In Vitro Propagation, Genetic Assessment, and Medium-Term Conservation of the Coastal Endangered Species Tetraclinis Articulata (Vahl) Masters (Cupressaceae) from Adult Trees

Tetraclinis articulata (Vahl) Masters is an endangered tree growing in coastal and arid environments that is widely exploited by the timber and resin industry, among other applications. In this context, the use of in vitro techniques is highly encouraged for its propagation. We present a protocol for micropropagation using twigs from adult trees as a source of explants. The Schenk and Hildebrandt basal medium (SH) supplemented with 30 g L−1 sucrose, 6.5 g L−1 plant agar, 4.0 mg L−1 6-benzyladenine (BA), and 0.05 mg L−1 1-naphthaleneacetic acid (NAA) provided the optimum multiplication rate (90.48 ± 9.52 explants with basal shoots and 2.58 ± 0.29 basal shoots per explant). Application of activated charcoal (AC) or ½ Knop solution in a liquid overlay produced significantly longer shoots. Supplementation of solid media with indole-3-butyric acid (IBA) or NAA gave low rooting percentages (<17%). Addition of 0.9 g L−1 AC improved rooting (40%) but rooting performance was optimal (66.7%) after a pulse treatment consisting of 4 h immersion in liquid SH medium without growth regulators, followed by 8 weeks of cultivation. Rooted microplants were successfully acclimatized (93.33%) in a peat moss and vermiculite mixture (1:1 v/v ratio). The genetic stability of the in vitro regenerated plantlets was confirmed using the randomly amplified polymorphic DNA (RAPD) technique. Explant survival and growth remained higher than 90% after 28 weeks of cold storage at both 4 °C and 10 °C. The protocol presented here allows for largescale T. articulata production and could be applied for both ex situ conservation strategies and industrial purposes.

Efectos del pretratamiento con Trichoderma y Bacillus en la germinación de semillas de Agave victoriae-reginae T. Moore

La aplicación de tratamientos pregerminativos es fundamental para mejorar las tasas de germinación de las semillas de especies forestales, entre los cuales el uso de microorganismos es uno de ellos. En este estudio se evaluó el porcentaje de germinación de semillas de Agave victoriae-reginae tratadas con Trichoderma spp. y Bacillus spp. Se probaron tres tratamientos: T1 (Trichoderma), T2 (Bacillus) y T3 (Testigo), con tres repeticiones de 100 semillas cada una. Las semillas se sumergieron en una solución de 1 × 106 UFC (tratamientos T1 y T2), y en agua corriente (T3), luego se sembraron sobre Sphagnum peat moss y se registró el porcentaje de germinación diariamente. La germinación comenzó a los 5 días después de la siembra, lo que significa que las semillas no presentaron latencia. Entre el 8° y 12° día se registró un aumento acelerado de la germinación en los tres casos, hasta que la el proceso finalizó a los 26 días, con 85 % de germinación total para semillas tratadas con Trichoderma, 86.7 % con Bacillus y 74 % con el testigo. Se observó un efecto significativo del tratamiento sobre el porcentaje de germinación; incluso el uso de ambos microorganismos aceleró el proceso de germinación con respecto al testigo. Estos resultados sugieren que el uso de Trichoderma spp y Bacillus spp. como tratamientos pregerminativos puede mejorar la germinación de A. victoriae-reginae y su conservación a largo plazo, lo que contribuye a la permanencia de esta especie en peligro de extinción.

Micropropagation of Feverfew (Tanacetum parthenium) and Quantification of Parthenolide Content in Its Micropropagated and Conventionally Grown Plants

Feverfew (Tanacetum parthenium) is a well-known multi-functional plant with anti-inflammatory, cardiotonic, antiangiogenic, and anticancer effects. The therapeutic value of this plant is due to its phytochemical constitutes, especially parthenolide. Tissue culture techniques have been applied to improve the bioactive components of many herbal plants. Hence, this study, was carried out to establish a protocol for micropropagation of the feverfew plant and to quantify parthenolide content in its micropropagated and conventionally grown plants. To establish an aseptic culture, different concentrations of sodium hypochlorite (NaOCl) were investigated for seed surface sterilization. Besides, the effects of plant growth regulators (PGRs) on the callus induction, shoot organogenesis from callus and in vitro rooting were evaluated. Additionally, the parthenolide yield of the micropropagated and conventionally grown plants was determined by using high-performance liquid chromatography (HPLC). The results showed that surface sterilization of feverfew seeds with 6% NaOCl for 15 min obtained 65.00 ± 2.69% aseptic seeds. Murashige and Skoog (MS) medium supplemented with 0.4 mg/L thidiazuron (TDZ) and 2 mg/L 2,4-dichlorophenoxy acetic acid (2,4-D) resulted in 86.00 ± 1.72% callus induction. The highest number of shoots (5.00 ± 0.15) per explant was obtained in the treatment of MS medium supplemented with 5 mg/L zeatin. MS medium fortified with 3 mg/L indole-3-butyric acid (IBA) produced the maximum number of roots per plantlet (8.90 ± 0.35). A total of 90% of the micropropagated plantlets survived when planted in perlite + peat moss (1:1 v/v); the micropropagated plantlets were successfully established in the ex vitro conditions. According to parthenolide analysis, its level was significantly higher in the micropropagated plants than conventionally grown plants. Among different solvents, ethanolic extraction obtained the highest parthenolide content of the feverfew plant. Hence, it can be concluded that micropropagation of feverfew could be applied to produce disease-free planting materials and to improve the parthenolide content of the feverfew plant.

