Vigorous Growth Research Articles

Biorefining Potential of Wild-Grown Arundo donax, Cortaderia selloana and Phragmites australis and the Feasibility of White-Rot Fungi-Mediated Pretreatments.

Arundo donax, Cortaderia selloana and Phragmites australis are high-biomass-producing perennial Poalean species that grow abundantly and spontaneously in warm temperate regions, such as in Mediterranean-type climates, like those of Southern Europe, Western United States coastal areas, or in regions of South America, South Africa and Australia. Given their vigorous and spontaneous growth, biomass from the studied grasses often accumulates excessively in unmanaged agro-forestry areas. Nonetheless, this also creates the demand and opportunity for the valorisation of these biomass sources, particularly their cell wall polymers, for biorefining applications. By contrast, a related crop, Miscanthus × giganteus, is a perennial grass that has been extensively studied for lignocellulosic biomass production, as it can grow on low-input agricultural systems in colder climates. In this study Fourier transform mid-infrared spectroscopy (FTIR), high-performance anion-exchange chromatography (HPAEC) and lignin content determinations were used for a comparative compositional characterisation of A. donax, C. selloana and P. australis harvested from the wild, in relation to a trial field-grown M. × giganteus high-yielding genotype. A high-throughput saccharification assay showed relatively high sugar release values from the wild-grown grasses, even with a 0.1M NaOH mild alkali pretreatment. In addition to this alkaline pretreatment, biomass was treated with white-rot fungi (WRF), which preferentially degrade lignin more readily than holocellulose. Three fungal species were used: Ganoderma lucidum, Pleurotus ostreatus and Trametes versicolor. Our results showed that neutral sugar contents are not significantly altered, while some lignin is lost during the pretreatments. Furthermore, sugar release upon enzymatic saccharification was enhanced, and this was dependent on the plant biomass and fungal species used in the treatment. To maximise the potential for lignocellulose valorisation, the liquid fractions from the pretreatments were analysed by high performance liquid chromatography – photodiode array detection – electrospray ionisation tandem mass spectrometry (HPLC-PDA-ESI-MSn). This study is one of the first to report on the composition of WRF-treated grass biomass, while assessing the potential relevance of breakdown products released during the treatments, beyond more traditional sugar-for-energy applications. Ultimately, we expect that our data will help promote the valorisation of unused biomass resources, create economic value, while contributing to the implementation of sustainable biorefining systems.

English

Mycorrhization is known to have beneficial effects on growth vigour and protection against certain pathogens in several plant species including plantains, which has so far been little studied in the Kisangani forest region. This study aimed to determine the importance and biodiversity of mycorrhizae under plantains in the slash-and-burn and non-burn cropping systems. This research was carried out in two experimental sites located at Kisangani region in DR Congo, namely: Simi-Simi and Masako villages. Thus, 96 samples each consisting of the plantain roots and the rhizospheric soil, as well as 4 soil samples were analysed. The mycorrhization rate of the roots was calculated and sporal description to determine the mycorrhizal taxa was carried out. The overall mycorrhization rate was 40.75%. The mycorrhizal spore number was higher in non-burned fields than burned fields. There was no significant difference between the 2 practices at Masako, but the difference was significant at Simi-Simi. Moreover, vigorous plants revealed higher number of spores than non-vigorous plants. There was a significant difference between the two types of plantains. Genera of mycorrhizal spores identified were Glomus (54.96%), Gigaspora (27.84%), Acaulospora (10.50%) and Scutellospora (6.71%). The mycorrhizal sporal numbers significantly varied among plantain cultivars. The presence of tree species in the plantain plantations at high density positively influenced mycorrhization to a small extent. The above sporal genera showed a positive correlation with pH, nitrogen, clay, sand and phosphorus and negatively with organic carbon. These results showed the possibility of isolating high-performance biofertilizing mycorrhizal strains from vigorous plantain crops. Key words: Mycorrhizae, plantain, Kisangani, slash field, burned field, non-burned field.

