Trichome Length Research Articles

The Essential Oil Composition of Trachymene incisa Rudge subsp. incisa Rudge from Australia.

Trachymene incisa subsp. incisa is an Australian endemic taxon that varies greatly in the abundance and length of the leaf trichomes. The essential oil composition of five populations of this subspecies, three corresponding to the typical glabrous form and two of the particularly hairy variant, has been analyzed in an attempt to determinate if that variability is also reflected in their composition. The oils have been extracted by hydrodistillation and analyzed by Gas Chromatography (GC) and Gas Chromatography coupled to Mass Spectrometry (GC–MS). The essential oils of T. incisa subsp. incisa were characterized by the high amount of sesquiterpenes that were the major fraction. The sesquiterepene hydrocarbons were significantly higher in the hairy variant in comparison to the glabrous one. According to the main compound, three different chemotypes were found: I.—β-selinene + bicyclogermacrene and II.—γ-bisabolene + α-pinene for the typical glabrous variant and III.—bicyclogermacrene + β-caryophyllene for the hairy variant.

Effect of Drought on Trichome Density and Length in Cotton (Gossypium Hirsutum)

Cotton is a major cash crop and backbone of the textile industry in Pakistan which is badly affected by sucking insects. Drought is an important abiotic factor in trichome development. The objective of the study was to determine the effects of drought on trichome density and length. Trichome density was measured in two ways, one through the scaling method and the other through counting the trichome density manually. The scaling method is qualitative grading while quantitative grading includes trichomecount in a card of optimized length. Three scales were finalized to classify leaves on the basis of trichomes which were counted in a specific area (0.25cm2) on abaxial side of the leaf. In drought stress, trichomes density and length were measured and compared to that in normal conditions. Trichome density varies from 12 to 56 in 0.25cm2 under drought stress. On the basis of correlation of trichome density with stomatal conductance, photosynthetic rate, PAR and transpiration ratio under drought and normal conditions, it was concluded that trichome density increased as a result of drought stress.

HOMEODOMAIN PROTEIN8 mediates jasmonate-triggered trichome elongation in tomato.

Plant hormones can adjust the physiology and development of plants to enhance their adaptation to biotic and abiotic challenges. Jasmonic acid (JA), one of the immunity hormones in plants, triggers genome-wide transcriptional changes in response to insect attack and wounding. Although JA is known to affect the development of trichomes, epidermal appendages that form a protective barrier against various stresses, it remains unclear how JA interacts with developmental programs that regulate trichome development. In this study, we show that JA affects trichome length in tomato by releasing the transcriptional repression mediated by Jasmonate ZIM (JAZ) proteins. We identified SlJAZ4, a negative regulator preferentially expressed in trichomes, as the critical component in JA signaling in tomato trichomes. We also identified a homeodomain-leucine zipper gene, SlHD8, as the downstream regulator of JA signaling that promotes trichome elongation. SlHD8 is also highly expressed in trichomes and physically interacts with SlJAZ4. Loss-of-function mutations in SlHD8 caused shorter trichomes, a phenotype that was only partially rescued by methyl jasmonate treatment. Our dual-luciferase and chromatin immunoprecipitation-quantitative PCR assays revealed that SlHD8 regulates trichome elongation by directly binding to the promoters of a set of cell-wall-loosening protein genes and activating their transcription. Together, our findings define SlHD8-SlJAZ4 as a key module mediating JA-induced trichome elongation in tomato.

