Highest Shoot Research Articles

Germplasm screening of Myrtus communius Var. Italica l. for cultivar development from dir lower (Malakand Division), Pakistan

Habb-ul-Aas is a commercial drug obtained from Myrtus communis L and widely used for abdominal disorders in Pakistan. This sclerophyllous shrub is commonly found in the Lower Dir, Malakand Division, Pakistan. This plant is used as crude drug in herbal as well as pharmaceutical industry due to presence of aromatic oil obtained from various parts of the plant. Two varieties viz., italic and baetica of the plant exist in the world; however, no study reported before about the existence of this species up to the varietal level from Pakistan. The current study was undertaken to characterize the existing germplasm by using certain morphometric parameters in relation to physiognomic features. They exhibit high variability among characters, especially for characteristics useful in selecting cultivars for commercial production. Among the various ecotypes, MBT3 possessed high shoot length (29.96cm), leaf area (2.3cm), fruit volume (0.97ml) & fruit weight (0.88g) and pulp (0.87g) and therefore recommended for the cultivar development.

The role of plant growth-promoting bacteria in alleviating drought stress on pepper plants

Plant growth-promoting bacteria (PGPB) are important microorganisms that can be used to improve plant responses against biotic and abiotic stresses. Thus, 60 bacterial strains were isolated from pepper plants cultivated in a semiarid region in southeast Ethiopia. Initial screening for drought tolerance revealed that 12 (20.0%) isolates were able to grow in the presence of 2 M NaCl (w/v), 11 (18.33%) isolates were shown thermotolerance capacity up to 65 °C and 18 (30.0%) isolates were shown maximum tolerance for polyethylene glycol concentration (15%). Moreover, 16 (26.67%) of the strains were strong biofilm producers, while 54 (90%) were EPS producers with a better production in the medium containing 10% glucose. Also, the highest flocculation yield was recorded by AAUSR23 (148 mg/L) at 0.5 M of NaCl. A subset of 10 strains was identified based on a semi-automated Biolog MicroPlate identification system and belonged to fourteen genera (Bacillus spp, Pseudomonas spp. Stenotrophomonas spp, Enterobacter spp, Achromobacter spp, Comamonas spp, Acinetobacter spp, Burkholderia spp, Serratia spp, Ocrobactrum spp, Pantoea spp, Rhizobium spp, Aeromonas spp, and Klebsiella spp). Four selected strains produce auxin on the root tip of Arabidopsis thaliana when treated with DR5::GUS. The bacterized seeds of pepper with four selected drought resistant bacterial strains were evaluated in the greenhouse; the inoculated plants showed 23.6–52.8% and 41–79.6% higher shoot and root lengths, respectively, compared with the control. Our results showed that drought resistant bacteria isolated from the rhizosphere and endophyte of pepper grown on water deficient lands might be used for alleviating drought stress in crop plants.

Exploring Ni-accumulation in serpentinophytic taxa of Brassicaceae from Albania and Greece

The family Brassicaceae includes the highest proportion of Ni-hyperaccumulating plants in western Eurasia. Though increasingly relevant for scientific research and biotechnological applications, data about metal concentrations in native populations are still incomplete. The Balkan peninsula is a major diversity centre for Ni-hyperaccumulators due to the wide distribution of ultramafic soils across the area. Using Atomic Absorption Spectrophotometry and material from our field collections, we determined Ni concentration in 31 accessions of 22 taxa from nine tribes: Aethionemeae, Alysseae, Arabideae, Cardamineae, Coluteocarpeae, Erysimeae, Hesperideae, Iberideae and Isatideae. Results confirm that Ni-hyperaccumulation ability is phylogenetically restricted to Alysseae and Coluteocarpeae. Highest Ni-concentrations and bioaccumulation factors were found in Bornmuellera, Odontarrhena and Noccaea. Plants of the facultative serpentinophyte O. chalcidica from the type locality displayed shoot Ni levels > 2000 μg g−1 DW despite growing on non-ultramafic soils with low Ni. This resulted in a remarkably high bioaccumulation factor (91.7). High and low shoot Ni concentrations were instead detected in O. muralis accessions from serpentine and non-serpentine sites, respectively. Hyperaccumulation was confirmed in the endemic O. euboea, for which previous reports were contrasting. Shoot Ni concentration was negatively related to soil Ni concentration in non-accumulating taxa, suggesting efficient exclusion mechanisms on Ni-rich soils.

