Molecular mechanism of lycopene cyclases regulating carotenoids ratio in different branches during tea leaf and flower development

Carotenoids are essential components in tea quality, contributing to leaf color and aroma. However, little information about carotenoids in different tea cultivars and their biosynthesis regulation mechanism during leaf development is known. Here we analyzed carotenoids by HPLC in the buds and leaves of 113 tea cultivars harvested on the same day. By profile clustering, carotenoids were divided into five groups. Same group cultivars displayed divergence in the total content of carotenoids but a similar molar ratio. To figure out the molecular mechanisms of this phenomenon, we further characterized all functional lycopene cyclases, which are the branch point of the carotenoid biosynthesis pathway. Two β-lycopene cyclases(CsLCYB1 and CsLCYB2) and one ε-lycopene cyclase(CsLCYE1) were cloned. Subcellular localization analysis showed that all cloned CsLCYs were localized in plastids. Enzyme activity assays in E. coli indicated both CsLCYBs catalyzed lycopene into β-carotene, and CsLCYE1 produced δ-carotene and ε-carotene. We found CsLCYB1 and CsLCYE1 predominantly expressed in leaf, while CsLCYB2was mainly expressed during flowering stages. Suppression by antisense oligonucleotides reduced CsLCYB1 and CsLCYE1 transcripts and led to reduction of both β,β-branch and β,ε-branch carotenoids in leaf. The expression levels of CsLCYB1 showed a significant positive correlation withβ,β-branch carotenoids in leaf. Our study provides carotenoid profiles of different tea cultivars, which can assist tea producers in selecting cultivars of interest. Meanwhile, we proposed the molecular mechanism of carotenoids reflecting the tenderness of tea plant leaf from a metabolic flux perspective, and suggested lycopene cyclase that could be applied to the breeding of tea varieties with different branch carotenoids.

Effects of different LEDs light spectrum on the growth,leaf anatomy,and chloroplast ultrastructure of potato plantlets in vitro and minituber production after transplanting in the greenhouse

Light spectrum plays an important role in regulating the growth and development of in vitro cultured potato(Solanum tuberosum L.) plantlets. The status of potato plantlets at the end of in vitro stage influences the minituber production after transplanting. With 100 μmol m^-2s^-1 total photosynthetic photon flux density(PPFD), a light spectrum study of 100% red light emitting diodes(LEDs) light spectrum(RR), 100% blue LEDs light spectrum(BB), 65% red+35% blue LEDs light spectrum(RB), and 45% red+35% blue+20% green LEDs light spectrum(RBG) providing illumination at the in vitro cultured stage of potato plantlets for 4 weeks using fluorescent lamp as control(CK) was performed to investigate the effects of LEDs light spectrum on the growth, leaf anatomy, and chloroplast ultrastructure of potato plantlets in vitro as well as the minituber yield after 2 months transplanting in the greenhouse. Compared to CK, RB and RBG promoted the growth of potato plantlets in vitro with increased stem diameter, plantlet fresh weight, plantlet dry weight, and health index. Furthermore, BB induced the greatest stem diameter as well as the highest health index in potato plantlets in vitro. Root activity, soluble protein, and free amino acid were also significantly enhanced by BB, whereas carbohydrates were improved by RR. In addition, thickness of leaf, palisade parenchyma and spongy parenchyma was significantly increased by BB and RBG. Chloroplasts under BB and RBG showed well-developed grana thylakoid and stroma thylakoid. Unexpectedly, distinct upper epidermis with greatest thickness was induced and palisade parenchyma and spongy parenchyma were arranged neatly in RR. After transplanting in the greenhouse for 2 months, potato plantlets in vitro from BB, RB, and RBG produced high percentage of large size tuber. BB improved fresh and dry weights of the biggest tuber but decreased tuber number per plantlet. In addition, RBG increased tuber number as well as tuber fresh and dry weight slightly. Our results suggested monochromatic blue LEDs as well as combined red, blue or/and green LEDs light spectrum were superior to fluorescent lamp spectrum in micro-propagation of potato plantlets. Therefore, the application of RBG was suitable;BB and RB could be used as alternatives.

