Survival Rate Of Plantlets Research Articles

In vitro propagation of theDendrobium wardianum

In the present study, we investigatedthepropagation of Dendrobium wardianum by in vitro culture technique. The results showed that:the most suitable protocorm multiplication medium is MS mediumsupplemented with 2 mg/l BAP, 1 mg/l IBA, 40 g/l mashed banana after 8 weeks of culture, with a protocorm multiplier of 18.8;MS medium supplemented with 1.5 mg/l KIN, 30 g/l mashed carrot gave the best on in vitro shoot regeneration after 8 weeks of culture, with 32.58 shoots/explant, shoot height of 2.5 cm and 3.5 leaves/shoot. Shoots were rooted well on MS medium supplemented with 1 mg/l αNAA, 30 g/l mashed carrot with the highest mean number of roots (10.8 roots per shoot) and the longest mean root length (3.01 cm) after 6 weeks of culture.In the nursery, a mixture of forest moss, volcanic pumice, and coconut fibre (30:30:40) ratio was regarded as the best substrate due to the high survival rate of plantlets (96.6%) and healthy plantlets (9.10 cm in height with 8.7 leaves and 3.8 new roots/plantlet) at 6 weeks after planting.

Effects of different healing agents on acclimatization success of in vitro rooted Garnem (Prunus dulcis × Prunus persica) rootstock

Continuing productivity of the acclimatization stage of plantlets means successful micropropagation. Due to the free water and high humidity in the culture container environment, poorly developed cuticle results in rapid water loss and drying of plantlets with watery stems and leaves, incomplete stomata, and large intercellular space. When plantlets are exposed to an environmental condition different from the culture medium, problems, such as rapid water loss and drying, may be encountered, and the survival rate of plantlets in vitro may be reduced. The aim of this study was to reduce the stress factors that occur during the acclimatization phase. For this reason, various healing agents have been used. Some of these compounds are ascorbic acid (AsA), salicylic acid (SA), and sodium nitroprusside (SNP). In the study, the response of AsA (100.0 and 200.0 mg L−1), SA (100.0 and 200.0 mg L−1), and SNP (100.0 and 200.0 µM) applications on growth parameters (survival rate (%), node count (pieces per plant), count of leaves (pieces per plant), shoot length (mm), and shoot diameter (mm)) and physiological variable (Soil Plant Analysis Development (SPAD)) were examined. The AsA100 (100.0 mg L−1 ascorbic acid), AsA200 (200.0 mg L−1 ascorbic acid), and SNP100 (100.0 µM sodium nitroprusside) applications resulted in an improvement in node count, leaf count per plant, shoot length, and shoot diameter parameters. The highest shoot length (60.50 ± 7.81 mm) and node count (16.83 ± 1.15 pieces per plantlet) were achieved with the AsA100 application. The maximum stem diameter (2.31 ± 0.37 mm) was determined with the SNP100 application. There were no statistically significant differences found in the survival rate, leaf count, and SPAD parameter. The current study determined that AsA, SA, and SNP applications were effective in regulating several growth parameters in Garnem plantlets and in reducing acclimation stress thereby facilitating adaptation to external conditions.

Establishment of an In Vitro Micropropagation Protocol for Hibiscus moscheutos L. ‘Berry Awesome’

