Stomata Density Research Articles

Vine performance benchmarking of indigenous Cypriot grape varieties Xynisteri and Maratheftiko

Aim: The aims of this study were to (1) formulate a baseline understanding of the performance of the indigenous Cypriot white grape Xynisteri and the red grape Maratheftiko (Vitis vinifera L.), and (2) compare these varieties to Shiraz and Sauvignon blanc grown in a Cypriot vineyard.Materials and results: The investigation involved multiple dry grown vineyards from the Krasochoria region of Lemesos, Cyprus, during the 2017, 2018 and 2019 vintages. Vine performance measurements, including midday stem water potential, stomatal conductance, chlorophyll content, stomata density, vine phenology and vegetative and reproductive measurements, were taken at flowering, veraison and pre-harvest. Xynisteri had the greatest stomatal density, more shoots, more leaves, heavier bunches, greater yield, higher leaf water potential at harvest, and a stomatal conductance equal to Maratheftiko, but greater than that of both Shiraz and Sauvignon blanc. Maratheftiko had the longest shoots, largest shoot diameter and the greatest chlorophyll content out of all four varieties.Conclusions: This study identified the ability of the indigenous Cypriot grape varieties, Xynisteri and Maratheftiko, to better tolerate hot and dry conditions when compared to more commonly cultivated varieties grown in the same environmental conditions.Significance and impact of the study: The changing climate of wine growing regions worldwide is placing great pressure on the resources for sustainable viticulture. Many vineyards in hot climate zones base their businesses on European grape varieties traditionally grown in regions with abundant water resources. It is therefore necessary for the global wine industry to investigate grape varieties that are indigenous to hot climates. The eastern Mediterranean island of Cyprus is one such place, with more than 10 indigenous grape varieties that grow well in a hot climate without irrigation. Consumer studies have demonstrated that wines made from these Cypriot varieties are equally, if not more, acceptable than wines made from more traditional European grapes; therefore, the potential for their use in other hot wine growing regions is promising.

Micro-morpho-anatomical mechanisms involve in epiphytic adaptation of micropropagated plants of Vanda tessellata (Roxb.) Hook. ex G. Don.

Vanda tessellata (Roxb.) Hook. ex G. Don. (grey orchid, family Orchidaceae) is an epiphytic orchid of horticultural importance and currently under threat due to overharvesting and habitat destruction. Micropropagation protocols were developed for the production of grey orchid but the survival success of in vitro regenerated plantlets is uncertain due to lack of understanding about the adaptation mechanism during hardening. The present study describes the structural adaptation mechanism of V. tessellata when the in vitro regenerated plantlets were acclimatized under the greenhouse conditions. Light microscopy has been implicated to identify the adaptational alterations during in vitro to ex vitro transition of micropropagated plantlets. The in vitro induced morpho-anatomical anomalies were more prominently observed in the density of stomata, veins (architecture) and raphides, leaf, and root structural parameters such as water cells and velamen tissues. The results indicated that remarkable reconciliation occurred in structural developments of mechanical and vascular tissues upon epiphytic adaptations of V. tessellata. The study could help in understanding the adaptation mechanism of in vitro regenerated plantlets (especially velamen tissues of epiphytic roots) when transferred to the greenhouse for acclimatization. RESEARCH HIGHLIGHTS: Vanda tessellata is an epiphytic orchid of horticultural importance. Comparative micro-morpho-anatomical analysis at subsequent stages of in vitro regeneration was conducted. Foliar structural and developmental mechanisms towards epiphytic adaptation were studied. In vitro induced structural abnormalities were repaired and epiphytic adaptation was visualized. Stomata, leaf, and root architectures and velamen tissues were well developed in acclimatized plantlets. The report could be useful in the conservation and sustainable utilization of Vanda tessellata.