Individual Leaf Area of Early Flowering Arabidopsis Genotypes Is More Affected by Drought than Late Flowering Ones: A Multi-Scale Analysis in 35 Genetically Modified Lines

Plants acclimate to drought optimizing the trade-off between biomass production and water loss while ensuring their survival and reproduction. Plants also modify their growth or phenology as complementary strategies in response to stress. Despite evidence of an interaction between flowering time and plant growth response to environmental stresses, this interaction in response to drought is under debate. To contribute to the analysis of this interaction, leaf growth of 35 genetically modified lines of Arabidopsis thaliana and their common wild-type, Col-0 was analyzed by a quantitative multi-scale phenotyping approach from cellular to whole plant scale both in well-watered and soil moderate water deficit conditions. These genotypes were selected for the various physiological functions potentially altered by their genetic modification and that could interact with plant growth and/or their drought responses. In all genotypes, leaf expansion decreased in response to drought both at the whole rosette and the individual leaf levels. Additionally, epidermal cell area and/or epidermal cell number decreased in response to the drought treatment. In contrast, the number of rosette leaves was reduced in only half of the genotypes and leaf growth duration was only modified in 4 of them. Despite long photoperiod conditions, the duration of the vegetative phase, i.e. the time elapsed between germination and flowering stage, varied from 12 to 27 days among genotypes under well watered conditions. Our analyses revealed that the differences of flowering time observed in well-watered condition impacted the leaf area response to drought. Early-flowering genotypes slightly decreased their final leaf number, but strongly reduced their individual leaf area compared with the late-flowering ones. This result underlines the difficulty to analyze plant response to environmental stresses when genotypes with different flowering dates are compared.

Tracking and Monitoring Leaf Development, Coupling Law and Regulation Techniques during Flowering Period of Hybrid Foxtail Millet (<i>Setaria italica</i>(L.) P. Beauv.) Parental Lines

The determining factor of Setaria italica (L.) P. Beauv. is the coupling of its flowering stage and outcrossing rate which leads to low and unstable seed yields in self-pollinated foxtail millet hybrids and thereby limits their large-scale application. In this study, Datong 27, Datong 29 and gu 83 were screened and identified through meticulous observations of their pollination habitats. High exposure rate, degree of exposure and plump of stigma are good factors to accept foreign pollen. Datong 27 and Datong 29 have some additional characteristics, such as long filaments and exposed and full anthers that contain a large amount of pollen. We transformed into a series of stigma-exposed and plump sterile lines that easily accepted exotic pollen. New restorer lines with anthers that were full of powder and exhibited quick recovery, which improved the parental lines’ heterosexual characteristics. By tracking and monitoring the leaf development of the new sterile and restorer lines, a coupling law of leaf development was determined and a series of flowering control measures were formulated. These factors ensured that the parental lines encounter one another during the flowering stage. By utilizing fertilizer and water, the vitality of the female stigma, amount of powder scattered and powder loosening time were prolonged, which increased hybrid seed yields from 1500 to 3000 kg/hm2. These findings were helpful in resolving the technical problems of seed production that restricted the propagation of foxtail millet hybrids and supporting future large-scale applications.

Screening of Broad-spectrum Resistance Resources against Rice Bacterial Leaf Streak

[ Objectives] Rice materials with broad-spectrum resistance against several pathogenic strains of Xanthomans oryzae pv. Oryzicola （Xooc） at multiple growth stages were screened, in order to provide reliable resistance sources for variety breeding against rice bacterial leaf streak. [ Methods] A total of 1 100 rice lines with rich genetic background were offered as selective objects, and highly susceptible cultivar Jingang 30 was used as the control. Inoculation was carried out with five strong pathogenic strains of Xooc through acupuncture method at various growth stages for resistance identification. [ Results] Fourteen disease-resistant materials were obtained through preliminary screening, accounting for 1.27% of the total materials. Nine materials moderately resistant to bacterial leaf streak were obtained via secondary screening, accounting for 0.82% of the total materials. Besides, three of them （ RL6, RL9 and RLL4） were resistant to a number of pathogenic strains of Xooc at three growth stages. In particular, RL16 presented broad-spectrum resistance to multi-strains with high resistance levels. Six of them （ RI2, RIA, RIS, RL8, RL11 and RL12） were resistant to single strain at single growth stage. [ Conclusions] The obtained three materials have broad-spectrum resistance to bacterial leaf streak at multiple growth stages, which can be served as an important source to cultivate disease-resistant rice varieties. RL6 maintains high broad-spectrum resistance at all growth stages, which can be used as a prior resistance source for rice variety breeding. Six materials obtained with resistance against bacterial leaf streak at particular growth stages can be used as candidate resistance sources.

