太空生存太空生存太空生存 (25).pdf

Evaluation of wheat growth,morphological characteristics,biomass yield and quality in Lunar Palace-1,plant factory,green house and field systemsChen Donga,1,2,Lingzhi Shaob,1,2,Yuming Fub,c,1,2,Minjuan Wangc,2,Beizhen Xiea,b,c,2,Juan Yua,2,Hong Liua,b,c,n,2aSchool of Biological Science and Medical Engineering,Beihang University,Beijing 100191,ChinabInstitute of Environmental Biology and Life Support Technology,Beihang University,Beijing 100191,ChinacInternational Joint Research Center of Aerospace Biotechnology and Medical Engineering,Beihang University,Beijing 100191,Chinaa r t i c l e i n f oArticle history:Received 19 September 2014Received in revised form2 February 2015Accepted 17 February 2015Available online 25 February 2015Keywords:WheatBioregenerative Life Support Systems(BLSS)Plant factoryGreen houseFielda b s t r a c tWheat(Triticum aestivum L.)is one of the most important agricultural crops in both spacesuch as Bioregenerative Life Support Systems(BLSS)and urban agriculture fields,and itscultivation is affected by several environmental factors.The objective of this study was toinvestigate the influences of different environmental conditions(BLSS,plant factory,greenhouse and field)on the wheat growth,thousand kernel weight(TKW),harvest index(HI),biomass yield and quality during their life cycle.The results showed that plant heightpartially influenced by the interaction effects with environment,and this influencedecreased gradually with the plant development.It was found that there was no significantdifference between the BLSS and plant factory treatments on yields per square,but the yieldof green house and field treatments were both lower.TKW and HI in BLSS and plant factorywere larger than those in the green house and field.However,grain protein concentrationcan be inversely correlated with grain yield.Grain protein concentrations decreased underelevate CO2condition and the magnitude of the reductions depended on the prevailingenvironmental condition.Conditional interaction effects with environment also influencedthe components of straw during the mature stage.It indicated that CO2enrichedenvironment to some extent was better for inedible biomass degradation and had asignificant effect on“sourcesink flow”at grain filling stage,which was more beneficial torecycle substances in the processes of the environment regeneration.&2015 Published by Elsevier Ltd.on behalf of IAA.1.IntroductionBioregenerative Life Support System(BLSS)is an artificialecosystem consisting of many complex symbiotic relation-ships among higher plants,animals,and microorganisms1,2.As a consequence of the increasing importance of cropin BLSS,wheat(Triticum aestivum L.)plants can providehuman beings with fresh air,clean drinking water,nutrient-rich food and necessary spiritual consolation,which areessential for long-term manned space missions 3,4.Imp-rovement of the crop yield and quality by biotechnology andContents lists available at ScienceDirectjournal homepage: Astronauticahttp:/dx.doi.org/10.1016/j.actaastro.2015.02.0210094-5765/&2015 Published by Elsevier Ltd.on behalf of IAA.nCorresponding author at:School of Biological Science and MedicalEngineering,Beihang University,Beijing 100191,China.Tel./fax:86 10 82339837.E-mail addresses:wenjian_(C.Dong),(L.Shao),(Y.Fu),(M.Wang),(B.Xie),(J.Yu),LH(H.Liu).1These authors contributed equally to this work.2Tel.:86 10 82339283.Acta Astronautica 111(2015)102109engineering control technologies is therefore a matter ofinterest for researchers in both space 5 and unban agricul-ture fields 6.In addition,what differences of wheat yield andquality in different cultivation environment should be inves-tigated to identify the mechanisms of plant adaptation.Oncethese mechanisms are identified,decision support tools forgrowing plants can be optimized.These tools will be criticalfor developing a sustainable advance life support system forspace exploration.Plant factories are artificially controlled environmentsystems which are able to stably produce high-quality cropswith less water,nutrition,pesticides,and labor consumption.The systems control lighting,temperature,humidity,water,the concentration of carbon dioxide,etc.in order to create anartificial and efficient cultivation environment in an indoorspace 7,8.Plant factory systems are emerging plant produc-tion industry in the future.In Asia,plant factory systems inTaiwan,Japan,and China already cultivated high-profit see-dlings,herbs,fruits,and vegetables for consumers.However,previous studies focused on controlling technologies andstrategies of plant factories 9 or production of leaf vege-tables 10,11,a few of them concerned yield and quality ofwheat plants in the plant factories.In a smaller scale,an agricultural greenhouse is con-structed to provide appropriate microclimate conditions forplant growth and crop production.The greenhouses are nor-mally covered with transparent materials to the solar radia-tion such as glass or plastic