Highest Percentage Of Rooting Research Articles

Micropropagation and non-steroidal anti-inflammatory and anti-arthritic agent boswellic acid production in callus cultures of Boswellia serrata Roxb.

Micropropagation through cotyledonary and leaf node and boswellic acid production in stem callus of a woody medicinal endangered tree species Boswellia serrata Roxb. is reported. The response for shoots, roots and callus formation were varied in cotyledonary and leafy nodal explants from in vitro germinated seeds, if inoculated on Murshige and Skoog's (MS) medium fortified with cytokinins and auxins alone or together. A maximum of 8.0 ± 0.1 shoots/cotyledonary node explant and 6.9 ± 0.1 shoots/leafy node explants were produced in 91 and 88% cultures respectively on medium with 2.5μM 6-benzyladenine (BA) and 200mg l(-1) polyvinylpyrrolidone (PVP). Shoots treated with 2.5μM IBA showed the highest average root number (4.5) and the highest percentage of rooting (89%). Well rooted plantlets were acclimatized and 76.5% of the plantlets showed survival upon transfer to field conditions. Randomly amplified polymorphic DNA (RAPD) analysis of the micropropagated plants compared with mother plant revealed true-to-type nature. The four major boswellic acid components in calluses raised from root, stem, cotyledon and leaf explants were analyzed using HPLC. The total content of four boswellic acid components was higher in stem callus obtained on MS with 15.0μM IAA, 5.0μM BA and 200mg l(-1) PVP. The protocol reported can be used for conservation and exploitation of in vitro production of medicinally important non-steroidal anti-inflammatory metabolites of B. serrata.

ROOTING OF BLUEBERRY HARDWOOD CUTTINGS AS AFFECTED BY WOOD TYPE

Difficulty in propagation using cuttings is a factor that limits blueberry expansion. The success of propagation by cuttings depends on the capacity of adventitious root formation of the cultivar and new root system quality. This work aimed to evaluate the effect of branch type on the rooting of hardwood cuttings of the blueberry cultivars ‘Delite’, ‘Bluebelle’ and ‘Briteblue’. The plant material used was derived from whip segments originating from the crown and lateral shoots from old canes, with about 7.0 cm length and 5.5 mm diameter, and 6.0 cm and 3.5 mm, respectively. The cultivar ‘Briteblue’ showed the highest percentage of rooting (60%), while the cultivar ‘Bluebelle’ had the lowest (35%). The source of cutting wood affected the percentage of cuttings that survived with 81 and 65% of the cuttings from lateral and whip canes rooting, respectively. Therefore, it was concluded that the cultivar ‘Briteblue’ was easy to propagate with hardwood cuttings and lateral branches provided a high percentage of rooting, independent of the cultivar.

Short communication. N-(2-chloro-4-pyridyl)-N-phenylurea(4-CPPU) enhances in vitro direct shoot organogenesis of Citrus aurantium L. epicotyl segments compared to other commonly used cytokinins

The effect of three concentrations of five different cytokinins, i.e. 6-benzylamino purine, 2-isopentyl adenine, kinetin (Kin), thidiazuron and N-(2-chloro-4-pyridyl)-N-phenylurea (4-CPPU), was evaluated on the in vitro direct shoot organogenesis of epicotyl explants of sour orange (Citrus aurantium L.). The basal medium used was that of Murashige and Tucker and epicotyl explants were incubated in medium supplemented with the prementioned cytokinins for 45 days. The addition of Kin and 4-CPPU in the medium enhanced the direct shoot organogenesis of sour orange epicotyl segments. The concentration of each of these two cytokinins which gave the best results, was combined with indole-3-acetic acid (IAA) or α-naphthalene acetic acid (α-NAA) at concentrations ranging from 0.01 mg L–1 to 0.2 mg L–1. The inclusion of IAA at 0.2 mg L–1 in the medium with 4-CPPU at 0.05 mg L–1 resulted in 100% successful direct shoot organogenesis, while the combination of Kin at 0.25 mg L–1 with IAA or α-NAA each at 0.01 mg L–1 presented equally high organogenesis percentages (91.7%). The incubation of the produced shoots, in medium supplemented with either indole-3-butyric acid or α-NAA resulted in high rooting percentages (up to 90%) and the rooted explants were successfully acclimatized under mist (85%). Although 4-CPPU has been used in in vitro cultureof various species, this is the first report on its use in the direct shoot organogenesis of citrus species and could be ofgreat value in citrus genetic transformation protocols using epicotyl segments, since this cytokinin resulted in theabsolute organogenesis percentage.

