Plantlet Survival Research Articles

Nano-silicon stabilized biometric and foliar micro-morpho-anatomical traits during in vitro propagation of Cyperus rotundus L. – A model C4 ecotype

Advancements in micropropagation techniques facilitated the incorporation of nanoparticles in the propagation of many commercially important plants. Under in vitro conditions, the adventitious shoots are regenerated with undesirable structural disorders, which increase the rate of mortality of in vitro-produced propagules. In the present study, the effect of Silicon nanoparticles (SiNPs) along with the optimized plant growth regulators (PGRs) in the nutrient medium were tested for their growth-promoting effects on in vitro developing shoots of Cyperus rotundus L. Silicon NPs at 5.0 mg/L induced a higher number of shoots (23 shoots/culture vessel) with improved shoot morphology, rhizogenesis (7.0 roots with 4.0 cm root length), photopigments [(chl a - 474.0 μg/g fresh weight (FW); chl b- 509.0 μg/g FW)] and biomass (3.0 g FW), which were comparatively superior to the morphometric outcomes of the control experiments. The occurrence of morphometric and anatomical disorders in the leaves such as non-functional stomata with increased stomatal density, underdeveloped epidermal cells, undifferentiated costal and intercostal regions, and reduced mesophyll, sclerenchyma, xylem vessels, and phloem elements was observed in the controlled shoots. Silicon NPs at 5.0 mg/L in the medium reduced the in vitro-induced structural abnormalities and modulated foliar micro-morpho-structural differentiation of leaves by promoting positive structural alterations in the leaf thickness, differentiation of dermal tissues, Kranz anatomy, vascularization, stomatal complex, and mechanical tissues. These overall developmentssupported the hardening and survival of plantlets ex vitro. The present findings report the role of SiNPs as the ‘structural stabilizer’ during in vitro plantlet development of C. rotundus, as a target species and representative model for the C4 plants.

Indirect plant regeneration in Dioscorea rotundata and Dioscorea alata yam genotypes using different explants

Yam (Dioscorea sp.) is an important staple crop for millions of smallholder farmers in West Africa. In this study, we aimed to develop an efficient indirect plant regeneration system for three important yam genotypes “Kukrupa,” “Mankrong Pona” and “Matches.” The potential of leaf primordia, petioles and axillary bud explants for callus induction on Murashige and Skoog (MS) medium supplemented with different concentrations (0, 3, 5, 7 and 9 mg/l) of 2,4-dicholorophenoxy acetic acid (2,4-D) or picloram were tested. Callus induction was influenced by auxin concentration as well as explant. The highest callus induction was achieved using leaf primordia (“Kukrupa” and “Mankrong Pona”) explants on 3 mg/l picloram or axillary buds (“Matches”) on 5 mg/l picloram. Transfer of callus to 6-benzylaminoapurine (BAP) amended medium resulted in the formation of at least two shoots per callus clump. Plantlets were obtained on basic yam medium supplemented with 0.2 mg/l 1-naphthalene acetic acid (NAA), 3 mg/l kinetin and 0.5 mg/l BAP after four weeks. Post acclimatization plantlet survival was high (75 − 82.5%). The indirect plant regeneration protocol reported through this study helps in the improvement of important yam genotypes through tissue culture-oriented genome editing, in vitro mutagenesis and also for its mass propagation.

Mycorrhizae enhance minituber weight and nutrient content in potatoes transferred from in vitro to hydroponic culture under different phosphorus levels

The survival and productivity of potato plantlets transplanted from in vitro to commercial hydroponic minituber culture are crucial. Mycorrhizal fungi are an efficient tool to enhance potato nutrient uptake, survival, and productivity under these conditions. This study aimed to assess the effect of mycorrhizal fungi on improving the yield of minitubers and nutrient uptake in potatoes transferred from the in vitro environment to the greenhouse. This study was conducted in a greenhouse in Hamadan province, I.R. Iran, in 2013. The experimental design was factorial, including treatments with and without inoculation with the mycorrhizal fungus Rhizophagus irregularis and varying phosphorus (P) concentrations in Hoagland’s solution (100%, 75%, 50%, and 25% of its maximum content, i.e. 0.965, 0.482, 0.241, and 0.12 mM H2PO4 -) with three replications on potato plantlets transferred from in vitro to pots. The results indicated that the highest colonization percentage was achieved with 25% P and inoculation. The highest number of minitubers (8.9), total minituber weight per plant (53.2 grams), plant height (54.6 cm), minituber (0.38%) and leaf (0.363%) P content, minituber (33 mg/kg) and leaf (65 mg/kg) manganese (Mn) content, and minituber (38 mg/kg) and leaf (65 mg/kg) zinc (Zn) content were obtained with inoculation and 75% P of Hoagland nutrient solution, which was statistically comparable to the inoculation with 100% P treatment. In summary, inoculating potato plantlets with mycorrhiza can enhance minituber yield and nutrient uptake and potentially replace approximately 50% of the P requirement in hydroponic solutions.