Biomass production and uptake of sulfur, chromium and micronutrients by Tanzania guinea grass grown with sulfur and chromium.

Soil contamination caused by improper waste disposal can affect plant growth. Tropical forage plants have rapid growth, high biomass production and vigorous regrowth. Chromium (Cr) is one of the most common contaminants in the environment. Sulfur (S) is a nutrient involved in various cell detoxification processes. The objective was to assess the effects of excess Cr on biomass production and concentrations of this metal, S and cationic micronutrients, under conditions of varying supply of S for Tanzania guinea grass. The experiment was conducted in randomized complete blocks in a 3 × 4 factorial scheme, corresponding to three levels of S (0.1, 1.9 and 3.7mmol L-1) and four levels of Cr (0.0, 0.5, 1.0 and 2.0mmol L-1) in three replicates. Root surface area, shoot and root biomass production, concentrations of total S, sulfate-S, Cr and cationic micronutrients, and Cr transport factor were determined. S level of 1.9mmol L-1 reduced the toxicity by Cr in Tanzania guinea grass, expressed by the higher shoot and root dry weight production, greater stability in the cellular concentration of sulfate-S and higher concentrations of micronutrients. It was concluded that the high availability of S reduced the toxicity by Cr(VI) in Tanzania guinea grass, expressed by the higher shoot and root dry weight production, greater stability in the cellular concentration of sulfate-S and higher concentration of micronutrients in the grass shoots.

Expression of cytokinin responsive and ethylene biosynthesis genes in rice callus with different regeneration rates

This study aimed to investigate the correlation between callus regeneration rate and the expression of several genes responsible for cytokinin response and ethylene biosynthesis in the Ciherang, Mentik Wangi Susu, Hwayoung and Tarabas rice varieties. The callus regeneration rate of each rice variety was in vitro tested using N6 media, while the gene expression during the callus regeneration stages was examined using quantitative real‐time PCR (qRT‐PCR). Our results showed that the callus of Ciherang and Mentik Wangi Susu showed earlier green spot formation that then turned brown at a later stage, resulting in a low regeneration rate. While Hwayoung and Tarabas showed late green spot formation, high shoot regeneration was observed in both calluses. Gene expression analysis of regeneration media‐grown calluses showed that two cytokinin‐responsive genes, OsRR2 and OsRR6, were highly expressed in the Ciherang and Hwayoung callus, respectively. We also observed that ethylene biosynthesis genes such as OsACS1 and OsACO1 were highly expressed in the Mentik Wangi Susu and Hwayoung callus, respectively. Moreover, the expression of OsBBM1 was high in Hwayoung and Tarabas. Thus, the positive correlation between the expression of cytokinin‐responsive and ethylene biosynthesis genes with somatic embryogenesis activity likely depends on the induction level of OsBBM1.

Endemik Mor Mercan (Origanum sipyleum L.) Bitkisinin In Vitro Çoğaltımı

Türkiye'nin endemik bitki türlerinden biri olan “Mor Mercan” adıyla bilinen Origanum sipyleum L., Lamiaceae familyasından olup yüksek tıbbi ve aromatik değere sahiptir. Origanum türlerinin antikanserojenik, sitotoksik, antibakteriyel, antidiyabetik, antifungal, antiviral, insektisidal etkilerinin olduğunu çeşitli bilimsel çalışmalar gösterilmiştir. Bununla birlikte, genetik kaynakların korunmasında değerli ve tehlike altındaki tıbbi bitkilerin hızlı bir şekilde çoğaltımı konusunda yeni araçlar sağlayan ileri biyoteknolojik yöntemler ile Origanum sipyleum L.'nin çoğaltımı hakkında çok az bilimsel çalışma bulunmaktadır. Bu nedenle bu çalışma, İzmir/Bozdağ'dan toplanan Origanum sipyleum L. genetik kaynak materyalinin biyoteknolojik yöntemlerden biri olan in vitro teknikler kullanılarak çoğaltılması amacıyla yapılmıştır. İki eksplant (nodal segment ve sürgün ucu) tipi ve dört farklı ortamın;(MS+0,5 mg L-1 BAP + 0,1 mg L-1 IAA; MS+1,0 mg L-1 BAP+0,1 mg L-1 IAA; ½MS+ 0,5 mg L-1 BAP + 0,1 mg L-1 IAA; ½MS+ 1,0 mg L-1 BAP + 0,1 mg L-1 IAA) Origanum sipyleum L’un sürgün sayısı ve sürgün uzunluğuna etkileri araştırılmıştır. Eksplant başına en yüksek sürgün sayısı (5,56 adet/eksplant) 1,0 mg L-1 BAP+ 0,1 mg L-1 IAA içeren MS ortamında büyüyen nodal eksplantlardan elde edilmiştir. Geliştirilen bitkicikler, toprak-perlit (2:1) karışımından oluşan saksı karışımına başarıyla nakledilmiştir.