Innovative protocol for “ex vitro rooting” on olive micropropagation

Abstract The commercial micropropagation of olive trees is currently limited by the production cost. An ex vitro method for olive microshoot rooting could reduce both the production cost per plant and the propagation time. In this study a successful ex vitro rooting protocol tested on seven olive cultivars is reported. The explants of cv. Maurino were collected from fifth, sixth, and seventh proliferative subcultures carried out on MSM medium, while for the other cultivars the explants were collected from only seventh proliferative subculture. Continuous light during the rooting phase was a prerequisite for the success of the ex vitro protocol. The best source of microshoots for a high rooting percentage was the seventh proliferative subculture. Cvs. Coratina, Maremmano, Maurino, Picholine, and S. Francesco showed high rooting percentages with a range of 62–76%; whereas for cvs. Correggiolo and Frantoio the experimental conditions need to be optimised. Up to 90% of the rooted microplants survived, and continuous growth of shoots was subsequently observed. The proposed protocol can be easily applied to several different olive cultivars to produce microplants by commercial laboratories. The approach makes olive micropropagation in the nursery industry both possible and profitable.

In vitro propagation of Drosera intermedia in a single step

A simple and efficient protocol for the micropropagation of Drosera intermedia, using cultures initiated from in vitro produced seedlings, is described. Shoot proliferation was significantly influenced by Murashige and Skoog (MS) macronutrient concentration, showing higher multiplication rates for 1/4 MS (the lowest concentration), but was not affected by the addition of 0.1 mg dm-3 kinetin. In all cases a multiplication percentage above 90 % was recorded. High rooting percentages (up to 100 %) were obtained in multiplication phase on 1/4 MS medium without growth regulators. In average 15.8 plantlets per initial shoot was produced after 8 weeks of culture. All plantlets were successfully acclimatized to ex vitro conditions, exhibiting normal development.

Micropropagation of Teucrium fruticans L., an ornamental and medicinal plant

An efficient protocol for in vitro propagation of the valuable ornamental and medicinal plant Bush germander (Teucrium fruticans L.) was developed through axillary shoot proliferation. A Murashige and Skoog agar medium supplemented with benzylaminopurine (6.6 μM), α-naphthaleneacetic acid (0.053 μM), and sucrose (3%) significantly improved the production of multiple shoots directly from nodal segment explants, resulting in an average of 2.8 shoots per segment with an average of 6.8 nodes per shoot that would be potential newly formed explants. The new shoots were developed without a marked decrease in the average height of the shoots. Shoots treated with 2.5 μM indole-3-butyric acid showed the highest average root number (7.9) and the highest percentage of rooting (94%). Plantlets were hardened off and transferred to jiffy pots for acclimatization under greenhouse conditions, resulting in a 100% survival rate.

FINE ROOT BIOMASS AND PRODUCTION IN A SEMIARID MEXICAN SHRUBLAND

I describe the vertical distribution of root biomass and root productivity in a xeric shrubland of central Mexico. The effect of the soil nitrogen on root production was evaluated with a fertilization experiment. The highest percentage of roots was found at a depth of 40 to 60 cm. Monthly variation in root biomass for diameter class was significant. Fine and very fine roots were the most important fraction in terms of biomass and production. The highest production of fine root occurred in native soil versus the other treatments.

Peroxidases, lignin and anatomy during in vitro and ex vitro rooting of gardenia ( Gardenia jasminoides Ellis) microshoots

In vitro and ex vitro rooting of gardenia (Gardenia jasminoides Ellis) microshoots with or without indolic-3-butyric acid (IBA) was studied in order to improve acclimatization of microplants after root formation and transplantation. Peroxidase (POD) activity and isoforms, lignin content and anatomical observations were evaluated in the course of the three interdependent phases (induction, initiation and expression) of microshoot rooting. Microshoots treated or not treated with IBA achieved high rooting percentages both in vitro and ex vitro. At the end of the 2-week acclimatization period, the percentage of surviving microplants ranged from 80% to 100%, for in vitro and ex vitro rooted microshoots, respectively. Microshoots rooted in vitro and ex vitro showed a relationship between rooting and POD activity but in a different time course. It appeared that root formation occurred after the microshoots had reached and passed a peak of maximum enzyme activity. In all treatments, electrophoretic analysis (native PAGE) of PODs revealed the appearance of one anionic and three cationic POD isoforms (C(1), C(3) and C(4)). An additional cationic POD isoform (C(2)) appeared only in the ex vitro rooting. The lignin content was similar in microshoots rooted both in vitro and ex vitro. The sequential anatomical changes during the rooting process were similar in both in vitro and ex vitro rooting treatments. In the case of in vitro rooting, pith cells had vacuoles entirely filled with a dark substance, while in the case of ex vitro rooting, pith cells contained many amyloplasts. The origin of the adventitious roots, in both rooting conditions, was located in the cambial ring. Roots with organized tissue systems emerged from the microshoot stem 10-14 days after the root induction treatments; on day 10 for rooting in vitro, while a 4-day delay was noted in microshoots rooted ex vitro.