Photoelectric Characterization of Dye Sensitized Solar Cells Using Natural Dye from Pawpaw Leaf and Flame Tree Flower as Sensitizers

Natural dyes from flame tree flower, Pawpaw leaf and their mixtures were used as sensitizers to fabricate dye-sensitized solar cells (DSSC). The photoelectrochemical performance of the Flame tree flower dye extract showed an open-circuit voltage (VOC) of 0.50 V, short-circuit current density (JSC) of 0.668 mA/cm2, a fill factor (FF) of 0.588 and a conversion efficiency of 0.20%. The conversion efficiency of the DSSCs prepared by pawpaw leaf extract was 0.20%, with VOC of 0.50 V;short-circuit current density, JSC of 0.649 mA/cm2 and FF of 0.605. The conversion efficiency for the flame tree flower and pawpaw leaf dye mixture was 0.27%, with VOC of 0.518 V, JSC of 0.744 mA/cm2 and FF of 0.69. Although the conversion efficiencies, Jsc and the Voc of the prepared dye cells were lower than the respective 1.185%, 7.49 mA/cm2 and 0.64V reported for ruthenium, their fill factors (FF) were higher than that of ruthenium (0.497). It was also observed that both the short-circuit current density and the fill factors of the cells were enhanced using mixed dye.

育苗容器对紫叶紫薇容器苗生长、开花及生理的影响

【目的】探讨育苗容器类型和规格对紫叶紫薇容器苗生长、开花及生理的影响,筛选出培育紫叶紫薇容器苗的适宜育苗容器,为高效培育紫薇容器苗提供理论依据。【方法】以紫叶紫薇优良新品种‘丹红紫叶’2年生苗木为研究材料,选用黑色塑料营养杯(C1)、白色无纺布美植袋(C2)、黑色控根容器(C3)3个类型以及16×16(D1)、21×21(D2)、25×25(D3)3种规格(直径×高,cm),组成9种容器组合处理,测定不同处理容器苗生长、开花及生理指标。【结果】(1)不同育苗容器处理对紫叶紫薇容器苗的生长、开花及生理指标均影响显著,同一容器类型苗木的生长、根系、生物量、花期、花径、花序、可溶性蛋白含量、可溶性糖含量、相对叶绿素含量、净光合速率、气孔导度、蒸腾速率等指标均随着育苗容器规格的增大而显著增加。(2)地径生长量、总根长、总根表面积、总根体积、根尖数、地上部干质量、地下部干质量、总干质量、花期均以C3D3处理最大,比最小的C1D1处理分别显著提高817.12%、108.12%、94.60%、75.66%、144.14%、135.67%、228.45%、164.65%、34.48%;苗高生长量、冠幅生长量、叶面积、花序长和宽均以C1D3处理最高,比最低的C1D1处理分别显著提高116.05%、81.39%、114.95%、70.44%和65.79%;相对叶绿素含量、水分利用效率均以C3D3处理最大,可溶性蛋白和可溶性糖含量、净光合速率、气孔导度均以C1D3处理最高;胞间CO_(2)浓度、水分利用效率在各处理之间无显著差异。(3)各处理隶属函数法综合评价得分排序为:C3D3>C1D3>C2D3>C3D2>C2D2>C1D2>C2D1>C3D1>C1D1。【结论】黑色控根容器在地径生长量、根系生长指标、生物量、花期和花径、叶绿素相对含量及净光合速率方面表现最佳;紫叶紫薇2年生苗的最适宜育苗容器是直径25 cm、高25 cm的黑色控根容器。