Evaluación de biocarbón de caña de azúcar en el desarrollo de Pinus greggii Engelm. ex Parl. en condiciones de vivero

Existe la necesidad de sustituir componentes de los sustratos para el desarrollo de las plántulas en vivero forestal, por productos de bajo costo y sobre todo por materiales renovables. El biocarbón es liviano, poroso y presenta una alta capacidad de retención de agua. Por lo anterior, el objetivo de este estudio fue evaluar el uso de biocarbón a base de bagazo de caña de azúcar en la producción de plantas de pino prieto (Pinus greggii Engelm. ex Parl.), bajo condiciones de vivero. Se evaluaron cuatro tratamientos: (a) biocarbón con suelo forestal, (b) sustrato forestal (mezcla de 12.5% peat moss, 12.5% agrolita, 25% vermiculita y 50% corteza de pino), (c) biocarbón con sustrato forestal, ambos en una relación 1:9 (biocarbón:suelo, biocarbón:sustrato), y (d) suelo forestal solo. Se evaluó el efecto del biocarbón y de la fertilización (N, P y K) en el desempeño de los tratamientos en suelo y sustrato forestal. Las variables evaluadas fueron: altura de planta, diámetro de tallo, biomasa aérea, biomasa radical, biomasa total aérea, a relación biomasa aérea/radical; además la concentración de nutrientes acumulados (N, P, Ca, Mg, K y Na) en la parte aérea y radical. Los resultados obtenidos indican que como resultado de la adición de biocarbón al suelo y la fertilización, la altura, diámetro, biomasa (aérea y total) de pino prieto, fueron semejantes a las obtenidas en sustrato forestal, solo o combinado con biocarbón. Estos resultados se asociaron a la adición de biocarbón al suelo que incrementó la absorción de N y su concentración en la biomasa aérea, y favoreció la disponibilidad de Mg, Ca, K y P, éstos dos últimos elementos adicionados en la fertilización. Se concluye que la combinación de biocarbón y suelo en una relación (1:9) (p/p) con adición de fertilizante (N, P y K) puede ser empleado en el desarrollo de Pinus greggii Engelm ex Parl en vivero.

An Efficient and Easy Micro-propagation of Reseda Lutea (Resedaceae) a Rare and Medicinally Valuable Plant of Saudi Arabia

The goal of this work was to look at the propagation of Reseda lutea L. by organogenesis in tissue culture. Explants from in vitro grown seedlings were taken from the axillary bud. After seven days of culture on MS medium supplemented with 1.0 mg/l BA, the adventitious buds developed. After three weeks of culturing on MS medium supplemented with 1.5 mg/l BA, the maximum multiplication of shoots (16.12 shoots/explant) was discovered, with an average (7.37 cm) shoots/explant. These shoots were sub-cultured on MS media with varying concentrations of NAA and IBA for root initiation. The MS medium combined with IBA produced the greatest percentage of root development (92%) and the greatest number of roots (7.37 roots/plant). In MS media supplemented with 0.5 NAA, the longest roots (3.08 cm) were found. After 17 days in a glasshouse, the plantlets were acclimatized in pots containing Peat moss and pearlite, 98 percent of the plantlets were acclimatized. To get a plant in a pot, the complete procedure took about 75 days. The technique proposed could aid in the preservation of the plant both in vivo and in vitro.

SUBSTRATE MIXING FORMULATIONS FOR CITRUS NURSERY MANAGEMENT

The length of citrus seedling development is determined by several factors, including the physical and chemical qualities of the substrate, which affect rootstock growth and, as a result, the quality of field seedlings. The purpose of this study was to see how the ‘Swingle’ citrumelo rootstock developed with different substrate formulations. The experiment was carried out in a seedling nursery from seeding to grafting, and six treatments were carried out, as follows: 60% peat moss, 30% fine grade horticultural vermiculite, 10% rice hulls (1); 60% peat moss, 30% fine grade horticultural vermiculite, 10% rice hulls (2); 50% peat moss, 30% fine grade horticultural vermiculite, 20% rice hulls (3); 50% peat moss, 30% fine grade horticultural vermiculite, 20% rice hulls (4); 50% peat moss, 20% fine grade horticultural vermiculite, 30% rice hulls (5); 50% peat moss, 20% fine grade horticultural vermiculite, 30% rice hulls (6). In addition, the experiment was divided into two stages: seeding (stage 1) and seedling nursery (stage 2). In a completely randomized design, the experiment has six treatments, four replications, and 51 plants per plot. When container transplanting was performed, the emergence percentage of seedlings was determined; thus, eight plants per plot were examined. For the second stage, was used a completely randomized design with 6 substrate formulations, 4 replications, and 20 seedlings per plot. Stem height, stem diameter, leaf number, area meter, root dry matter, leaf and stem dry matter, and quality index were measured on seedlings every 28 days. All substrate formulations improved seedling development until grafting, except for the 30% rice hulls, which hampered seedling development in ‘Swingle' citrumelo.