Differentiation in the genetic basis of stem trichome development between cultivated tetraploid cotton species

BackgroundCotton stem trichomes and seed fibers are each single celled structures formed by protrusions of epidermal cells, and were found sharing the overlapping molecular mechanism. Compared with fibers, cotton stem trichomes are more easily observed, but the molecular mechanisms underlying their development are still poorly understood.ResultsIn this study, Gossypium hirsutum (Gh) and G. barbadense (Gb) were found to differ greatly in percentages of varieties/accessions with glabrous stems and in trichome density, length, and number per trichopore. Gh varieties normally had long singular and clustered trichomes, while Gb varieties had short clustered trichomes. Genetic mapping using five F2 populations from crosses between glabrous varieties and those with different types of stem trichomes revealed that much variation among stem trichome phenotypes could be accounted for by different combinations of genes/alleles on Chr. 06 and Chr. 24. The twenty- six F1 generations from crosses between varieties with different types of trichomes had varied phenotypes, further suggesting that the trichomes of tetraploid cotton were controlled by different genes/alleles. Compared to modern varieties, a greater proportion of Gh wild accessions were glabrous or had shorter and denser trichomes; whereas a smaller proportion of Gb primitive accessions had glabrous stems. A close correlation between fuzz fiber number and stem trichome density was observed in both Gh and Gb primitive accessions and modern varieties.ConclusionBased on these findings, we hypothesize that stem trichomes evolved in parallel with seed fibers during the domestication of cultivated tetraploid cotton. In addition, the current results illustrated that stem trichome can be used as a morphological index of fiber quality in cotton conventional breeding.

Location, location, location: Feeding site affects aphid performance by altering access and quality of nutrients.

Aphid feeding behavior and performance on a given host plant are influenced by the plants’ physical and chemical traits, including structural characters such as trichomes and nutritional composition. In this study, we determined the feeding behavior and performance of soybean aphids (Aphis glycines) on the stem, the adaxial (upper), and the abaxial (lower) leaf surfaces during early vegetative growth of soybean plants. Using the electrical penetration graph technique, we found that aphids feeding on the stem took the longest time to begin probing. Once aphids began probing, the sieve elements were more conducive to feeding, as evidenced by less salivation on the stem than either leaf surface. In whole-plant assays, stems harbored higher aphid populations, and aphids had shorter development time on stems than the adaxial and the abaxial leaf surfaces. We compared trichome density and length on the stem, the adaxial, and the abaxial leaf surfaces to investigate whether plant trichomes affected aphid feeding and performance. There were higher density and longer trichomes on stems, which likely resulted in aphids taking a longer time to probe. Still a negative impact on aphid population growth was not observed. Analysis of phloem sap composition revealed that vascular sap-enriched exudates from stems had higher sugars and amino acids than exudates from leaves. In artificial diet feeding assays, the population of aphids reared on a diet supplemented with stem exudates was higher than on a diet supplemented with leaf petiole exudates which is in agreement with results of the whole-plant assays. In summary, our findings suggest that the performance of soybean aphids on a specific plant location is primarily driven by accessibility and the quality of phloem composition rather than structural traits.

Detection of a major QTL conditioning trichome length and density on chromosome arm 4BL and development of near isogenic lines targeting this locus in bread wheat.

The online version contains supplementary material available at 10.1007/s11032-021-01201-8.

Diversification of yellow-flowered Sempervivum (crassulaceae) species from the Balkan Peninsula: Evidence from the morphometric study of the epidermal structures of rosette leaves

Several related yellow-flowered houseleek species which occur on the Balkan Peninsula are divided into two complexes: Sempervivum ciliosum (S. ciliosum, S. jakucsii, S. klepa, S. octopodes, and S. galicicum) and the S. ruthenicum complex (S. ruthenicum, S. leucanthum, S. kindingeri, and S. zeleborii). Due to strong phenotypic plasticity and a limited number of studies, it is difficult to assert at this point whether all the above species are well defined in the taxonomic sense. Detailed studies of the epidermal structures have not been conducted for any of the species in either complex. The aim of this study was to investigate the degree of variability of the epidermal structures together with their potential usefulness for the taxonomic characterization of the species studied. A total of 18 quantitative characters of the epidermal structures of the adaxial and abaxial surfaces of the rosette leaves were analysed within 16 populations. In all species, the epidermal cells are polygonal or irregularly shaped, with straight or sinuous anticlinal walls, while the rosette leaves are amphistomatic with anisocytic stomata. Simple biseriate multicellular glandular trichomes were found on the adaxial and abaxial surfaces and the margins of the rosette leaves. The results of the descriptive statistics, univariate (ANOVA) and multivariate statistical analysis (CDA, AHC) showed low to high variability in the epidermal cells, guard cells and trichomes. The multivariate analysis showed diversification among the complexes and species. The length of the marginal and apical trichomes of the rosette leaves contributed most to diversification.

