A CHEMOSYSTEMATIC STUDY OF SELECTED TAXA OF CAPSICUM

Six taxa of Capsicum were chosen for a comparative chemosystematic study. A “key” individual from each taxon was selected for intensive chemical investigation. Thirteen flavonoids were isolated from leaf material and characterized by paper chromatography and absorption spectroscopy. The C-glycosylflavones vitexin and isovitexin, and orientin and iso-orientin, as well as O-glycosides of the flavones apigenin, luteolin, and chrysoeriol, were isolated from the key individuals. Chromatographic analysis of collections from various regions of South America, Central America, and Mexico showed in general that flavonoid variability is more common in cultivated taxa than in wild. Three groups of Capsicum were recognized and the main systematic conclusions were: (1) The white-flowered taxa in Group I, C. baccatum var. baccatum and C. baccatum var. pendulum, have identical flavonoids, corroborating previous conclusions that they are one species. The absence of chrysoeriol in this group separates it from Groups II and III. (2) The purple-to-white-flowered C. eximium var. eximium and C. eximium var. lomenlosum, Group II, have a complex flavonoid chemistry which appears to link Groups I and III. (3) Two purple-flowered species, C. cardenasii and C. pubescens, Group III, are chemically distinct from the other taxa examined.     

Bidirectional cytoplasmic and nuclear introgression in the New World cottons Gossypium barbadense and G. Hirsutum (Malvaceae)

Patterns of interspecific cytoplasmic (plastid and mitochondrial) and nuclear introgression are typically asymmetrical: cytoplasmic gene flow or “capture” is frequently observed without evidence of nuclear introgression. In contrast, nuclear introgression without concomitant cytoplasmic introgression has rarely been demonstrated. Gossypium barbadense L. and G. hirsutum L. have large indigenous ranges in the New World semiarid tropics, with an extensive area of sympatry in the Caribbean and Central America. Numerous accessions of both species were surveyed for diagnostic cpDNA restriction sites. These data, in conjunction with previous information on nuclear markers, lead to several conclusions: 1) introgression between G. hirsutum and G. barbadense is bidirectional for both nuclear and cytoplasmic genes; 2) patterns of introgression between the two species are not symmetrical—in G. barbadense, introgression of G. hirsutum alleles is largely restricted to modem cultivars and is uncommon in areas of sympatry; in contrast, introgression of G. barbadense alleles into G. hirsutum is relatively common in areas of sympatry and is rare in modem cultivars; 3) nuclear introgression is geographically more widespread and more frequently detected than cytoplasmic introgression. Several mechanisms may underlie the differential patterns of cytoplasmic and nuclear gene flow observed, including differential fitness of infraspecific and interspecific cytonuclear combinations and selection against female function in interspecific backcrosses. Possible explanations for the observed asymmetrical patterns of introgression include differences in population sizes combined with phenological differences that bias interspecific pollen transfer.     

FLORAL PIGMENTATION STUDIES IN THE GENUS GOSSYPIUM. IV. EFFECTS OF DIFFERENT GROWING ENVIRONMENTS ON FLAVONOID PIGMENTATION

Petal extracts of Gossypium were analyzed chromatographically to determine if flavonoid constituents are modified by different environments. In the initial phase, fourteen inbred stocks from four species were grown in a plot that was replicated in five different localities ranging from the Mojave Desert to Raleigh, North Carolina. Petal samples were collected from each stock at each site, and chromatograms developed from these samples looked highly similar regardless of the locality of the growing site. In the second phase, two stocks were phytotron grown under a series of regimes in which daylength, temperature, and mineral nutrition were varied. Each stock showed very little floral flavonoid variation despite the growing conditions. A chromatographic survey of leaf extracts from these same phytotrongrown plants showed them to be much more variable. In cotton, flower petal constituents appear to be less variable than leaf constituents. The chemotaxonomic significance of these results are discussed.     