The bZIP Transcription Factors in Current Jasmine Genomes: Identification, Characterization, Evolution and Expressions.

Jasmine, a recently domesticated shrub, is renowned for its use as a key ingredient in floral tea and its captivating fragrance, showcasing significant ornamental and economic value. When cultivated to subtropical zone, a significant abiotic stress adaptability occurs among different jasmine varieties, leading to huge flower production changes and plantlet survival. The bZIP transcription factors (TFs) are reported to play indispensable roles in abiotic stress tolerance. Here, we performed a genome-level comparison of bZIPs using three-type jasmine genomes. Based on their physicochemical properties, conserved motif analysis and phylogenetic analysis, about 63 bZIP genes were identified and clustered in jasmine genomes, noting a difference of one member compared to the other two types of jasmines. The HTbZIP genes were categorized into 12 subfamilies compared with A. thaliana. In cis-acting element analysis, all genes contained light-responsive elements. The abscisic acid response element (ABRE) was the most abundant in HTbZIP62 promoter, followed by HTbZIP33. Tissue-specific genes of the bZIPs may play a crucial role in regulating the development of jasmine organs and tissues, with HTbZIP36 showing the most significant expressions in roots. Combined with complicated protein interactions, HTbZIP62 and HTbZIP33 might play a crucial role in the ABA signaling pathway and stress tolerance. Combined with RT-qPCR analysis, SJbZIP37/57/62 were more sensitive to ABA response genes compared with other bZIPs in DJ amd HT genomes. Our findings provide a useful resource for further research on the regulation of key genes to improve abiotic stress tolerance in jasmine.

Effect of different cytokinin sources on in vitro/ex vitro multiplication and rooting rate in Eucalyptus spp.

Eucalyptus globulus Labill. is of great interest to the pulp industry. However, the species is highly susceptible to leaf spot caused by Teratosphaeria nubilosa and has a low rooting capacity. In order to overcome these limitations, INIA has been implementing a genetic improvement program for this species and the generation of interspecific hybrids. The strategy is based on the selection of E. globulus clones with high precocity or foliage turnover, since the adult foliage is more tolerant to T. nubilosa. In addition, controlled crosses of E. globulus and E. maidenii with E. grandis are carried out to incorporate disease resistance and ease of rooting. The multiplication of the selected materials is carried out by micropropagation, but the low rooting capacity is a trait that needs improvement. The cytokines necessary for in vitro proliferation can have a negative effect on the rooting process. Benzyladenine is the most commonly used cytokine because of its low cost and easy availability, with some negative effects on rooting, while meta-topolin is a cytokine of lesser impact. The objective of this study was to evaluate the effect of benzyladenine and meta-topolin on the multiplication rate, rooting percentage and plantlets survival of E. globulus, E. grandis × E. globulus, and E. grandis × E. maidenii. In multiplication media, benzyladenine was supplied at 0.4 µM, while two concentrations of meta-topolin (0.4 and 2 µM) were used. Preliminary results indicated a higher multiplication rate with the inclusion of meta-topolin in both concentrations. The in vitro rooting percentage of explants treated with meta-topolin was 51% and 44%, at 0.4 and 2 µM, respectively, while with benzyladenine was lesser (37%). After 28 days post-transplanting, survival was higher in meta-topolin-derived plants. Meta-topolin improved multiplication, in vitro rooting and acclimation of plants. The use of this hormone could improve micropropagation protocols, facilitating rooting and multiplication of valuable genotypes.