Pod Trichome Characterisation Using Foldscope, Morphological Characterization and Genetic Diversity Among Indigenous Collections of Pigeonpea [Cajanus cajan (L.) Millsp.

Background: Association of several morphological traits such as trichome length and trichome density on the pod surface have been found to influence host plant resistance to insect pests. Genetic diversity analysis is used to identify the divergent genotypes and to utilize these genotypes to exploit heterosis. Further, morphological characters are stable across environments owing to oligogeneic nature, they serve as morphological markers in breeding which can be used in varietal or genotypic identification, varietal purification and even in seed production. Hence, the current study aimed to investigate on host plant resistance using portable paper microscope ‘foldscope’, genetic diversity and morphological characters.Methods: A total of 154 germplasm lines with three checks were evaluated in Augmented Block Design (ABD) at Zonal Agricultural Research Station (ZARS), Kalaburagi, during kharif, 2018 to study their genetic diversity. Trichome length and trichome density were recorded using ‘foldscope’ 75 randomly selected genotypes, then correlated with shrivelled seed yield per plot due to pod fly incidence. Morphological characterization of 14 qualitative traits were recorded.Result: Grouping of 157 germplasm lines into twelve clusters indicated a wider genetic diversity for the traits studied, of which 7 clusters were solitary with one entry each. The genotypes with more trichome density and length had less damage by the pod fly. Large variations for morphological characters was observed among the genotypes for qualitative traits such as pod colour, stem colour, flower colour, seed morphology and pod trichomes.

Strengthening mass transfer with the Tesla-valve baffles to increase the biomass yield of Arthrospira platensis in a column photobioreactor

In this study, the Tesla-valve (TV) baffles were used to optimize the flow field in a column photobioreactor (PBR) in order to promote mass transfer of CO2 gas in the solution. The TV baffles were composed of many tilted plates with central holes and curved arcs facing downwards, installed along inner rising section of the column PBR. Many clockwise and anti-clockwise vortices were generated during the rising flow while passing through proposed TV baffles. An optimum TV baffle structure (30° plate angle, 8 cm arc width) decreased mixing time by 36.4% and increased the mass transfer coefficient by 50%. The TV baffles supported the movement of the A.platensis cells between light and dark regions to enhance their photochemical efficiency ϕPSII by 24.6% and Fv/Fm by 12.7%. Therefore, the biomass yield increased by 28.1% and exhibited an increased helix pitch and trichome length in comparison with traditional column PBR without baffles.

Response of roadside tree leaves in a tropical city to automobile pollution

One of the sources of air pollutants in the surrounding environment is the automobile emissions. Automobiles produce gaseous and particulate matters which are toxic and inflict damage to roadside plants. Roadside trees are notable for the absorption, sequestering of contaminants and the effective interceptor of airborne pollution. In view of this, the present work was based on investigating the macro-morphological and micro-morphological changes that boost the tolerance and continued existence of four roadside trees, namely Ficus platyphylla, Mangifera indica, Polyalthia longifolia and Terminalia cattapa in the incidence of vehicle exhaust emissions in Kumasi Metropolis, Ghana. Three arterial roads representing three different traffic volumes of extreme, heavy and severe were considered as observational sites. Kwame Nkrumah University of Science and Technology Campus was selected as the control site. The macro-morphological characteristics of the four tree species showed reduced leaf area, whilst the micro-morphological results revealed that stomata size, number and index were reduced at the arterial roadsides in all the four tree species. There was increased epidermal cell number and length and trichome length at the polluted arterial roadsides when compared to the control. These variations can be considered as pointers of environmental stress and could be used as indicators of urban air pollution.

Taxonomic implication of leaf epidermal anatomy of selected taxa of Scrophulariaceae from Pakistan.