Polyol-ester impact on boron foliar absorption and remobilization in cotton and coffee trees

ABSTRACT Foliar fertilization can be recommended to treat boron (B) deficiency in coffee and cotton. Considering that B foliar fertilizers with polyol-boron complexes can affect B uptake and mobility differently within the plant, and coffee and cotton have different cuticles and stomata density, a differential response would be expected. We aimed to study the foliar application of boric acid combined with sorbitol on B uptake and translocation in cotton and coffee. Green-house grown plants received B as boric acid and [...]

Differential Susceptibility of Diverse Salix spp. to Melampsora americana and Melampsora paradoxa.

Melampsora spp. willow rust is the most serious disease of shrub willow bioenergy production in the northeastern United States. Recent phylogenetic studies have identified several Melampsora spp. present on willow in the Northeast; however, in-depth understanding of Melampsora spp. host susceptibility remain unresolved. In this study, a panel of 82 rust isolates collected from the northeastern United States were genotyped via ribosomal DNA sequencing and a subset of these isolates were assayed for host susceptibility. This work revealed that Melampsora americana is the most prevalent species in the sampled geographic region and that there is potential for rust resistance breeding using the Salix spp. taxa assayed. Additionally, leaf morphology traits of these Salix spp. hosts were quantified for correlation analysis, revealing that trichome density and stomata density are possible contributors to resistance. This work provides foundational rust pathology information, which is crucial for M. americana resistance breeding.

SlTLFP8 reduces water loss to improve water-use efficiency by modulating cell size and stomatal density via endoreduplication.

Improving plant water-use efficiency (WUE) is important to plant survival and crop yield in the context of water limitation. In this study, SlTLFP8 (Tubby-like F-box protein 8) was identified as an osmotic-induced gene in tomato. Transgenic tomato with up-regulated expression of SlTLFP8 showed enhanced water-deficient resistance, whereas knockout mutants generated by CRISPR/Cas9 were more sensitive to water deficit. SlTLFP8 overexpression significantly enhanced WUE by suppressing transpiration under both water-sufficient and water-deficient conditions. Further study showed that overexpressing SlTLFP8 significantly increased leaf epidermal cell size and thereby decreased stomatal density 10-20%, conversely SlTLFP8 knockout resulted in decreased cell size and thereby increased stomatal density 20-50%. SlTLFP8 overexpression and knockout modulated ploidy levels in leaf cells. Changes in expression of cell cycle related genes also indicated that SlTLFP8 affected cell size and stomatal density through endocycle transition. Despite changes in stomata density and transpiration, altering the expression of SlTLFP8 did not change photosynthesis. Additionally, biomass was not altered and there was little difference in fruit yield for transgenic and wild type lines under water-sufficient and water-deficient conditions. Our results demonstrate the effect of SlTLFP8 on endoreduplication and the potential of SlTLFP8 for improvement of WUE. BRIEF SUMMERY: This work found a new mechanism of TLP (Tubby like protein) response to water-deficient stress. SlTLFP8, a member of TLP family, regulates water-deficient resistance by modulating water loss via affecting stomatal density. Expression of SlTLFP8 was induced by osmotic stress. Transgenic tomato lines with SlTLFP8 overexpression or SlTLFP8 knockout showed significantly differences in water-use efficiency (WUE) and water-deficient resistance. The difference of leaf water loss caused by transpiration is the main explanation of the difference in WUE and water-deficient resistance. Additionally, overexpressing SlTLFP8 significantly decreased stomatal density, while SlTLFP8 knockout resulted in increased stomatal density, and SlTLFP8 affected stomatal density through endoreduplication and altered epidermal cell size. Despite changes in stomata density, altering the expression of SlTLFP8 did not result in distinct changes in photosynthesis, biomass and yield of tomato.

