Leaf Photosynthetic Pigment Contents Research Articles

Enhancing sweet potato (Ipomoea batatas) resilience grown in cadmium-contaminated saline soil: a synergistic approach using Moringa leaf extract and effective microorganisms application

Raising soil contamination with cadmium (Cd2+) and salinization necessitates the development of green approaches using bio-elicitors to ensure sustainable crop production and mitigate the detrimental health impacts. Two field trials were carried out to study the individual and combined effects of foliage spraying of Moringa leaf extract (MLE) and soil application of effective microorganisms (EMs) on the physio-biochemical, osmolytes, antioxidants, and performance of sweet potato grown in Cd2+-contaminated salty soil (Cd2+ = 17.42 mg kg−1 soil and soil salinity ECe = 7.42 dS m−1). Application of MLE, EMs, or MLE plus EMs significantly reduced the accumulation of Cd2+ in roots by 55.6%, 50.0%, or 68.1% and in leaves by 31.4%, 27.6%, or 38.0%, respectively, compared to the control. Co-application of MLE and EMs reduced Na+ concentration while substantially raising N, P, K+, and Ca2+ acquisition in the leaves. MLE and EMs-treated plants exhibited higher concentrations of total soluble sugar by 69.6%, free proline by 47.7%, total free amino acids by 29.0%, and protein by 125.7% compared to the control. The enzymatic (SOD, APX, GR, and CAT) and non-enzymatic (phenolic acids, GSH, and AsA) antioxidants increased in plants treated with MLE and/or EMs application. Applying MLE and/or EMs increased the leaf photosynthetic pigment contents, membrane stability, relative water content, water productivity, growth traits, and tuber yield of Cd2+ and salt-stressed sweet potato. Consequently, the integrative application of MLE and EMs achieved the best results exceeding the single treatments recommended in future application to sweet potato in saline soil contaminated with Cd2+.

Exogenous Hemin alleviated cadmium stress in maize (Zea mays L.) by enhancing leaf photosynthesis, AsA-GSH cycle and polyamine metabolism.

Cadmium (Cd) stress is one of the principal abiotic stresses that inhibit maize growth. The research was to explore (hemin chloride) Hemin (100 μmol L−1) on photosynthesis, ascorbic acid (AsA)-glutathione (GSH) cycle system, and polyamine metabolism of maize under Cd stress (85 mg L−1) using nutrient solution hydroponics, with Tiannong 9 (Cd tolerant) and Fenghe 6 (Cd sensitive) as experimental materials. The results showed that Hemin can increase leaf photosynthetic pigment content and ameliorate the ratio of Chlorophyll a/chlorophyll b (Chla/Chlb) under Cd stress. The values of ribose 1, 5-diphosphate carboxylase/oxygenase (RuBPcase) and phosphoenolpyruvate carboxylase (PEPCase), and total xanthophyll cycle pool [(violoxanthin (V), antiflavin (A) and zeaxanthin (Z)] increased, which enhancing xanthophyll cycle (DEPS) de-epoxidation, and alleviating stomatal and non-stomatal limitation of leaf photosynthesis. Hemin significantly increased net photosynthetic rate (Pn), stomatal conductance (gs), transpiration rate (Tr), photochemical quenching coefficient (qP), PSII maximum photochemical efficiency (Fv/Fm), and electron transfer rate (ETR), which contributed to the improvement of the PSII photosynthetic system. Compared with Cd stress, Hemin can reduce thiobartolic acid reactant (TBARS) content, superoxide anion radical (O2−) production rate, hydrogen peroxide (H2O2) accumulation, and the extent of electrolyte leakage (EL); decreased the level of malondialdehyde (MDA) content and increased the activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT); slowed the decrease in dehydroascorbic acid reductase (DHAR) and monodehydroascorbate reductase (MDHAR) activity and the increase in glutathione reductase (GR) and ascorbate peroxidase (APX) activity in leaves; promoted the increase in AsA and GSH content, decreased dehydroascorbic acid (DHA) and oxidized glutathione (GSSG), and increased AsA/DHA and GSH/GSSG ratios under Cd stress. Hemin promoted the increase of conjugated and bound polyamine content, and the conversion process speed of free putrescine (Put) to free spermine (Spm) and spermidine (Spd) in maize; decreased polyamine oxidase (PAO) activity and increased diamine oxidase (DAO), arginine decarboxylase (ADC), ornithine decarboxylase (ODC) and S-adenosylmethionine decarboxylase (SAMDC) enzyme activities in leaves under Cd stress.