Cuttings of Wollemi pine tolerate moderate photoinhibition and remain highly capable of root formation

The Wollemi pine was discovered in 1994 at the base of a deep rainforest canyon in the Wollemi National Park, southeastern Australia. Only three populations have been found, comprising less than 100 adult trees. Ex situ conservation collections were quickly established, and also a commercial propagation program to produce plants for horticulture. We investigated vegetative propagation methods, focussing on rooting of cuttings with different amounts of foliar pruning, irradiance or fertiliser application, and we compared anatomy and rooting of cuttings at two different stages of stem development. We related root production to levels of photoinhibition experienced during the propagation phase, quantifying photoinhibition by measuring chlorophyll fluorescence. Maximum photochemical efficiency (FV/FM) of cuttings declined during daily stress periods, particularly after many weeks without roots in the propagation environment, but these declines did not inhibit root formation. Mean percentage of cuttings that formed roots was usually high (79.4–94.0%). Treatments that alleviated photoinhibition, such as low irradiance or foliar fertilisation, did not increase rooting percentages. Other treatments that did not alleviate photoinhibition, such as incorporation of fertiliser in the medium or no pruning, did accelerate formation of an extensive root system. Soft cuttings had a less-developed sclerenchyma ring in their cortex compared with firm cuttings, but both cutting types provided high rooting percentages. Our results showed that cuttings under mist irrigation can be prone to long periods of moderate photoinhibition and yet remain highly capable of root production.

The effects of photoperiod and light spectrum on stock plant growth and rooting of cuttings of Cotinus coggygria ‘Royal Purple’

SummaryExtending the season of production and improving the scheduling of ornamental crops are key commercial objectives for nurserymen. In some woody species, the period in which cuttings can be rooted successfully is transient, thus limiting the opportunities for scheduled production. Optimum rooting often occurs in early- to mid-summer coinciding with periods of active shoot growth. The relationship between this shoot activity and root initiation was investigated in Cotinus coggygria ‘Royal Purple’. Shoot growth on stock plants was manipulated by altering the photoperiod or light quality. Results indicated there were seasonal effects on rooting, but the importance of shoot activity varied with harvest time. Cuttings harvested in August had high rooting percentages, irrespective of photoperiod, and despite shoot growth terminating in response to the short-day treatment. In contrast, by September, rooting percentage was highest in cuttings from plants under long-days, which had maintained greatest shoot growth activity. Cotinus shoots grown in vitro under 16 h days showed reduced shoot growth and increased rooting competence compared with shoots grown under 8 h days. Growing stock plants under polythene films, which altered the amount and quality of the incident light, influenced the rooting of cuttings harvested in August, but no consistent relationship with shoot activity was apparent. From a practical viewpoint, maintaining shoot activity late in the season may prolong the period for propagation by cuttings; but, from a scientific viewpoint, processes associated with an active shoot apex do not provide a complete explanation of seasonal variation in rooting.

SHOOT ORGANOGENESIS AND PLANT REGENERATION FROM LEAF CALLUS CULTURES OF BLACK BARK SILVER BIRCH (BETULA PENDULA ROTH. ‘MELANOCORTEA’)

A 50-year-old specimen was used for in vitro cloning of silver birch dark bark form (Betula pendula 'Melanocortea'). For callus induction leaves were cultivated on Simola (S) medium. The effects of different media (MS, WPM and S) in combination with different cytokinin levels (BA and zeatin) on adventitious bud formation from callus segments were tested. The best effect was obtained on medium S containing 5 and 10 mg l -1 zeatin. The effect of different auxin concentrations (IBA and NAA) on the rooting of adventitious shoots indicated that highest percentage of rooting (100%) was achieved on half-diluted MS medium in combination with 0.5 mg l -1 NAA + 0.5 mg l -1 IBA. The high percentage (97%) of acclimatized plants obtained, showed that the practice of opening the test tubes some days before pricking out under ex vitro conditions and high humidity facilitated acclimatization. The successful acclimatization was probably due to the better aeration of the rooting system in a substrate of peat and zeolite.