Indigenous Rhizobacteria treatment in controlling diseases Phytophthora palmivora and increasing the viability and growth of cocoa seedling

Rhizobacteria play a positive role as biocontrol agents as well as Plant Growth Promoting Rhizobacteria (PGPR) agents. The research objective was to obtain indigenous rhizobacteria isolates on cocoa plants that have the potential to inhibit the attack of P. palmivora fungal pathogens, and act as PGPR in vitro and in vivo. The results of the study concluded that isolates TRI 7/1, TRI 8/8, GM 7/9 and GM 7/10 had the highest ability to inhibit the growth of pathogen. The lowest disease severity (20%) was obtained in the seedlings treated using isolates TRI 7/1 and TRI 8/8. Rhizobacterial isolates GM 3/6, GM 5/6, GM 7/9 and GM 8/8 produce high amounts of IAA. Rhizobacteria isolates GM 5/6, GM 7/9 and GM 8/8 has very high peroxidase enzyme activity. High production of HCN compounds was obtained in rhizobacteria isolates TRI 3/3, TRI 4/10 and TRI GM 8/11. All rhizobacterial isolates gave an increase in the value of maximum growth potential, germination and vigor values for growth strength compared with the control. The rizobacteria treatments using isolates TRI 7/1, TRI 8/8, GM 7/9 and GM 7/10 were able to increase plant height, stem diameter and number of leaves at 30, 40, 50, 60, and 70 DAP compared to control treatment.

The magic of genomics in creating hybrid potato

The magic of genomics in creating hybrid potato

Signature Text,Image and Audio Hiding in a Color Image using Steganography and Cryptography

Data Transmission in network security is one of the foremost vital issues in today’s communication world. the end result of that’s that Data security has gained utmost importance because of the unprecedented increase within the data generated over the web, which could be a basic necessity of any application in information technology. The vigorous growth within the field of data communication has made information transmission much easier. But this kind of advancement has opened many possibilities of data being snooped. So, day-by-day maintaining of data security is becoming an inseparable part of computing and communication. In this report, we’ve got explored techniques that blend cryptography and steganography together. Steganography may be a specialty of science to manage and conceal a chunk of important information inside image, audio, video, or text documents. Steganography may be a method and study of composing a secret communication specified only the source and also the targeted beneficiary will realize the concealed information. the information concealed or covered process starts with the steganography method by identifying a network canopy and redundant parts, i.e. only permitted persons would be able to change without affecting the standard of that medium. The encoding method generates a Stego medium by substituting these redundant bits with the concealed message content. In this report, various approaches for information hiding using both cryptography and steganography is proposed keeping in mind two considerations-size of the encrypted object and degree of security. Here, signature image, text, audio information is kept hidden into a cover image using the private key of sender and receiver, which extracts the data from stego image employing a public key. This approach is often used for message authentication, message integrity, and non-repudiation purpose.

Growth performance, tolerance and vigor dynamics of Salvia candidissima subsp. occidentalis Hedge against heavy metal contamination

In this study, ecotoxicological and ecophysiological effects of some different heavy metal compounds (CdCl2, PbCl2, and CuCl2) on Salvia candidissima subsp. occidentalis Hedge (Lamiaceae) were examined. Seeds of this plant were exposed to three different concentrations of CdCl2 (2, 6, 10 ppm), PbCl2 (50, 100, 500 ppm), and CuCl2 (20, 60, 150 ppm). The results indicated that increasing CdCl2 and PbCl2 concentrations had no specific inhibitory impacts on seed germination rates, growth performance, biomass, and seedling vigor index, but increasing concentrations of CuCl2 had significant inhibitory effects on these parameters. The metal tolerance index of all applications showed that all heavy metal treatments reduce this value.