The family Scrophulariaceae consists of taxonomically complex genera and species. The delimitation of the taxa within this family is always challenging. In this paper, we studied leaf epidermis anatomical characteristics and its taxonomic significance of four species belonging to four genera of the family Scrophulariaceae collected from northern Pakistan. The species were examined under light and scanning electron microscopes (LM and SEM). Qualitative and quantitative foliar epidermal anatomical features were examined for both adaxial and abaxial surfaces. Qualitative characters like epidermal cell shape, epidermal cell cover, anticlinal wall, trichomes type, stomata type and stomata position were examined. Quantitative characters like the length and width of leaf epidermis, stomata, stomatal pore, subsidiary cell and trichomes for both adaxial and abaxial surfaces were studied and measured. Stomatal index within the species and between the species was found to be different on adaxial and abaxial surfaces. Diacytic stomata and glandular trichomes on epidermis were only found in Anticharis glandulosa while rest of the taxa has anomocytic type stomata and dendroid trichomes on both surfaces. Based on the micromorphological characters, we did principal component analysis (PCA), and cluster analysis for the species delimitation and identification. A taxonomic key has been provided to delimit and identify the studied taxa based on foliar epidermal characters. The aim of the present research was to elucidate the micromorphological characters to distinguish the studied taxa for taxonomic purposes.

High impact of PGPR on biostatistic of Aphis craccivora (Hemiptera: Aphididae) on yardlong bean

Abstract. Triwidodo H, Listihani. 2020. High impact of PGPR on biostatistic of Aphis craccivora (Hemiptera: Aphididae) on yardlong bean. Biodiversitas 21: 4016-4021. Plant growth-promoting rhizobacteria (PGPR) are root colonizing bacteria that live and develop near plant roots, which boost plant growth and act as antagonist agents. This research is aimed to asses the effect of PGPR on biostatistics of Aphis craccivora Koch on yardlong bean (Vigna unguiculata subsp. sesquipedalis). The research was conducted at WiSH Laboratory in Bogor, Indonesia, by tested PGPR mixture of Rhizobium, Bacillus polymyxa, and Pseudomonas fluorescens. The research discovered that the application with seed treatment and watered of PGPR affects the biology of Aphis craccivora in terms of lengthening its stadia of second instar nymph, lengthening its life cycle, and declining its fecundity. The application of PGPR also affects the biostatistics of Aphis craccivora. PGPR applied plants have a gross reproduction rate (GRR), net reproduction rate (Ro) and intrinsic increase rate (r) of Aphis craccivora that are lower than control. PGPR could slower the doubled time (DT) of Aphis craccivora to become lengthier than control. PGPR could improve plant growth: it could increase the number and length of roots, number of root nodules, plant height, number of leaves, as well as length and density of trichome.

The Influence of Cyclohexanone/Cyclohexanol on the Growth and Nitrogen Removal of Arthrospira platensis and the Cyclohexanone/Cyclohexanol Biotransformation

Arthrospira platensis is a candidate for removing nitrogen from caprolactam wastewater, but the concentrated cyclohexanone (CHN) and cyclohexanol (CHL) in the wastewater have an unknown effect on A. platensis growth. The aim of this study was to evaluate the feasibility of A. platensis for caprolactam wastewater treatment and obtain safe exposure concentrations of CHN and CHL. The biotransformation of CHN and CHL was investigated. Considering the changes of growth rate and pigment contents, the safe exposure concentrations of individual CHN and CHL were ≤ 800 and ≤ 400 mg L−1, respectively. For binary mixture, the safe exposure concentration was ≤ 200 + 100 mg L−1 CHN + CHL. Both chemicals induced decreased trichome length at all concentrations, but trichomes were large enough to be harvested efficiently by gravity filtration using filter membranes with a pore size of 25–40 μm under safe exposure. The nitrogen removal rate showed no difference in CHN and CHL treatment under safe exposure concentrations compared with the control, and the maximal nitrogen removal rate was 18.66 mg L−1 d−1. Besides, A. platensis catalyzed interconversion between CHN and CHL which preferred to convert CHN into CHL when chemicals coexisted. Results highlight the potential of A. platensis for the nitrogen removal from caprolactam wastewater when CHN and CHL were under the safe exposure concentrations.