Flavonoid as chemotaxonomic markers in endemic/endangered species of Rauvolfia from Southern Western Ghats of India: A preliminary study

Preliminary analysis of flavonoid chromatographic migration profiles of endemic/endangered species of Rauvolfia L from Southern Western Ghats of India were carried out. Paper chromatogram showed maximum separation in the solvent system of forestral. In the paper chromatogram, number of flavonoid spots varied from 9 to 12 in the five taxa studied. The main aglycones detected in high performance liquid chromatography (HPLC) analysis were flavones apigenin and luteolin, flavonol kaempferol, myricetin, quercetin and anthocyanidins such as delphinidin and cyanidin. Flavonol Quercetin was detected in all the five species of Rauvolfia giving a chemotaxonomic significance to its presence at the generic level. The two species Rauvolfia serpentina and Rauvolfia tetraphylla could be regarded as the most primitive in the evolutionary line with respect to the flavonoid pattern. Rauvolfia densiflora has the most advanced pattern of flavonoids. The dendrogram generated by unweighted pair group method with arithmetic average (UPGMA) cluster analysis of chemo metric data showed a clear grouping of five species in three clusters. Flavonoid profiles were efficiently used for the identification of Rauvolfia beddomei, which due to morphological similarity, was erroneously suspected to be the medicinally significant species Rauvolfia micrantha. Flavonoid profiling using paper chromatography, in the solvent system of forestral could suggest an easy and quick procedure for identifying adulteration by substitution in Rauvolfia species.     

Genetic diversity and relationships of diploid and tetraploid cottons revealed using AFLP

Gossypium species (± 49) represent a vast resource of genetic diversity for the improvement of cultivated cotton. To determine intra- and inter-specific genetic relationships within a diverse collection of Gossypium taxa, we employed 16 AFLP primer combinations on three diploid species, Gossypium herbaceum L. (A1), Gossypium arboreum L. (A2) and Gossypium raimondii Ulbrich (D5), and 26 AD allotetraploid accessions (Gossypium barbadense L. and Gossypium hirsutum L.). A total of 1180 major AFLP bands were observed; 368 of these (31%) were polymorphic. Genetic similarities among all taxa ranged from 0.21 (between the diploid species G. arboreum and G. raimondii) up to 0.89 (within G. barbadense). Phenetic trees based on genetic similarities (UPGMA, N-J) were consistent with known taxonomic relationships. In some cases, well-supported phylogenetic relationships, as well as evidence of genetic reticulation, could also be inferred. UPGMA trees and principal coordinate analysis based on genetic similarity matrices were used to identify genetically distinct cultivars that are potentially important sources of germplasm for cotton improvement, particularly of fiber quality traits. We show that AFLP is useful for estimating genetic relationships across a wide range of taxonomic levels, and for analyzing the evolutionary and historical development of cotton cultivars at the genomic level. Received: 17 January 2000 / Accepted: 4 May 2000     

FLORAL PIGMENTATION STUDIES IN THE GENUS GOSSYPIUM. I. SPECIES SPECIFIC PIGMENTATION PATTERNS

Previous work on cotton flower pigments is outlined. The major flavonoids are glycosides of gossypetin, quercetin, and kampferol. Twelve flavonol glycosides have been tentatively isolated and identified, while a number of minor components remain unidentified. The gossypetin glycosides are gossypin, gossypitrin and a C₇-linked glycoside of unknown sugar residue. The quercetin glycosides include isoquercitrin, rutin, a third C₃-linked glycoside with unknown sugar residue, quercimeritrin and a second C₇-linked glycoside with sugar residue unknown. The kampferol glycosides include trifolin, kampferol rutinoside and 2 other C₃-linked glycosides with unknown sugar residues. The major anthocyanin throughout the genus is cyanidin. Mutants which affect visible flower color were studied in 3 species (G. arboreum, G. hirsutum, and G. barbadense). The majority of these mutants act to decrease or prevent the synthesis of gossypetin glycosides. The only exceptions to this are the mutants at the Y_a locus in G. arboreum, which affect all of the C₇-linked glycosides in one case, and in the other reduce over-all flavonol production. In all instances, the species could be positively identified by the residual array of pigments not affected by the mutant alleles concerned; i.e., visual similarity of phenotypes did not obscure the basic pattern of pigmentation characteristic of the different species.     

大刺儿菜和小刺儿菜的植物化学分类学研究

大刺儿菜和小刺儿菜是形态相似的两个近缘类群,其分类学地位一直存在争论,的有学者把它们归并为一个种。本文通过对其叶的黄酮类化合物层析谱进行比较研究,结果表明两个类群都显示出各自的特征斑点;结合其形态学特征,支持将它们作为两个独立的种。     

Profiling and Elucidation of the Phenolic Compounds in the Aerial Parts of Gynura bicolor and G. divaricata Collected from Different Chinese Origins