Evaluation of manihot glaziovii scion-cassava understock grafting for cassava growth and root yield during rainy and dry seasons

ABSTRACT Grafting of cassava (Manihot esculenta Crantz) understocks with scions from Manihot glaziovii was proposed to improve the cassava root yield and as a temporal approach to overcoming the problem of cassava mosaic disease (CMD). This work compared performance of nongrafted KU50 with M. esculenta grafted as understock with M. glaziovii, KU50 or HB80 scions. KU50 and HB80 are released M. esculenta varieties. Work was conducted in the field using a randomized complete block design (RCBD) with four replicates in two seasons (rainy and dry seasons) in Thailand. The M. glaziovii grafted plants were larger than nongrafted controls. Grafting also increased fresh root yield by 25% (dry season) and 37% (rainy season) and dry matter content by 19% (dry season) and 42% (rainy season) over the nongrafted controls. Net photosynthesis (Pn), stomatal conductance (gs) and growth parameters indicated that the grafted plants had a higher photosynthetic capacity and more vigorous growth than nongrafted controls during the dry season. Correlation coefficients of Pn and gs with growth and productivity parameters at different ages of the plant were highly significant during the dry season but not in the rainy season. This study demonstrated that M. glaziovii–cassava grafting improved cassava growth and root yield.

Changes in soluble and non-cellulosic carbohydrates composition and calcium content during stem tip cuttings propagation and production of Eustoma grandiflorum

Stem tip cuttings of Eustoma grandiflorum (Raf.) Shinn. ‘Kiri no Mine’ were rooted under a mist to determine the feasibility of vegetative propagation and to produce acceptable plants without showing any physiological disorder at flowering. Stem tip cuttings were rooted with 50 mm 2-(1H-indol-3-yl)acetic acid (IAA) treatment. However, physiological disorders, such as die-back symptoms at the shoot apex and scorches at the margin of leaves, developed from the smallest leaves and affected nearly 50% of the cuttings. These disorders were from either leaching of macro- and micro-elements, particularly calcium (Ca), coupled with little or no translocation of radioactive Ca from the base of the cuttings to the young leaves and growing point. Plants from rooted cuttings that did not show any physiological disorder symptoms flowered later and produced fewer flowers than seed-propagated plants. Due to a reduction in growth vigor of some plants exhibiting a reduced number of top breaks and flowers, plants flowered 16 days later than plants without reduced vigor and produced only 4.3 flowers, as compared to 14.2 flowers of normal plants without showing reduced growth vigor. Although concentrations of the macro- and micro-elements of rooted plants were similar to those of seeded plants after planting rooted cuttings in a growing medium, reduction in growth vigor observed in some rooted plants cannot be explained by the leaching of macro- and micro-elements during the mist. Thus, carbohydrate and protein, which may have been leached from the cuttings were analyzed. Soluble carbohydrate content and monosaccharide composition hydrolyzed from polysaccharides after DEAE-cellulose anion-exchange chromatography was analyzed. Leachate contained primarily glucose, uronic acid, galactose, and protein in fraction III, suggesting that leaching of calcium in conjunction with carbohydrates and glycoprotein may be the cause of the expression of physiological disorder symptoms that affect the development of rooted cuttings. The reduction in growth vigor could be related to the leaching of free carbohydrates or polysaccharides, and some of the polysaccharides could be cell wall components rich in uronic acid. Calcium could be leached from cell wall fragments as a calcium-glycoprotein complex and the Ca concentration may not be restored during the resumption of new growth in 20 days when rooted cuttings were planted. Limiting factors for stem tip cutting propagation were physiological disorders, especially die-back of the shoot apex and reduced growth vigor observed at flowering when no physiological disorder symptoms were observed in rooted cuttings.

Remobilization of Storage Nitrogen in Young Pear Trees Grafted onto Vigorous Rootstocks (Pyrus betulifolia)

The remobilization of storage nitrogen (N) is affected by growth characteristics of young pear trees. Aboveground parts of young pear trees grafted on P. betulifolia grew more vigorously than that on dwarfing rootstocks. Therefore, the remobilization of storage N within young pear trees on vigorous rootstocks may be different from that on dwarfing rootstocks. A 15N tracing experiment, including six groups of one-year-old pear trees grafted on vigorous rootstocks in 2016, was conducted to investigate the mobilization of storage N from 2016 to 2018. Results indicated that about 44%, 31.4% and 24.6% of storage N remobilized in new growth was derived from the trunk, shoots and roots, respectively. Most of storage N remobilized in new organs were supplied by trunks and shoots. About 82.2% of storage N withdrawn from senescent leaves were recovered in the trunk and shoots during autumn. The aboveground parts played a more important role than roots in the cycling process of storage N in young pear trees. However, as compared with young pear trees on dwarfing rootstocks, more storage N recovered in new organs were supplied by roots of that on vigorous rootstocks, due to vigorous growth and more nutrient requirement of aboveground parts.