Physiological and rhizospheric response characteristics to cadmium of a newly identified cadmium accumulator Coreopsis grandiflora Hogg. (Asteraceae)

Screening for superior cadmium (Cd) phytoremediation resources and uncovering the mechanisms of plant response to Cd are important for effective phytoremediation of Cd-polluted soils. In this study, the characteristics of Coreopsis grandiflora related to Cd tolerance and accumulation were analyzed to evaluate its Cd phytoremediation potential. The results revealed that C. grandiflora can tolerate up to 20 mg kg−1 of Cd in the soil. This species showed relatively high shoot bioconcentration factors (1.09–1.85) and translocation factors (0.46–0.97) when grown in soils spiked with 5–45 mg kg–1 Cd, suggesting that C. grandiflora is a Cd accumulator and can potentially be used for Cd phytoextraction. Physiological analysis indicated that antioxidant enzymes (i.e., superoxide dismutase, peroxidase, and catalase) and various free amino acids (e.g., proline, histidine, and methionine) participate in Cd detoxification in C. grandiflora grown in soil spiked with 20 mg kg–1 of Cd (Cd20). The overall microbial richness and diversity remained similar between the control (Cd0) and Cd20 soils. However, the abundance of multiple rhizospheric microbial taxa was altered in the Cd20 soil compared with that in the Cd0 soil. Interestingly, many plant growth-promoting microorganisms (e.g., Nocardioides, Flavisolibacter, Rhizobium, Achromobacter, and Penicillium) enriched in the Cd20 soil likely contributed to the growth and vitality of C. grandiflora under Cd stress. Among these, some microorganisms (e.g., Rhizobium, Achromobacter, and Penicillium) likely affected Cd uptake by C. grandiflora. These abundant plant growth-promoting microorganisms potentially interacted with soil pH and the concentrations of Cd and AK in soil. Notably, potassium-solubilizing microbes (e.g., Rhizobium and Penicillium) may effectively solubilize potassium to assist Cd uptake by C. grandiflora. This study provides a new plant resource for Cd phytoextraction and improves our understanding of rhizosphere-associated mechanisms of plant adaptation to Cd-contaminated soil.

Transcriptome analysis reveals the effects of strigolactone on shoot regeneration of apple

We have demonstrated that strigolactone inhibitor, Tis108, could be used to improve shoot regeneration of apple, and provided insights into the molecular mechanism of strigolactone-mediated inhibition of adventitious shoot formation. Lack of an efficient transformation system largely stagnated the application of transgenic and CRISPR technology in apple rootstock. High shoot regeneration ability is an important basis for establishing an effective transformation system. In this study, we first demonstrated the inhibitory effects of strigolactones on the adventitious shoot formation of apple rootstock M26. Next, we successfully verified that strigolactone-biosynthesis inhibitor, Tis108, could be used to improve the shoot regeneration of woody plants. Our results also suggest strigolactone-biosynthesis gene, MdCCD7, can be a target gene for biotechnological improvements of shoot regeneration capacity. Furthermore, we have employed transcriptome analysis to reveal the molecular mechanism of strigolactone-mediated inhibition of adventitious shoot formation. Differentially expressed genes associated with photosynthesis, secondary growth, and organ development were identified. WGCNA suggests SLs might affect shoot regeneration through interaction with other hormones, especially, auxin, cytokinin, and ethylene. We were able to identify important candidate genes mediating the cross-talk between strigolactone and other hormones during the process of adventitious shoot formation. Overall, our findings not only propose a useful chemical for improving shoot regeneration in practice but also provide insights into the molecular mechanism of strigolactone-mediated inhibition of adventitious shoot formation.

