method] Photo-conversion film and Iongevous anti-dropping film were compared in terms of light, air and soil temperature utilizing the Facilities of leafy agriculture high tunnel intelligent monitoring system. Verifying the results by farmland experiment. [Result] Photo- conversion film indeed improved the light quality of high tunnel compared with the Iongevous anti- dripping film. The air and soil temperature was raised several degrees. Results of farmland experiment show that the average value of brassica chinensis fresh weight increased 19.15% compared to the control. [Conclusion] Photo-conversion film promotes more crop growth than Iongevous anti-dropping film due to improvement of light quality, air and soil temperature.展开更多
[Objective] The study aimed to investigate the activity and gene expression of caspase-like proteases in tobacco leaves growing under different light qualities. [Method] By covering tobacco plants with white, red, yel...[Objective] The study aimed to investigate the activity and gene expression of caspase-like proteases in tobacco leaves growing under different light qualities. [Method] By covering tobacco plants with white, red, yellow, blue and purple films to obtain different light quality, the changes of chlorophyll content, activity and gene expression of caspase-like proteases in the tobacco leaves were studied. [Results] Compared with treatments of white, red and yellow film, blue and purple films delayed the decrease of chlorophyll content and senescence of tobacco leaves at the late growth stage, and relatively lowered the activity and gene expression of caspase-like proteases during growth, development and senescence periods. [Conclusion] Different light qualities exhibited various effects on the growth, development and senescence of tobacco leaves, possibly by affecting the activity and gene expression of caspase-like proteases to some extent.展开更多
Climate change and extreme weather pose significant challenges to the traditional viticulture regions.Emerging high-altitude grape-producing regions with diverse orientations have shown great potential in coping with ...Climate change and extreme weather pose significant challenges to the traditional viticulture regions.Emerging high-altitude grape-producing regions with diverse orientations have shown great potential in coping with this challenge.Stable,high-quality wine grape production may be achieved by synchronizing the meso-and microclimate.To clarify the role of high altitude and row orientation in meso-and microclimate and the response of berries to it,we evaluated seven years(2012-2018)of climate data,two years of basic grape(Cabernet Sauvignon,Vitis vinifera L.)quality,and one-year microclimate from veraison to harvest.By comparing two locations(Sidon 2047 m,Sinon 2208 m)in Yunnan Province,China,we found that the average temperature has been stable at approximately 15℃ for seven years,with no extreme weather or,noticeable global warming.The light intensity(LI)in the north-south(NS)was more balanced than the east-west(EW)direction,and the east-west to the south(EW-S)canopy side was almost higher than the other sides.High LI was associated with high photosynthetically active radiation(PAR),ultraviolet(UV),and infrared(IR)light and vice versa.The north-south to the east(NS-E)and east-west to the north(EWN)sides were characterized by lower LI and higher UV and IR light,and higher total anthocyanin content.Most anthocyanin synthesis-related genes,for example,VvF3'H and VvF3'5'H,were highly expressed in NS-E from veraison to maturity.Perhaps UV and IR light induced their expression.This study provides new insights on the role of differently orientated rows in controlling grape quality due to varied light quality.The findings are globally significant,particularly in the context of climate change,and offer fresh insights into berry physiological responses and decision-making for the management of existing vineyards.展开更多
Short basal internodes are important for lodging resistance of rice(Oryza sativa L.).Several canopy indices affect the elongation of basal internodes,but uncertainty as to the key factors determining elongation of bas...Short basal internodes are important for lodging resistance of rice(Oryza sativa L.).Several canopy indices affect the elongation of basal internodes,but uncertainty as to the key factors determining elongation of basal internodes persists.The objectives of this study were(1)to identify key factors affecting the elongation of basal internodes and(2)to establish a quantitative relationship between basal internode length and canopy indices.An inbred rice cultivar,Yinjingruanzhan,was grown in two split-plot field experiments with three N rates(0,75,and 150 kg N ha−1 in early season and 0,90,and 180 kg N ha−1 in late season)as main plots,three seedling densities(16.7,75.0,and 187.5 seedlings m−2)as