Isolation of phloridzin-degrading, IAA-producing bacterium Ochrobactrum haematophilum and its effects on the apple replant soil environment

We isolated and identified a bacterium that could produce IAA and degrade phloridzin in the rhizosphere soil of healthy replanted apple (the rootstock is M9T337 and the scion is Yanfu 3), providing a theoretical basis for reducing the obstacles associated with apple replant disease (ARD). Isolates were screened using Salkowski colorimetry and screening medium for phloridzin. The isolate of interest (W6) was identified as Ochrobactrum haematophilum based on morphological analysis, physiological and biochemical tests, and 16S rDNA sequencing. In a laboratory experiment, W6 produced auxin and promoted the growth of Arabidopsis thaliana roots, and its degradation rate of 100 mg · L−1 phloridzin was 62.0%. In a pot experiment, W6 significantly reduced the phenolic acid contents of replanted soil, lowered the abundance of the harmful fungus Fusarium solani, and increased soil enzyme activities, thereby improving the micro-ecological environment of replant soil. W6 increased the root antioxidant enzyme activity and leaf photosynthetic pigment content of replanted Malus hupehensis Rehd. seedlings, effectively alleviating the decrease in net photosynthetic rate, transpiration rate and stomatal conductance caused by ARD. In a field experiment, W6 also promoted the growth of replanted apple (the rootstock is M9T337 and the scion is Yanfu 3) saplings. Therefore, W6 can promote apple growth and degrade phenolic acids, and it can be used as an effective treatment for the reduction of ARD.

Improving the Estimation of Apple Leaf Photosynthetic Pigment Content Using Fractional Derivatives and Machine Learning

As a key functional trait, leaf photosynthetic pigment content (LPPC) plays an important role in the health status monitoring and yield estimation of apples. Hyperspectral features including vegetation indices (VIs) and derivatives are widely used in retrieving vegetation biophysical parameters. The fractional derivative spectral method shows great potential in retrieving LPPC. However, the performance of fractional derivatives and machine learning (ML) for retrieving apple LPPC still needs to be explored. The objective of this study is to test the capacity of using fractional derivative and ML methods to retrieve apple LPPC. Here, the hyperspectral data in the 400–2500 nm domains was used to calculate the fractional derivative order of 0.2–2, and then the sensitive bands were screened through feature dimensionality reduction to train ML to build the LPPC estimation model. Additionally, VIs-based ML methods and empirical regression models were developed to compare with the fractional derivative methods. The results showed that fractional derivative-driven ML methods have higher accuracy than the ML methods driven by the original spectra or vegetation index. The results also showed that the ML methods perform better than empirical regression models. Specifically, the best estimates of chlorophyll content and carotenoid content were achieved using support vector regression (SVR) at the derivative order of 0.2 (R2 = 0.78) and 0.4 (R2 = 0.75), respectively. The fractional derivative maintained a good universality in retrieving the LPPC of multiple phenological periods. Therefore, this study highlights that the fractional derivative and ML improved the estimation of apple LPPC.

Photosynthesis Performance and Antioxidative Enzymes Response of Melia azedarach and Ligustrum lucidum Plants Under Pb-Zn Mine Tailing Conditions.