Investigating the Quality and Efficiency of Biosolid Produced in Qatar as a Fertilizer in Tomato Production

This study evaluated biosolid quality over time and the efficiency of using amounts (5 and 7 kg/m2) of municipal class A biosolids in Qatar to fertilize tomato plants (Solanum lycopersicum). Random samples were subjected to physical and chemical analysis, which revealed excellent particle uniformity and stability with minor odor defects. The analysis confirmed the product was nutrient-rich while pollutant levels were below the international standards. The nominated rates were used to fertilize tomato plants in pots grown in a greenhouse for four months with a control treatment of manure and Peat-Moss, before measuring the plant biological characteristics. Plants were examined via chemical analysis of nutrients and pollutants both for the whole plant and for stems, fruits, and leaves. Results indicated that both experimental treatments enhanced plant growth and development as compared to the control treatment. However, the chemical analyses also revealed levels of zinc, copper, and manganese in the plant fruits that were well in excess of the maximum acceptable levels, as defined by international health organizations. This study found that while the application of class A biosolids as organic fertilizer for tomato plants greatly enhanced the overall plant growth, the plant fruits contained toxic levels of trace heavy metals.

Adventitious Rooting of Lavandula x intermedia Cuttings

Due to challenges associated with lavender propagation, Texas hybrid lavender (lavandin) growers require revised propagation information. Therefore, experiments investigated effects of media and plant growth regulators (PGR) on rooting of three different lavandin (Lavandula x intermedia) cultivars. PGRs applied to cuttings were naphthaleneacetic acid (NAA), or indole-3-butyric acid (IBA) at three concentrations. In addition, four rooting media were examined. Cuttings exposed to a peat moss/sand medium had the greatest mean overall rooting percentage, number of roots, and regardless of cultivar, cuttings exposed to the peat moss/sand medium had the longest roots. In general, mean rooting data were also greatest for cuttings dipped in NAA at 0.5 and 1.0 g·L−1 (500 and 1000 ppm, respectively). Overall, across all media and PGR treatments ‘Grosso' cuttings tended to have the greatest rooting percentage and longest roots. In addition, compared to the no PGR treatment, ‘Provence' and ‘Hidcote Giant' cuttings exposed to the peat moss/sand medium and greater PGR concentrations produced cuttings with an increased mean rooting percentage and longer roots. When rooting lavandin cultivars, results indicate correct media selection, PGR formulation, and PGR concentration determine propagation success. Index words: lavandin, Lavandula x intermedia Emeric ex Loisel, peat moss, perlite, rooting percentage, root quality, sand. Chemicals used in this study: indole-3-butyric acid (IBA; 0.5, 1.0, and 1.5 g.L−1); naphthaleneacetic acid (NAA; 0.5, 1.0, and 1.5 g.L−1). Species used in this study: ‘Grosso', ‘Provence', and ‘Hidcote Giant' lavandin (Lavandula x intermedia Emeric ex Loisel.).

Influence of Substrate Composition and Container Size on the Growth of Tissue Culture Propagated Apple Rootstock Plants

Substrate composition and container size are considered crucial for apple rootstock grown in a plug seedling system. This study investigated the effect of substrate material’s proportion and different container volumes on the growth of apple rootstock (M-9) plants propagated by tissue culture. In substrate composition, three different ratios of peat moss (PM): vermiculite (VL): perlite (PL) at 1:1:1 (S1), 1:2:3 (S2), 3:1:2 (S3) were used. For container size, plants were grown in 1000 mL (C1), 500 mL (C2), and 300 mL (C3) containers filled by 1:1:1 mixture of PM, VL and PL. In both cases, plants were treated eleven weeks in a green house. Our results demonstrate that the plant height, number of leaves, leaf area, shoot fresh weight and root fresh weight of apple rootstock were significantly higher in substrate composition S3 compared with S1 composition. However, chlorophyll content (SPAD) and photosynthesis rate were unaffected by variation of substrate composition. Furthermore, rootstock grown in C1 container showed plant height, number of leaves, leaf area, number of nodes, root length, shoot and root’s fresh and dry weight were significantly higher than those grown in C2 and C3 volume containers. The chlorophyll content and transpiration rate were not significantly affected by the different container volumes. These results suggest that the substrate ratio 3:1:2 of PM:VL:PL and container size 1000 mL were more favorable than other treatments for initial growth and development of the tissue culture propagated apple rootstock plants.