Ability of Wayside Trees as Pb Absorbent on Jl Jenderal Soedirman Purwokerto

Air pollution can be determined by using plants as a bioindicator. The purposes of this research were 1) to determine the ambient air Pb concentration and Pb concentration in some leaves of wayside trees on Jl Jenderal Soedirman Purwokerto, 2) to find out the stomata characteristics i.e. size and density of stomata related to their ability to absorb Pb. The research method used was the survey method. The wayside tree leaf samples were taken with purposive sampling. The variables used in the research include variables such as aerial Pb and Pb concentrations of leaves, while the dependent variable was anatomical responses. The main parameters observed in the form of air Pb concentrations, Pb in leaf and stomata anatomical characters. The support parameters are traffic density. The results of this study showed that the concentration of Pb in Jl Jenderal Sudirman within 1 hour is 0.0147 μg/m³. Pb concentration was the highest in the leaves of Schima wallichii (0.3524 ppm), and the lowest was in Hibiscus tiliaceus (0.2354 ppm). Pb accumulated in the leaves caused a very significant effect on the density, length, and width of the leaf stomata of shade plant on Purwokerto’s Jenderal Sudirman Road. Pb concentration in leaves positively correlated with the density, length, and width of stomata (p<0.05).

Phenotypic and molecular changes in cassava (Manihot esculenta Crantz.) genotypes as a response to water-deficit stress

Three local Indonesian cassava (Manihot esculenta Crantz) genotypes, Adira 4, Roti, and Ubi Kuning retained their growth under a water deficit environment. To understand the physiological and molecular responses of cassava plants under such stress, we observed leaf stomata characteristics, i.e. stomata dimension (width and length) and density, and molecular expression of aquaporin (AQP) gene, respectively. The observation was performed on all genotypes on day 26 and 45 after water-deficit treatment. Quantification of gene expression was performed by comparing the threshold cycle (Ct) values of AQP with Ct values β-tubulin for each genotype. Results showed that water deficit treatment significantly affected both stomata density, length and width in all genotypes. On day 26 after treatment, the density of stomata in Roti and Ubi Kuning increased two times higher than the stomata density in plants under well-watered supply. Stomata length of Roti and Adira 4 under water stress was 0.4 times shorter than those under normal water supply. Relative expression of AQP, encoding AQP PIP2 proteins, in the Roti genotype showed that the gene transcripts have no significant elevation after experiencing water stress. In Adira 4, the expressions of AQP increased two-times at day 26 under water-deficit treatment compared with AQP expressions in well-watered treatment and continued to elevate up to three times higher at day 45 than those of expressed in Adira 4 plants under well-water treatment. In addition to stomata phenotypic changes, Ubi Kuning may regulate its water channel proteins AQP PIP2 to control turgor pressure in the beginning phase of water stress conditions. These results showed that three cassava genotypes responded differently under water deficit stress and these may serve as basic knowledge for further analysis.

KARAKTERISASI STOMATA DAUN PEGAGAN (Centella asiatica (L.) Urban.) PADA KETINGGIAN WILAYAH BERBEDA DI PULAU AMBON

The purpose of this study was to determine the anatomical structure of pegagan leaves through stomata characterization at several different locations on Ambon Island. Survey method was used in this research. The sample was taken in nine villages were spread from lowlands to the highlands on Ambon Island. The procedure of semi-permanent preparations was done by whole mount method. Stomata characterization was done towards the stomata number, stomata density, and stomata index. The collected data were analyzed by descriptive analysis and performed in the form of table or figure. the research result shows that leaf with high stomata number was tend to high in stomata density and stomata index. Based on this research result, it could be conclude that there are no difference of stomatal structure of Pegagan leaves in all location were sample collected. The difference has shown by numbers, density, and stomatal index. The highest Numbers, density and stomatal index shown on Pegagan leaves in lowland, and the lowest that shown in this research on Pegagan leaves in highland