不同树龄国槐叶片性状特征及其适应策略研究

叶片性状的变异与相关关系能够反映植物的资源利用方式和适应生存策略。为探讨不同树龄国槐叶片性状特征及其变异规律,以聊城市不同树龄国槐叶片为研究对象,通过测定叶面积(leaf area,LA)、叶鲜重(leaf fresh weight,FW)、叶干重(leaf dry weight,DW)、叶长(leaf length,LL)、叶宽(leaf width,LW)、叶柄长(petiole length,PL)、叶厚度(leaf thickness,LT)、叶轴长(rachis length,RL)、叶形指数(leaf shape index,LI)、比叶面积(specific leaf area,SLA)、叶干物质含量(leaf dry matter content,LDMC)、叶组织密度(leaf tissue density,LTD)、比叶重(specific leaf weight,SLW)共13项指标,运用单因素方差分析、变异系数分析探究不同树龄叶片性状特征,经相关性分析、主成分分析探究各树龄国槐叶片的适应规律。结果表明,后备资源的DW、LL、PL极显著高于其他树龄的(P<0.01);国槐13个叶片性状的总体变异系数在8.57%~81.48%,不同树龄叶片性状中后备资源的LTD变异系数最大,为92.86%,2级古树LDMC变异系数最小,仅5.84%;LA、FW、DW、LL和LW呈极显著正相关(P<0.01),SLA与FW、DW、LTD、SLW呈极显著负相关(P<0.01),与LT呈极显著正相关(P<0.01);LDMC与FW、DW、LTD、SLW呈极显著正相关(P<0.01);后备资源叶片性状呈高LDMC、SLW,低SLA的特点,采取的是“快速投资-收益型”策略;2级古树和1级古树呈高SLA,低LDMC、SLW的叶片性状组合,采取的是“缓慢投资-收益型”策略。研究结果为制定不同龄级国槐养护管理策略提供科学依据。

栽培密度和收获期对工业大麻“云麻7号”主要农艺性状及花叶产量的影响

为了探明花叶用工业大麻在云南地区种植的最佳栽培密度和收获期,以云南主栽的工业大麻品种“云麻7号”为材料,分别于2019、2020年在云南省曲靖市沾益区进行大田随机区组试验。两年均设置4个栽培密度(0.5、1、2、3万株/hm^(2))和4个收获期(140、150、160、170 d),在收获期测定株高、茎粗、花叶产量、茎秆产量以及CBD含量等指标。于170 d收获时,两年的株高均在密度2万株/hm^(2)下达到最大值,分别为346.8 cm和267.1 cm,两年的茎粗均在密度0.5万株/hm^(2)下达到最大值,分别为44.3 mm和49.3 mm。2019年在140 d收获和3万株/hm^(2)密度条件下,花叶产量达到最大值3375 kg/hm^(2),2020年在170 d收获和2万株/hm^(2)密度条件下,花叶产量达到最大值5426 kg/hm^(2)。2019年在150 d收获和3万株/hm^(2)密度条件下,茎秆产量和地上部总产量均达到最大值,分别为7560 kg/hm^(2)和11014 kg/hm^(2),2020年在170 d收获2万株/hm^(2)密度条件下,茎秆产量达到最大值5632 kg/hm^(2),在170 d收获和3万株/hm^(2)密度下,地上部总产量达到最大值11001 kg/hm^(2)。大麻CBD含量两年均在160 d收获和1万株/hm^(2)密度条件下达到最大值,分别为1.2%和2.4%。栽培密度与收获期能影响工业大麻的花叶产量和CBD含量,栽培密度为3万株/hm^(2)和170 d时收获是“云麻7号”获得高产的重要栽培措施,同时在160 d收获和1万株/hm^(2)密度下栽培是获得高CBD含量的关键因素。