Hibiscus moscheutos L. ‘Berry Awesome’ is a complex hybrid of the new Proven Winners Summerific series of varieties with highly ornamental characteristics. Micropropagation of highly ornamental varieties is important for mass production of planting material for commercial purposes. The traditional methods for propagating Hibiscus varieties, such as cuttings or seed propagation, however, do not guarantee high rates of production of high-quality seedlings. To solve this problem, an attempt was made to develop protocols for micropropagation of Hibiscus moscheutos L. ‘Berry Awesome’ in vitro on agar and liquid medium using a bioreactor system, followed by ex vitro adaptation of the regenerants. The optimal method for sterilization of nodal explants as well as the optimal composition of the initiation medium for shoot proliferation and rooting were determined. For micropropagation on a liquid medium, a rocker-type bioreactor was used, and its advantages over micropropagation on an agar medium were demonstrated. The results showed that the best sterilization method for nodal segment explants was as follows: pretreatment by rinsing with running tap water, sterile water, and distilled water for 70 min and soaking for 5 min in a mixture of solutions of ethyl alcohol (96%), hydrogen peroxide (38%), and water in a ratio of 1:1:2. In this case, live and sterile explants accounted for 62.6%. The optimal initiation medium for axillary buds in nodal segments was the Murashige and Skoog (MS) medium supplemented with 0.1 mg L−1 N-(2-chloro-4-pyridinyl)-N’-phenylurea (CPPU), which resulted in 73.3% of axillary buds being induced. The optimal solid proliferation medium was MS medium supplemented with 0.1 mg L−1 CPPU with a proliferation coefficient of 5.8. In a liquid medium, the optimal concentration of CPPU was 0.05 mg L−1 with a proliferation coefficient of 9.2. The best medium for rooting/shoots with agar and in bioreactors was MS medium with the addition of 0.1 mg L−1 indole-3-butyric acid (IBA). The highest rooting rate was 99.0% in both types of media, and the survival rate of plantlets was 88.7% in solid media and 98.7% in the bioreactor.

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.

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.

Pinus massoniana somatic embryo maturation, mycorrhization of regenerated plantlets and its resistance to Bursaphelenchus xylophilus.

Pine wilt disease, caused by the pine wood nematode (PWN, Bursaphelenchus xylophilus), is a major quarantine forest disease that poses a threat to various pine species, including Pinus massoniana (masson pine), worldwide. Breeding of PWN-resistant pine trees is an important approach to prevent the disease. To expedite the production of PWN-resistant P. massoniana accessions, we investigated the effects of maturation medium treatments on somatic embryo development, germination, survival, and rooting. Furthermore, we evaluated the mycorrhization and nematode resistance of regenerated plantlets. Abscisic acid was identified as the main factor affecting maturation, germination, and rooting of somatic embryos in P. massoniana, resulting in a maximum of 34.9 ± 9.4 somatic embryos per ml, 87.3 ± 9.1% germination rate, and 55.2 ± 29.3% rooting rate. Polyethylene glycol was identified as the main factor affecting the survival rate of somatic embryo plantlets, with a survival rate of up to 59.6 ± 6.8%, followed by abscisic acid. Ectomycorrhizal fungi inoculation with Pisolithus orientalis enhanced the shoot height of plantlets regenerated from embryogenic cell line (ECL) 20-1-7. Ectomycorrhizal fungi inoculation also improved the survival rate of plantlets during the acclimatization stage, with 85% of mycorrhized plantlets surviving four months after acclimatization in the greenhouse, compared with 37% non-mycorrhized plantlets. Following PWN inoculation, the wilting rate and the number of nematodes recovered from ECL 20-1-7 were lower than those recovered from ECL 20-1-4 and 20-1-16. The wilting ratios of mycorrhizal plantlets from all cell lines were significantly lower than those of non-mycorrhizal regenerated plantlets. This plantlet regeneration system and mycorrhization method could be used in the large-scale production of nematode-resistance plantlets and to study the interaction between nematode, pines, and mycorrhizal fungi.

Enhanced shoot and plantlet quality of Gerbera (Gerbera jamesonii Revolution Yellow) cultivar on medium containing silver and cobalt nanoparticles