Induction of autotetraploid Moringa plant (Moringa oleifera) using oryzalin

Abstract. Ridwan, Witjaksono. 2020. Induction of autotetraploid Moringa plant (Moringa oleifera) using oryzalin. Biodiversitas 21: 4086-4093. Moringa (Moringa oleifera Lam.) is a plant with high nutritional content and has been widely used as a vegetable and health food ingredient, but its utilization and productivity have not been optimal. Increasing plant productivity can be done by increasing biomass which can be obtained through increasing plant ploidy. This study aims at obtaining tetraploid Moringa by induction using oryzalin compound. Moringa germinating seeds were soaked in oryzalin water solutions for 1, 3, and 5 days with concentrations of 0 µM (control), 15 µM, 30 µM, 60 µM, and 120 µM with 10 seeds for each treatment. We have recovered two tetraploid Moringa plants and two chimeric plants of diploid and tetraploid genomes. Immersing germinating seeds for 1 day in 15 or 60 µM oryzalin concentration effectively induced autopolyploid in Moringa. Tetraploid plants exhibit typical morphological characteristics of a tetraploid, such as low stomata density, larger stomata size, and larger leaflet size compared to the diploid counterpart. The induced tetraploid plants have significantly increased protein, fat, and calcium content compared to the diploid counterpart emphasizing their values as functional food. This polyploidy induction method can be used to produce Moringa tetraploid lines from various accessions in the attempts of developing and selecting high yielding tetraploid Moringa cultivars.

Cekaman Garam NaCl danTeknik Aplikasi Azolla pada Tanaman Padi

Efforts to increase production potential can be carried out by extensification in a less productive saline land. Salinity is a major problem in the growth of most plants. Azolla is a plant that is sensitive to salinity, but if it is applied well, it can grow optimally at high salinity levels. The purpose of this study is to obtain an azolla application technique that is effective in increasing the adaptation of rice plants to NaCl saline soil conditions. The experimental design used was Randomized Block Design (RBD) with 2 factors and 3 replications. The first factor was the azolla application technique consisted of 3 levels: fresh azolla composted, fresh azolla immersed, and fresh azolla as a ground cover. The second factor was the levels of NaCl salt stress consisted of 4 levels: control DHL 0, 2, 4, and 8 dS m-1. The adaptation ability of rice plants based on variable plants height growth rate, number of tillers, strove dry weight, root dry weight, stomata density, leaf chlorophyll (SPAD), age of flowering, number of paddy grain, and harvest index. The results showed how to test content up to 2 dS m-1 which increased rice growth especially the application of azolla composted. Increasing stress to 4 and 8 dS m-1showed bad effects on vegetative, physiology, and yields of rice components. The stronger of salt stress the higher all plants growth variables except the age of flowering that actually showed the acceleration of flowering. Application of composted azolla can increase the root dry weight and azolla as a ground cover can increase the numbers of paddy grains. Keywords: azolla, NaCl, rice, stress

Karakterisasi Morfologi, Anatomi, dan Fisiologi Tujuh Klon Unggul Kopi Robusta

&lt;em&gt;Morphological characterization of superior Robusta coffee plants has been widely studied, but for the anatomical and physiological character is still relatively limited. Result of this characterization is important as a basic information in order to create the new superior varieties. The purpose of this study was to investigate the morphological, anatomical, and physiological characteristics of seven clones of Robusta coffee (SA 203, BP 534, BP 42, BP 409, BP 939, BP 308 and BP 436). The experiment was conducted at Pakuwon Experimental Station and Integrated Laboratory of Indonesian Industrial and Beverage Crops Research Institute, Sukabumi, West Java, from October to November 2019. The Completely Randomized Design with 7 Robusta coffee clones as treatments and three replications was used in this study. The variable observed were morphological (leaf area), anatomical (stomata shape and density) and physiological characters (chlorophyll a, chlorophyll b and total chlorophyll). The results showed that the leaf area of the first and third leaves of seven clones of Robusta coffee were relatively uniform. The stomata shape of Robusta coffee leaf is parasitic type (Rubiaceous) type. The SA 203 and BP 409 clones have the fewest stomata contents. The content of chlorophyll a, b, and total in the first and third leaves varies between clones. Chlorophyll content in the basal, middle, and apical leaf were relatively uniform, except clones SA 203 and BP 939 for the first leaf, and SA 203 and BP 436 for third leaf. The correlation analysis showed a positive relationship between leaf area and chlorophyll content.&lt;/em&gt;

Barley strigolactone signalling mutant hvd14.d reveals the role of strigolactones in abscisic acid-dependent response to drought.