Lead–zinc (Pb–Zn) mine tailings pose a great risk to the natural environment and human health because of their high toxicity. In this study, the responses of photosynthesis, chlorophyll fluorescence, and antioxidative enzyme of Melia azedarach and Ligustrum lucidum in the soil contaminated by Pb–Zn mine tailings were investigated. Results showed that Pb–Zn mine tailings significantly reduced net photosynthetic rates and leaf photosynthetic pigment content of both trees, and the reduction of net photosynthetic rates was mainly caused by their biochemical limitation (BL). The chlorophyll fluorescence parameters from Pb–Zn tailing stressed leaves indicated that Pb–Zn tailings affected PSII activity which was evident from the change values of energy fluxes per reaction center (RC): probability that an electron moves further than QA− (ETO/TRO), maximum quantum yield for primary photochemistry (TRO/ABS), the density of PSII RC per excited cross-section (RC/CSO), the absorption of antenna chlorophylls per PSII RC (ABS/RC), and the turnover number of QA reduction events (N). Pb–Zn mine tailings also affected the oxidation and reduction of PSI, which resulted in a great increase of reactive oxygen species (ROS) contents and then stimulated the rate of lipid peroxidation. Both trees exhibited certain antioxidative defense mechanisms as elevated superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) activities, then declined under high level of Pb–Zn tailing treatment. Comparatively, L. lucidum showed less extent effect on photosynthesis and higher antioxidative enzyme activities than M. azedarach; thus L. lucidum was more tolerant than M. azedarach at least under the described Pb–Zn tailing treatment. These results indicate that the effect of Pb–Zn mine tailings on photosynthesis performance mainly related to imbalance of the PSII activity and PSI redox state in both trees. We propose that M. azedarach and L. lucidum could relieve the oxidative stress for phytoremediation under the appropriate Pb–Zn mine tailing content.

De novo transcriptome analysis of an albino mutant Pasphiopedilum pacific shamrock reveals reduced expression of genes related to chloroplast biosynthesis and division

Paphiopedilum pacific shamrock is an orchid with high ornamental value. Understanding the mechanisms responsible for leaf color in albino mutants is important for ornamental development and breeding. In this study, we compared the leaf photosynthetic pigment content and transcriptome of albino mutants ppa01 and wild-type P. pacific shamrock. Photosynthetic pigment in mutants was less than 2% of the wild type and chl a/b was 60% less than the wild type. Transcriptome sequencing yielded 6.27 Gb and 5.67 Gb clean data from the mutant and wild-type leaves, respectively. De novo assembly yielded 104,763 unigenes with 15,400 greater than 1 kb in length. In unigene expression analysis, 3170 differentially expressed genes (DEGs) were identified with 2231 (70.38% of total DEGs) down-regulated. Results from GO and KEGG enrichment analysis, KEGG pathway analysis and qPCR suggest that the reduction of chloroplast biosynthesis and division in the mutant was due to low expression levels of ppGLK1 and ppFtsz. Mutants were associated with fewer chloroplasts in leaf cells, abnormal chloroplast structures, impaired chlorophyll biosynthesis, and thus reduced total chlorophyll and carotenoid contents. Furthermore, down-regulated expression of ppNYC1 reduced transformation of chlorophyll b into chlorophyll a, leading to a chl a/b decline. The research will guide future studies of leaf pigment mutations and the breeding of P. pacific shamrock.

Elma Bitkisi (Malus domestica L.)’nde Foliar Uygulanan Salisilik Asitin Donmaya Karşı Etkileri

In our study we aim to increase frost resistance and improve the yield and quality of apple is important in Turkey and world economy. Phenological and morphological observations, physiological and biochemical analyzes were carried out in apple (Malus domestica L.) plants. It was studied to determine the effects of foliar Salicylic acid (0, 500 ppm/plant and 1000 ppm/plant) on adaptation of this plant when exposed to freezing stress, the quality and yield. Leaf photosynthetic pigment contents, total protein amount, proline amount, superoxide dismutase and peroxidase enzymatic activities were measured. The study planned by random experimental design and statistical analysis of data with SPSS program (LSD test) were made. It was determined that fruit and shoot numbers were increased in samples exposed to 500 ppm salicylic acid and while fruit weights were increased in samples exposed to 500 ppm and 1000 ppm salicylic acid compared to the control. Also, colour of plants were darkened. Chla, chlb, total chl, proline, superoxide dismutase and peroxidase amounts were increased significantly compared to the control group. Increases occured in the carotenoid and the protein amounts are not significant statistically. In the light of obtained data, foliar application of salicylic acid were found to reduce the effects of freezing stress and to increase the yield and quality of apple plants.

