In vitro hardening of red raspberry through CO2 enrichment and relative humidity reduction on sugar-free medium

1993 ◽  
Vol 73 (4) ◽  
pp. 1105-1113 ◽  
Author(s):  
Ribo Deng ◽  
Danielle J. Donnelly

Micropropagated shoots of red raspberry (Rubus idaeus L. ’Comet’) were rooted on modified Murashige-Skoog medium lacking sucrose, in specially constructed plexiglass chambers, under ambient (340 ± 20 ppm) or enriched (1500 ± 50 ppm) CO2 and ambient (ca. 100%) or reduced (90 ± 5%) relative humidity. Cultured plantlets were evaluated for their survival, rooting and relative vigor, leaf and root number, stem and root length, total leaf area, total fresh and dry weight, gas exchange rate, and stomatal features, prior to transplantation to soil and at intervals for 6 wk ex vitro. In vitro CO2 enrichment promoted plantlet growth, rooting and both the survival and early growth of transplants. CO2 enrichment increased stomatal aperture of plantlet leaves but did not apparently increase water stress at transplantation. Reduced in vitro RH did not affect plantlet growth but decreased stomatal apertures and stomatal index on leaves of cultured plantlets and promoted both the survival and early growth of transplants. In vitro CO2 and RH levels did not affect the photosynthetic rate of either plantlets or transplants. Only the stomata on leaves of plantlets from the ambient CO2 and reduced RH treatment were functional. Normal stomatal function was not observed in persistent leaves of transplants from the other treatments, even 2 wk after transplantation. In vitro CO2 enrichment acted synergistically with RH reduction in improving growth of plantlets both in vitro and ex vitro. Hardened red raspberry plantlets obtained through CO2 enrichment and RH reduction survived direct transfer to ambient greenhouse conditions without the necessity for specialized ex vitro acclimatization treatment. Key words: Acclimatization, growth analysis, photosynthesis, Rubus idaeus L., stomata, tissue culture

HortScience ◽  
1993 ◽  
Vol 28 (10) ◽  
pp. 1048-1051 ◽  
Author(s):  
Ribo Deng ◽  
Danielle J. Donnelly

Micropropagated `Festival' red raspberry (Rubus idaeus L.) shoots were rooted in specially constructed plexiglass chambers in ambient (340 ± 20 ppm) or enriched (1500 ±50 ppm) CO2 conditions on a medium containing 0, 10, 20, or 30 g sucrose/liter. Plantlet growth and leaf 14CO2 fixation rates were evaluated before and 4 weeks after ex vitro transplantation. In vitro CO2 enrichment promoted in vitro hardening; it increased root count and length, plantlet fresh weight, and photosynthetic capacity but did not affect other variables such as plantlet height, dry weight, or leaf count and area. No residual effects of in vitro CO2 enrichment were observed on 4-week-old transplants. Sucrose in the medium promoted plantlet growth but depressed photosynthesis and reduced in vitro hardening. Photoautotrophic plantlets were obtained on sucrose-free rooting medium under ambient and enriched CO2 conditions and they performed better ex vitro than mixotrophi plantlets grown with sucrose. Root hairs were more abundant and longer on root tips of photoautotrophic plantlets than on mixotrophic plantlets. The maximum CO2 uptake rate of plantlet leaves was 52% that of greenhouse control plant leaves. This did not change in the persistent leaves up to 4 weeks after ex vitro transplantation. The photosynthetic ability of persistent and new leaves of 4-week-old ex vitro transplants related neither to in vitro CO2 nor medium sucrose concentration. Consecutive new leaves of transplants took up more CO2 than persistent leaves. The third new leaf of transplants had photosynthetic rates up to 90% that of greenhouse control plant leaves. These results indicate that in vitro CO2 enrichment was beneficial to in vitro hardening and that sucrose may be reduced substantially or eliminated from red raspberry rooting medium when CO2 enrichment is used.


HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 587d-587
Author(s):  
Jeffrey Adelberg ◽  
Kazuhiro Fujiwara ◽  
Chalermpol Kirdmanee ◽  
Toyoki Kozai

Two triploid clones of melon from the same tetraploid parent were grown in vitro with and without sugar, rooted without sugar in media both in a laboratory controlled environment chamber (in vitro) and a greenhouse acclimatization unit (ex vitro), and compared for subsequent nursery growth in the greenhouse unit. The clone `(L-14 c B) × L-14' produced more shoots in both photomixotrophic (with sucrose) or photoautotrophic (sugar-free) conditions. Both genotypes were equally likely to root in sugar-free media, and `(L-14 × B) × L-14' rooted as well from either photoautotrophic and photomixotrophic shoots but `(L-14 × B) × Mainstream' rooted less frequently from photoautotrophic shoots. Seventy-six percent (76%) of the shoots were able to root photoautotrophically in vitro, whereas 47% of the ex vitro shoots were rooted. About 85% of plantlets from all treatments survived after transfer to the nursery. After growth in the greenhouse nursery, the sizes of plants (fresh and dry weight, leaf area) were the same for either clone, from either photoautotrophic or photomixotrophic shoots. Also, after growth in the nursery, plantlets that had been rooted in vitro were larger than those rooted ex vitro. Photoautotrophic rooting demonstrates a concept for integrating micropropagation and plug-type vegetable transplant production.


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 468b-468
Author(s):  
Stephen F. Klauer ◽  
J. Scott Cameron ◽  
Chuhe Chen

After promising results were obtained with an open-style split trellis (two top wires) in its initial year, two new trials were established in 1997 in northwest (Lynden) and southwest (Woodland) Washington. For the split trellis, actual yields were 33% (machine-picked 1/2 season) and 17% (hand-picked) greater, respectively, for the two locations compared to the conventional trellis (one top wire). In Woodland, canes from the split trellis had 33% more berries, 55% more laterals, 69% more leaves, and 25% greater leaf area compared with the conventional trellis. Greatest enhancement of these components was in the upper third of the canopy. Laterals were also shorter in this area of the split canopy, but there was no difference in average total length of lateral/cane between trellis types. Total dry weight/cane was 22% greater in the split trellis, but component partitioning/cane was consistent between the two systems with fruit + laterals (43%) having the greatest above-ground biomass, followed by the stem (30% to 33%) and the leaves (21% to 22%). Measurement of canopy width, circumference, and light interception showed that the split-trellis canopy filled in more quickly, and was larger from preanthesis through postharvest. Light interception near the top of the split canopy was 30% greater 1 month before harvest with 98% interception near the top and middle of that canopy. There was no difference between the trellis types in leaf CO2 assimilation, spectra, or fluorescence through the fruiting season, or in total nitrogen of postharvest primocane leaves.


2016 ◽  
Vol 8 (9) ◽  
pp. 168
Author(s):  
Fatemeh Feizi ◽  
Mousa Mousavi

<p>The main propagation method of <em>Cassia fistula</em> is sowing seeds. The seed germination is usually low because of its impermeable hard coat. Therefore, this experiment evaluated the effects of TiO<sub>2</sub> nanoparticles and scarification methods on seed germination and seedling growth <em>in vitro</em> condition. The tree seeds were treated with, hot water, H<sub>2</sub>SO<sub>4</sub> (36N), and mechanical scarification and culture on ¼ MS salt mixture. The medium was supplemented with different concentrations of TiO<sub>2</sub> nanoparticles. The results showed that the highest percentage and rate of germination was recorded in seeds treated with mechanical scarification. The highest shoot and root dry weight was recorded for seeds treated with mechanical scarification and grown on MS media supplemented with 1.5 mg/ml TiO<sub>2</sub> nanoparticles. TiO<sub>2</sub> nanoparticles did not show any significant effects on the percentage and rate of germination. Different growing soil mixtures had significant effects on the growth of the ex vitro transferred plantlets. Coco peat and peat moss mixture (1:1) was found to be more effective in increasing the number of leaves and root length of the seedlings.</p>