• AgNPs enhanced shoot multiplication and CoNPs enhanced in vitro rooting and subsequent growth. • Abnormal phenomena (vitrification, yellowing of the leaf and browning of the explant) reduced in the rooting stage. • Ethylene, cellulase and pectinase activities reduced and antioxidant activity increased in the rooting stage. The effects of silver nanoparticles (AgNPs) and cobalt nanoparticles (CoNPs) in Murashige and Skoog (MS) medium were investigated with regard to shoot multiplication, in vitro rooting, acclimatization, growth and flowering of Gerbera ( Gerbera jamesonii Revolution Yellow) cultivar. The results showed that AgNPs had effects on the shoot multiplication stage, while CoNPs had effects on the in vitro rooting, acclimatization, growth and flowering stages. Single shoots grown on MS medium supplemented with 2 mg L −1 AgNPs recorded optimal shoot multiplication efficiency, with shoots taller than 2 cm in height as well as reduced vitrification and yellowing of the leaf after 4 weeks of culture. In addition, the 2.5 cm shoots cultured on MS medium with 0.0465 mg L −1 CoNPs being used instead of CoCl 2 .6H 2 O gave rooting two days earlier and improved in vitro rooting. Moreover, reduction in vitrification, yellowing of the leaf and browning of the explant were observed in the rooting stage. There were reductions in ethylene accumulation and cellulase and pectinase enzyme activities, while the antioxidant activity increased in the rooting stage after 4 weeks, and this all enhanced the survival rate of plantlets in the acclimatization at the nursery stage.

In vitro Propagation of Curcuma caesia Roxb. via Bud Culture Technique and ISSR Profiling of the Plantlets for Genetic Homogeneity

An in vitro propagation protocol has been developed for Curcuma caesia Roxb., an endangered medicinal plant by Foundation for Revitalisation of Local Health Traditions and Central Forest Department of India. The plant bears poorly germinated seeds and produces two-storage organs: rhizomes and multiple root tubers. Only rhizomes have medicinal-economic values. They serve as propagules too, which results in a shortage of planting material. Therefore, a complete one-year production cycle of C. caesia has been standardized through in vitro propagation including explants establishment (one month), subculture cycles (seven months), rooting (one month) followed by primary hardening (one month) and secondary hardening (two months). Dormant shoot buds on rhizome served as explants for culture initiation on Murashige and Skoog (MS) medium supplemented with different concentrations of 6-benzyladenine (BA) and kinetin (KIN) in combination with citric acid (CA), adenine sulfate (AdS) and indole- 3-acetic acid (IAA). Maximum bud break (70%) was obtained on MS with 8 mg L-1 BA, 8 mg L-1 KIN, 100 mg L-1 CA, 200 mg L-1 AdS and 2 mg L-1 IAA (standard medium). Shoot production potential continued on this medium during the subsequent seven-month-long subculture cycle. The in vitro raised shoots rooted best on ½-strength MS containing 1 mg L-1 indole-3-butyric acid. Plantlet survival rate was >95% after acclimatization. The genetic homogeneity of plantlets with the mother plant was analyzed using Inter Simple Sequence Repeats which generated a monomorphic banding pattern to confirm the uniformity of in vitro raised plantlets of C. caesia.

Optimization of Bacillus subtilis-based fermentation of anaerobic digestate and biohazard-free application in endophyte-assisted hardening of micropropagated plantlets for increasing survivability

Anaerobic digestion of agricultural waste helps to decarbonize the energy sector while also increasing the use of stabilized residues in agriculture. Although digestate (Dg) contains amino acids, vitamins, humic acids, and micronutrients, using it directly poses an unknown risk to crops due to the presence of pathogens, heavy metals, and excessive ammonia, necessitating processing for agricultural application as fertilizer. The study aimed to minimize the undesired effects of Dg by optimizing fermentation with Bacillus subtilis CW-S and using it as a potential inoculant for endophytic-assisted hardening of micropropagated potato plantlets. The single factor test results revealed that Dg concentrations of 70%, 80%, and 90% had a greater positive impact on cell concentration than concentrations of 50%, 60%, and 100%. According to the Box-Behnken design, diluted (80%) Dg produced a higher cell concentration (4.36 × 108 CFU/mL) than undiluted (100%) (1.18 × 108 CFU/mL). In hardening experiments, Bacillus subtilis CW-S fermented digestate (FDg) had a significantly higher plantlet survival rate of 90.25% and a root length of 5.22 (cm) with greater Serendipita indica infection, whereas Dg (unprocessed) had a lower survival rate of 67.88% and a root length of 3.13 (cm) with less Serendipita indica infection. According to the findings, FDg could be employed as a non-threat bioinoculant for widespread agricultural application.