Strigolactones (SLs) are a group of plant hormones involved in many aspects of plant development and stress adaptation. Here, we investigated the drought response of a barley (Hordeum vulgare L.) mutant carrying a missense mutation in the gene encoding the SL-specific receptor HvD14. Our results clearly showed that hvd14.d mutant is hyper-sensitive to drought stress. This was illustrated by a lower leaf relative water content (RWC), impaired photosynthesis, disorganization of chloroplast structure, altered stomatal density and slower closure of stomata in response to drought in the mutant compared to the wild type parent cultivar Sebastian. Although the content of abscisic acid (ABA) and its derivatives remained unchanged in the mutant, significant differences in expression of genes related to ABA biosynthesis were observed. Moreover, hvd14.d was insensitive to ABA during seed germination. Analysis of Arabidopsis thaliana mutant atd14-1 also demonstrated that mutation in the SL receptor resulted in increased sensitivity to drought. Our results indicate that the drought-sensitive phenotype of barley SL mutant might be caused by a disturbed ABA metabolism and/or signalling pathways. These results together uncovered a link between SL signalling and ABA-dependent drought stress response in barley.

SISTEM PERBAIKAN EKOFISIOLOGI TANAMAN SENGON (Paraserianthes falcataria (L) Nielsen ) DI KECAMATAN WAGIR, 161 MALANG

Sengon plant (Paraserianthes falcataria (L) Nielsen) in Indonesia is one of the types of plants developed in the development of Community Forestry especially in Wagir District, Malang Regency. This study was conducted to analyze the effect of environmental conditions, especially temperature and humidity on stomata density and chlorophyll levels in the plant Sengon (Paraserianthes falcataria (L) Nielsen) and analyze the soil nutrient content under the Sengon stand (Paraserianthes falcataria (L) Nielsen) on plant physiology in Sukodadi Village, Wagir District, Malang Regency. The techniques used are field surveys, leaf sampling to measure physiological properties (stomata density and chlorophyll content), and soil sampling to measure soil chemical properties (macro nutrient content), as well as direct observations in the field to measure environmental factors (temperature and humidity). Analysis of the data used is multiple linear regression in SPSS to determine whether there is influence of temperature and humidity on the physiology of stomata and chlorophyll as well as descriptive analysis on soil factors. Research result is that temperature and humadity have an effect on chlorophyll. This support to possibility of temperature and humadity system in the region so that agreed crops will affect the concentration of chlorine.

Stomata Polymorphism in Leaves of Apple Trees (Malus domestica Borkh.) Growing under Mountain and Plain Conditions

Stomata polymorphism in leaves of apple trees (Malus domestica) growing under mountain and plain conditions has been studied using scanning electron microscopy. The leaves of this species were hypostomatic with anomocytic stomata and radially diverging cuticular folds combined into bundles (cuticular bundles), the number of which usually corresponded to the number of epidermal cells surrounding the stomata. The average size of stomata increased linearly as the number of cuticular bundles increased. Under favorable conditions (600-m altitude above sea level), a high density of rounded stomata was observed. Stress conditions, such as high temperatures and droughts on the plain (300-m altitude) or high insolation and temperature drops in the mountains (1200-m altitude), provided the same effect on the micromorphology of the leaf surface, while the effect of altitude was manifested in the reduction of the size of epidermal cells.

Sheathing the blade: Significant contribution of sheaths to daytime and nighttime gas exchange in a grass crop.