冠层水平互花米草叶片光合色素含量的高光谱遥感估算模型

PDF HTML阅读 XML下载 导出引用 引用提醒 冠层水平互花米草叶片光合色素含量的高光谱遥感估算模型 DOI: 10.5846/stxb201304270834 作者: 作者单位: 福建师范大学地理科学学院,福建师范大学地理科学学院,福建师范大学地理科学学院,福建师范大学地理科学学院,福建师范大学地理科学学院,福建师范大学地理科学学院,福建师范大学地理科学学院 作者简介: 通讯作者: 中图分类号: 基金项目: 福建省科技计划项目(2010R1037);福建师范大学研究生科技创新基金资助 Hyperspectral remote sensing estimation models for foliar photosynthetic pigment contents at canopy level in an invasive species, Spartina alterniflora Author: Affiliation: Fujian Nomal University,Fujian Nomal University,,,,, Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:以闽江河口鳝鱼滩湿地互花米草(Spartina alterniflora)的实测冠层高光谱反射率和叶片光合色素含量(LPPC)为数据源,在分析LPPC与原始光谱反射率、一阶导数光谱反射率、22种已报道光谱指数和14种新构建的植被指数相关性的基础上,利用直线回归、指数回归、对数回归以及乘幂回归方法,系统地比较了36种植被指数在估算互花米草LPPC中的表现。研究表明:(1)一阶导数光谱反射率组合的植被指数用于估算互花米草的LPPC优于原始光谱反射率;(2)红边区域一阶导数光谱是估测互花米草LPPC的最佳波段;(3)对于单一色素含量的估算,叶绿素a (Chla)的最佳估算指数为FDNDVI[723,703];叶绿素b (Chlb)的最佳估算指数为FDRVI[723,525];类胡萝卜素(Cars)的最佳估算指数为FDNDVI[723,703];(4)对于使用统一参量同时估算Chla、Chlb、Cars,由FDRVI[723,703]建立的对数估算模型效果最佳。研究成果可为湿地植物生化参量反演提供参考,也可为闽江河口湿地入侵种互花米草的动态监测和生态评估管理提供有力的科学依据。 Abstract:Foliar photosynthetic pigments are the most important biochemical parameters relative to the physiological function of wetland plants. Quantitative estimation of photosynthetic pigments can provide important information about the dynamics of the vegetation productivity, vegetation stress, or nutrient cycles within wetland ecosystems. However, the estimation of foliar photosynthetic pigments is complicated because canopy reflectance in the visible and near infrared wavelengths is affected by confounding effects that come not only from foliar photosynthetic pigment contents variation but also from the changing environmental conditions of wetland ecosystem. Our objective was to address the question by establishing hyperspectral remote sensing estimation models for foliar photosynthetic pigments at canopy level in an invasive species, Spartina alterniflora. In this study, the hyperspectral reflectance of canopy leaf and leaf photosynthetic pigment contents (LPPC) from S. alterniflora in Min River Shanyu beach were recorded as data source. The correlation between LPPC and raw spectral reflectance, the first derivative reflectance, 22 reported vegetable indices and 14 new formed indices were determined. Based on the results of correlation analysis, a total of 36 indices were tested by linear regression, exponential regression, logarithm regression and the power of regression to explore their potentials in LPPC estimation in S. alterniflora. The results showed that: (1) This study selected 5 wavebands in the region of 400-900 nm, which appeared to be the optimal wavebands for the S. alterniflora foliar photosynthetic pigments estimation. Of the selected wavebands, the most frequently occurring wavebands were 723 nm, 703 nm, 525 nm, 752 nm, 668 nm. (2) Vegetation index portfolio by the first derivative reflectance was evidently better than raw reflectance for estimating LPCC in S. alterniflora. Combining the optimal wavebands, the results indicated that the first derivative of reflectance in the red edge region (680-760 nm) was the optimal band for estimating LPCC. (3) For a single pigment content, the best indexes for estimating chlorophyll a (Chla), chlorophyll b (Chlb) carotenoids (Cars) were FDNDVI[723,703], FDRVI[723,525], and FDNDVI[723,703], respectively. The three new formed indices were proved to have better linearity with corresponding photosynthetic pigment. (4) Using the same index to estimate different pigments, the best model was the logarithmic model using FDRVI[723,703], with high predicted correlation coefficients R2 of 0.6997, 0.7187, and 0.7132, respectively. This study would not only provide a good reference for hyperspectral remote sensing retrieval of biochemical variables in wetland vegetation, but also provide a strong scientific basis for the dynamic monitoring of S. alterniflora and management of ecological assessment in Min River estuary. 参考文献 相似文献 引证文献

Genetic Dissection of Photosynthetic Pigment Content in Cotton Interspecific Chromosome Segment Introgression Lines