Transcriptome analysis for understanding the mechanism of dark septate endophyte S16 in promoting the growth and nitrate uptake of sweet cherry

Sweet cherry is one of the most popular fresh fruits in the world. Previously, we isolated a soilborne dark septate endophyte (DSE) strain, S16, which promoted the growth of Gisela 5 sweet cherry rootstock. However, little is known about the molecular mechanism of the effect of S16 on the growth of sweet cherry. In this study, the physiological parameters and transcript profiles of sweet cherry roots were analyzed under S16 treatment compared with a control to elucidate the molecular mechanisms of the effect of this strain on sweet cherry growth. After inoculation with S16, sweet cherry seedlings exhibited more vigorous growth. Moreover, we identified 4249 differentially expressed genes (DEGs) between S16-treated plants and the control. Many of the DEGs are involved in pathways related to plant growth, such as cellular metabolic and plant hormone pathways. Additionally, some genes involved in nitrate regulation were also enriched; and these genes may be involved in the regulation of nitrate uptake in plants. Physiological index detection demonstrated that S16 could improve the nitrate assimilation of sweet cherry via NO3− transporters. This RNA-seq dataset provides comprehensive insight into the transcriptomic landscape to reveal the molecular mechanisms whereby the DSE influences the growth of sweet cherry.

Seedling-stage screening method for tolerance of upland rice genotypes to low pH stress

One of the causes of generally low upland rice productivity in Indonesia is low fertility and soil pH. The use of genotypes with high yielding capacity and tolerant of acid soils can increase rice productivity. This study aimed to develop an early and efficient selection method, to determine rice genotypes tolerant to low pH. This research was conducted using a seed germination technique on rice paper medium with varied acidity level (pH 6.5, 5.5 and 4.5). Research data on the germination test showed that germination variables: growth uniformity, relative growth rate, vigour index, T50, and root length can be used as early indicators for determining rice genotypes tolerant to low pH. Research data showed that genotype Pae Huko is relatively more tolerant to low pH than the other three tested genotypes. Pae Huko had the highest values for relative growth rate, growth uniformity, vigour index, and T50 of 92.12%, 87%, 73.3, and 1.6 days, respectively. It had also the highest root length of 14.27 cm. The results give an indication that the method can be used as an early screening for determining tolerant rice genotypes to low pH. Further test (glasshouse experiment) is required to confirm the current results.

Effects of mowing interval on turfgrass clipping tissue characteristics and soil nitrogen dynamics

AbstractUnderstanding the role of clipping biomass in nutrient budgets of turfgrass systems is critical to improving N use efficiency (NUE). The objective of this study was to evaluate the effect of mowing frequency on clipping tissue characteristics, N mineralization (NMin, %), and NH3 volatilization (AV, %) from decomposing ‘TifTuf’ bermudagrass [Cynodon dactylon (L.) Pers. × Cynodon transvaalensis Burtt Davy] clippings applied to the soil surface. Turfgrass clippings were collected from two research facilities in Athens, GA, at 3‐, 7‐, 10‐, and 14‐d mowing intervals (MIs). A subsample of clippings from each plot was ground and analyzed using near‐infrared spectroscopy to determine tissue characteristics. Soil from each location was packed into polyvinyl chloride cylinders, treated with grass clippings on the surface or left unamended, and incubated for 90 d. Cumulative evolved NH3 was trapped, and inorganic N was extracted from each cylinder and analyzed colorimetrically after 90 d. Rates of NMin varied significantly across treatments and locations, making it difficult to generate informed recommendations for reducing N fertilization based on MI. Although dry yield (g m–2) and tissue characteristics (carbohydrates, cellulose, and lignin) were found to be significant parameters in predicting NMin, no clear relationship was established between MI and tissue characteristics in this study. More frequent mowing (3‐d MI) appeared to support more vigorous turfgrass growth through greater net clipping yield and may also decrease AV as a function of smaller clipping yield for unique mowing events. Mowing more than one time per week may be more N‐use efficient and promote healthier turfgrass systems overall.