Gynura bicolor and G. divaricata are not only known to be nutritive as cultured vegetables, but also beneficial as folk medicines in East Asia. As demonstrated by the current phytochemical knowledge, the genus Gynura is a promising source of phenolics with multiple medicinal activities. To expand this phytochemical knowledge, the phenolic secondary metabolites of G. bicolor and G. divaricata were studied. From the aerial parts of these two species, collected in five different Chinese locations, two fractions of phenolic compounds with different polarity were obtained by extraction and chromatographic separation. Using UPLC/MS/MS analysis, a total of 53 phenolics were either identified by comparison with respective reference compounds or tentatively characterized by their chromatographic behavior, UV‐absorption patterns, and MS fragmentations. Some naturally existing positional isomers of O‐caffeoylquinic acid, O‐p‐coumaroylquinic acid, O‐feruloylquinic acid, and dicaffeoylquinic acid as well as their methyl esters were qualitatively characterized by their specific fragmentation patterns in targeted MS/MS. In addition, the aerial parts of the two Gynura species contained kaempferol, quercetin oligoglycosides, and a variety of derivatives of benzoic acid, hydroxycinnamic acid, and caffeic acid. Furthermore, the distribution of phenolic compounds in the two species from different Chinese origins was discussed. Finally, an investigation of the total phenolic content and in vitro antioxidant activity of the various phenolic fractions was completed, to evaluate the potential of the extracts of these species for medicinal development. The free‐radical‐scavenging activities of the extracts derived from plants originating from Nanjing were proven to be higher than those of the other extracts, which correlated well with their total phenolic content.     

HEARTWOOD FLAVONOIDS AND THE INFRAGENERIC RELATIONSHIPS OF RHUS (ANACARDIACEAE)

Heartwood flavonoids of 23 taxa of Rhus L. were surveyed in order to assess infrageneric relationships and classification. Fourteen flavonoids and two coumarins were detected in the heartwood extracts. All taxa were characterized by a flavonoid complement consisting of eight 5-deoxyflavonoids involving several aglycone classes (e.g., flavonols, flavones, aurones, chalcones and dihydroflavonols) and the aurone rengasin. None of the 5-hydroxyl analogs of the 5-deoxyflavonoids were detected in the heartwood extracts. Infraspecific flavonoid patterns were uniform in different populations, although the presence of 3′,4′-dihydroxyflavone 4′-O-β-glucoside varied in some taxa. Taxa of Rhus subgenus Rhus consistently differed from all taxa of Rhus subgenus Lobadium in lacking glycosides of fisetin, butein and 3′,4′-dihydroxyflavone. The major evolutionary trend in the heartwood flavonoids of Rhus appears to be accumulation of simple mono- or diglucosides. Data from heartwood flavonoids suggest that Rhus be treated as consisting of two subgenera (Rhus and Lobadium) and that subgenus Lobadium be divided into three sections.     

A CHEMOTAXONOMIC STUDY OF LEMNACEAE

One hundred eighty-six clones of Lemnaceae, representing world-wide collections of 22 taxa, were grown in axenic cultures reproduced by clonal subcultures. Following morphological examinations under a range of culture conditions, a “key” clone was selected to represent each taxon. These key clones were completely representative of the qualitative flavonoid chemistry of the taxa as determined from a number of clones. With the exceptions of Spirodela polyrhiza and S. biperforala which produce identical flavonoids, the flavonoid associations of each species of Lemnaceae were unique in the family. Through paper chromatographic comparisons of purified compounds, plus visible and ultraviolet absorption spectroscopy of isolated individual flavonoids, a total of 47 different compounds was described. These substances included: glycosides of anthocyanidins (cyanidin and petunidin); glycosides of flavonols (kaempferol and quercetin); glycosides of flavones (apigenin and luteolin); and several glycoflavones (C-glycosyl-flavones). When grown under equivalent controlled conditions of culture, infraspecific variation in the qualitative production of these 47 flavonoids was detected in only one flavone glycoside of the species Lemna perpusilla. The reliability of the flavonoid patterns under various conditions of culture was investigated. Under 62 different regimes S. oligorhiza and S. polyrhiza showed only minor variations in their flavonoid glycosides. Studies of other taxa supported this generalization. Under controlled conditions, morphological intergradation obscured identification of many collections. Each could be conclusively identified by its flavonoid chemistry.     