In vitro propagation of Iphigenia indica, an alternative source of colchicine

The present study involves in vitro propagation of Iphigenia indica (Kunth.) through multiplication of whole corms and corm buds. The whole corms produced very small micro-corms, which developed plants individually whereas corm buds multiplied to produce numerous shoots at variable rates in presence of α-naphthaleneacetic acid (NAA) and 6-benzylaminopurine (BAP). The best response in corm and bud multiplication was obtained in Murashige and Skoog's basal medium (MS) supplemented with 2.69 μM NAA and 8.88 μM BAP. The shoots regenerated were further cultured on MS medium containing NAA and indole-3-butyric acid (IBA) for initiation of roots. MS medium with 5.38 μM NAA and 4.92 μM IBA induced highest percentage of roots (81%) within 2 weeks in culture.

Field and in vitro methods of propagation of the African locust bean tree (Parkia biglobosa (Jacq.) (Benth.)

SummaryStem cutting in non-mist propagators, air layering and in vitro propagation were investigated as means of vegetative propagation of Parkia biglobosa. The results of the non-mist propagation experiment show that it is possible to root single-node stem cuttings from juvenile P. biglobosa plants in non-mist propagators. The highest percentage of rooting (35%) was achieved by the application of 1000 g m±3 IBA and NAA. Propagation of single-node stem cuttings from mature trees was, however, not a success. The results from the air layering experiment indicate that it is also possible to propagate P. biglobosa by air layering. The application of hormone (200 g m±3 IBA and NAA) produced the highest percentage of rooting of air layers (16%). The results of the in vitro propagation experiment reveal that the method offers an alternative opportunity for rapid multiplication of the tree. MS medium supplemented with 6.mg.l±1 IAA was the best for shoot initiation (81.7%) whereas 4±5 mg l±1 IAA gave the highest percentage of explants with roots (8.3%). Root promotion did not correspond well with IBA in both MS and WPM media. Transplanted in vitro rooted shoots were well acclimatized in the greenhouse and all plantlets exhibited some mature characteristics including compound leaves and multiple roots.

106 Propagation of Alnus maritima from Softwood Cuttings

Alnus maritima [Marsh.] Nutt. (seaside alder) is a rare, North American species with strong potential for use in managed landscapes. Information on the propagation and production of this species is not available. Our objective was to evaluate the potential for using softwood cuttings to propagate A. maritima, with emphasis on how IBA and plant provenance affect rooting success. Propagation trials were conducted with cuttings from seven trees native to the Delmarva Peninsula and seven trees from Oklahoma. Cuttings from both provenances were collected on 14 June and 23 Aug. Cuttings were wounded; treated with 0, 1, or 8 g/kg IBA; and placed under intermittent mist in a greenhouse for 9 weeks. The highest percentage of rooting (67.9) was achieved for the Oklahoma provenance by using 8 g/kg IBA in June. Across IBA treatments, rooting of cuttings from Oklahoma, 54.8% (June) and 12.4% (August), was higher than rooting of cuttings from Delmarva, 27.1% (June) and 3.1% (August). IBA at 8 g/kg caused a higher rooting percentage than the other IBA rates at both times of the season. More cuttings collected 14 June rooted (41%) than those collected 23 Aug. (7.7%) over IBA treatments. Another experiment involved cuttings from one juvenile, greenhouse-grown seedling from Oklahoma that showed 100% rooting with both 1 and 8 g/kg IBA. Shoot growth appeared more vigorous on rooted cuttings from these juvenile stems than on plants derived by rooting mature tissue collected in nature. We conclude that using softwood cuttings can be an effective way to multiply clones of A. maritima, particularly when stock plants are juvenile and cuttings are treated with IBA.

Micropropagation of Two Red Raspberry Clones: Effect of Medium Composition on Multiplication, Microshoot Size and Rooting

Abstract A method for micropropagation of two red raspberry (Rubus idaeus) clones from the Norwegian red raspberry breeding programme by shoot tip cultures was tested. Both clones (N71-B3: DistadxViking and N71–2709: VikingxVeten), showed promising regeneration rates. They were micropropagated using modified MS medium and the medium of Anderson. The cytokinin/auxin ratio and the time of introduction of the hormones to the cultures was varied. The meristems were subcultured to fresh medium every 4 weeks. Growth started after one cycle in culture. After 10 weeks in culture several leaves were formed, and multiplication started. The average multiplication factor differed for both clones and media and no regeneration was obtained when auxin levels exceeded the level of cytokinin. The highest multiplication factors (3–4) were found for N71-B3 on Anderson medium. Microshoot quality was classified with respect to shoot size. Clone N71-B3 had more medium sized and large shoots on Anderson medium than on MS, while these differences were not as marked for N71–2709. Cytokinin levels were ranged from 0 to 3.0 mg/l and were tested for multiplication factor and shoot size for N71-B3 in both media. Increasing amounts of cytokinin generally gave increasing amounts of small shoots, but increasing the level above 0.6 mg/l had no further effect on the multiplication factor. Shoot tips were rooted in the greenhouse directly in peat and plantlets were evaluated for growth capacity after rooting. The highest rooting percentage obtained was 97.4% and there was a positive correlation between high rooting percentages and succeeding growth. In the summer of 1989, the plantlets were planted in field experiments to study growth and phenological characters.