Vigorous growth and high yielding of rice (Oryza sativa) introgression lines and transformants carrying a PRR37 allele from wild rice O. longistaminata

AbstractWild rice species are expected to possess genes that are potentially useful for rice breeding. Backcross inbred lines (BILs) derived from a cross of a japonica rice ‘Shiokari’ and a progeny line from a cross of a japonica ‘Taichung 65’ and Oryza longistaminata MwM were examined for agronomic traits. Some BILs showed vigorous growth and increased yield relative to ‘Shiokari’. One of such BILs was further analysed using QTL mapping followed by map‐based cloning to identify the causal gene. An allele of OsPRR37, which encodes a pseudo response regulator protein, in O. longistaminata was found responsible for the traits and named OlPRR37. OlPRR37 was expressed more than an OsPRR37 allele from a japonica ‘Nipponbare’ in the heterozygotes of the two alleles. The genomic clone of OlPRR37 and the coding sequences of both OlPRR37 and the ‘Nipponbare’ allele driven by the promoter of OlPRR37 similarly functioned as high‐yielding genes in transgenic rice. Thus, higher expression of PRR37 by the OlPRR37 promoter likely conferred the increased yield. Accordingly, OlPRR37 may be used to improve rice productivity.

Plant community response to thinning and repeated fire in Sierra Nevada mixed-conifer forest understories

Fire suppression in the western United States has significantly altered forest composition and structure, resulting in a higher risk of stand-replacing fire, large-scale drought mortality, and bark beetle outbreaks. Mechanical thinning and prescribed fire are common treatments designed to reduce high-severity fire risk, but few studies have tracked long-term understory plant community response to these treatments with repeated fire application that emulates historic fire regimes. We evaluate changes in understory plant diversity and composition, as well as light availability, soil moisture, and litter depth over two decades following a factorial field experiment crossing thinning and two applications of prescribed fire at the Teakettle Experimental Forest (TEF) in the southern Sierra Nevada. We compare responses in experimental fuels treatments against those in nearby old-growth, mixed-conifer forests with restored low-severity fire regimes in Yosemite and Kings Canyon National Parks. We hypothesized that 1) understory plant richness, evenness, and beta diversity would increase with each burn event; 2) repeated fire after initial thinning would produce the highest understory plant diversity; 3) the second burn would reduce shrub cover, especially in the initially thinned treatments that demonstrated vigorous Ceanothus cordulatus growth after initial treatments; 4) the second burn would increase light availability and bare ground while reducing litter depth; and 5) treatments with initial thinning followed by multiple prescribed burns would show the greatest similarities to reference forests in diversity metrics, shrub cover, and environmental conditions. Although initially local (10 m2-scale) understory plant richness and diversity increased most following thinning combined with prescribed fire, this treatment did not generate understory conditions similar to those in nearby reference forests over the long term. Vigorous shrub growth resulted in low understory evenness and beta diversity over time, which a secondary burn treatment did not alter. Burning without thinning retained a more heterogeneous understory following initial treatment. Two years after the second burn treatment, this burning without thinning resulted in high understory richness and evenness similar to reference forest understories. Our results suggest management treatments may need to focus on creating heterogeneity in burn effects to limit shrub cover and foster more diverse understory communities.

KARSKY - NEW WINE HARVEST COMPLEX-RESISTANT GRAPE VARIETY WITH COLORED PULP AND JUICE

The newest Karsky grape variety, complexly stable with colored pulp and juice, was bred in Greece in 2014 by crossing the Ommonia varieties with a mixture of pollen from the EFIAGE-3 and EFIAGE-4 varieties. The duration of the production period is 146-155 days. Vigor of shoot growth is strong (2.1-3.0 m.). The yield is high. The average weight of a bunch is 180 g. It is characterized by high winter hardiness, drought resistance and increased resistance to fungal diseases. The flower is hermaphrodite. Cylindrical-conical bunch of medium density. The berry is small, round, blue-black in color with a thick waxy bloom. The skin is firm and firm. Intensely colored pulp and juice with varietal flavor. The sugar content is very high. The variety is intended for the production of intensely colored wines of various categories, high-quality juices, suitable for the production of grape vodka.