Indole-3-butyric acid immediately induced adventitious root of Dendrodium milla nayla x Dendrobium striaenopsis planted on coco-hust and wood charcoal

Orchids are one of the most favorite cut flowers, flowering potted plants, and have developed into a highly profitable industry. The development of acclimatization method is a necessity for the high survival rate of plantlets. The aim of this study was to investigate the effect of low indole-3-butyric acid (IBA) concentration on faster root formation of Dendrobium hybrid planted on coco- husk and charcoal in a short time. Plantlets derived from the seed culture of Dendrodium milla nayla x Dendrobium striaenopsis were harvested and pre-acclimated, planted on charcoal or coco-husk, and regularly sprayed with 0.25, 0.50, 0.75, and 1.0 mg/L IBA twice a week for one month. The results showed that IBA at 0.50 mg/L provided the most appropriate concentration for immediate root induction and growth of Dendrobium hybrid planted on coco-husk. Root number (1.75) and root length (0.28 cm) showed the highest and the most important indicator of adventitious root induction

In vitro regeneration and conservation of Wrightia tinctoria Roxb., a medicinally important woody plant

Wrightia tinctoria Roxb. (WTR) is a medicinal plant with soft wood that belongs to Apocynaceae family. The therapeutic constituents of this plant are used in treating many human ailments like psoriasis, diabetics and cancer. In view of low percent of natural regeneration, over exploitation due to its medicinal (treatment of human ailments) and commercial importance (toy making and pala indigo dye) and the hurdles faced by the Etikoppaka toy making industry (Vizag, A.P. India), there is dier need for conservation and production of propagules of this valuable soft woody and medicinally important tree. This study is undertaken to optimize and develop large scale regeneration and hardening protocol in Vadlamudi, Guntur Dt., A.P. using nodal explants of fifteen days old (in vitro) seedling. The nodal explants are inoculated on MS media amended with BAP (1.5 mg/L) + NAA (0.1 mg/L), induced 14 shoots per explant in 30 days with a length of 5.2 cm and 85-90% shoot initiation. The shoots when inoculated on Murashige Skoog media reinforce with IBA (3.5mg/L), showed eight roots per one shoot explant with maximum length of 6.9 cm. 99 % shoots initiated roots within 21 days of shoot inoculation. After 28 days of rooting, the plantlets are acclimatized to natural conditions through different stages and the % of survival rates of plantlets in the natural conditions was found to be 55 %.

Effect of Growing Media and Nutrition on Establishment of Vanda coerulea Plantlets during Hardening

Vanda Coerulea is an endangered orchid species and also possesses high market value. Apart from in vitro multiplication techniques, there is a need for proper hardening management for in vitro derived plantlets. So, the present study was carried out to identify the best potting mixture along with best nutritional composition for establishment of plantlets. Well grown six months old in vitro grown plantlets with well-developed roots were selected for the study. Plantlets were removed from the culture medium and washed gently under running tap water, and the media traces from the roots were removed. Plantlets were then treated with Bavistin (0.1%) solution for 2 minutes and transferred to the potting medium. Five different compositions of sterilized potting medium viz. leaf mould, coco-chips, brick chips, sphagnum moss, and cocopeat were taken. Each composition of medium was formulated in 1:1:1 ratio comprising three media in one formulation. Spraying of four different compositions of inorganic nutrients NPK (0:0:0; 10:10:10; 20:20:20 and 30:30:30) were done in weekly interval @ 0.1%. It was observed that the highest average survival rate of plantlets (58.33 %,), highest plant height (6.85cm) and maximum number of leaves (6.33) were found in media comprising of leaf mould + sphagnum moss + brick chips. Similarly, NPK 20:20:20 shows better in terms of survival percentage of plantlets (41.66 %,), highest plant height (6.76cm) and maximum number of leaves (6.33). The interaction effect of leaf mould + sphagnum moss + brick chips with weekly spraying of NPK 20:20:20 shows better result in terms of survival percentage of plantlets (91.66 %,), plant height (8.40 cm) and number of leaves (7.33). These combinations of media and nutrition can be used for establishment and development of plantlets at hardening.