2019 ◽  
Vol 87 (1) ◽  
Author(s):  
Masna Maya SINTA ◽  
Dian Mutara AMANAH

Aklimatisasi merupakan masa transisi sebelum kultur in vitro dapat ditanam di lingkungan ex vitro. Di daerah tropis, stevia seyogianya ditanam di dataran tinggi. Pengembangan klon stevia yang sesuai untuk dataran rendah di kawasan tropis sangat penting untuk memungkinkan penggunaan mekanisasi pada pertanaman stevia yang luas. Tujuan penelitian ini adalah menentukan pengaruh kondisi eksplan dan periode hardening terhadap daya hidup dan pertumbuhan pada tahap aklimatisasi dan pertumbuhan awal stevia klon BS 22 pada area terbuka di dataran rendah di wilayah tropis. Penelitian pertama dilangsungkan menggunakan umur tunas yang berbeda: 0, 1, 2, dan 3 minggu yang dikultur pada media padat sebagai sumber bahan eksplan. Penelitian kedua menggunakan satu buku stevia pada periode hardening dalam media cair selama 1, 4, 7 dan 10 hari. Aklimatisasi dilaksanakan dengan menanam eksplan dalam medium tumbuh campuran pada multi-tray dan diletakkan di dalam sungkup plastik tertutup selama 1 bulan. Tanaman yang berhasil hidup kemudian dipindah ke polibeg pada area terbuka dengan sinar matahari penuh. Pengamatan daya hidup dan pertumbuhan dilakukan pada akhir tahap aklimatisasi dan setelah 2 bulan di area terbuka. Hasil penelitian menunjukkan bahwa eksplan umur 1 minggu yang dikultur pada media padat mempunyai daya hidup tertinggi yakni 83%. Buku tunggal stevia yang dikultur pada medium cair pada tahap hardening selama 4 hari meningkatkan daya hidup menjadi 97% selama aklimatisasi 1 bulan. Setelah aklimatisasi, tinggi tanaman secara rata-rata adalah 2,6 cm dengan 10,6 helai daun. Tanaman yang dipindah ke area terbuka tumbuh pesat dengan tinggi tanaman mencapai 12 cm dengan 30 helai daun dan daya hidup 63% setelah 2 bulan. Hal ini menunjukkan bahwa stevia klon BS 22 mungkin sesuai untuk dataran rendah di daerah tropis.  [Kata kunci: tanaman pemanis, eksplan tunas, tahap hardening, daya hidup, tropika] AbstractAcclimatization is a transition period before in vitro culture can be planted in ex vitro environment. In the tropical region, stevia is should be planted at high altitude areas. The development of stevia clones suitable for low land area in the tropics is important to make it possible to apply mechanization in a large scale stevia plantation. The purpose of this research was to determine the effect of explant conditions and hardening period on survival rate and growth during acclimatization stage and early growth of stevia clone B 22 in an open area at low altitude area in the tropics. The first experiment was conducted using different shoot ages: 0, 1, 2 and 3 weeks cultured on solid media as an explant material source. The second experiment was using single node of stevia in different hardening periods in liquid media for 1, 4, 7 and 10 days.  Acclimatization was carried out by planting the explants on a mixture growing medium in multi-trays and placed inside a closed plastic tunnel for 1 month. The survival rate and growth parameters were observed at the end of acclimatization stage and after 2 months in the open area. The results show that 1-week explant age on solid media had the highest survival rate at 83%. Hardening single node of shoot in a liquid medium for 4 days increased the survival rate to 97% in 1 month acclimatization stage.  After acclimatization, the plant height on average was 2.6 cm with 10.6 leaves. The survived plants planted in an open area grew rapidly to 12 cm in height with 30 leaves and survival rate 63% within 2 months. It indicates that stevia clone BS 22 may suitable for a low altitude area in the tropics. [Key words: sweetener plant, shoot explant, hardening period, survival rate, tropics]  


HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 560d-560
Author(s):  
Dennis P. Stimart ◽  
John C. Mather

Cotyledons from developing embryos 6 to 8 weeks old of Liatris spicata (blazing star) were cultured on Murashige-Skoog (MS) medium containing 0, 0.4, 4.4, and 44.4 μ M benzyladenine (BA) or 0, 0.2, 2.2, and 22.2 μ M thidiazuron (TDZ) to induce adventitious shoot formation. The highest percent of cotyledons forming shoots with highest shoot counts was on medium containing 2.2 μ M TDZ. Vitreous shoots formed on medium with 22.2 μ M TDZ. Callus derived from cotyledons and cultured on medium containing 4.44 μ M BA or 2.2 μ M TDZ formed adventitious shoots with highest shoot counts on 4.44 μ M BA. Adventitious shoots derived from cotyledons and callus were rooted on MS medium with 5.0 μ Mindole-3-butyric acid, acclimatized and grown ex vitro. All micropropagated plants appeared similar to each other.


HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 434b-434
Author(s):  
Myrna Stenberg ◽  
Michael E. Kane ◽  
Nancy Philman

Micropropagation is a commercially viable and ecologically sound method for producing native herbaceous wetland plants used for wetland revegetation projects. The ability to rapidly screen, select and store germplasm of wetland species genotypes with desirable characteristics of growth rate and habit, nutrient uptake capacity, and/or substrate preference would significantly impact how micropropagated wetland plants are marketed. Early screening of plantlet growth ex vitro may provide an efficient method to select for specific characteristics of growth rate and habit. Five micropropagated lines of Pontederia cordata of differing phenotype were established in vitro from Florida populations. Rooted microcuttings were established ex vitro in a shallow outdoor tank. Growth and development were monitored over a 9 week period. Significant differences in shoot growth and number, leaf area and number, flowering and dry weights were observed between the different Pontederia cordata varieties.


1990 ◽  
Vol 115 (3) ◽  
pp. 364-368 ◽  
Author(s):  
Yves Desjardins ◽  
André Gosselin ◽  
Michel Lamarre

Asparagus (Asparagus officinalis L.) transplants and in vitro-cultured clones were grown and acclimatized under two photosynthetic photon flux (PPF) conditions (ambient and ambient + 80 μmol·s-1·m-2) and three atmospheric CO2 concentrations (330, 900, and 1500 ppm). Short- and long-term effects were measured in the greenhouse and after two seasons of growth in the field, respectively. In the greenhouse, CO2 enrichment (CE) and supplemental lighting (SL) increased root and fern dry weight by 196% and 336%, respectively, for transplants and by 335% and 229%, respectively, for clones. For these characteristics, a significant interaction was observed between SL and CE with tissue-cultured plantlets. In the absence of SL, CE did not significantly increase root or shoot dry weight. No interaction was observed between CE and SL for transplants, although these factors significantly improved growth. It was possible to reduce the nursery period by as much as 3 weeks with CE and SL and still obtain a plant size comparable to that of the control at the end of the experiment. Long-term effects of SL were observed after two seasons of growth in the field. Supplemental lighting improved survival of transplants and was particularly beneficial to in vitro plants. Clones grown under SL were of similar size as transplants after 2 years in the field.


HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1032D-1032
Author(s):  
Joo Hyun Lee ◽  
Yong-Beom Lee ◽  
Kyu Sook Lee

Wasabi japonica plantlets were acclimatized in a hydroponic system to determine effective procedures. The plantlets were cultured on solid Murashige-Skoog medium with 3% sucrose. Shoots that formed roots were transplanted into hydroponic systems: 1) acclimatization in ebb-and-flow (EBB) for subirrigation (medium: granulated rockwool and coir); and 2) acclimatization in deep flow technique (DFT). The plantlets were acclimatized for 5 weeks under two irradiance treatments, 50 and 300 mmol·m-2·s-1. Photosynthetic capacity in high PPF was higher than that in low PPF during acclimatization. Electron transport rate from PS II (ETR) and biomass production increased significantly with increased light availability. The fresh weight, dry weight, and leaf area of plantlets in high PPF were higher than those in low PPF. In particular, the dry weight and ETR of the plantlets grown in high PPF increased more than twice as much as those in low PPF. At 50 mmol·m-2·s-1 PPF, growth indexes, such as number of leaves, leaf length, leaf width, leaf area, fresh weight, and dry weight, were higher in EBB (granulated rockwool) > EBB (coir culture) > DFT. At 300 mmol·m-2·s-1 PPF, those indexes were higher in DFT > EBB (granulated rockwool) > EBB (coir). The Wasabi japonica plantlets acclimatized in a hydroponic system also had a superior performance when they were transferred to the field.


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