Sinorhizobium medicae WSM419 Genes That Improve Symbiosis between Sinorhizobium meliloti Rm1021 and Medicago truncatula Jemalong A17 and in Other Symbiosis Systems.

Some soil bacteria, called rhizobia, can interact symbiotically with legumes, in which they form nodules on the plant roots, where they can reduce atmospheric dinitrogen to ammonia, a form of nitrogen that can be used by growing plants. Rhizobium-plant combinations can differ in how successful this symbiosis is: for example, Sinorhizobium meliloti Rm1021 forms a relatively ineffective symbiosis with Medicago truncatula Jemalong A17, but Sinorhizobium medicae WSM419 is able to support more vigorous plant growth. Using proteomic data from free-living and symbiotic S. medicae WSM419, we previously identified a subset of proteins that were not closely related to any S. meliloti Rm1021 proteins and speculated that adding one or more of these proteins to S. meliloti Rm1021 would increase its effectiveness on M. truncatula A17. Three genes, Smed_3503, Smed_5985, and Smed_6456, were cloned into S. meliloti Rm1021 downstream of the E. coli lacZ promoter. Strains with these genes increased nodulation and improved plant growth, individually and in combination with one another. Smed_3503, renamed iseA (increased symbiotic effectiveness), had the largest impact, increasing M. truncatula biomass by 61%. iseA homologs were present in all currently sequenced S. medicae strains but were infrequent in other Sinorhizobium isolates. Rhizobium leguminosarum bv. viciae 3841 containing iseA led to more nodules on pea and lentil. Split-root experiments with M. truncatula A17 indicated that S. meliloti Rm1021 carrying the S. medicae iseA is less sensitive to plant-induced resistance to rhizobial infection, suggesting an interaction with the plant's regulation of nodule formation. IMPORTANCE Legume symbiosis with rhizobia is highly specific. Rhizobia that can nodulate and fix nitrogen on one legume species are often unable to associate with a different species. The interaction can be more subtle. Symbiotically enhanced growth of the host plant can differ substantially when nodules are formed by different rhizobial isolates of a species, much like disease severity can differ when conspecific isolates of pathogenic bacteria infect different cultivars. Much is known about bacterial genes essential for a productive symbiosis, but less is understood about genes that marginally improve performance. We used a proteomic strategy to identify Sinorhizobium genes that contribute to plant growth differences that are seen when two different strains nodulate M. truncatula A17. These genes could also alter the symbiosis between R. leguminosarum bv. viciae 3841 and pea or lentil, suggesting that this approach identifies new genes that may more generally contribute to symbiotic productivity.

Modifications Induced by Rootstocks on Yield, Vigor and Nutritional Status on Vitis vinifera Cv Syrah under Hyper-Arid Conditions in Northern Chile

Hyper-arid regions are characterized by extreme conditions for growing and lack of water (<100 mm annual rainfall average), where desertification renders human activities almost impossible. In addition to the use of irrigation, different viticultural strategies should be taken into account to face the adverse effects of these conditions in which rootstocks may play a crucial role. The research aim was to evaluate the effects of the rootstock on yield, vigor, and petiole nutrient content in Syrah grapevines growing under hyper-arid conditions during five seasons and compare them to ungrafted ones. St. George induced lower yield than 1103 Paulsen. Salt Creek induced higher plant growth vigor and Cu petiole content than ungrafted vines in Syrah, which was correlated to P petiole content. However, Salt Creek and St. George rootstocks induced an excess of vigor in Syrah according to Ravaz Index. Rootstocks with V. berlandieri genetic background should be used in Syrah growing under hyper-arid conditions to maintain adequate levels of plant vigor and to avoid deficiencies or toxicity of macro and micronutrients.