Response of micropropagated tissue culture banana (Musa spp.) to acclimatization using arbuscular mycorrhiza fungi

The production of banana seedlings through tissue culture provides a reliable source of numerous, disease free, quality plantlets. However, the micropropagation process is faced with a number of challenges. In this study we are focusing on the improvement of survival and growth of the resultant plantlets during the acclimatization process. The viability of arbuscular mycorrhiza fungi (AMF) symbiont in the acclimatization process was assessed. Tissue culture bananas (Kienyeji, Kiganda and Ng’ombe local cultivars) were inoculated with single species AMF Rhizophagus irregularis and Funneliformis mosseae as well as commercial AMF Rhizatech. The survival rate was assessed and plant growth evaluated at a two week interval. Destructive harvesting was conducted followed by assessment of root, shoot and total biomass. The results demonstrated that Kiganda treated with Rhisophagus irregularis and Funneliformis mossae recorded better survival rates compared to treatments with NPK fertilizer and commercial AMF (Rhizatech). Kienyeji cultivar however had a better survival rate when treated with commercial AMF (Rhizatech). Ng’ombe cultivar was very resilient having 100 % survival rate when treated with indigenous AMF, commercial AMF (Rhizatech) and NPK. There were significant differences in the shoot dry weight, root dry weight and biomass in the three banana cultivars. Kiganda and Kienyeji cultivars had the highest biomass when treated with Funneliformis mossae of 0.52 g and 0.83 g respectively. The results in this study confirm that the use of AMF in the acclimatization process improves the overall seedling output of the micropropagation process during the nursery stage of production.

Optimization of a Protocol for Launching Grapevine Infection with the Biologically Active cDNA Clones of a Virus.

Grapevine leafroll disease (GLRD) is the most globally prevalent and destructive disease complex responsible for significant reductions in grape yield and quality as well as wine production. GLRD is associated with several positive-strand RNA viruses of the family Closteroviridae, designated as grapevine leafroll-associated viruses (GLRaVs). However, the specific etiological role of any of these GLRaVs in GLRD has not been demonstrated. Even though GLRaV-3 is considered the chief GLRD agent, little is known about the molecular, cellular, and pathological properties of this virus. Such a knowledge gap is due to multiple factors, including the unavailability of biologically active virus cDNA clones and the lack of reliable experimental systems for launching grapevine infection using such clones. In this work, we tested four methods for inoculating tissue-cultured grapevine plantlets with cDNA clones of GLRaV-3: (i) vacuum agro-infiltration; (ii) agro-pricking; (iii) agro-drenching; and (iv) agro-injection. We showed that vacuum agro-infiltration was the most effective of these methods. Furthermore, we examined the impacts of different experimental conditions on the survival and infectivity rate of grapevines after infiltration. To verify the infectivity rate for different treatments, we used RT-PCR, RT-qPCR, and Western blotting. We found that humidity plays a critical role in the survival of plantlets after agro-infiltration and that the use of RNA silencing suppressor and dormancy treatment both had strong effects on the infection rates. To our knowledge, the experimental protocol reported herein is the most effective system for launching the infection of grapevine using cDNA clones of grapevine viruses featuring up to a 70% infection rate. This system has strong potential to facilitate grapevine virology research including the fulfillment of Koch's postulates for GLRD and other major virus diseases as well as identifying the molecular, cellular, and pathological properties of GLRaVs and, potentially, other important grapevine viruses.

Sterilization method of contaminated oil palm plantlets affects the survival rate during acclimatization

Contamination in the in vitro culture is a critical problem causing the failure of seed production. Contamination in the oil palm plantlet is detrimental, considering that oil palm propagation is difficult and takes a long time. This research aimed to study the effect of sterilization during acclimatization of the contaminated oil palm plantlets by fungi on viability and to determine the optimum viability achieved from the contaminated materials. The materials used were contaminated plantlets of oil palm with roots, four leaves, and a height of about 17 cm. The plantlets were removed from the tube and cleaned with running tap water, then were sterilized, with treatments P1: soaking in benomyl-mancozeb-sodium hypochlorite and mannitol and rinsing with aquadest, P2: soaking in benomyl-mancozeb, P3: soaking in mancozeb. Cleaning plantlets under running tap water was carried out as a control treatment. The results showed that at 10 weeks after acclimatization, the survival rate of plantlets in each treatment (P1, P2, and P3) was significantly higher than that of the control. Sterilization methods affect the time new leaves emerge, leaf condition after sterilization treatment, and shoot height. The lowest fungal contamination after treatments was found in P2, followed by P3. After 3 months, plantlet survival rate decreased, with the highest survival rate in treatment P3 (32.3%) followed by treatment P2 (22.5%). In conclusion, acclimatization of contaminated oil palm plantlets can be carried out using a suitable sterilization treatment. Sterilization affects the survival rate and growth of in vitro-contaminated oil palm plantlets during acclimatization.