The role of hydraulic conditions of coagulation and flocculation on the damage of cyanobacteria

Limited information exists on the damage of harmful cyanobacteria cells, such as Raphidiopsis raciborskii and Dolichospermum circinale, caused by the hydraulic conditions at water treatment plants especially when it comes to the mechanical stresses imposed by coagulation and flocculation. To close this gap, this study evaluated the impacts of rapid and slow-mixing on R. raciborskii and D. circinale cells and trichomes. The hydraulic conditions used during the experiment were selected based on AWWA, which are widely applied in the absence of specific treatability tests. Cellular integrity was evaluated by the Erythrosine B staining method and logistic regression was used to study the association between organism integrity and hydraulic conditions (i.e., velocity gradient and mixing time). Wilcoxon rank-sum test was used to verify if there was a significant reduction of the trichome length and cell integrity. Rapid-mixing (velocity gradient of 750 s−1 for 60 s) reduced the odds of finding intact D. circinale to <50%, whereas the odds of finding intact R. raciborskii cells did not significantly decrease. The odds of finding intact cells of R. raciborskii were 124 times greater than D. circinale. Rapid-mixing also reduced the length of D. circinale trichomes by approximately 50% but did not significantly decrease R. raciborskii trichomes. Slow-mixing did not significantly affect organisms or trichomes of either species. The results indicate that AWWA recommendations for coagulation may cause damage to D. circinale but not to R. raciborskii, suggesting that the operation of water treatment plants could be adjusted according to the dominant cyanobacterium present in the reservoir to avoid cell rupture and metabolite release.

Preference for Oviposition by Sweetpotato Whitefly, Bemisia tabaci (Gennadius)1, in Two Soybean Genotypes, and Volatile Release

Soybean, Glycine max (L.), in the field is very susceptible to infestation by sweetpotato whitefly, Bemisia tabaci (Gennadius). Preference for oviposition by whitefly in two soybean genotypes was evaluated, and a profile of volatile compounds in healthy plants was obtained. The average number of eggs per square centimeter was 4.1 to 13.7 in ‘Nainari’ variety and 15.1 to 28.4 in an experimental line. Trichome averaged 6.5 per square centimeter in Nainari and 6.8 in the experimental line. The average length of trichomes of Nainari was 311 microns and in the experimental line was 342. Solid-phase microextraction and gas chromatography-mass spectrometry were used to obtain the profile of volatile compounds in two Nainari soybean genotypes and one experimental line: cis-3-hexenyl acetate; cis-3-methyl-1,3-pentadiene; 4-methyl-1,3-pentadiene; cis-3-hexenyl valerate; cis-2-hexen-1-ol; 9-ethyl-9-heptyloctadecane; tetradecane; tridecane; and 2,6-bis(1,1-dimethylethyl)-4-(1-oxopropyl) phenol. In plants infested with whitefly eggs and nymphs, eight compounds were identified in Nainari and seven in the experimental line: M-xylene; 1-octen-3-ol; d-limonene; cedrene; propanoic acid, 2-methyl-, 2-methyl propyl ester; 3-methylnonane; longifolene; caryophyllene; 2,5-cyclohexadiene-1,4-dione, 2,6-bis (1,1-dimethylethyl)-; alpha-farnesene; pentanoic acid, 2,2,4-trimethyl-3-carboxyisopropyl, isobutyl ester, and 2,6-bis(1,1-dimethylethyl)-4-(1-oxopropyl) phenol. Differences in the profile of volatile compounds in healthy Nainari plants might explain oviposition repellency.