Despite representing a sizeable fraction of the canopy, very little is known about leaf sheath gas exchange in grasses. Specifically, estimates of sheath stomatal conductance, transpiration and photosynthesis along with their responses to light, CO2 and vapour pressure deficit (VPD) are unknown. Furthermore, the anatomical basis of these responses is poorly documented. Here, using barley as a model system, and combining leaf-level gas exchange, whole-plant gravimetric measurements, transpiration inhibitors, anatomical observations, and biophysical modelling, we found that sheath and blade stomatal conductance and transpiration were similar, especially at low light, in addition to being genotypically variable. Thanks to high abaxial stomata densities and surface areas nearly half those of the blades, sheaths accounted for up to 17% of the daily whole-plant water use, which -surprisingly- increased to 45% during the nighttime. Sheath photosynthesis was on average 17-25% that of the blade and was associated with lower water use efficiency. Finally, sheaths responded differently to the environment, exhibiting a lack of response to CO2 but a strong sensitivity to VPD. Overall, these results suggest a key involvement of sheaths in feedback loops between canopy architecture and gas exchange with potentially significant implications on adaptation to current and future climates in grasses.

Loss of Function of Fatty Acid Desaturase 7 in Tomato Enhances Photosynthetic Carbon Fixation Efficiency.

Fatty Acid Desaturase 7 (FAD7) generates polyunsaturated fatty acids, promoting the desaturation of chloroplast membranes; it also provides an essential precursor for the synthesis of jasmonic acid (JA), a phytohormone that can influence plant growth, development, and primary metabolism. This study examined the effects of spr2, a null mutation in SlFAD7, on the growth, morphology, and photosynthetic traits of tomato, Solanum lycopersicum. Although the spr2 mutant had a lower density of stomata than wild type plants, the two genotypes had comparable stomatal conductance, transpiration rates, and intracellular CO2 levels; in addition, spr2 had significantly thinner leaf blades, which may help maintain normal levels of CO2 diffusion despite the lower number of stomata. Surprisingly, spr2 also had significantly higher carbon assimilation (A) and maximum quantum efficiency of PSII (Fv/Fm) than wild type plants at both of the light intensities tested here (220 or 440 µmol m−2 s−1), despite having lower levels of chlorophyll than wild type plants under low light (220 µmol m−2 s−1). Furthermore, CO2 response curves indicated higher in vivo Rubisco activity (Vcmax) in spr2 compared to wild type plants, as well as an enhanced maximum rate of electron transport used in the regeneration of ribulose-1,5-bisphosphate (Jmax). These data indicate that loss of function of FAD7 can enhance the efficiency of both light-dependent and light-independent reactions in photosynthesis. Consistent with this, the spr2 mutant also displayed enhanced growth, with significantly more leaves and a more compact growth habit. In contrast to spr2, another tomato mutant impaired in JA synthesis (acx1) showed no enhancements in growth or photosynthetic efficiency, suggesting that the enhancements observed in spr2 are independent of the effects of this mutation on JA synthesis. These data demonstrate that loss of function of FAD7 can enhance photosynthesis and growth, potentially through its impacts on the chloroplast membranes.

Physiological and anatomical differentiation of two sympatric weed populations.

In the vineyards of Rhineland-Palatinate (Germany), two different types of Shepherd’s Purse (Capsella bursa-pastoris) coexist: (1) the common type called ‘wild type’, and (2) the decandric type called Capsella apetala or ‘Spe’ with four stamens in place of the four petals. In this study, we compare the anatomical and physiological characters of rosette leaves of the respective types. Progeny of individual plants was cultivated in growth chambers under low- and high-light conditions. Under low-light conditions, the stomata densities of the adaxial and abaxial epidermis did not differ between the two types. When grown under high-light conditions, wild type and Spe, both exhibited increased stomata densities compared to low-light conditions, but Spe to a lesser extent than the wild type. The maximal photosynthetic capacity of Spe was lower in both, low-light and high-light conditions compared to wild-type plants. Under all CO2 concentrations, Spe seemed to be less productive. The less effective CO2 assimilation of the Spe mutant C. apetala was accompanied by later flowering. This fact prolonged the vegetative phase of Spe by about two weeks and was sufficient for the maintenance of both populations stably over years.