Micropropagation and Arbuscular Mycorrhizae Assisted Growth in Phlomis cashmeriana Royle ex Benth., an endemic medicinal herb of Kashmir Himalaya

ABSTRACT Phlomis cashmeriana (Lamiaceae) is an ornamental cum medicinal perennial herb endemic to Kashmir Himalaya. Two arbuscular mycorrhizal (AM) fungal inocula on post-transplanting performance of ‘in vitro’-raised P. cashmeriana plantlets were tested. The two AM fungal inocula consisted of two mono-specific cultures of Funneliformis geosporus and Acaulospora mellea applied in combination and one crude consortium of AM fungal spores isolated from rhizosphere soil of P. cashmeriana growing in natural habitat. Complete plantlets of P. cashmeriana were raised by direct and indirect organogenesis from leaf and node explants on Murashige and Skoog medium supplemented with various cytokinins and auxins. In vitro-raised plantlets responded to both the mycorrhizal treatments in a significantly different way. The inoculated plantlets fared significantly better than the un-inoculated ones in terms of the plant height, number of shoots etc. Among the two inocula tested, plantlets inoculated with the mixed consortium of AM fungi consistently performed better in terms of survival rate of plantlets (100%) and other parameters viz., plant height, number of shoots and roots per plant, number of leaves per plant, leaf area and biomass production. The study suggests the use of mixed consortium of AM fungi over mono-specific cultures for the sustainable cultivation and conservation of in vitro-raised P. cashmeriana – a medicinally important endemic plant species of Kashmir Himalaya. Therefore, this is easy to use AMF and also the present research can be extended to other such medicinally important plant species which require conservation and sustainable development.

Development of an Improved Micropropagation Protocol for Red-Fleshed Pitaya ‘Da Hong’ with and without Activated Charcoal and Plant Growth Regulator Combinations

Micropropagation protocols for red-fleshed Hylocereus species (Cactaceae) have been developed; however, these methods prolong the sprout duration from areoles and produce irregular micro-propagules in ‘Da Hong’ pitaya. Thus, the present study aimed to establish an improved micropropagation protocol for this cultivar. Shoot regeneration and root induction of self-pollinating seedling segments were evaluated in response to combinations of activated charcoal (AC; 200 mg/L), α-naphthaleneacetic acid (NAA; 0.05, 0.10, and 0.20 mg/L), and 6-benzylaminopurine (BAP; 1.00, 2.00, and 4.00 mg/L). The correlations among plantlet growth characteristics and plantlet survival rate after transplantation under field conditions were calculated. Increasing the NAA concentration increased the number of roots but reduced root length. The addition of AC enhanced shoot length and prevented the regeneration of dried-out, clustered, and abnormal shoots. Plantlets treated with 200 mg/L AC and 0.10 mg/L NAA produced the highest number of shoots, i.e., 4.1 shoots, which however, were shorter and lighter than those cultured with AC alone. Plantlets grown on medium supplemented with BAP showed no advantage in shoot number, shoot weight, plantlet surface area, or plantlet volume. The weight and shoot surface area of plantlets were strongly correlated. All plantlets grew well at 4 weeks post-transplantation. Overall, these results support this improved micropropagation method to regenerate robust ex vitro plantlets.

In vitro Propagation of Banana (Musa paradisiaca L.) Plant Using Shoot Tip Explant