Isolation of the trypsin inhibitors in Ascaris lumbricoides var. suum using affinity chromatography

A method for isolating three water-soluble trypsin inhibitors from Ascaris lumbricoides var. suum by affinity chromatography is described. The trypsin inhibitors captured by affinity chromatography are resolved into three species by chromatography on CM-Sephadex at pH 8.1. The inhibitors are named in the order that they are released from the CM-Sephadex column. Ascaris Trypsin Inhibitor 1 is the same as inhibitor CM-1 described by [3.] and inhibitor Peak I of U. Kucich and [4.]. Ascaris Trypsin Inhibitor 2 is the inhibitor described by [2.] and inhibitor CM-2 of [3.]. Ascaris Trypsin Inhibitor 3 is the same as inhibitor Peak II of [4.]. Ascaris Trypsin Inhibitor 1 is 80%, Ascaris Trypsin Inhibitor 2 is 8%, and Ascaris Trypsin Inhibitor 3 is 12% of the water-soluble trypsin inhibitors present in Ascaris. With this procedure all of the Ascaris trypsin inhibitors can be isolated in a few days. This shortens the exposure of personnel to crude extracts of Ascaris and diminishes the biological hazard of working with them. Frequent exposure to Ascaris extracts may evoke an anaphylactic response in personnel.     

Cuticular lipids for species recognition of mole crickets (Orthoptera: Gryllotalpidae): II. Scapteriscus abbreviatus,S. acletus,S. vicinus,S. sp., and Neocurtilla hexadactyla

Qualitative analyses were made from whole-body cuticular extracts of Scapteriscus abbreviatus, Scapteriscus acletus, Scapteriscus vicinus, and Neocurtilla hexadactyla by isothermal and temperature-programmed gas chromatography. Adults of both sexes and nymphs of each species were collected in Florida. The chromatographic profiles of peaks were distinct and easily recognizable for each species, regardless of sex or developmental stage. Distinct sexual differences were found in S. acletus and S. abbreviatus. Specimens of S. abbreviatus from Puerto Rico and S. vicinus from Bolivia produced gas chromatography (GC) traces very similar to those of conspecifics collected in Florida. Evidence is presented to illustrate the potential importance of volatile cuticular lipid analysis as a tool for mole cricket identification. Cuticular extracts of an undescribed short-winged species of Scapteriscus from Bolivia were also examined and produced GC traces unlike those of any other species analyzed to date.     

Sampling nucleotide diversity in cotton

Background  

Cultivated cotton is an annual fiber crop derived mainly from two perennial species, Gossypium hirsutum L. or upland cotton, and G. barbadense L., extra long-staple fiber Pima or Egyptian cotton. These two cultivated species are among five allotetraploid species presumably derived monophyletically between G. arboreum and G. raimondii. Genomic-based approaches have been hindered by the limited variation within species. Yet, population-based methods are being used for genome-wide introgression of novel alleles from G. mustelinum and G. tomentosum into G. hirsutum using combinations of backcrossing, selfing, and inter-mating. Recombinant inbred line populations between genetics standards TM-1, (G. hirsutum) × 3-79 (G. barbadense) have been developed to allow high-density genetic mapping of traits.     

Phytochemical Analysis,Estimation of Quercetin,and <i>in Vitro</i> Anti-Diabetic Potential of Stevia Leaves Samples Procured from Two Geographical Origins

The current study used RP-HPLC to compare phytochemicals and estimate the bioactive constituents found in Stevia rebaudiana Bert. (SRB) leaves collected from two different geographical sources. SRB leaves were collected from Bangalore, Karnataka, India, and Reduit, Mauritius. Extracts were prepared using ethanol and aqueous solvents. Proximate analysis was used to evaluate moisture content, ash values, crude fibers, and extractive values. Following that, preliminary phytochemical screening was done on both ethanol leaves extracts, and subsequently total flavonoid content was determined. In addition, TLC chromatograms and RP-HPLC studies were performed on both plant extracts to determine the presence of flavonoid components in both leaves extracts, followed by in vitro anti-diabetic activity was performed with alpha amylase and alpha glucosidase enzymes against Acarbose as standard. Results revealed that both the extracts from two different geographical sources varied significantly with the yield, content of chemicals, and presence of quercetin (flavonoid) content when estimated through the RP-HPLC standardized method. Glycosides, flavonoids, proteins, steroids, saponins, terpenoids, and phenols were found in various concentrations during phytochemical screening. Among both zones, the ethanol leaves extract of SRB taken from Mauritius had a greater content of phytochemicals and a higher yield than other extracts due to the soil nature. The Mauritius sample had greater total flavonoid levels as well as more quercetin (0.92 ± 0.011) than the other extracts. Following that, ethanol extract inhibited enzymes (alpha amylase, alpha glucosidases) more than aqueous extract, and this inhibition was dose dependent. Among them, the Mauritius ethanol sample showed higher anti-diabetic efficacy than the Indian sample, but this difference was not significant. Overall, SRB ethanol leaves extracts outperformed other leaves extracts in terms of yield, phytoconstituents, and total flavonoids. Overall, both SRB samples had high quercetin levels and possessed anti-diabetic potential, but they were greater in the Mauritius sample, demonstrating that plant traits are influenced by geographic location.     