Sterilization method of contaminated oil palm plantlets affects the survival rate during acclimatization

Contamination in the in vitro culture is a critical problem causing the failure of seed production. Contamination in the oil palm plantlet is detrimental, considering that oil palm propagation is difficult and takes a long time. This research aimed to study the effect of sterilization during acclimatization of the contaminated oil palm plantlets by fungi on viability and to determine the optimum viability achieved from the contaminated materials. The materials used were contaminated plantlets of oil palm with roots, four leaves, and a height of about 17 cm. The plantlets were removed from the tube and cleaned with running tap water, then were sterilized, with treatments P1: soaking in benomyl-mancozeb-sodium hypochlorite and mannitol and rinsing with aquadest, P2: soaking in benomyl-mancozeb, P3: soaking in mancozeb. Cleaning plantlets under running tap water was carried out as a control treatment. The results showed that at 10 weeks after acclimatization, the survival rate of plantlets in each treatment (P1, P2, and P3) was significantly higher than that of the control. Sterilization methods affect the time new leaves emerge, leaf condition after sterilization treatment, and shoot height. The lowest fungal contamination after treatments was found in P2, followed by P3. After 3 months, plantlet survival rate decreased, with the highest survival rate in treatment P3 (32.3%) followed by treatment P2 (22.5%). In conclusion, acclimatization of contaminated oil palm plantlets can be carried out using a suitable sterilization treatment. Sterilization affects the survival rate and growth of in vitro-contaminated oil palm plantlets during acclimatization.

Respons Pertumbuhan Planlets Anggrek Phalaenopsis terhadap Pemberian BA dan NAA Selama Aklimatisasi

Orchid plants are a type of plant that belongs to the Orchidaceae family which has approximately 900 genera and estimated to have 15.000- 25.000 species. Orchid plants can be cultivated vegetative and generative. Tissue culture is one of the vegetative propagation methods of orchids. Acclimatization is a critical period for tissue cultured plantlets. Acclimatization is a critical period for plantlets resulting from tissue culture. Plant growth regulators can help stimulate plantlet growth during the acclimatization period. growth regulators is one of the success factors in acclimatization. This study aims to determine the best BA and NAA concentrations and the best treatment combination for acclimatization of Phalaenopsis orchids. This research was conducted from March to July 2022 at the Research and Experimental station, University of Bangka Belitung. This study used a factorial randomized block design (RBD). The factors tested were the concentrations of BA and NAA solutions. The results showed that the acclimatization of Phalaenopsis orchids was successful, indicated by the high percentage of plantlet survival. The highest average growth was shown at concentrations of 10 ppm BA and 10 ppm NAA. The treatment combination showing the highest average growth was BA 20 + NAA 10 ppm.Keywords : Acclimatization, BA, NAA, Phalaenopsis

Clonal propagation and hardening of epiphytic orchids (Aerides multiflora and Rhyncostylis retusa) for sustainable conservation and utilization