subplots,and three replications in the 2015 early and late seasons in Guangzhou,China.Light intensity at base of canopy(Lb),light quality as determined from red/far-red light ratio(R/FR),light transmission ratio(LTR),leaf area index(LAI),leaf N concentration(NLV)and final length of second internode(counted from soil surface upward)(FIL)were recorded.Higher N rate and seedling density resulted in significantly longer FIL.FIL was negatively correlated with Lb,LTR,and R/FR(P<0.01)and positively correlated with LAI(P<0.01),but not correlated with NLV(P>0.05).Stepwise linear regression analysis showed that FIL was strongly associated with Lb and LAI(R2=0.82).Heavy N application to pot-grown rice at the beginning of first internode elongation did not change FIL.We conclude that FIL is determined mainly by Lb and LAI at jointing stage.NLV has no direct effect on the elongation of basal internodes.N application indirectly affects FIL by changing LAI and light conditions in the rice canopy.Reducing LAI and improving canopy light transmission at jointing stage can shorten the basal internodes and increase the lodging resistance of rice.展开更多
Light-emitting diodes(L EDs)are a new light source with low energy consumption and high photoelectric conversion efficiency,and they can satisfy the energy-saving needs of plant culture systems.However,the effects of ...Light-emitting diodes(L EDs)are a new light source with low energy consumption and high photoelectric conversion efficiency,and they can satisfy the energy-saving needs of plant culture systems.However,the effects of LED light sources on rice tissue culture and rice seedling cultivation are poorly understood.This study aimed to evaluate the effects of LEDs on the growth of tissue culture plantlets and seedlings of the rice(Oryza sativa L.)cultivar Nipponbare.The best light source for rice tissue culture was different from that for rice seedling cultivation.Blue(B)LED light was the most appropriate light for rice tissue culture.Under a B LED light,the time required for callus proliferation,differentiation and regeneration was the shortest,and the frequency of plantlet ititin,dfferetiation and regeneration was the highest.Ablue:red(B:R)=1:1LED light facilitated the growth of rice seedlings and produced the highest chlorophyll and carotenoid contents and photosynthetic rates in the rice seedlings.Abundant photosynthetic products were more effectively generated in the rice seedlings under the B:R=1:1 LED and R LED lights than under the B LED light.B LED light is the most appropriate light for rice tissue culture plantlets and can be used as an alternative light source for rice tissue culture,and B:R=1:1 LED light facilitated the cultivation of robust rice seedlings and can be used as the primary light source for rice factory seedling cultivation.展开更多
基金Supported by National Algae System(CARS-50)Modern Agricultural(Laver)Industrial Technology System of Jiangsu Province(JATS[2023]381)Research Project of Nantong City(MS22022065).
文摘[Objectives]To study the differences of growth rate,morphology,ultrastructure,pigment content and antioxidant enzyme activity of free-living conchocelis of cultivated type of Neopyropia yezoensis under different light qualities(white,red,blue,and green light).[Methods]The study was carried out through light quality design and culture,growth rate determination,microstructure and ultrastructure observation,chlorophyll a content and carotenoid content determination,phycobiliprotein content determination,malondialdehyde(MDA)content determination,superoxide dismutase(SOD)activity determination.[Results]After 21 d of culture,the specific growth rate(SGR)and chlorophyll a content of free-living conchocelis of N.yezoensis were significantly increased by white light(WL),followed by red light(RL)and green light(GL),and they were the lowest under blue light(BL).Compared with the WL group,the BL group had the highest content of phycoerythrin(PE),and the RL and GL groups had the highest content of phycocyanin(PC).The algal body of WL group was normal black brown,and the cell wall was the thickest.In RL and GL groups,the algal bodies were green,and their diameters and cell wall thicknesses were similar to those in WL group.In BL group,the algal body was bright red,the diameter was the smallest,the cell wall was the thinnest,and the ultrastructure showed that the number of plastoglobulus on the thylakoid was the largest.After BL irradiation,the highest MDA content and the lowest SOD activity were observed.The results revealed that WL is the most beneficial to the growth of free-living conchocelis,followed by RL and GL,while BL has adverse effects.[Conclusions]This study explored the most suitable light quality conditions for the propagation of free-living conchocelis.It is expected to provide germplasm guarantee for the production and seedling of N.yezoensis.