The island cotton NBS‐LRR gene GbaNA1 confers resistance to the non‐race 1 Verticillium dahliae isolate Vd991

Wilt caused by Verticillium dahliae significantly reduces cotton yields, as host resistance in commercially cultivated Gossypium species is lacking. Understanding the molecular basis of disease resistance in non‐commercial Gossypium species could galvanize the development of Verticillium wilt resistance in cultivated species. Nucleotide‐binding site leucine‐rich repeat (NBS‐LRR) proteins play a central role in plant defence against pathogens. In this study, we focused on the relationship between a locus enriched with eight NBS‐LRR genes and Verticillium wilt resistance in G. barbadense. Independent virus‐induced gene silencing of each of the eight NBS‐LRR genes in G. barbadense cultivar Hai 7124 revealed that silencing of GbaNA1 alone compromised the resistance of G. barbadense to V. dahliae isolate Vd991. In cultivar Hai 7124, GbaNA1 could be induced by V. dahliae isolate Vd991 and by ethylene, jasmonic acid and salicylic acid. Nuclear protein localization of GbaNA1 was demonstrated by transient expression. Sequencing of the GbaNA1 orthologue in nine G. hirsutum accessions revealed that all carried a non‐functional allele, caused by a premature peptide truncation. In addition, all 10 G. barbadense and nine G. hirsutum accessions tested carried a full‐length (～1140 amino acids) homologue of the V. dahliae race 1 resistance gene Gbve1, although some sequence polymorphisms were observed. Verticillium dahliae Vd991 is a non‐race 1 isolate that lacks the Ave1 gene. Thus, the resistance imparted by GbaNA1 appears to be mediated by a mechanism distinct from recognition of the fungal effector Ave1.     

Allozyme evidence for the origin and diversification of Gossypium barbadense L.

Summary Gossypium barbadense L. is a commercially important cotton species of tropical South American origin presently grownin many regions of the world. The species is morphologically diverse, consisting of a wide range of wild (or feral), commensal, landrace, and highly improvedcommercial forms. We performed allozyme analysis on 153 accessions representing the spectrum of G. barbadense diversityto ascertain the geographic origin of the species, its patterns of diffusion subsequent to domestication, and to reveal infraspecific relationships. Levels ofgenetic variation in G. barbadense are moderate. Of 59 loci scored, 24 were polymorphic, with a mean number of alleles perlocus of 1.69 and an average panmictic heterozygosity of 0.062. Principal component analysis revealed geographic clustering of accessions into six relativelydiscrete regions. Gene frequencies at many loci are significantly heterogeneous among these regions, with an average G _STof 0.272. Northwestern South America contains the greatest genetic variability; we suggest that this region is the ancestral home of the species. The data indicate separate diffusion pathways from this region into Argentina-Paraguay and into eastern and northern South America east of the Andes. Caribbean Island and Central American forms appear to be derived from the latter. These diffusion pathways are in accordance with morphological evidence and historical record. In contrast to expectations based on geographic proximity, Pacific Island forms have their closest affinity to accessions from eastern South America. Advanced cultivated stocks seem largely derived from western Andean material, but also contain introgressed G. hirsutum germ plasm. Introgression was relatively high (22%–50% of accessions) in commercial stocks and in forms from Argentina-Paraguay and various Pacific Islands, but was conspicuously low or absent in material from Central America and the Caribbean, where commensal and commercial forms of both species are sympatric.     