Silicon mitigates potassium deficiency by enhanced remobilization and modulated potassium transporter regulation

Silicon (Si) improves plant growth and development especially under stress conditions. Although Si alleviates growth suppression and deficiency symptoms of several nutrient disorders, underlying regulatory processes have remained indefinite. Here, we analyzed the impact of Si on nutritional, metabolic and transcriptional responses in roots and shoots of barley subjected to potassium (K) deficiency. On the long run, Si nutrition improved root and shoot growth as well as metabolite homeostasis and partly reverted the K deficiency signature of the transcriptome back to adequate only in fully expanded leaves but hardly in roots. In the short term, Si supply to K-starved roots enhanced first the expression of the vacuolar K exporter KCO1 together with root-to-shoot translocation rates of rubidium (Rb) that was used as tracer for K. The typical K deficiency response, marked by upregulation of the K importer genes HAK1 and AKT1, set in a few days later but then at several-fold higher levels. Lower root K and higher shoot K contents in Si-supplied plants indicated more efficient remobilization of root K pools and higher root-to-shoot translocation, which on the long run restored K-dependent metabolic processes in shoots for the sake of continued assimilate provision to roots. These results provide a sequence of physiological processes by which Si partially recovers plants from K deficiency and indicate that Si interferes with systemic K deficiency signaling in roots to alter the regulation of K transporters. • · Mitigation of K deficiency by Si supply relies on an improved metabolic status of the leaves for sustained assimilate provision of roots • Under K starvation, Si enables stronger depletion of the root K pool and enhances K remobilization for root-to-shoot translocation • In K-starved plants, Si activates vacuolar K exporter genes in roots and subsequently stimulates the K deficiency response

FIELD SCREENING OF BRINJAL ACCESSIONS FOR RESISTANCE AGAINST BRINJAL SHOOT AND FRUIT BORER, Leucinodes orbonalis (Lepidoptera: Guenee)

Resistance potential of 100 brinjal accessions against brinjal shoot and fruit borer (BSFB) was evaluated under field condition at Sivapuri village, Chidambaram, Tamil Nadu, India in Kharif 2020. The data obtained from this study revealed that amongst the 100 accessions screened, the lowest shoot and fruit damage was observed on the genotype IC-136546 followed by IC-136451 whereas, the highest shoot and fruit damage was observed on Manapaarai Local followed by IC-089847. Based on the standard scale, none of the accessions show immune response to BSFB. Hence, the accessions which imparted resistance against the BSFB were selected for breeding to develop BSFB resistance varieties.

GREEN SYNTHESIS OF MANGANESE OXIDE NANOPARTICLES USING KIGELIA AFRICANA (LAM.) BENTH. AQUEOUS ROOT EXTRACT AND INFLUENCE ON CHICKPEA (CICER ARIETINUM LINN.) SEED GERMINATION AND PLANT GROWTH

Use of different seed priming treatments improves seed germination and thus increases plant growth and yield potential. Eco-friendly, cost-effective, simple, and effective seed treatments need to be developed for a high-consuming crop like chickpea (Cice rarietinum Lin.). In the present study, manganese oxide nanoparticles were synthesized using an aqueous extract of roots of Kigelia africana (Lam.) Benth and used as nano priming agents for chickpea seeds. The synthesized nanoparticles were found to have rod-like morphology with heterogeneous size distribution. The nanoparticle’s average size was found to be 67 nm with a metal content of 52.04 %. The sprout’s emergence was found to be high in nanometal-treated chickpea seeds than in untreated and metal treated seeds. The seedling rate after ten days of sowing was found to be high in nanoparticle-treated seeds. The nanometal treatment shows low mean germination time, high germination rate, root length and shoot length of the chickpea compared to untreated samples. The present study results demonstrates that seed priming with manganese oxide nanoparticles could enhance seed germination and growth through an eco-friendly and sustainable nanotechnological approach.

Indirect organogenesis for high frequency shoot regeneration of two cultivars of Sansevieria trifasciata Prain differing in fiber production

Sansevieria trifasciata is used as an indoor plant, in traditional medicine and as a fiber source. Here we characterized fibers of two of varieties of S. trifasciata, Lorentii and Hahnii, and report a protocol for their propagation based on indirect shoot organogenesis. Structural and ribbon fibers were scattered within leaf parenchyma when viewed with confocal laser scanning microscopy. Chemical analysis of the fibers by mass spectrometry and high-performance chromatography revealed higher contents of cellulose and xylose in Lorentii than in Hahnii and significant differences for total lignin between both. A protocol for de novo shoot production was then developed using leaf explants. Time-course histological analyses showed that the first events of transdifferentiation were triggered preferentially in cells surrounding fibers and vascular bundles. Callogenesis and shoot performances were quantified for both varieties, and 2,4-D at 2 and 3 mg·L-1 yielded the best results for primary calli induction and fresh calli mass. The length, number, and mass of shoots produced did not differ significantly between the two cultivars. The fast morphogenic response of S. trifasciata to in vitro culture may be useful for mass propagation or other biotechnological purposes such as metabolite production.