Investigation of Varietal Characteristics of Tomato Plants for Determining the Diverse Preferences of Bemisia Tabaci (Aleyrodidea: Hemiptera)

The whitefly (Bemisia tabaci) is a well-known pest of vegetables and ornamental cash crops including tomato plant. Tomato plant disorders, in many instances, are related mostly with the silver leaf whitefly (Bemisia tabaci) feeding. It is well thought out that tomato plant is one of the most favorable host plants for the whitefly. Thus we aimed to study distinctive morphological characteristics of the leaves in seven selected tomato varieties including trichome density, trichome length, leaf lamina thickness and RGB value (red, green, blue) and HSB value (hue, saturation, brightness). Seven hybrid F1 tomato varieties such as TO-1057, TAI-1757, T‑1359, Advanta-1247, New Super, Sultan and Super were tested for the whitefly preferences. Our study suggests that T‑1359 is the highly preferred variety for the whitefly adults (5.32 ± 0.81) and nymphs (6.30 ± 1.13) population. In contrast, Advanta-1247 exhibits the lowest population of whitefly adults (2.71 ± 0.70) and nymphs (1.88 ± 0.43). This study systematically identifies the morphological characters of the tomato plants alongside the whitefly population. The study can be potentially extended to other crops as well.

Variation for Resistance to Alternaria tenuissima and Potential Structural Mechanism among Different Cultivars of Chrysanthemum morifolium

Black spot disease, caused by the necrotrophic fungus Alternaria tenuissima (Fr.) Wiltsh (A. tenuissima), is considered a highly destructive disease of Chrysanthemum (Chrysanthemum morifolium Ramat.). A set of 17 accessions of commercial chrysanthemum cultivars were evaluated for resistance to A. tenuissima by seedling artificial inoculation. It was found that the reaction of the accessions to artificial inoculation ranged from resistant to highly susceptible. Five varieties of chrysanthemum (‘Zhongshan Taogui’, ‘Jinba’, ‘Zhongshan Jinguan’, ‘Jinling Wanhuang’ and ‘Jinling Yangguang’) were resistant; two varieties of chrysanthemum (‘Zhongshan Xinggui’ and ‘Zhongshan Jinkui’) were moderately resistant; and others were susceptible to various degrees, four varieties of chrysanthemum (‘Zhongshan Zihe’, ‘Zhongshan Jiuhong’, ‘Zaoyihong’ and ‘Jinling Jiaohuang’) were highly susceptible, especially. Some leaf morphological features of two resistant and two highly susceptible cultivars were further researched. Trichome density, length, height, gland size and stomata density were found to be associated with plant passive resistance. Resistant varieties that were identified in present study will be promising germplasm for exploitation of breeding programmes aimed at developing A. tenuissima-resistant cultivars and increasing genetic diversity.

Epidermal structures of leaves in some Mentha х piperita L. varieties in connection with they productivity

Relevance. It is known that peppermint (Mentha х piperita L.) is characterized by significant polymorphism, due to both genetic factors and growing conditions. Cultivated varieties and populations are distinguished by their economically significant characteristics, such as yield, winter hardiness, resistance to diseases, the content and composition of essential oil. Identification of new highly productive varieties and populations of Mentha x piperita L., distinguished by high productivity of essential oil in the Non-chernozem zone of the Russian Federation, as well as identification of morphological features characteristic of highly productive varieties, remains relevant.Methods. The object of the study was plants of 8 varieties of 2 year old plants and samples of Mentha x piperita L. from the collection of the SI Botanical Garden Rostovtsev RGAU-Moscow Agricultural Academy named after K.A. Timiryazev and from the collection of the Botanical Garden of All-Russian Institute of Medicinal and Aromatic Plants (VILAR), were used as the object of the study. Peppermint leaves (FS.2.5.0029.15 Peppermint leaves) and essential oil (GOST R 53593-2009) are used as herbal medicinal products. Microscopy used Primo Star Carl Zeiss light microscopes and LOMO MIKMED-1. Quantitative determination of the essential oil was carried out by distillation with water vapor, followed by measuring the volume of the resulting oil (GF RF XIV). The oil content was expressed in volumetric-weight percent in terms of dry raw materials.Results. As a result of a comparative study of the epidermal structures of the leaves of plants of 8 varieties of Mentha х piperita L., the density of stomata, the type of stomatal apparatus, density of location and length of multicellular trichomes, density and diameter of essential oil glands, and content of essential oil were determined. The variety specificity and variation of these indices are noted over a wide range, which is explained by the significant intraspecific variability characteristic of the genus Mint (Mentha L.). The most promising varieties of essential oil content were identified.