基金Supported by National Apple Industry Programs of Ministry of Agriculture(CARS-28)~~
文摘[Ohjective] The aim of the study is to investigate the productivity and light quality in two high density M26 dwarf rootstock apple orchards in central China so as to provide some management guidance for close planting of dwarf rootstock apples.[Method] The technical parameters of individual trees and group parameters as shoot number and composition and canopy coverage were determined, and the light quality in the canopy, fruit production and quality were investigated. [Result] Slender spindle （SS） orchard has 54 thousands shoots per 667 m^2. Coverage rate is 76%. Leaf area index is 1.9. The ratio of long, medium and spur shoots is 1：1：8. Fruit yield is 3 263 kg/667 m^2 with 85% first grade fruit. Light interception in the canopy is 58% while the ratio of canopy with good light is 65%. Modified slender spindle （MSS） orchard has 93 thousands shoots per 667 m^2 and the coverage is 77%. Leaf area index is 3.3. The ratio cf long, medium and spur shoots is 1：2：7. Fruit yield is 3 931 kg/667 m^2 with 85% first grade fruit. The light interception in the canopy is 73% while the ratio of canopy with good light is 35%. [Conclusion] Apple orchard with M26 dwarf rootstock trained as SS and MSS tree form in medium planting density may be useful to the management of the similar orchards in Central China.
基金Supported by National Natural Science Foundation of Shanghai,China(12ZR1427600)the Fund from Ministry of Science and Technology of China for Momentous Scientific Research of Agriculture Program of Shanghai,China(number 1-8,2014)National Key Technology R&D Program(2014BAD05B05-05)~~
文摘Phytochemicals（including proteins, lipids, carbohydrates, vitamins, minerals,phenolic compounds and so on） are one of the most important groups of the bioactive compounds in vegetables and fruits, benefit for human health. The phytochemicals biosynthesis is affected by environmental factors, and light in particular. Light effects can be categorized in photoperiod, intensity and quality. While it is widely known that light intensity can positively affect phytochemicals accumulation, the effects of light quality are more complex and often reported with mixed results. So this review focuses on the currently knowledge about different light quality on the control of phytochemicals biosynthesis. A better knowledge on these regulatory mechanisms will be useful for modifying phytochemicals biosynthesis in vegetables and fruits.
基金supported by the National Natural Science Foundation of China (31571615)the earmarked fund for China Agriculture Research System (CARS-04-PS19)。
文摘Under natural conditions, plants constantly encounter various biotic and abiotic factors, which can potentially restrict plant growth and development and even limit crop productivity. Among various abiotic factors affecting plant photosynthesis, light serves as an important factor that drives carbon metabolism in plants and supports life on earth. The two components of light(light quality and light intensity) greatly affect plant photosynthesis and other plant's morphological, physiological and biochemical parameters. The response of plants to different spectral radiations and intensities differs in various species and also depends on growing conditions. To date, much research has been conducted regarding how different spectral radiations of varying intensity can affect plant growth and development. This review is an effort to briefly summarize the available information on the effects of light components on various plant parameters such as stem and leaf morphology and anatomy, stomatal development, photosynthetic apparatus, pigment composition, reactive oxygen species(ROS) production, antioxidants, and hormone production.
基金supported by the National Natura1 Science Foundation of China(39730340)
文摘The photosynthetic characteristics of strawberry (Fragariaananassa Duch. cv. Toyonoka)leaves under illumination of identical light intensity(55-57% natural light) withdifferent light quality were studied. It was showed that the chlorophyll content,maximal photochemical efficiency of PSⅡ(Fv/Fm), Fm/Fo, amount of inactive PSⅡreactioncenters (Fi-Fo) and rate of QA reduction were positively correlated with the red-light/blue-light ratios, but the chlorophyll (a/b) ratios were negatively correlated withthem. Carotenoid content of the leaves was maximum under the blue film, than under greenfilm, red film, white film and yellow film, and negatively correlated with the red/far-red ratios. The apparent quantum yield (AQY), photorespiratory rate (Pr) and carboxylationefficiency (CE) were also strongly affected by light quality. The photosynthetic rate(Pn) in strawberry leaves under green film was significantly lower than under all otherfilm. Our results suggested that light quality is an essential factor regulating thedevelopment of PSⅡ, and phytochrome and an independent blue light photoreceptor,possibly a cryptochrome, can regulate photosynthetic performance.