The study involves devising an efficient method for in vitro protocorm-based plant production, as well as ex vitro establishment of Aerides multiflora and Rhynchostylis retusa. Both the orchids fall prey to the unscrupulous collection from the wild as they are widely used in the traditional medicinal system. Tissue culture technology can be effectively used for mass production of both the orchid species if the planned methodology is used for transplanting the regenerated plantlets into field conditions. MS medium supplemented with natural additives proved to be most optimal for protocorm development from seed explants (giving an average of 94 % to 97 % germination) and further multiplication while Mitra medium was best suited for complete plantlet regeneration from cultured protocorms. In A. multiflora an average of 3.33 shoots and 2.67 roots per protocorm, and in R. retusa mean number of 4.33 shoots and 3.10 roots per protocorm could be obtained on Mitra medium. Tissue culture raised plantlets of both the orchids were hardened in vitro and then shifted under polyhouse conditions. Peat moss, coconut husk, bark shavings, charcoal, and brick pieces, in varying combinations, were tried for optimal growth. Based on the best plantlet survival rate, 90 % in A. multiflora and 100 % in R. retusa, the growth medium combination of peat moss with charcoal, and bark shavings was selected to be the most optimal for orchid growth when kept at a temperature of 25–30 °C, relative humidity 60–70 %, and periodic watering only to avoid drying. The standardized methodology can be utilized for the field plantation of these two important orchids as a means of conservation and propagation strategy.

Improvements in morphometric and structural traits of Vitex trifolia L. to exogenous application of nano-silicon in vitro

The present study aimed to analyze the effect of silicon nanoparticles (SiNPs) on the in vitro proliferation of shoots, biomass production, foliar micro-structural features, and root-inducing ability in Vitex trifolia L. Bud breaking was achieved from axillary meristems on 2.5 mg L−1 of 6-benzylaminopurine (BAP) in Murashige and Skoog's (MS) medium. The shoots were proliferated (18.0 ± 0.39 shoots) on 0.75 mg L−1 BAP with 0.2 mg L−1 1-Naphthaleneacetic acid (NAA). Among the varied concentrations of Aerosil300 (hydrophilic silica) used, 6.0 mg L−1 SiNPs with optimal growth regulators into the medium had a positive impact on shoot proliferation (24.0 ± 0.30 shoots) and fresh biomass production. The light microscopic evaluation showed that the leaves developed without SiNPs possessed underdeveloped cuticle, trichomes, stomata, epidermal cells, and photosynthetic and vascular tissues. The SiNPs treatment resulted in well-differentiated tissue systems and favored an increase in width of the lamina, differentiation of palisade and spongy tissues, thickening of cell walls, increased density of trichomes, organized guard cells in stomata, and improved xylem and phloem tissues. The shoots were effectively rooted on half-strength MS medium containing 3.0 mg L−1 NAA, and the shoots derived from SiNPs treatment had the highest rooting efficiency (8.0 roots per shoot). The findings highlight that the use of SiNPs significantly promoted tissue systems and morphology of V. trifolia, which favored the survival of plantlets under in vivo conditions.

In Vitro Propagation of Origanum scabrum (Boiss. & Heldr.): An Endemic Medicinal Plant of Greece.

The aim of the study was to develop an efficient micropropagation protocol of Origanum scabrum, which will allow its commercial exploitation in the pharmaceutical and horticultural industries. First, the effect of the date of the explant collection (20 April, 20 May, 20 June, 20 July, 20 August) and the position of the explant on the plant stem (shoot apex, 1st node, 3rd node, 5th node) on the establishment of in vitro cultures was studied (1st experiment: Stage I). Next, the effect of temperature (15 °C, 25 °C) and the node position (microshoot apex, 1st node, 5th node) on the microplant production and ex vitro survival of plantlets was studied (2nd experiment: Stage II). The optimum season to collect explants from wild plants was shown to be during the vegetative growth of the plants (April to May), while the shoot apex and the 1st node were the most suitable explants. For the proliferation and production of rooted microplants, the best results were obtained from single-node explants excised from microshoots produced from 1st node-explants collected on 20th of May. Temperature did not affect microshoot number, leaf number and the percentage of rooted microplants, while microshoot length was higher at 25 °C. Moreover, microshoot length and the percentage of rooted microplants were higher in those derived from apex explants, while the survival of plantlets was not affected by treatments and ranged between 67% and 100%.