Karakter Anatomi Daun sebagai Bentuk Adaptasi Tumbuhan Penyusun Zonasi Mangrove di Banggai Kepulauan, Provinsi Sulawesi Tengah

Mangrove is an essential ecosystem that are located in the transition area of fresh and sea water. Therefore, species that grow are typical species that are able to adapt to the saline environment. The aim of this research is to characterize leaf anatomical structure for every species that compose the communities found in each mangrove zonations, including their similarities and dissimilarities characteristic. Sampling of examined leaf was carried out in the mangrove areas of Peling Island and Bakalan Island by making plots in four sites of the mangrove ecosystem area. Methods for leaf anatomical preparations were carried out using the paraffin-tert-butanol and paradermal sections. Anatomical characters as an adaptation to saline habitat are found in all species of mangrove plants, including thick cuticle and epidermal cells, thick leaves and water-storage tissue (hypodermis). In addition, there is found the presence of cork warts and sclereid as characteristic of the genus Rhizophora. Based on quantitative character observations, the mesophyll (palisade to sponge) ratio range from 0.28 ± 0.04 μm to 1.19 ± 0.42 μm, leaf thickness ratio 289,41 ± 38,21 μm to 695,20 ± 97,50 μm and the highest stomata density is owned by Lumnitzera littorea

PENGARUH FOTOAUTOTROFIK TERHADAP PERTUMBUHAN TUNAS KRISAN DALAM PROSES KULTUR IN VITRO SERTA PERBEDAAN STOMATA INVITRO DAN EXVITRO KRISAN

Chrysanthemum (Chrysanthemum indicum L.) is an ornamental plant that is included in an important contribution in the ornamental plant business. Related to chrysanthemum buds grown in vitro in culture tubes or bottles with a tightly closed to avoid bacterial and fungal contamination and to protect the humidity of the culture environment. However, this tight cap often affects the composition of the gas in a jar or bottle, which inhibits plant growth. The purpose of this study was to study the effect of photoautotrophic on the growth of chrysanthemum buds in the in vitro culture process and the differences in invitro and exvitro chrysanthemum stomata. This research was conducted in March 2016 to May 2016 in the Microtechnical Laboratory, IPB University. Research results obtained from research on the position given to research conducted on the number of roots, the number of books and the number of shoots. The influence of the environment of exvitro also significantly affects the number of stomata, stomata width and stomata density. Keywords :ex vitro, in vitro, photoautotrophic

Growth and Physiological Responses of Sugarcane to Drought Stress at an Early Growth Stage

A pot experiment was conducted in a net house to evaluate the effects of drought stress (a 20-day water withholding treatment from 100-120 days after planting) on the growth and physiology of five sugarcane cultivars. The results showed that water stress at an early stage significantly affected sugarcane growth and physiology. Water stress resulted in reductions in plant height, stalk diameter, and leaf number of sugarcane, in addition to reductions in the photosynthetic pigment content, Fv/Fm, and SPAD (Soil Plant Analysis Development) readings after the 20-day withholding water period (120 DAP), and in stem, root, and leaf fresh weights, and leaf area at 150 DAP. Besides, drought stress led to increases in stomata density and decreases in stomata length. Variation was also found among the cultivars in response to water stress. Significant genotypic differences in stem fresh weight and leaf area under water stress among the cultivars were observed. The highest value of stem fresh weight under stressed conditions was recorded in ROC22 (50.6 g), followed by QĐ159 (46.5g), ROC16 (46.2g), ROC10 (46.1g), and VL06 (44.4g). However, the highest DTI was recorded in ROC16, followed by VL06, ROC10, QĐ93-159, and ROC22, respectively.