文摘An experiment was carried out to examine the effects of light quality on the growth and development of antirrhinum under three different temperatures 19℃, 24℃ and 27℃ in glasshouses. Five different colour filters (i.e. 'Red absorbing', 'Blue absorbing', 'Blue and Red absorbing' and two 'partially Blue absorbing' materials) were tested, with one clear polythene as a control. Plant height, internode length and leaf area were significantly affected by the spectral filters as well as the temperature.Analysis of color filter's effect on presumed photoreceptors to exist indicated that antirrhinum plant height was regulated by the action of a blue acting photoreceptor (BAP) and not the phytochrome. There was no evidence for an effect ofphytochrome or BAP on time to flowering, however, increasing temperature levels effectively decreased the time to flowering. To predict the effects of different spectral qualities and temperature, simple models were created from data on plant height, internode length and time to flowering. These models were then applied to simulate the potential benefits of spectral filters and temperature in manipulation of growth control and flowering in antirrhinum.
基金Supported by Fund of Shangqiu Academy of Agriculture and Forestry Sciences
文摘[Objective] This study was conducted to provide theoretical and data reference for high-quality high-yield production of Shangqie 1 under controlled light quality environment and light quality control of other eggplant varieties. [Method] With Shangqie1 as an experiment material, the effects of red light, blue light, red-blue light, red-blue light and white light(control) on the carbon-nitrogen metabolism and root vitality of eggplant were investigated. [Result] Different light quality significantly affected sugar and starch contents in leaves of eggplant. Under the red-blue light(5∶1) treatment, the sucrose, total sugar and starch contents were the highest, and the values were higher than those under the white light treatment by 3.47%, 13.61% and 33.49%,respectively. The fructose content was the highest under white light. Under red-blue light(3∶1) and red-blue light(5∶1), the nitrate nitrogen contents were higher than that under white light, indicating that compound light affects nitrate content not only by simple superposition of light quality, but also by other type of interaction effect. The free amino acid and soluble protein contents under blue, red-blue(3∶1), red-blue(5∶1) and red light treatments were all higher than those under the white light treatment, and the blue light treatment exhibited the highest values, which were higher than those under white light by 24.89% and 46.62%, respectively, with significant differences. The red-blue light(5 ∶1) treatment exhibited the highest root vitality of eggplant, which was higher than that under the white light treatment by 31.85%. The red light treatment had the second highest root vitality, which was higher than that under the white light treatment by 19.30%, followed by the red-blue light(5∶1) treatment, and the blue light treatment showed the lowest value. [Conclusion] Under red-blue light(5 ∶1) treatment, eggplant had vigorous carbon-nitrogen metabolism and the highest root vitality.
基金supported by basic institutional funding of scientific activities at the Charles University[Progres Q43].
文摘The possibility of associative learning in plants is a topic of ongoing controversy.In one published study,growing pea plants were reported to associate two stimuli(airflow and light)and thereafter use one(airflow)as an indicator for the other(light),similar to dogs in Pavlov’s famous experiments.However,this observation could not be independently repeated.Here we examine a possible reason for the failure of a published reproduction attempt,which used substantially different light quality during plant cultivation prior to experimental treatments than in the original study.This could have resulted in dramatically different growth characteristics.While the relevance of the original report of plant associative learning remains questionable,greater attention should be paid to good documenting and standardizing the light conditions,in particular spectral quality,not only in studies of plant learning and memory,but also in other areas of experimental plant biology.
基金supported by the National Natural Science Foundation of China(32170252,U20A2029)the Natural Science Foundation of Guangdong Province(2022A1515010968)+1 种基金the Natural Science Foundation of Hunan Province(2021JJ30097,2022JJ30127)the Natural Science Foundation of Changsha City(kq2202150).