Size-controlling interstocks affect growth vigour by downregulating photosynthesis in eight-year-old ‘Red Fuji’ apple trees

Size-controlling interstocks affect growth vigour by downregulating photosynthesis in eight-year-old ‘Red Fuji’ apple trees

Root-growth Characteristics Contributing to Nitrogen Efficiency of Reciprocally Grafted Potatoes (Solanum tuberosum L.) Under Hyroponic Conditions

To assess whether grafting could improve the nitrogen (N) efficiency of potato cultivars and to determine which physiological and morphological characteristics are predominantly contributing to N efficiency, a hydroponic experiment was conducted. Two contrasting potato cultivars (Agria: N‑efficient and Van Gogh: N‑inefficient) were grafted reciprocally onto each other. Grafted and non-grafted control plants were grown in a growth chamber for 42 days in 8 L pots filled with continuously aerated nutrient solution under two N rates (Low-N : 0.5 mM N and High-N : 3.0 mM N) by using a deep water culture (DWC) technique. The shoot and root fresh (FW) and dry (DW) weights, main stem length, number of leaves, total leaf area, photosynthetic activity of leaves, shoot and root N concentration, total N uptake, total root length and root volume of potato plants were significantly increased with increased N rate. The grafted plants produced significantly higher above ground biomass than non-grafted ones, indicating that N efficiency was significantly improved by the reciprocally grafting under low and high N rates. Non-grafted cv. Agria showed higher numbers of shoot and root FW and DW, total leaf area, intensity of photosynthesis net measurements, compared to non-grafted cv. Van Gogh under both N rates. In reciprocal grafting, the growth performance of cv. Agria slightly increased when it was grafted onto cv. Van Gogh, whereas a significant increase in crop growth performance was recorded when cv. Van Gogh was grafted onto cv. Agria. The N efficiency of non-grafted cv. Agria was closely associated with its vigorous root growth and active root system under both N conditions. Same root morphological characteristic could not be exhibited by the N‑inefficient cv. Van Gogh. Our study suggested that root morphological characteristics are contributing more than shoot characteristics to N efficiency of potatoes. These traits could be useful characters to breed/select N‑efficient potato rootstocks for sustainable agriculture in the future.

Organic and inorganic elicitors enhance in vitro regeneration of Rosa canina

BackgroundRosa canina is one of the most popular rose species which is widely used as the rootstock for the propagation of rose cultivars. The purpose of the present study is to improve the in vitro propagation efficiency of this valuable plant species using various growth stimulants in a proliferation medium. In this study, in vitro-derived axillary buds of R. canina were inoculated in Vander Salm (VS) medium supplemented with varying levels of organic or inorganic elicitors including casein hydrolysate (200, 400, and 600 mg/l), glutamic acid (2, 4, 8, and 12 mg/l), proline (500, 1000, 1500, and 2000 mg/l), and silver nitrate (25, 50, 75, and 100 mg/l), separately. Benzyl amino purine (BAP) as well as naphthalin acetic acid (NAA) were added to all media at a constant rate to promote shoot proliferation. ResultsThe results indicated that the supplementation of casein hydrolysate to the VS medium markedly stimulated shoot regeneration by 173% in comparison to control. Shoot proliferation was also positively influenced by glutamic acid at all levels, however, at a lesser extent compared to casein hydrolysate. Silver nitrate at 100 mg/l induced the longest shoots (2.52 ± 0.248 cm) and maximum leaf number (8.90 ± 0.276) among all treatments. Although it did not encourage efficient shoot regeneration, the highest quality shoots with maximum growth vigor were observed in this treatment. ConclusionIn this study, the promising role of casein hydrolysate in combination with plant growth regulators has been emphasized for the improved efficiency of R. canina regeneration protocol. Moreover, the addition of silver nitrate to the culture medium seems vital for enhancing the quality of regenerated shoots. The results of this study could be beneficial either for the further pharmaceutical or biochemical investigations of R. canina or commercial purposes for mass propagation of this specimen.