Liquid Culture System: An Efficient Approach for Sustainable Micropropagation

Micropropagation of important forestry, horticultural and medicinal plants have made revolutionary changes in terms of research and commercialization. However, there are a variety of factors which influence the scaling-up and commercialization aspects, which decide whether mass propagation will be effective and lucrative. Low rates of shoot multiplication, increased costs of media components, loss of cultures due to contamination, and difficulties with hardening and acclimation are the key obstacles to scaling up micropropagation technology. These restrictions have forced a large number of in vitro technologies developed for a range of plant species to be used only under research laboratories settings. To apply tissue culture technology to large-scale propagation, it is required to develop techniques that are relatively simple to adopt, have high multiplication rate with high levels of reproducibility, and exhibit higher survival of plantlets when transferred to ex vitro conditions. Efficient techniques include utilization of liquid culture systems and replacement of agar with other gelling agents. These techniques allow development of micropropagules that not only function better in post-vitro soil conditions and are comparatively less expensive, but will also help develop a workable micropropagation technique that can be applied to the mass production of desirable plant species. The current review describes liquid culture system as an efficient approach to produce large number of plants at low production cost.

Production and verification of lemon × acid lime hybrid populations via embryo rescue

Interspecific hybridization between canker-tolerant Konkan Seedless lemon (C. limon Burm) andcommercially grown Kagzi lime (C. aurantifolia Swingle) is significantly impeded by the occurrence of nucellarembryony. Hence, the objective of our work was to enhance hybrid seedlings’ recovery and to confirm theirhybridity through polymorphic SSR markers. Results revealed quite a satisfactory germination (< 58%) from allthe stages of embryos and media used, but younger and oldest embryos produced more than 87% germinationon all three media tested. MS medium supplemented with 500 mg l-1 malt extract plus 1.5 mg l-1 GA3 and 20μll-1NAA proved better for the survival of plantlets, obtained from the culture of either aged or younger embryos,though it was highest in plantlets, obtained from the culture of 80-90 days old embryos. The seedlings obtainedfrom culture 80-90 old embryos (DAP or days after pollination) on MS medium supplemented with 500 mg l-1malt extract plus 1.5 mg l-1 GA3 and 20μl l-1 NAA had the highest root and shoot length at 30 days after culture(DAC). SSR loci CCSM4 and CAC-33 expressed the highest polymorphism, showing their ability to distinguishthe hybrids of Konkan Seedless (lemon) × Kagzi lime (acid lime) .

A standardized protocol for genetically stable artificial seed production of Ficus religiosa L. using ISSR fingerprinting

Ficus religiosa LQuery. has several ornamental, medicinal, and economical applications. The in vivo propagation of this species has shown various limitations. Due to this reason, the present study efforts on genetically uniform artificial seed production from in vitro developed shoot tips of this species. The in vivo shoot tips were cultivated on Murashige and Skoog (MS) media containing different growth regulators. The maximum shoot response (93.67%) and the longest shoot length (3.85cm) were exhibited with 0.5mg L-1 6-furfuryl-amino purine (Kn), 0.2mg L-1 benzyladenine (BA) and 0.1mg L-1 2,4-dichlorophenoxyacetic acid (2,4-D) in combination. A treatment of 3% sodium alginate and 75mM calcium chloride having a polymerization time of 15min was exhibited to be superior for artificial seed production of these in vitro grown shoot tips. Artificial seed-derived micro shoots yielded the highest root response (94.44%) and roots per shoot (4.61) with 0.5mg L-1 indole-3-butyric acid (IBA) and 0.1mg L-1 BA in combination on ½-strength MS media. In comparison to 4°C-kept artificial seeds, 24°C-stored artificial seeds had superior germination potential across all storage times. The soil:organic manure (1:1) generated 90% of plantlet survival after 28days of primary hardening than other mixtures tested. The secondary hardening displayed 92% of plant survival after 60days. The banding patterns of ISSR analysis between the mother plant and hardened plants were discovered to be monomorphic. This methodology provides a promising and affordable approach to the large-scale plant productionof this significant species.

Metabolically active angiosperms survive passage through the digestive tract of a large-bodied waterbird.

Avian vectors, such as ducks, swans and geese, are important dispersers of plant propagules. Until recently, it was thought that small vegetative propagules were reliant on adherence to vectors and are unlikely to survive passage through the avian digestive tract. Here, we conclusively demonstrate that metabolically active angiosperms can survive passage through the digestive tract of a large-bodied waterbird. In addition, we show that extended periods of air exposure for up to 7 days does not inhibit the survival of plantlets embedded in faecal matter. Following air exposure, plantlets (n = 3000) were recovered from 75 faecal samples of mute swans, Cygnus olor, with the survival of 203 plantlets. The number of recovered and surviving plantlets did not significantly differ among durations of air exposure. For recovered plantlets, the long-term viability and clonal reproduction of two duckweed species, Lemna minor and L. gibba, were confirmed following greater than eight months of growth. These data further amplify the key role of waterbirds as vectors for aquatic plant dispersal and demonstrate the internal transport (i.e. endozoochory) of metabolically active plantlets. These data suggest dispersal of vegetative plant propagules by avian vectors is likely to be a common occurrence, underpinning connectivity, range expansion and invasions of some aquatic plants.