文摘Proper timing of flowering under different environmental conditions is critical for plant propagation.Light quality is a pivotal environmental cue that plays a critical role in flowering regulation.Plants tend to flower late under light with a high red(R)/far-red(FR)light ratio but early under light with a low R/FR light ratio.However,how plants fine-tune flowering in response to changes in light quality is not well understood.Here,we demonstrate that F-box of Flowering 2(FOF2),an autonomous pathway–related regulator,physically interacts with VASCULAR PLANT ONE-ZINC FINGER 1 and 2(VOZ1 and VOZ2),which are direct downstream factors of the R/FR light receptor phytochrome B(PHYB).We show that PHYB physically interacts with FOF2,mediates stabilization of the FOF2 protein under FR light and end-of-day FR light,and enhances FOF2 binding to VOZ2,which leads to degradation of VOZ2 by SCF^(FOF2) E3 ligase.By contrast,PHYB mediates degradation of FOF2 protein under R light and end-of-day R light.Genetic interaction studies demonstrated that FOF2 functions downstream of PHYB to promote FLC expression and inhibit flowering under both high R/FR light and simulated shade conditions,processes that are partially dependent on VOZ proteins.Taken together,our findings suggest a novel mechanism whereby plants fine-tune flowering time through a PHYB–FOF2–VOZ2 module that modulates FLC expression in response to changes in light quality.
基金financially supported by the National Key R&D Program of China(Nos.2018YFD0900305,2018YFD 0901500)the China Agriculture Research System of MOF and MARA,Central Public-interest Scientific Institution Basal Research Fund CAFS(No.2020TD27)the‘Young Talent of Fishery Sciences’project from Laboratory for Marine Fisheries and Aquaculture(No.2018-MFS-T12).
文摘Saccharina japonica gametophytes can survive a long period under unfavorable environmental conditions,while they also delay in growth and/or reproduction.Although the reproduction in delayed gametophyte of S.japonica was known to be strongly influenced by light intensity,light quality,and photoperiod,no previous studies have evaluated their interactive effects on gametogenesis.To evaluate these effects,we used an orthogonal experiment to expose delayed gametophytes of S.japonica to different light intensities,light qualities,and photoperiods for 12 days.The results showed that changes in light intensity rather than light quality and photoperiod significantly affected the relative growth rates of the delayed gametophytes.Blue light had the greatest promotion on reproduction rate.The optimal light conditions in the early vegetative growth phase in gametogenesis induction for the delayed gametophytes were at 60–80μmol photons m^(−2) s^(−1) with daylength of 12 or 16 hours under white or blue light.When the delayed gametophytes were maintained in a constant light condition from delayed state to gametogenesis,the beneficial photoperiods for vegetative growth and reproductive rate were both 16L(16 hours of light):8D(8 hours of dark).However,when the delayed S.japonica gametophytes achieve the optimal growth state during the first 6 days and then they were cultured at different light conditions for the following 6 days,the reproduction rate increased as the daylength decreased and attained a peak value in group of 8L:16D photoperiod,indicating that photoperiod adjustment at the transition period is crucial in the gametogenesis induction process of delayed gametophyte of S.japonica.
基金This research was supported by the National Natural Science Foundation of China(Grant No.U1504320)Financial Project of Henan Province(Grant No.2019ZC23)We thank Liwen Bianji,Edanz Group China(www.liwenbianji.cn/ac),for editing the English text of a draft of this manuscript.
文摘Previous studies have shown that high light intensity can induce anthocyanin synthesis(AS)in petunia plants.To identifywhich kind of light quality plays a role in inducing such metabolic process,and what transcripts participate in controlling it,we carried out whole-transcriptome sequencing and analysis of petunia petals treated with different light-quality conditions.Among the red and white light treatments,a total of 2205 differentially expressed genes and 15,22,and 20 differentially expressed circRNAs,miRNAs,and lncRNAs,were identified respectively.The AS-related genes,including the structural genes CHSj,F3H,F35H,DFR,and ANS,and the regulatory genes AN4,DPL,PHZ and MYBx were found to be downregulated under red light condition compared with their levels under white light condition.Furthermore,the light photoreceptor Cryptochrome 3(CRY3)and a series of light-dependent genes,such as PIF,HY5,andBBXs,were also determined to respond to the light treatments.The anthocyanin contents in early petunia petals under red light were significantly lower than that under white and blue light.The results of qRT-PCR further confirmed the expression pattern of some AS-related and light-response genes in response to different light quality.Yeast two-hybrid results showed that the key elements in the light signal pathway,HY5 can interact with BBX19,BBX24 and BBX25.And PHZ,the important AS regulator can induce anthocyanin synthesis in response to blue light quality fromtransient expression analysis in petunia petals.These findings presented here not only deepen our understanding of how light quality controls anthocyanin synthesis,but also allow us to explore potential target genes for improving pigment production in petunia flower petals.