Photosynthesis provides an important foundation for cotton yield and fiber quality.Photosynthetic pigments play an important role in absorption,transfer,and transition of photo energy.In this study,quantitative trait loci(QTLs) mapping was conducted for leaf photosynthetic pigment content using interspecific chromosome segment introgression lines(CSIL).Forty four QTLs(LOD 3) for chlorophyll-a content,chlorophyll-b content,carotenoid content,chlorophyll-a/b ratio value and total chlorophyll content were detected in CSIL population by QTLIciMapping 3.0.Among them,fifteen QTLs were detected in two years.Forty four QTLs were located on fifteen chromosomes including A1(chr.1),A8(chr.8),A9(chr.9),A11(chr.11),A13(chr.13),D1(chr.15),D3(chr.17),D5(chr.19),D6(chr.25),D7(chr.16),D8(chr.24),D9(chr.23),D10(chr.20),D11(chr.21),and D12(chr.26) with the explained phenotypic variation of 1.25-5.59%.QTLs(qCa-D1-1,qCb-D1-1,qCx.c-D1-1,and qTC-D1-1) influencing chlorophyll-a content,chlorophyll-b content,carotenoid content and total chlorophyll content were located near NAU3714 on chr.D1.It may make a breakthrough in increasing cotton yield through the breeding for high photosynthetic efficiency using the chromosome segment near NAU3714 with modified backcrossing pyramiding breeding(MBPB) technique.

Hybrid larch (Larix x eurolepis Henry): a good candidate for cadmium phytoremediation?

Studies related to phytoremediation by conifers are still at their beginning. Thus, we investigated the ability of a hybrid larch (Larix x eurolepis) to accumulate cadmium (Cd). One-month-old clonal plantlets grown in vitro were exposed for 1 week to a high Cd concentration (1.5 mM). No significant effect was observed on root and shoot biomass, root length, and needle number as a result of Cd treatment. Leaf photosynthetic pigment content and total soluble protein concentration in roots and shoots remained unchanged compared to control plantlets. Taken together, these results suggested that hybrid larch tolerated Cd in our conditions. The high Cd concentration in shoots (200 μg Cd gram(-1) dry weight) showed the good capacity of larch to translocate Cd and thus a potential use of this species for phytoremediation. Furthermore, under our conditions, phytochelatin biosynthesis pathway was slightly stimulated, suggesting that this pathway did not reach the threshold and/or another mechanism of Cd storage may be involved to explain larch tolerance to Cd.

Effect of Fertilization on Photosynthetic Features in Phyllostachys pubescens

The changes of leaf area index (LAI), leaf photosynthetic pigment content, photosynthetic rate of Phyllostachys pubescens in one leaf development cycle (two years) under different fertilization (no fertilization: CK, fertilization at the leave-expansion period: T1, fertilization at the end of August: T2) were studied. The bamboo showed a high LAI potential under T1, which was 14.5% and 23.9% higher than that of T2 and CK, respectively. Fertilization significantly promoted the synthesis of chlorophyll. The average SPAD (soil and plant analyzer development) achieved the highest values under T1, which was 73% and 17.8% higher than that of T2 and CK, respectively. Fertilization caused diurnal changes in photosynthetic rate during the entire leaf development period, and the photosynthetic rate under T1 was significantly higher than that of T2 and CK. The effect of fertilization on photosynthetic rate varied seasonally, especially for T1.

Low temperature impact on photosynthetic parameters of coffee genotypes

The objective of this work was to evaluate photoprotective mechanisms related to low positive temperatures in Coffea canephora (Conilon clones 02 and 153) and C. arabica ('Catucaí' IPR 102) genotypes, involved in cold temperature tolerance. To accomplish this, one-year-old plants were successively submitted to: temperature decrease of 0.5ºC day-1, from 25/20ºC to 13/8ºC; a three-day chilling cycle at 13/4ºC; and a recovery period of 14 days (25/20ºC). During the experiment, leaf gas exchange, chlorophyll a fluorescence and leaf photosynthetic pigment content were evaluated. Total activity of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) and ribulose-5-phosphate kinase (Ru5PK) were quantified to measure the activity of photosynthesis key enzymes. All genotypes showed low temperature sensitivity, but displayed diverse cold impact and recovery capabilities regarding the photosynthetic-related parameters studied. Catucaí IPR 102 cultivar showed better ability to cope with cold stress than the Conilon clones, especially Conilon 02, and had full recovery of leaf gas exchange, fluorescence parameters, enzymatic activity, and higher contents of the photoprotective pigments zeaxanthin and lutein.