修枝强度对刺槐林木生长、干形及花叶的影响

为通过修枝科学高效地培育刺槐林并实现全面利用,以刺槐实生人工林为研究对象,通过修枝抚育措施,选取6种修枝强度进行随机区组试验,以生长指标、干形指标及花叶形态与生物量为监测指标,分析比较不同修枝强度下刺槐的响应。从生长指标来看,刺槐林分平均胸径、平均材积在1/2修枝强度下生长更好且存在显著差异;修枝对平均树高、平均冠幅影响不大;随着修枝强度的增大,枝下高也随之增大。从干形指标来看,各修枝强度对尖削度无显著影响;形率上除常规修枝外,其他修枝强度均与对照相比有显著性差异;对高径比的分析表明,1/2修枝强度下干形更加细长,对照则更粗壮;随着修枝强度的增加,活冠高逐渐降低,对照与常规修枝二者存在显著差异。从单株叶数量与重量看,1/3修枝强度下收获最多。从刺槐复叶形态上看,不同修枝强度下的刺槐复叶长无显著差异,修枝强度对刺槐复叶宽与小叶长宽都有显著影响。单株花数量与重量则是对照收获最多。对于刺槐花的形态,不同修枝强度对花序长宽无显著影响,不同修枝强度下龙骨瓣、翼瓣、旗瓣与花萼在不同的花期会有不同的表现。刺槐林分对不同修枝强度的响应具有显著差异性,可通过修枝科学高效地培育刺槐林并实现全面利用。为实现能源林培育,1/2修枝强度下生长指标最好,且修下的枝同样可作为薪炭燃烧。为培育无节、饱满、通直的优质建筑材,采用1/2修枝强度对刺槐林生长、干形的促进效果最好。叶的生物量与形态指标对饲料林培育十分关键,以1/3修枝强度最佳;花的生物量与形态指标对蜜源林培育十分关键,以不修枝为宜。

乌蒙乡不同海拔梯度刺叶高山栎叶功能性状特征及其对环境因子的响应

为理解刺叶高山栎(Quercus spinosa)对于高海拔环境的适应机制,探究其生态适应策略,通过测定云南禄劝乌蒙乡三个不同海拔梯度样地刺叶高山栎的12个叶功能性状特征,利用方差分解分析和冗余分析揭示叶功能性状对环境因子的响应,进一步利用叶片性状网络与主成分分析对其生存适应策略进行解析。结果表明:(1)乌蒙乡刺叶高山栎叶功能性状均存在变异,变异系数范围在6.12%—54.97%之间,其中叶含水量变异程度最高,变异系数为54.97%,叶碳含量变异程度最小,变异系数为6.12%;(2)乌蒙乡刺叶高山栎绝大部分叶功能性状存在显著的沿海拔分异规律:比叶面积、叶绿素含量、叶碳含量和叶氮含量均随海拔上升呈显著上升趋势,叶厚度、叶干重、叶干物质含量、叶含水量和叶碳氮含量比沿海拔上升呈显著下降趋势;(3)研究区域内,土壤因子对刺叶高山栎叶功能性状变异起决定作用,土壤总钾、总氮、速效磷与含水量是重要土壤因子;(4)乌蒙乡刺叶高山栎形成以比叶面积为中心的叶功能性状网络,并通过调节以叶碳含量为代表性状(即资源获取)与叶氮磷含量比为代表性状(即养分利用)两个功能模块适应环境变化;(5)研究区域内,在不同海拔梯度分布的刺叶高山栎适应环境变化采取不同经济策略;高海拔分布的刺叶高山栎通过提高光合效率以及采取更为积极的“快速投资⁃收益型”资源策略以适应生境。总之,乌蒙乡不同海拔梯度刺叶高山栎叶功能性状沿海拔梯度分异明显,土壤养分及其含水量是造成这种分异的主要因素,导致了不同的适应策略产生。

1951–2021年欧洲地区木本植物的格网物候数据集

植物物候记录了植物重复生命周期事件的发生时间,是指示全球变化的重要指标。植物物候研究有助于理解生态系统对全球变化的响应,也是模拟陆地生态系统的物质和能量平衡的重要基础。本数据集基于过去70年欧洲物候项目(Pan European Phenology Project,PEP725)整编的6种代表性木本植物的地面观测物候数据,采用三种考虑春季冷激和积温累积过程的物候模型(Unified、Unichill和时空耦合模型)在大洲尺度上对物候数据进行建模和分析,研制了欧洲地区代表性木本植物格网物候数据集。本数据集包含1951–2021年欧洲地区(34°57′N–72°3′N,25°3′W–40°3′E)6种木本植物的逐年展叶始期和开花始期格网数据,空间分辨率为0.1°,时间分辨率为天。数据集的质量评估表明,欧洲地区各物种展叶始期和开花始期平均误差分别为7.9和7.6天,与其他区域尺度研究中春季物候的模拟误差接近,因此本文格网物候数据具有较高的模拟精度。本数据集旨在更好地表征欧洲地区大洲尺度植物物候的时空格局,为区域其他来源的植物物候数据产品提供有价值的验证参考,亦可为全球变化和陆地生态系统模拟等研究领域提供支撑物候数据。