Mycorrhizal species selectivity of sweet sorghum genotypes and their effect on nutrients uptake

ABSTRACT This study aimed to find the effects of several mycorrhiza species on agronomic characteristics and nutrient uptake of various sweet sorghum genotypes under the semi-arid Mediterranean soil conditions. Four sweet sorghum genotypes were inoculated with three mycorrhiza species under greenhouse conditions. The plants were evaluated for growth parameters such as shoot height, root length, root morphology (root surface, root diameter and volume), shoot and root dry weight, uptake of macro and micro mineral nutrients, root colonisation and mycorrhizal dependency. Mycorrhizal species significantly improved growth and productivity of sorghum genotypes. Inoculation of Funneliformis mosseae, Claroideoglomus claroideum and Claroideoglomus etunicatum resulted in the highest shoot and total dry matter biomass production in Ashana, Hereahri and Yellow genotypes, respectively. Mycorrhiza inoculated white genotype had higher root colonisation and root development, and shoot P, K, Ca and Mg contents. Yellow genotypes produced significantly higher shoot and total dry weight and also were highly mycorrhiza dependent among the four genotypes. Compared to the control treatment mycorrhizal inoculation increased shoot Zn concentration but had non-consistent effects on shoot Cu, Fe and Mn contents. Conclusively, our findings confirmed that sweet sorghum genotypes responded selectively to arbuscular mycorrhizal fungi (AMF) colonisation for their growth parameters and nutrients uptake.

Spatial overlap between lugworm (Arenicola marina) and eelgrass (Zostera marina) distribution in coastal waters: The role of environmental stressors

This study investigates the role of external physical and chemical stressors on the distribution of lugworms and eelgrass in sandy sediments at three shallow locations along the Danish coasts. The density of and spatial overlap between lugworm and eelgrass distribution were quantified during May–October in 2017 and 2018 and related to the potential role of two environmental stressors: Physical disturbance by waves and high levels of sulfide in the sediment. The inverse relationship between the density of lugworms and eelgrass shoots at the study sites suggests a general antagonistic distribution. The spatial overlap between these species was quantified by Levins’ index. The overlap was asymmetrical and much higher for lugworms than for eelgrass with the smallest overlap at the two locations mostly impacted by physical and chemical stress. Almost no eelgrass was present at these two impacted locations when lugworms exceeded 30 ind m−2, while the critical density approached 70 ind m−2 at the less impacted location. These results suggest that eelgrass is less resistant than lugworms to biological interactions when exposed to environmental stress. Eelgrass apparently require large and coherent meadows with high shoot density to tolerate multiple biological and environmental stressors. The knowledge acquired in this study improves the general understanding of species interactions in coastal ecosystems and is important for appropriate planning and management of future eelgrass restoration ventures.

Antifungal Potential of Azotobacter salinestris Strain Azt 31 against Phytopathogenic Fusarium spp. Associated with Cereals.

Antifungal efficacy of Azotobacter salinestris against trichothecene-producing Fusarium spp. was investigated in maize, sorghum, and wheat. The three cereals were subjected to four treatments as control (T1), Fusarium alone (T2), combination of Fusarium and A. salinestris treatment (T3), and only A. salinestris (T4). All the treatments were evaluated for total mass of seedlings, root and shoot length, seed germination, and vigor index (VI), and extent of rhizoplane colonization by A. salinestris was investigated. Further, greenhouse studies were conducted to learn the efficacy of A. salinestris in vivo conditions. Antifungal efficacy was tested by the dual-culture method which resulted in significant reduction in Fusarium growth. Infection by Fusarium was reduced up to 50% in treated cereals such as maize, sorghum, and wheat, and there was also significant increase in seedling mass in the three hosts. Maize showed the highest VI (1859.715), followed by sorghum (1470.84), and wheat (2804.123) with A. salinestris treatment. In addition, seed germination was enhanced to 76% in maize, 69% in sorghum, and 68% in wheat, respectively. Efficacy of rhizoplane colonization showed successful isolation of A. salinestris with high CFU rate, and furthermore, significant colonization inhibition by Fusarium spp. was observed. In the greenhouse conditions, on the 45th day of the experimental set-up, the highest shoot length/root length recorded in maize was 155.70/70.0 cm, in sorghum 165.90/48.0 cm, and in wheat 77.85/56.0 cm, and the maximum root mass recorded was 17.53 g in maize, 4.52 g in sorghum, and 1.90 g in wheat. Our present study showed that seed treatment by A. salinestris, may be used as an alternate biocontrol method against Fusarium infection in maize, sorghum, and wheat.