基金supported by the National Key Research and Development Program of China(2017YFB0403901).
文摘The extensive environment,especially low temperature and weak lighting in winter and spring,which limits the growth of pepper(Capicum annuum L.)seedlings,the use of plant factory with artificial lighting technology can effectively control the lighting environment to produce high-quality seedlings.In this study,white LED lamps with R:B ratio of 0.7(L0.7)and 1.5(L1.5)and red-blue LED lamps with R:B ratio of 3.5(L3.5)were used to cultivate seedlings of“CAU-24”pepper in the light intensity of 250μmol/m^(2)·s and photoperiod of 12 h/d,white fluorescent lamps with R:B ratio of 1.7(F1.7)was used as control.The results showed that plant height,stem diameter,hypocotyl length,biomass accumulation,light energy use efficiency(LUE)and electric energy use efficiency(EUE)of pepper seedling under L1.5 were the highest.After 36 days of sowing,the dry weight of shoot reached 302.8±45.2 mg/plant.Leaf area reached maximum value of 153.5±22.0 cm^(2) under L0.7.The contents of chlorophyll a,chlorophyll b and total chlorophyll of pepper seedling leaves under all kinds of LED light were greater than F1.7,but there was no significant difference in net photosynthetic rate.The total dry weight with lamp electric power consumption of L1.5 were 3.0 g/(kW·h)which was 1.5,2,and 3 times greater than that of L3.5,L0.7,and F1.7,respectively.Therefore,compared with fluorescent lamp and other LED lamps,the white LED light quality with R:B ratio of 1.5 is suitable for pepper seedling production in plant factory because of the high LED lighting efficiency,greater LUE and EUE.
基金financially supported by the National Natural Science Foundation of China (31760044,31260039)Key Course of Hunan Province (Ecology),Jishou University (2015005)
文摘Objective： Light quality has effect on the accumulation of gypenosides in the medicinal plant Gynosternma pentaphyllum in the family Cucurbitaceae, while the squalene synthase （SS） and squalene epoxidase （SE） are the key enzymes for gypenoside biosynthesis, The objective of this study was to elucidate the rela- tionship between light quality and biosynthesis key enzyme involving the regulation of gypenoside accu- mulation. Methods： The content of total gypenosides was measured by colorimetric method and the expression of SS and SE gene was determined by quantitative Real-time PCR in the seedlings of G. pentaphyllum which were grown with different light quality. Results： Light quality showed remarkable impacts on the accumulation of total gypenosides. The highest content of total gypenosides in the plant under red light condition was determined, followed by blue light and white light, while the lowest content was recorded under dark condition, qRT-PCR analysis proved that the expression levels of SS and SE genes were also affected by light quality. The high-level gene expressions of SS and SE were found in the plant under red light condition, followed by blue light, with the least content in darkness. The statistical analysis revealed that the total gypenosides were significantly different in different light treatment and the content of total gypenosides was positively related to the expression of SS and SE genes. Conclusions： Light quality regulates gypenoside accumulation via altering the expression of SS and SE in G. pentaphyllum.
基金Supported by the National Natural Science Foundation of China (Nos.42177459,41776156,41271521)。
文摘Pavlova sp.is not only one of the most popular microalgae in aquaculture,but also a source of high-quality biodiesel feedstock.With white light as a control(W),Pavlova sp.was cultured in this study under varying light quality,including monochromatic red light(R),blue light(B),and combinations thereof with different proportions(illuminators of m Rn B,comprised of m red light units and n blue ones,m+n=7),to examine the effects of illuminating light quality on biocomponent production and biodiesel quality.The results show that combined monochromatic light,especially 2R5B,3R4B,4R3B,and 5R2B,could improve the growth of Pavlova sp.The dry weight of harvested algae powder in the 5R2B group reached 418.03 mg/L,and was 22.65%higher than that in the control group(W).Lipid production under combined monochromatic light of 4R3B reached 107.86 mg/L,and was 25.61%higher than in the control(W).In addition,illumination using 4R3B increased the proportion of C16∶0(palmitic acid)and C16:1(palmitoleic acid)fatty acids in Pavlova sp.by 15.55%and 21.94%,respectively,which translates into improved biodiesel quality.All cetane numbers(CN)for 4R3B–6R1B were over 51,while iodine values(IV)and degrees of unsaturation(DU)were reduced,leading to more stable biodiesel suitable for longterm storage.In addition,protein production under 6R1B was as high as 31.56 mg/L,1.8 times greater than under W.Light quality is proposed as an effective tool to regulate biocomponent production by microalgae.