南酸枣花芽形态分化过程及叶片营养生理特性

【目的】探究南酸枣花芽分化的外部形态变化与内部解剖结构的对应关系,揭示叶片中营养物质动态变化与花芽分化进程的关系。【方法】采用石蜡切片法观察南酸枣花芽;测定分化关键期叶片可溶性蛋白、可溶性淀粉、可溶性糖、全磷、全氮、全钾、有机质含量变化。【结果】1)南酸枣的花类型为单花类型或聚伞圆锥花序,雄花为花序,雌花为花序或单花。南酸枣花芽多为混合芽,成年雄树花芽萌发率达99%,雌树花芽萌发率达70%。2)南酸枣花芽分化可划分为9个时期:未分化期、生理分化期、苞片形成期、萼片形成期、花序形成期、花瓣形成期、雄蕊形成期、雌蕊形成期、侧花序发育期。南酸枣花芽分化从3月底开始,2月下旬芽萌动后约40天进入生理分化期,6月中下旬为雌雄原基分化盛期,翌年3月,雌、雄花的侧花序发育完全。3)花芽横、纵径的增长呈现先快后慢的趋势,生理分化期雌、雄花芽横径较未分化期分别提高了211.36%和231.11%,生理分化期南酸枣花芽体积处于快速增加期;花序形成期雌、雄花芽横径较花萼形成期分别提高了5.43%和10.00%,生长速度变缓。4)芽基叶片可溶性蛋白含量于花序形成期具最低值,雌、雄叶片中可溶性蛋白和可溶性淀粉含量均于花序形成期达峰值,分别为2.29、2.51和25.43、21.50 mg·g^(−1);花序形成期雌、雄叶片氮的含量降幅大,相较未分化期分别下降了22.88%和32.51%,全氮含量下降25.35%和34.09%,全磷含量下降41.07%和39.67%,全钾含量下降23.94%和22.52%。雌花芽叶片的碳氮比值范围在21.01~26.52,雄花芽范围在21.14~28.90。【结论】南酸枣自芽萌发至雌、雄蕊原基始分化约需4个月,雌花生理分化进程晚于雄花10天左右,花序发育完全约需1年时间。叶片中高含量的氮、磷、钾元素有利于花芽的生理分化,较高的碳氮比可调节南酸枣花芽的形态分化过程;叶片需积累较多的可溶性糖及可溶性淀粉有利于花序形成;生理分化期(4月下旬)和花序分化期(6月上旬)是花芽分化进程中较关键的时期,南酸枣高效水肥管理及花果调控应着重关注这两个时期。

不同性质艾柱燃烧红外光谱特征研究

目的 探索不同性质艾柱的燃烧红外光谱特征。方法 选取碳化艾柱及不同存储年份(3、5、10年)、不同叶绒比(3∶1、5∶1、10∶1)、不同紧密度(低、中、高)的普通艾柱做为实验样品,使用傅立叶红外变换光谱仪对样品进行燃烧红外光谱测试,并分析峰值与形状等光谱特征;主要指标为特征峰波长,特征峰峰高,红外波段(1.28~25.00μm)、近红外波段(1.28~3.00μm)、ATP能量代谢特征波段(2.0~2.5μm)、人体红外辐射峰值波段(7.5~10.0μm)辐射强度。结果 碳化艾柱燃烧红外单光束光谱峰值位于4.012μm,普通艾柱(存储3年、叶绒比3∶1、中紧密度)峰值位于4.630μm;扣除大气背景辐射后,光谱均在4.241μm或15.000μm附近出现波峰或波谷。与普通艾柱(存储3年、叶绒比3∶1、中紧密度)比较,碳化艾柱红外波段辐射强度更高;特征峰波长更长;特征峰高度更低(P<0.05)。与存储3年艾柱比较,存储10年艾柱的红外波段、近红外波段、ATP能量代谢特征波段、人体红外辐射峰值波段辐射强度更高(P<0.05);存储5年艾柱的ATP能量代谢特征波段辐射强度更高(P<0.05)。与存储5年艾柱比较,存储10年艾柱的红外波段、近红外波段、ATP能量代谢特征波段、人体红外辐射峰值波段辐射强度更高(P<0.05)。与叶绒比3∶1艾柱比较,叶绒比10∶1艾柱的红外波段、近红外波段、ATP能量代谢特征波段、人体红外辐射峰值波段辐射强度更高(P<0.05);叶绒比5∶1艾柱的红外波段、ATP能量代谢特征波段、人体红外辐射峰值波段辐射强度更高(P<0.05)。与低紧密度艾柱比较,中、高紧密度艾柱的红外波段、人体红外辐射峰值波段辐射强度更高(P<0.05)。结论 碳化艾柱辐射强度较强,但其光谱异于普通艾柱,增加普通艾柱的存储年份及叶绒比可以加强艾柱辐射强度,且紧密度适中的普通艾柱更优,为传统艾灸的作用机制研究提供基础。