Responses of butter leaf lettuce to mixed red and blue light with extended light/dark cycle period

To investigate the effects of extended light/dark (L/D) cycle period (relative to the diurnal L/D cycle) on lettuce and explore potential advantages of abnormal L/D cycles, butter leaf lettuce were grown in a plant factory with artificial light (PFAL) and exposed to mixed red (R) and blue (B) LED light with different L/D cycles that were respectively 16 h light/8 h dark (L16/D8, as control), L24/D12, L48/D24, L96/D48 and L120/D60. The results showed that, all the abnormal L/D cycles increased shoot dry weight (DW) of lettuce (by 34–83%) compared with the control, and lettuce DW increased with the L/D cycle period prolonged. The contents of soluble sugar and crude fiber in lettuce showed an overall upward trend with the length of L/D cycle extended, and the highest vitamin C content as well as low nitrate content were both detected in lettuce treated with L120/D60. The light use efficiency (LUE) and electric use efficiency (EUE) of lettuce reached the maximum (respectively 5.37% and 1.76%) under L120/D60 treatment and so were DW, Assimilation rate (A), RC/CS, ABS/CS, TRo/CS and DIo/CS, indicating that longer L/D cycle period was beneficial for the assimilation efficiency and dry matter accumulation in lettuce leaves. The highest shoot fresh weight (FW) and nitrate content detected in lettuce subjected to L24/D12 may be related to the vigorous growth of root, specific L/D cycle seemed to strengthen root growth and water absorption of lettuce. The openness level of RC in PSII (Ψo), ETo/CS, and PIabs were all the highest in lettuce treated with L24/D12, implying that slightly extending the L/D cycle period might promote the energy flowing to the final electron transfer chain. In general, irradiation modes with extended L/D cycle period had the potential to improve energy use efficiency and biomass of lettuce in PFAL. No obvious stress or injury was detected in lettuce subjected to prolonged L/D cycles in terms of plant growth and production. From the perspective of shoot FW, the optimal treatment in this study was L24/D12, while L120/D60 was the recommended treatment as regards of the energy use efficiency and nutritional quality.

Deficit irrigation effects on five pomegranate cultivars water use efficiency and biochemical parameters

The purpose of this study was to compare the effects of two irrigation levels [100 percent of field capacity (FC) (control)] and 30 percent FC (deficit irrigation) on vegetative growth, biochemical status, and water use efficiency of five pomegranate cultivars (Wonderful, Manfalouty, Acco, Assuity and 116) over two seasons in 2019 and 2020. The results showed that deficit irrigation reduced the dry weight of the shoots and roots, as well as the chlorophyll content of the leaves, in all the pomegranate cultivars. Meanwhile, under stress, proline content, total soluble sugars, total phenols, and peroxidase activity all increased significantly. The Manfalouty cultivar had the highest shoot and root dry weights, as well as the highest water use efficiency, proline content, and total phenols. Furthermore, when compared to other cultivars, the Wonderful cultivar had the highest chlorophyll content during both seasons. In comparison to the other cultivars studied, the Wonderful cultivar showed the limited or no significant increase in peroxidase activity. This could be due to a genotype’s variable peroxidase activity potential in pomegranate cultivars under water stress. The obtained results may indicate that Manfalouty and Wonderful cultivars are more tolerant of deficit irrigation than the other cultivars studied.

Contribution of structural and functional adaptations of hyper-accumulator Suaeda vera Forssk. ex J.F. Gmel. for adaptability across salinity gradients in hot desert.