文摘In the next three to five years, China’s light industry will upgrade major product quality generally to world level. This will be done by strengthening quality control and supervision and the improvement in technology. The campaign was announced by Yu Zhen, president of the China National Council of Light Industry at the beginning of this year.
基金Supported by Jiangsu Agricultural Science and Technology Self-Innovation Funds(CX(13)3032)Nanjing Leading Science and Technology Innovative Talents and Entrepreneurs(2012-NJ-321)+4 种基金Jiangsu"Six Businesses Talents Peak"Program(2012NY-031)Nanjing Innovation Fund for Technology Based Firms(2013/074)New & High Technology Industry Development Project of Institutions of Higher Education in Jiangsu Province(JHB05-21)Technology Supporting Program of Jiangsu Province-Agriculture(SBE2014327)A Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)~~
文摘[Objective] The aim was to study the properties of novel ＂light fertilizer＂, photo-conversion film, in order to evaluate its effect on the environmental factors and morphogenetic process of crops in the high tunnel. [Method] Photo-conversion film and Iongevous anti-dropping film were compared in terms of light, air and soil temperature utilizing the Facilities of leafy agriculture high tunnel intelligent monitoring system. Verifying the results by farmland experiment. [Result] Photo- conversion film indeed improved the light quality of high tunnel compared with the Iongevous anti- dripping film. The air and soil temperature was raised several degrees. Results of farmland experiment show that the average value of brassica chinensis fresh weight increased 19.15% compared to the control. [Conclusion] Photo-conversion film promotes more crop growth than Iongevous anti-dropping film due to improvement of light quality, air and soil temperature.
基金Supported by National Natural Science Foundation of China(30460016)Science and Technology Plan from Yunnan Branch Office of China National Tobacco Corporation(2011YN03,2010YN03,07A01)~~
文摘[Objective] The study aimed to investigate the activity and gene expression of caspase-like proteases in tobacco leaves growing under different light qualities. [Method] By covering tobacco plants with white, red, yellow, blue and purple films to obtain different light quality, the changes of chlorophyll content, activity and gene expression of caspase-like proteases in the tobacco leaves were studied. [Results] Compared with treatments of white, red and yellow film, blue and purple films delayed the decrease of chlorophyll content and senescence of tobacco leaves at the late growth stage, and relatively lowered the activity and gene expression of caspase-like proteases during growth, development and senescence periods. [Conclusion] Different light qualities exhibited various effects on the growth, development and senescence of tobacco leaves, possibly by affecting the activity and gene expression of caspase-like proteases to some extent.
基金supported by the National Natural Science Foundation of China(Grant No.31772258)the National Key Research and Development Program(Grant No.2019YFD1000102-11)。
文摘Climate change and extreme weather pose significant challenges to the traditional viticulture regions.Emerging high-altitude grape-producing regions with diverse orientations have shown great potential in coping with this challenge.Stable,high-quality wine grape production may be achieved by synchronizing the meso-and microclimate.To clarify the role of high altitude and row orientation in meso-and microclimate and the response of berries to it,we evaluated seven years(2012-2018)of climate data,two years of basic grape(Cabernet Sauvignon,Vitis vinifera L.)quality,and one-year microclimate from veraison to harvest.By comparing two locations(Sidon 2047 m,Sinon 2208 m)in Yunnan Province,China,we found that the average temperature has been stable at approximately 15℃ for seven years,with no extreme weather or,noticeable global warming.The light intensity(LI)in the north-south(NS)was more balanced than the east-west(EW)direction,and the east-west to the south(EW-S)canopy side was almost higher than the other sides.High LI was associated with high photosynthetically active radiation(PAR),ultraviolet(UV),and infrared(IR)light and vice versa.The north-south to the east(NS-E)and east-west to the north(EWN)sides were characterized by lower LI and higher UV and IR light,and higher total anthocyanin content.Most anthocyanin synthesis-related genes,for example,VvF3'H and VvF3'5'H,were highly expressed in NS-E from veraison to maturity.Perhaps UV and IR light induced their expression.This study provides new insights on the role of differently orientated rows in controlling grape quality due to varied light quality.The findings are globally significant,particularly in the context of climate change,and offer fresh insights into berry physiological responses and decision-making for the management of existing vineyards.