南方红壤侵蚀区不同恢复阶段下马尾松叶经济型谱特征

在生态恢复过程中,植物为了适应环境的变化形成了资源获取与资源保守之间的权衡策略。叶经济型谱的提出为量化和描述植物的资源权衡策略提供了理论基础。本文以南方红壤侵蚀区不同恢复阶段下马尾松叶片性状为研究对象,探究生态恢复过程中马尾松叶片性状(比叶面积、叶干物质含量、叶相对含水率、叶全碳含量、叶全氮含量、叶全磷含量)的变化规律与叶片性状之间的相关性,以及不同恢复阶段下叶片性状之间的差异。结果表明,比叶面积、叶全氮含量、叶全磷含量随着恢复阶段演进逐渐上升;叶全碳含量与叶全氮含量、叶全磷含量呈显著负相关;随着恢复的进程,叶性状PCA1轴得分增加。以上结果表明,随着恢复阶段的进行,叶片性状组合由营养保守型性状向营养获取型性状转变。

木质与草质藤本叶性状及对不同光环境的适应策略

以华南地区9种木质藤本和5种草质藤本为研究对象,通过测量全阳和荫蔽环境下2类藤本叶性状指标,研究其叶性状差异及相关性,分析其叶经济谱并探讨2类藤本对不同光环境的适应性策略及应用。结果表明:14种藤本植物在不同光环境中表现出不同的适应策略,总体表现为采取SLA升高、LT降低、LWC提升、LDMC降低等策略来适应荫蔽环境。草质藤本的SLA极显著高于木质藤本,而木质藤本的LDMC极显著高于草质藤本,草质藤本在叶经济谱中更倾向于“快速投资−收益”型物种,木质藤本则更倾向于“缓慢投资−收益”型物种。叶功能性状SLA、LNC、LD、LDMC、LWC间紧密相关,表现出SLA与LDMC、LD呈极显著负相关,与LNC、LWC呈极显著正相关的权衡关系。聚类结果显示,绿萝和合果芋为耐荫植物,五爪金龙、鸡矢藤、珊瑚藤、玉叶金花、炮仗花、锦屏藤、冬红为中性偏阳植物,鹰爪花、络石、软枝黄蝉、叶子花、白花油麻藤为喜阳植物。

基于载荷谱的钢板弹簧耐久试验规范优化

文章以轻型客车的钢板弹簧为例,开展了基于试验场载荷谱的整车耐久试验规范优化。选取了能够表征钢板弹簧受力的板簧前端安装支座为载荷谱关键采集点,采集了试验场耐久规范的载荷谱,结合疲劳理论知识并通过N-code软件计算得到不同试验工况的伪损伤值。以保留原始载荷谱90%的伪损伤当量为目标生成了加速试验规范,进而从功率谱密度、统计值和雨流计数等方面对优化前后的耐久试验规范进行了分析和对比,结果表明,在保留原有试验规范的特征基础上可以实现明显的加速,试验周期缩短了60%。