Banana is a fruit crop which has high demand in Ethiopia, but its production is constrained by lack of disease free planting material with conventional propagation methods. For shoot initiation, shoot tip explants were cultured on MS medium supplemented with 0.5, 1.0, 1.5 and 2.0 mg/L BAP. Similarly, MS medium supplemented with BAP at 1.0, 1.5, 2.0 mg/L in combination with IBA at 0.25 and 0.50 mg/L were used for shoot multiplication. Half- strength MS medium augmented with IBA at 1.0, 2.0, 3.0 and 4.0 mg/l were used for root induction. MS medium without PGRs were used as controls. Finally, hardening of the in vitro derived plantlets was carried out in green house both in the primary and secondary acclimatization stages. Results showed that the highest shoot initiation percent (93.40%), highest mean number of shoots per explant (4.67) and lesser day for shoot induction (11.00) were observed in explant cultured on MS + 1.0 mg/L BAP. With shoot multiplication, highest shooting percent (92.60%), maximum number of shoots (7.67) and highest shoot length (5.27 cm) were recorded on MS + 1.5 mg/L BAP + 0.5 mg/L IBA. The highest rooting percent (93.40%), maximum root number per shoot (7.67) and highest root length (11.00 cm) were found on a half strength MS medium + 2.0 mg/L IBA. The survival rate of plantlets were 96.00% in coco peat substrate in primary acclimatization and 97.92% in forest soil, sand and manure substrates mixed at 3:2:1 ratio in secondary acclimatization. Overall, the result showed that the PGRs type, concentrations and combinations used are effective for mass propagation of banana variety studied in this experiment.

Study on in vitro propagation of Sophora tonkinensis Gagnep through stem node culture

In the present study, authors propagated Sophora tonkinensisGagnep plants using stem nodal culture. The results indicated that on MS medium supplemented with 30 g/l sucrose, 5.5 g/l agar, 200 ml/l coconut water, 1 g/l activated charcoal, 0.75 mg/l TDZ shoots proliferated from stem segments have the best count and height of shoots. The most appropriate medium for multiplication of shoots was the MS medium supplemented with 30 g/l sucrose, 5.5 g/l agar, 200 ml/l coconut water, 1 g/l activated charcoal, 0.75 mg/l TDZ, 0.5 mg/l IBA, 2.0 g/l peptone, 30 g/l carrot puree, pH 5.5 with the results of 20.60 shoots/explant, shoot height of 3.75 cm and 4.6 leaves/shoot after 8 weeks of culture. Root formation of shoots carried out on the MS medium supplemented with 30 g/l sucrose, 5.5 g/l agar, 200 ml/l coconut water, 1 g/l activated charcoal, 1.0 mg/l αNAA gave the best result. In the nursery, a mixture of humus + coconut fiber powder (70:30 ratio) was regarded as the best substrate due to the high survival rate of plantlets (92%) and healthy plantlets (10.30 cm high with 7.2 leaves and 4.3 new roots/a plantlet) at 10 weeks after planting

The effect of silver nanoparticles on the limitation of ethylene gas and hydrolytic enzymatic activity in micropropagation of rose (Rosa hybrida L. 'Baby love')

Micropropagation of rose (Rosa hybrida L. ‘Baby Love’) often encounter some abnormal phenomena such as yellow and abscission leaf, hyperhydricity, etc. These phenomena effect on the quality of shoots cultured in vitro as well as the survival rate of plantlets after transferred to greenhouse. This is due to the accumulation of ethylene in culture vessel, which leads to an increase in enzyme activity of cellulase and pectinase resulted in disrupting the cell wall binding and inducing organ abscission. In this study, the effect of silver nanoparticles (AgNPs) to overcome these abnormal phenomena as well as its effect on the growth and development of shoots and plantlets in rose cultured in vitro were evaluated. The results showed that after 6 weeks of shoot culture, the medium supplemented with 2 ppm AgNPs was the most suitable for in vitro shoot multiplication with the highest number of shoots/explant (6.67 shoots), shoot height (3.06 cm), fresh weight (451.00 mg), dry weight (58.33 mg), SPAD (32.28) and dry mass ratio(12.33%). Adding 3 ppm AgNPs into in vitro rooting medium may improve the growth and develop involve in plant height (3.06 cm), number of leaves (6.33), leaf length (1.50 cm), leaf width (1.50 cm), fresh weight (137.67 mg), dry weight (13.00 mg), number of roots (4.33), SPAD (39.37), dry mass ratio (9.40%) of rose plantlet after 4 weeks of culture. After treatment with AgNPs, the abnormal phenomena including ethylene gas accumulation (0.30 ppm), cellulase enzyme activity (0.14 UI/mL) and pectinase enzyme activity (0.40 UI/mL) was reduced compare with the other treatments and the control. In addition, the high survival rate (93.33%) of plantlets was also observed after 4 weeks transferred to greenhouse. On the other hand, the treatment with 5 ppm AgNPs also induced early rose in vitro flowering; however, when using AgNPs at high concentrations (7 ppm) inhibited growth, development, toxicity and even death of explants.