film 12,13.The temperatureinside a greenhouse is increased due to two main physicalreasons.The first reason is called the“heat trapping”which isbasically the trapping of infrared radiation by the greenhousecovering material.For this reason,the heat is built up insidethe greenhouse system by what it is called“greenhouseeffect”14.The second cause is that the greenhouse structureis an“enclosed”space 15.The greenhouse is constructed tobe an enclosure that helps to inhibit the convective heat lossby the outer ambient environment.This may bring manybenefits to the growth and development of crops comparedwith planting in the field.In the growth and development processes,plants areusually subjected to environmental changes,which influ-ence not only many biochemical processes,but also yieldand quality of food crops such as wheat plants 16,17.Thecultivation of plants in space(closed environment)or in thefield depends on different environmental factors 18,19.Although available information on different cultivationenvironments resulted in small differences in leaf vegeta-bles 20,very little work has been carried out on thesignificance of wheat output,quality and the component ofinedible biomass of the edible biomass in BLSS,plantfactory,agricultural greenhouse and the field systems.Inthis study,we investigate the influences of different cultiva-tion environments on the wheat growth,thousand kernelweight(TKW),harvest index(HI),biomass yield and qualityduring their life cycle.2.Materials and methods2.1.Test conditions2.1.1.BLSS-Lunar Palace 1(LP1)Lunar Palace 1 is like a micro-biosphere,which couldprovide astronauts with basic living requirements.Oxygen,water and food regenerate through biotechnology,making itpossible for astronauts to live in space for long periods.LunarPalace 1 now has one plant cabin and one comprehensivecabin.The plant cabin provides different environments for avariety of plants to grow.It consists of two planting rooms tocultivate high yielding crop plants.The experimental plantwas dwarf spring wheat(T.aestivum L.).All wheat plantswere cultivated in the bigger room.Planting area for springwheat was 40 m2.10 batches of wheat plants with 7-daygrowth interval were cultivated hydroponically.Every batchwas 4 m2and the growth period was about 70 days.Thewheat planting density was 1000 seeds per m2.Photosyn-thetic photon flux density(PPFD)levels were measured dailyat the top of plant canopy with a quantum sensor(Li-250A,Li-Cor,USA).Previous study has shown that although wheatis not sensitive to the blue light dose induction 21,22,thecombination of redwhite LED spectra can improve its out-put and photosynthetic rate 16.The parameters for wheatcultivation in different treatments are listed in Table 1.Themodified Hoagland nutrient solution 23 was the basicculture medium(Table 2).Table 1The parameters for wheat cultivation in different treatments.No.ParametersLP1Plant factoryGreen houseField1Temperature(1C)2171.32171.813.533.411.629.52Relativehumidity(%)5574.65575.35578.937.552.43CO2concentration(mol mol?1)10003000(most time)40073040012004007304LightingsystemLight emitting diodes(LEDs,redlight covers 80%and white covers20%);photosynthetic photon fluxdensity(PPFD)is 500 mol m?2s?1.(PPFD,light source is at 20 cm above)Light emitting diodes(LEDs,red light covers80%and white covers 20%);photosyntheticphoton flux density(PPFD)is500 mol m?2s?1.(PPFD,light source is at 20 cm above)SunlightSunlight5Lighting time(light/dark)24 h/0 h24 h/0 h1114 h/1310 h1114 h/1310 hC.Dong et al./Acta Astronautica 111(2015)1021091032.1.2.Plant factoryThe facility was located at Beihang University,Beijing,China.The wheat planting density was 1000 seeds per m2.The modified Hoagland nutrient solution 23 was used asbasic culture medium(Table 2).2.1.3.Green houseThe green house located at Haidian,Beijing,China(39154020N,116125029E).The width of green house was 8.5 m,the lengthwas 40 m and the height was 3.25 m.The green houses weredivided into 6 beds;each bed was 2 m wide and 5 m long.Forgreen house experiments,the wheat planting density was 1000seeds per m2.Wheat seeds were sown in 5 kg pots filled withsandy loam alluvial soil with the following properties:pH 6.5,organic carbon 0.35%,total nitrogen 0.034%and availablephosphate 4.2 ppm.Growing season was from March to Junein 2013.2.1.4.Field(Beijing)The location of field experiments was also at Haidian,Beijing,China(39154020N,116125029E).Growing seasonwas from March to June in 2013.2.2.MorphologyThe height and root length of wheat plants weremeasured every 5 days by a straight scale and verniercaliper.Plant height was estimated from the soil surface tothe tip of the tassel.Samples were selected at randomwithin measurement process.2.3.Edible biomassThe sugar,protein and fat of wheat seeds were determinedrespectively under different conditions according to themethod described by Gao 24.The thousand-kernel weight(TKW)of wheat seeds was weighed respectively under 4different treatments 25.At