17种石斛属植物表型性状多样性分析

以17种石斛属(Dendrobium Sw.)植物为研究对象,通过观测6个叶表型性状和15个花表型性状,从形态学角度对石斛属植物表型性状进行变异和多样性分析,并揭示各表型性状间的相互关系。结果表明:叶表型性状变异系数为28.78%~63.63%,花表型性状变异系数为31.26%~117.65%,不同表型性状变异幅度差异明显,花表型性状的变异幅度大于叶表型性状。21个表型性状的Shannon s多样性指数差异较小,为4.372~4.393,Shannon s多样性指数最大的是萼囊长、最小的是花柄长和唇瓣宽。Shannon s多样性指数与变异系数整体存在显著(p<0.05)线性相关。主成分分析结果显示:前4个主成分的累计贡献率达84.2%,可以反映17种石斛属植物表型性状的基本特征,其中花纵径、叶面积、侧萼长、萼囊长和叶长宽比是造成石斛属植物表型差异的主要因子。聚类分析结果表明:17种石斛属植物可聚为4组,聚类结果与传统分类存在一定差异。相关性分析结果表明:叶各表型性状间和花各表型性状间整体上存在显著或极显著(p<0.01)相关性,叶厚与除侧萼长、侧萼宽和萼囊长外的12个花表型性状均存在显著或极显著相关性。综合研究结果表明:石斛属植物表型性状变异丰富,拥有丰富的表型多样性,各表型性状之间有着密切且复杂的关系。

茶树品种‘嘉茗1号’不同部位主要组分分析

对茶树品种‘嘉茗1号’(Camellia sinensis‘Jiaming No.1’)不同部位〔包括花朵(不含花蕊,下同)、花蕾、花蕊、果实和叶片〕的主要组分进行测定和分析。结果显示:茶树品种‘嘉茗1号’花朵的水浸出物含量最高(718.1 mg·g^(-1)),显著(P<0.05)高于其他4个部位;叶片的茶多酚、咖啡碱、总黄酮、V C及5种儿茶素类组分含量总体显著高于其他4个部位;花朵中5种儿茶素类组分含量均最低;花蕾和花蕊中氨基酸种类最多(22种);花朵、花蕾、花蕊和果实中氨基酸主要以鲜味和甜味氨基酸有呈味贡献。综合来看,茶树品种‘嘉茗1号’的花和果实具有良好的开发利用前景。

汉麻花和叶挥发性成分分析

为明确汉麻不同花和叶的挥发性成分,以品种brosom为材料,利用顶空-气相色谱/质谱联用技术对其雌花、雄花、雌株老嫩叶、雄株老嫩叶的挥发性成分进行测定。结果表明,相对含量在0.05%以上的挥发性成分中,雌花检测到36种、雄花23种、雌株老叶32种、雌株嫩叶35种、雄株老叶26种、雄株嫩叶30种;萜烯类是花、叶的主要挥发性成分,其中单萜类是雌/雄花的优势成分,雌花主要成分为β-蒎烯和D-柠檬烯,雄花为α-蒎烯、β-蒎烯和D-柠檬烯;倍半萜类是雌株老/嫩叶优势成分,单萜类是雄株老/嫩叶优势成分;雌株老叶主要成分为β-蒎烯、D-柠檬烯、石竹烯和叶醇,雌株嫩叶为D-柠檬烯、石竹烯和β-金合欢烯,雄株老叶为α-蒎烯、β-蒎烯、石竹烯和叶醇,雄株嫩叶为α-蒎烯和β-蒎烯。挥发性成分相似率分析结果显示,雌花和雄花相似率较高,雌株老/嫩叶及雄株老/嫩叶相似率极高,而不同性别的花、叶间相似率较低。雄株老嫩叶α-蒎烯含量(>44.84%)显著高于雌株老嫩叶(<2.65%),雌株老嫩叶的β-金合欢烯含量(>9.18%)显著高于雄株老嫩叶(<0.33%),故α-蒎烯和β-金合欢烯可作为区分brosom雌/雄株的挥发性成分标识物。α-蒎烯、石竹烯、β-罗勒烯在雌/雄花中的差异表现丰富了汉麻雌/雄花在挥发性成分方面的基础知识。本研究结果为汉麻育种及其综合开发利用提供了理论基础。