The Potential of a Chlorophyll Content SPAD Meter to Quantify Nutrient Stress in Foliar Tissue of Sycamore (Acer pseudoplatanus), English Oak (Quercus robur), and European Beech (Fagus sylvatica)

The chlorophyll content (or SPAD meter) is a simple, portable diagnostic tool that measures the greenness or relative chlorophyll content of leaves. Compared with the traditional destructive methods of chlorophyll extraction, the use of this equipment saves time, space, and resources. The objective of this study was to establish a correlation between the leaf photosynthetic pigment content (chlorophylls, carotenoids) extracted in aqueous acetone, total leaf nitrogen (N) content, and chlorophyll fluorescence Fv/Fm values with the SPAD-502 readings in sycamore (Acer pseudoplatanus), beech (Fagus sylvatica), and English oak (Quercus robur) leaves displaying visual symptoms of N deficiency. In addition, this study aimed to determine a critical foliar N content below which a reduction in photosynthetic efficiency occurs. Irrespective of species, high correlations were recorded between SPAD readings, total leaf chlorophyll and carotenoid content, foliar N content, and leaf photosynthetic efficiency as measured by chlorophyll fluorescence Fv/Fm values; however, a poor correlation between SPAD values and total chlorophyll:carotenoid ratios was obtained. In the case of Acer pseudoplatanus, Fagus sylvatica, and Quercus robur, SPAD readings lower than 25 indicated impairment of leaf photosynthetic process that in turn were correlated with a foliar N content less than 1.5%, a value associated with a critical N deficiency. Results of this study indicate that the chlorophyll content SPAD-502 m potentially offers a useful nondestructive, handheld system to aid in the evaluation of tree health. However, users should be aware of the limitations of this system. Consistency in sample collection and seasonal timing may necessitate species and cultivar calibration equations to correlate SPAD values with reductions in tree vitality.

Effects of Salinity on the Photosynthetic Pigment Composition of Barley ( Hordeum vulgare L.) Grown under a Triple-Line-Source Sprinkler System in the Field

Summary The effects of salinity on the flag leaf photosynthetic pigment contents and photosystem two efficiency have been studied in several cultivars of barley (Hordeum vulgare L.) in four growing seasons. Barley was grown in a triple-line-source sprinkler system, that maintains a linear soil salinity gradient. Salinity induced minor increases in the flag leaf total chlorophyll content, but did not cause significant changes in the relative pigment composition. The photosynthetic pigment stoichiometry of flag leaves was in the ranges 20–40 : 100–200 : 110–180 : 90–150 : 230–290 : 1000 (mol: mol) for neoxanthin: V+A+Z pigments : lutein: β-carotene: chlorophyll b: chlorophyll a. We observed changes in the pigment stoichiometry from year to year, indicating that the pigment composition of the flag barley leaf depends markedly on the environmental conditions. The actual efficiency of photosystem two, measured at full sun in the field with modulated chlorophyll fluorescence techniques, had small changes in response to salinity in the triple-line-source sprinkler system, whereas the non-photochemical fluorescence quenching increased in response to moderate salinity.

Chemical Mutagenesis and Parthenolide Biosynthesis in Feverfew (Tanacetum parthenium)

Abstract N-nitroso-N-ethylurea (NEU) has been used as a mutagen to generate a range of plants of feverfew, Tanacetum parthenium, with altered morphologies and growth habits, to study the quantitative patterns of secondary metabolism in this medicinal species. Morphological and albino mutations were observed in a proportion of plants grown in vitro from seeds treated with 5 mM NEU. Selective micropropagation of variegated and semi-chlorophyllous lines led to the isolation of normal green, variegated mosaics, semi-chlorophyllous and true albino lines, together with shoots independently exhibiting abnormal growth. Differences in leaf photosynthetic pigment contents of such axenic cultured shoots were assessed spectrophotometrically, with mean chlorophyll concentrations in albino and semi-chlorophyllous tissues of 6% and 34%, and carotenoid concentrations of 8% and 43%, respectively, of mean values in normal green control leaves. HPLC assessments of selected NEU-treated lines for parthenolide, the major bioac...