Isolation Purification and Characterization of Antimicrobial Peptides from <Emphasis Type="Italic">Cuminum cyminum</Emphasis> L. Seeds

In this work, antimicrobial peptides from Cuminum cyminum L. seeds were isolated and purified for the first time by 50% ethanol extraction, C18 reverse phase column chromatography and ion exchange chromatography for separation different peptides fraction. Then isolated fractions were characterized by Gel electrophoresis (SDS-PAGE), high-pressure liquid chromatography and the peptides components and molecular weights were determined by liquid chromatography and mass spectrometry. The extracts were tested against some strains of bacteria (E. coli and Staphylococcus aureus) and one strain of fungi (Candida albicans) using well diffusion and broth dilution assays. The extracts from C. cyminum L. seeds demonstrated a high degree of activity (some antibacterial effect) against the bacteria strains and аntifungal activity against the Candida albicans. However, the study indicates that the crude peptide extracts from C. cyminum L. seeds have promising antimicrobial and antioxidant activities that can be harnessed as leads for potential bioactive compounds.     

Isolation and structural elucidation of a growth stimulant for arbuscular mycorrhizal fungus from Laminaria japonica Areschoug

Arbuscular Mycorrhizal (AM) fungi enhance terrestrial plant growth by forming a symbiotic relationship with the roots of its host plant. A growth stimulant for AM fungi was isolated from a brown alga Laminaria japonica Areschoug. The active substance for in vitro AM hyphal growth was isolated from 75% methanol extracts of L. japonica using a succession of chromatographic procedures, including flash chromatography equipped with an octa decyl silane (ODS) column, gel filtration chromatography and HPLC using an ODS column. Spores of Gigaspora margarita Becker & Hall, an AM fungus, were exposed to the compound in vitro, and hyphal growth of G. margarita was measured after two weeks of incubation. At 40 mg L⁻¹, the compound significantly stimulated the in vitro hyphal growth of G. margarita, compared to the control. This compound was elucidated as 5′-deoxy-5′-methylamino-adenosine by EIMS and NMR spectrum.     

Separation of Antioxidant-Rich Alternanthera Sessilis Red Extracts by Sephadex LH-20 and Identification of Polyphenols Using HPLC-QToF-MS/MS

This study aimed to fractionate Alternanthera sessilis Red (ASR) crude extracts and determine their antioxidant activities as well as the related active components in the whole plant. ASR was extracted with water and ethanol, and further separated using a Sephadex LH-20 column. Following the assessments of the polyphenolic contents and antioxidant activities of crude extracts (H₂O_ASR and EtOH_ASR) and fractions, a HPLC-QToF analysis was performed on the crude extracts and selected fractions (H₂O_ASR FII and EtOH_ASR FII). Three water fractions (H₂O_ASR FI, FII and FIII) and four ethanolic fractions (EtOH_ASR FI, FII, FIII and FIV) were derived from their crude extracts, respectively. EtOH_ASR FII exhibited the greatest total phenolic content (120.41 mg GAE/g fraction), total flavonoid content (223.07 mg RE/g fraction), and antioxidant activities (DPPH IC₅₀=159.43 μg/mL; FRAP=1.93 mmol Fe²⁺/g fraction; TEAC=0.90 mmol TE/g fraction). Correlation analysis showed significant (p<0.01) positive correlations between both TPC (r=0.748–0.970) and TFC (r=0.686–0.949) with antioxidant activities in the crude extracts and fractions. Flavonoids were the major compounds in the four selected samples tentatively identified using HPLC-QToF-MS/MS, with the highest number of 30 polyphenol compounds detected in the most active fraction, EtOH_ASR FII.     

Inter-Specific Differences in Cotton for Nutrient Partitioning from Subtending Leaves to Reproductive Parts at Various Developmental Stages: Consequences for Fruit Growth and Yield

A field study was carried out to unravel the inter-specific differences in cotton for the partitioning of N, P, K, S, Ca, Mg, Na and Cl from the subtending leaves to the reproductive parts of Gossypium hirsutum, G. barbadense and G. arboreum at various developmental stages. Results revealed significant differences among the species for the various parameters studied. Overall there was a greater fresh and dry matter yield of various reproductive parts and subtending leaves of G. hirsutum and G. barbadense than G. arboreum, although the leaf photosynthetic rate was similar. Age-dependent increase in leaf area/leaf mass ratio indicated a greater partitioning of earlier acquired assimilates to the growth of reproductive parts. Results indicated greater partitioning of N, P, S and Ca during later reproductive growth (from boll production to its opening) in G. hirsutum and G. barbadense but during earlier reproductive growth in G. arboreum (from bud up to flower formation) as was evident by decreased subtending leaf/reproductive parts ratio. It is concluded that better N, P, S and Ca partitioning ability of G. hirsutum and G. barbadense at the onset of boll development played a major role in the better yield and good quality fiber characteristics. This revised version was published online in July 2006 with corrections to the Cover Date.