基金supported by the Natural Science Foundation of Guangdong Province,China(S2012020011043)the National High Technology Research and Development Program of China(2014AA10A605)+2 种基金the Special Fund for Agro-scientific Research in the Public Interest(201503106)Modern Agriculture Industry Technology System for Rice in Guangdong Province(2016LM1066,2017LM1066,2018LM1066)the Swiss Agency for Development and Cooperation through its funding of “Closing Rice Yield Gaps in Asia” Project(CORIGAP)
文摘Short basal internodes are important for lodging resistance of rice(Oryza sativa L.).Several canopy indices affect the elongation of basal internodes,but uncertainty as to the key factors determining elongation of basal internodes persists.The objectives of this study were(1)to identify key factors affecting the elongation of basal internodes and(2)to establish a quantitative relationship between basal internode length and canopy indices.An inbred rice cultivar,Yinjingruanzhan,was grown in two split-plot field experiments with three N rates(0,75,and 150 kg N ha−1 in early season and 0,90,and 180 kg N ha−1 in late season)as main plots,three seedling densities(16.7,75.0,and 187.5 seedlings m−2)as subplots,and three replications in the 2015 early and late seasons in Guangzhou,China.Light intensity at base of canopy(Lb),light quality as determined from red/far-red light ratio(R/FR),light transmission ratio(LTR),leaf area index(LAI),leaf N concentration(NLV)and final length of second internode(counted from soil surface upward)(FIL)were recorded.Higher N rate and seedling density resulted in significantly longer FIL.FIL was negatively correlated with Lb,LTR,and R/FR(P<0.01)and positively correlated with LAI(P<0.01),but not correlated with NLV(P>0.05).Stepwise linear regression analysis showed that FIL was strongly associated with Lb and LAI(R2=0.82).Heavy N application to pot-grown rice at the beginning of first internode elongation did not change FIL.We conclude that FIL is determined mainly by Lb and LAI at jointing stage.NLV has no direct effect on the elongation of basal internodes.N application indirectly affects FIL by changing LAI and light conditions in the rice canopy.Reducing LAI and improving canopy light transmission at jointing stage can shorten the basal internodes and increase the lodging resistance of rice.
基金This work was financially supported by the National Key R&D Program of China(2017YFB0403903,2017YFD0100505).
文摘Light-emitting diodes(L EDs)are a new light source with low energy consumption and high photoelectric conversion efficiency,and they can satisfy the energy-saving needs of plant culture systems.However,the effects of LED light sources on rice tissue culture and rice seedling cultivation are poorly understood.This study aimed to evaluate the effects of LEDs on the growth of tissue culture plantlets and seedlings of the rice(Oryza sativa L.)cultivar Nipponbare.The best light source for rice tissue culture was different from that for rice seedling cultivation.Blue(B)LED light was the most appropriate light for rice tissue culture.Under a B LED light,the time required for callus proliferation,differentiation and regeneration was the shortest,and the frequency of plantlet ititin,dfferetiation and regeneration was the highest.Ablue:red(B:R)=1:1LED light facilitated the growth of rice seedlings and produced the highest chlorophyll and carotenoid contents and photosynthetic rates in the rice seedlings.Abundant photosynthetic products were more effectively generated in the rice seedlings under the B:R=1:1 LED and R LED lights than under the B LED light.B LED light is the most appropriate light for rice tissue culture plantlets and can be used as an alternative light source for rice tissue culture,and B:R=1:1 LED light facilitated the cultivation of robust rice seedlings and can be used as the primary light source for rice factory seedling cultivation.