IN VITRO DIPLOIDIZATION OF HAPLOID PLANTLET FROM ANTHER CULTURE OF EGGPLANT (Solanum melongena L.) USING PENDIMETHALIN

The availability of anther culture methods for producing pure lines in a doubled-haploid (DH) plant form makes it possible to accelerate the development of hybrid varieties in eggplant. Previous studies have developed an efficient eggplant anther culture method. However, the formation of spontaneous DH plants through this method is relatively low, ranging from 25%–30%. Recently several studies reported that pendimethalin effectively duplicates the chromosome numbers of several plant species in vitro. This study aimed to determine the pendimethalin effect on the diploidization of eggplant haploid plantlets from anther culture. The study compared three concentrations of antimitotic pendimethalin: 100 μM, 300 μM, and 1000 μM in three incubation durations: two, four, and six days. The results showed the treatment with a pendimethalin concentration of 300 μM incubated for two days gave the highest level of plantlet diploidization at 75.0%. In vitro, chromosomal duplication treatment using pendimethalin with different concentrations and duration of incubation time affected the plantlet survival and growth of eggplant haploid plantlets. The increase in pendimethalin concentration and incubation duration inhibited the physiology and growth of plantlets and affected alteration in the ploidy level of eggplant haploid plantlets.

Large-Scale In Vitro Propagation and Ex Vitro Adaptation of the Endangered Medicinal Plant Eryngium maritimum L.

The endangered medicinal plant Eryngium maritimum L. faces significant natural and anthropogenic threats. Therefore, in vitro propagation is recommended for both conservation and commercial purposes. The aim of the study was to develop a series of protocols for seed disinfection, in vitro multiplication and rooting, and ex vitro and field adaptation. For explant disinfection, the length and temperature of three consecutive disinfectants were investigated. Macrosalt modifications of MS medium and plant growth regulator addition to media effect on axillary bud propagation rate and rooting was studied. Survival and leaf growth during ex vitro and field adaptation in response to potting media, pot cell diameter, and light spectrum were tested. Seeds treated with diluted detergent at 40 °C for 180 min, followed by 0.01% KMnO4 for 3 h and commercial bleach for 11 min, achieved a lower rate of contamination and high germination rate. Axillary bud proliferation and rooting were enhanced by reducing nitrogen content in media and adding plant growth regulators. Potting media and pot size affect survival and growth ex vitro. Timely transplantation to field conditions before overwintering increases plantlet survival. In the present work, a suitable foundation is laid to scaleup the production of E. maritimum by micropropagation.

Inoculation with Oidiodendron maius BP Improves Nitrogen Absorption from Fertilizer and Growth of Vaccinium corymbosum during the Early Nursery Stage.

Blueberry roots are inefficient in taking up water and nutrients, a fact partially related to their scarcity of root hairs, but they improve nutrient uptake by associating with ericoid mycorrhizal and endophytic fungi. However, the benefits of this association are both cultivar- and fungus-dependent. Our objective was to assess the effect of inoculation with three native fungal strains (Oidiodendron maius A, O. maius BP, and Acanthomyces lecanii BC) on plantlet growth, plantlet survival, and nitrogen (N) absorption of the southern highbush blueberry (SHB) cultivars Biloxi and Misty. The fungal strains were inoculated into the peat-based substrate for growing blueberry cultivars, and plantlets produced by micropropagation were transplanted and grown for four months. The three inoculated strains positively affected the survival percentage in at least one of the cultivars tested, whereas O. maius BP positively affected plant biomass, N derived from fertilizer absorption, N content, and plant N recovery (%) in both Biloxi and Misty. Our results show that the O. maius BP strain may prove useful as a bio-inoculant to improve blueberry production during the nursery stage.