maturity,above-ground biomass(AGB)and grain yield per plant(GY)were also recorded.Harvest index(HIGY/AGB)was then calculated 26.2.4.Inedible biomassFor determination of inedible biomass components,plant tissues were dried in an oven for 48 h at 70 1C beforeweighing.The content of Neutral detergent solution(NDS),neutral detergent fiber(NDF),acid detergent fiber(ADF),acid detergent lignin(ADL)and acid-insoluble ash(Ash)inwheat straw was determined according to Van Soest et al.method 27 using FIWE six raw fiber extractor(VelpScien-tifica,Italy).The contents of hemicellulose,cellulose,lignin,ash and NDS were analyzed 28,29.2.5.Data statisticsThe experiment was set up in a completely randomizeddesign.All experiments were performed in triplicate.Theaverage value of total 6 measurements7standard devia-tion was regarded as the final result.All statistical analyseswere performed using SPSS 18.0.P values less than.05were considered statistically significant.3.Results and discussion3.1.The response of morphological characteristics todifferent treatmentsIt was found that the morphology of the wheat plantswas noteworthily influenced in different cultivation environ-ments(Fig.1).Harvest time in field condition was the longestand the index in LP1 was the shortest,which was about 70days.However,there was no significant difference in harvesttime of wheat plants between plant factory cultivation andgreen house cultivation as indicated in Fig.1A.Particularly ingreen house and field,straw height of wheat was greaterthan that in LP1 and plant factory.The plant height of LP1was 34.5 cm lower than that of field and 23.5 cm lowerthan that of green house.Closed environment may be able todwarf the wheat plants.Moreover,the interaction betweenenvironments and genotypes also affected plant height.Plantheight was partially influenced by the interaction effectswith environment,and this influence decreased graduallywith the plant development.Harvest time was related to the light systems,whichmeans continuous(24/0 h light/dark)lighting plays a sig-nificant role in maturity stage 3.Moreover,elevatedtemperature was one of the most critical influences onthe wheat harvest.Both in the LP1 and plant factory,thetemperatures were controlled accurately.On the contrary,due to the rhythm of day and night,the growth anddevelopment of wheat plants in the green house and inthe field may be slowed down.The development of plantheight is a dynamic accumulative process,which candirectly affect both the yield potential and the lodgingresistance.Meanwhile,plant height is a quantitative char-acter controlled by numerous genes and is easily affected byenvironmental conditions 30.The results showed that thewheat genotype and environmental conditions could bothaffect plant height,and the effects of environment on plantheight decreased gradually with plant development.Inrecent years great attention has been paid to investigatethe mechanisms of plant and ear height for increasingplanting density and preventing plants from lodging orbreaking 31.The clear tendency for tall straw and resis-tance to different environment suggests that this relation-ship has a genetic basis that could be explained either bylinkage,between one or more genes controlling resistanceTable 2Nutrient compositions.CompositionsConcentration(mg/L)Ca(NO3)2?4H2O945KNO3607(NH4)2HPO4115MgSO4?7H2O493FeEDTA28H3BO32.86MnSO4?4H2O2.13ZnSO4?7H2O0.22CuSO4?5H2O0.08(NH4)6Mo7O24?4H2O0.02pH5.86.3C.Dong et al./Acta Astronautica 111(2015)102109104and genes controlling straw height,or by pleiotropy,wheregenes that promote shorter straw also promote suscept-ibility.One possible pleiotropic mechanism is a decreasedtemperature(Table 1)at ear height in shorter genes ofwheat,leading to increased severity of straw height.3.2.The responses of edible biomass to different treatmentsThe analysis of variance revealed significant differencesamong treatments for wheat yields per square(Fig.2A),harvest index(HI)(Fig.2B)and thousand-kernel weight(TKW)of wheat seeds(Fig.2C).It was found that there wasno significant difference between the LP1 and plant factorytreatments on yields per square,but the yield of greenhouse and field treatments were both lower(Fig.2A),whichimplies that continuous lighting of whole phase had asignificant influence on wheat yield.That is to say,thegrowth and development of wheat plants had been affectedby light systems,especially illumination time.Similarly,TKW and HI in LP1 and plant factory were larger thanthose in the green house and field(Fig.2B and C).However,grain protein concentration can be inverselycorrelated with grain yield,especially in the green house andfield systems(Fig.3A).Results of our experiment suggest thatelevate CO2effect on grain protein concentration depends ongrowing environmental conditions.Because of the differenceof CO2concentration between day and night in the greenhouse,the largest level of CO2concentration may reach 10001200 ppm in the night.CO2concentration in LP1 was about10003000 ppm(Tabl