Effects of the Morphological Diversity of Leaf Surface and Phytochemicals Composition on Preference Behavior of Leafhopper and Planthoppers on some Solanaceous Crops

The present experiments were conducted to study the effect of different solanaceous host plants on the population density of the leafhoppers and planthoppers according to the morphological diversity of host surface and phytochemical composition on the preference behaviour of the insect pests during the two successive seasons 2017 and 2018 in Gharbia governorate. The leafhoppers, Empoasca decipiens and Empoasca decedens preferred eggplant as a host plant followed by tomato and pepper by using the three methods (leaf sample, yellow sticky traps, sweep net) during the two seasons. Meanwhile, Cicadulina chinai preferred tomato followed by eggplant and pepper by using the different methods. While, Balcutha hortensis preferred pepper followed by eggplant and tomato. On the other hand, the planthoppers, Sogatella futcifera preferred eggplant followed by pepper and tomato. Statistical analysis revealed that highly significant differences were recorded between the three host plants during the two seasons according to the average number of different leafhoppers and planthoppers by using the three sampling methods. Depending on the percentage of insect pest occurrence, sweep net recorded the highest percentage followed by yellow sticky traps and the lowest percentage of occurrence was recorded by leaf sample method. The insect population varied among leaf surface morphological characters. The Scanning Electron Microscope pictures revealed that, the trichome type was non-glandular in eggplant and tomato, while in pepper was hairiness. Population density exhibited significantly of trichome length on eggplant, whereas had less significantly on tomato leaves with higher hair density. Peppers, with no trichome had the lowest population of insect. Depending on the analysis of phytochemical composition of plant leaves, a highly positive correlated leafhopper and plant hoppers with higher ratios was found for the total protein, total nitrogen, α-esterase, β- esterase and Glutathione S-transferase (GST). However, the population density affected by the total ratio of carbohydrate of eggplant. While, there was a negative correlated between insect infestation and the contents of phenols, potassium, phosphorus and the plant soap acidity (pH), thus the population was high with low content of these components in eggplant followed by tomato then pepper. This study showed that the development of the host plant resistant to the insect pests is an important strategy of integrated pest management programs and the recognition of morphological and phytochemical characteristics may lead to develop resistance character in acceptable plant genotypes.

Conversion of NaHCO3 to Na2 CO3 with a growth of Arthrospira platensis cells in 660m2 raceway ponds with a CO2 bicarbonation absorber.

SummaryThe weight ratio of Na2 CO 3/NaHCO 3 was investigated in order to improve microalgal productivity in large‐scale industrial operations by converting NaHCO 3 to Na2 CO 3 with a growth of Arthrospira platensis cells in 660 m2 raceway ponds. Two microalgal cultivation systems with a NaHCO 3 by‐product (SPBP) and a CO 2 bicarbonation absorber (CBAP) were firstly thoroughly introduced. There was a 13.3% decrease in the initial weight ratio of Na2 CO 3/NaHCO 3 resulting in a 25.3% increase in the biomass growth rate with CBAP, compared to that of SPBP. Increased sunlight intensity, solution temperature and pH all resulted in both a higher HCO3- absorbance and CO32- release, thereby increasing the weight ratio of Na2 CO 3/NaHCO 3 during the growth of A. platensis. The biomass growth rate was peaked at 39.9 g m−2 day−1 when the weight ratio of Na2 CO 3/NaHCO 3 was 3.7. Correspondingly, the cell pigments (chlorophyll a and carotenoid) and trichome size (helix pitch and trichome length) reached to a maximum state of 8.47 mg l−1, 762 μg l−1, 57 and 613 μm under the CBAP system.