Micropropagation of hornbeam (Carpinus betulus L.) and ash (Fraxinus excelsior L.)

Shoot multiplication of hornbeam was stimulated onWPM, QL andDKW medium supplemented with a low concentration of BAP or BPA (0.1-0.2 mg I -1) andIBA (0.1 mg I -1). Low concentration of thidiazuron promoted axillary bud formation, higher concentration inhibited shoot elongation. Microshoots were rooted onWPM supplemented with a low auxin concentration (IBA or NAA 0.2-0.5 mg I -1). High rooting percentages were obtained. Shoot proliferation of ash was stimulated on MS andDKW medium supplemented withBAP orBPA (2.0-5.0 mg I -1) andIBA (0.1 mg I -1). Root formation was promoted onWPM containing a low auxin concentration. Rooted plantlets were transplanted into soil and after hardening off the micropropagated trees were planted in the field. The planted trees grew normally without showing signs of abnormality.

MICROPROPAGATION OF ARONIA ARBUTIFOLIA AND A. MELANOCARPA

Increasing interest in landscape use of Aronia arbutifolia and A. melanocarpa has led to the establishment of breeding programs and selection of improved phenotypes within the genus. A rnicropropagation system was developed to facilitate rapid and easy multiplication of improved forms of Aronia. Actively growing shoot tips of A. arbutifolia `Brilliantissima' and A. melanocarpa were used to initiate shoot proliferation from axillary buds. Optimum proliferation of shoots useful for micropropagation occurred on media supplemented with 0.5 to 1.0 mg 1-1 benzyladenine. Both Murashige and Skoog medium and Woody Plant medium supported vigorous shoot proliferation, but differences in culture morphology were evident. In vitro rooting and non-sterile rooting methods both resulted in high rooting percentages, the formation of numerous roots and subsequent rapid growth of plantlets.

Large scale micropropagation ofQuercus robur L. using adenine-type cytokinins and thidiazuron to stimulate shoot proliferation

High rates of oak shoot multiplication were achieved on low salt nutrient media (BTM, WPM) supplemented with adenine type cytokinin or BAP. Low concentration of (0.2-0.6 mg 1-1) stimulated formation of a large number of axillary shoots and their elongation. Thidiazuron in very low concentration (0.001 - 0.002 mg 1-1) promoted shoot proliferation, in high concentration stimulated formation of large callus. More than twelve thousand micropropagated shoots were rooted in low salt agar media supplemented with low concentration of auxin (IBA or NAA 0.2 - 0.5 mg 1-1). High rooting percentages (81 %) were obtained. Survival of the mieropropagated plantlets transplanted into soil was high (78 %). Micropropagated trees planted in the field withstood severe winter frosts without significant losses. At the end of the fifth growing season trees attained considerable size.

In vitro propagation of oak (Quereus robur L.) and linden (Tilia cordata Mill.)

Rapid multiplication of axillary shoots of oak and linden has been achieved on broad-leaved tree medium (BTM) and woody plant medium (WPM) containing low level of cytokinin (BAP 0.2–1.0 mg l-1). High rooting percentages (80–95%) were obtained on low salt, low sucrose media, containing low level of auxins. Rooted plants were transplanted into pots containing a mixture of peat and perlite. Most of the plants (90–95%) survived the transfer. After the hardening off period the new plants were planted in the field.

Juvenility and endogenous rooting substances inCastanea sativa Mill

The rooting response to exogenous auxin of cuttings in a juvenile phase of growth from plants ofCastanea sativa Mill. was determined and simultaneously the rooting potential of the water extracts was evaluated in presence of IAA by a bean rooting test. The level of the extractable rooting promoters was high in the cuttings which exhibited the highest percentage of rooting. An inhibition of the effect of IAA on rooting was detected in the cuttings which showed the lowest rooting response, the histogram differing not much from that of the adult plant. The results indicate that in chestnut the juvenile condition, easy rooting, is associated with high levels of endogenous rooting promoters.