Efficiency of shoot regeneration and micropropagation of purple passion fruit (Passiflora edulis Sims.) via internodal longitudinal thin cell layer culture

The thin cell layer culture technique (TCL) has been used for the effective tissue culture of several dozen plants with commercial importance such as field crops (rice, cereals), horticultural commodities (fruits, vegetables, ornamental plants), medicinal plants and herbs (Panax vietnamensis Ha et Grushv.), and even forestry trees (Pinus sp.), and woody fruit plants (Citrus spp., apple). In the present, TCL was used to evaluate the efficiency of shoot regeneration and propagation for purple passion fruit (Passiflora edulis Sims.). The internodes were cut longitudinally (lTCL) and was used as an initial material. The results showed that the shoot regeneration rate and number of shoots from internode-lTCL depended on position of internodes (1, 2, 3, 4 and 5) and the plant growth regulator (BA and NAA). After 8 weeks of culture, internode-lTCL derived from 3rd internode of P. edulis cultured on MS medium supplemented with 1.5 mg/L BA in combination with 1.0 mg/LNAA gave the highest shoot regeneration rate (83.33%), and number of shoots (3.00 shoots/explant). These shoots were cultured on modified MS (MSM) medium supplemented with 1.0 mg/L BA showed higher efficiency of shoot multiplication (3.56 shoots/explant and 6.67 cm height) than the other BA treatments. In addition, the highest rooting rate was 76.67% when cultured on MSM medium containing 2.0 mg/L IBA. The survival rate of plantlets was 83.33% when transferred into greenhouse condition after 10 weeks. The results of this study were the initial success in establishing an effective in vitro regeneration and propagation of Passiflora edulis Sims. through internode-lTCL.

Influence of Polyethylene Glycol on Leaf Anatomy, Stomatal Behavior, Water Loss, and Some Physiological Traits of Date Palm Plantlets Grown In Vitro and Ex Vitro.

Few reports explain the mechanism of PEG action on stomatal behavior and anatomical structure and analyze the photosynthetic pigments of in vitro date palm plantlets for better tolerance to ex vitro exposure. The main challenge for in vitro micropropagation of date palm techniques remains restricted to high survival rates and vigorous growth after ex vitro transplantation. In vitro hardening is induced by Polyethylene glycol PEG (0.0, 10, 20, 30 g L−1) for 4 weeks. Leaf anatomy, stomatal behavior, water loss %, photosynthetic pigments, and reducing sugars were examined in date palm plantlets (Phoenix dactylifera L.) cv. (Sewi) after 4 weeks from in vitro PEG treatment and after 4 weeks from ex vitro transplanting to the greenhouse. Leaf anatomy and the surface ultrastructure of in vitro untreated leaves showed a thin cuticle layer, wide opened malfunctioning stomata, and abnormal leaf anatomy. Furthermore, addition of PEG resulted in increasing cuticle thickness, epicuticular wax depositions, and plastids density, improving the stomatal ability to close and decreasing the stomatal aperture length while reducing the substomatal chambers and intercellular spaces in the mesophyll. As a result, a significant reduction in water loss % was observed in both in vitro and ex vitro PEG treated leaves as compared to untreated ones, which exhibited rapid wilting when exposed to low humidity for 4 h. PEG application significantly increased Chlorophylls a, b and carotenoids concentrations, especially 10, 20 g L−1 treatments, which were sequentially reflected in increasing the reducing sugar concentration. However, leaves of plantlets treated with PEG at 30 g L−1 became yellow and had necrosis ends with death. In vitro hardening by 20 g L−1 PEG increased the survival rate of plantlets to 90% after ex vitro transfer compared to 63% recorded for the untreated plantlets. Therefore, this application provides normal date palm plantlets developed faster and enhances survival after ex vitro transfer.