The role of ionic excretions and hyper-accumulation of salts through alterations of structural and functional traits in five populations of Suaeda vera Forssk. ex J.F. Gmel., a halophytic salt-indicator species of saline environments, was explored. Differently adapted populations of S. vera exhibited specific structural and functional responses for the survival in hyper-saline conditions. Better growth in population from moderately saline habitat (25-30 dS m-1) was linked to high shoot and root K+ and increased ion selectivity (K+/Na+ and Ca2+/Na+). Increased excretion of Na+ and Cl- with increasing salinity level was a critical mechanism in maintaining ionic balance. Drastic differences were observed for anatomical characteristics in populations inhabiting differentially salt-affected lands. The plants from highly saline sites were characterized by narrow metaxylem vessels, low proportion of cortical parenchyma, and reduced phloem area leading to stunted growth. Contrariwise, root area significantly increased due to high proportion of sclerified xylem tissue, which was associated with easier conduction of solutes and protection of roots from collapsing. Root sclerification particularly at the highest salinity regime was a key factor in the survival of this species in salt-affected compact soils. Leaf anatomical characteristics showed reduction with increasing salinity, but the leaf thickness responded otherwise. This contributed to increased leaf succulence because of high proportion of storage parenchyma in populations colonizing hyper-saline habitats. It was concluded that moderate salinity conditions were more suitable for the growth of S. vera, though some populations of this species were able to tolerate much higher salinity levels.

Effects of brassinolide on cadmium accumulation and growth of emerged accumulator plant Nasturtium officinale

ABSTRACT To assess the effects of brassinolide (BR) on the growth and phytoremediation ability of cadmium (Cd) accumulator plants, different BR concentrations were applied to emerged accumulator plant Nasturtium officinale growing in Cd-contaminated soil. Brassinolide application increased the biomass, photosynthetic pigment content, and antioxidant enzyme activity of N. officinale. When N. officinale was treated with 1.5 mg L−1 of BR, the highest shoot biomass was obtained, recording an increase of 26.06%, compared to the control. In addition, BR treatment decreased the Cd contents in the shoots of N. officinale, and the BR concentrations of 0.5, 1.0, 1.5, and 2.0 mg L−1 decreased the Cd content in shoots by 10.49%, 12.11%, 20.13%, and 17.23%, respectively, compared to the control. Brassinolide treatment also slightly inhibited the transportation of Cd from the roots to shoots. The findings revealed that BR had no significant effects on the Cd extraction amounts by stems, leaves, and shoots of N. officinale. However, BR promoted the growth of N. officinale and inhibited the Cd uptakes in the above-ground part of N. officinale. Thus, N. officinale could be used as a wild vegetable in the Cd-contaminated soil, although not suitable for phytoextraction as an accumulator plant.

IN-VITRO REGENERATION OF MULTIPLE SHOOTS FROM APICAL MERISTEMS OF COWPEA (Vigna unguiculata L. (WALP) USING DIFFERENT GENOTYPES (LOCAL AND IMPROVED) AND MEDIA COMPOSITIONS

Organogenesis in-vitro was evaluated in explants derived from shoot apices of four cowpea varieties cultured on Murashige and Skoog (MS) basal medium. To evaluate the response of the cowpea genotypes to in vitro regeneration, seedlings were drived from zygotic embryos excised from surface sterilized seeds after two weeks of culture on MS basal medium + vitamins supplement with 30% sucrose. To regenerate multiple shoots, apices of the in vitro seedlings with average length of 1cm were excised and cultured on MS supplemented with 0.5, 1.0 or 1.5mg/L 6-Benzylamino purine(BAP) with or without 0.1mg/L α-naphthaleneacetic acid (NAA) for six weeks. The highest shoot number was recorded with IT99k-573-2-1 and Danilla and shoot length was highest in Kanannado, IT04k-33-2-1and Danilla indicating that Danilla responded well to in vitro regeneration. To optimise the production of multiple shoots the effects of different concentratios (0.5, 1.0 and 1.5mg/L) of 6-benzyaminopurine (BAP) with or without 0.1mg/L α-naphthaleneacetic acid on the number of responding explant, number of multiple shoot produced and length of the shoots were tested. after six weeks of culture, the percentage of responding shoot apices was highest on media supplemented with 1.5mg/L BAP with and without 0.1mg/L NAA.The number of responding apices decreasing with decrease in the concentration of BAP. Maximum number of multiple shoots and the highest mean shoot length were also obtained when MS was supplemented with 1.5mg/L BAP with and without 0.1mg/L NAA.