Average Shoot Height Research Articles

THE ESTABLISHMENT OF THE RECIPIENT SYSTEMS OF GENETIC TRANSFORMATION FROM 'BENIHOPPE' STRAWBERRY (FRAGARIA ×ANANASSA DUCH.)

In order to research fruit-specific genetic expression, the vectors that contain a fruit-specific promoter were constructed. We wanted to prove that in strawberry, so the recipient systems of genetic transformation from 'Benihoppe' strawberry were established. Effects of the basal medium, the types and concentrations of plant hormones and plant growth regulators on shoot regeneration from leaves of strawberry were studied using orthogonal experimental designs in order to establish a shoot regeneration system from leaves. The results showed that IBA played a vital part in proliferation of shoots. The optimum medium for shoot induction was MS + TDZ 2.0 mg/L + IBA 0.2 mg/L, the regeneration rate 90.00%. The optimum medium for shoot proliferation was MS + 6-BA 0.5 mg/L + IBA 0.2 mg/L and the average number of in shoots was 7.67. The optimum medium for shoot subculture was MS + 6-BA 0.5 mg/L + 2,4-D 0.1 mg/L and the average height of shoots was 5.98 cm. The optimum medium for shoot rooting was 1/2MS + 6-BA 0.5 mg/L + 2,4-D 0.1 mg/L and average number of shoots rooting was 4.5. The calliwere fully suppressed with 20 mg/L ofkanamycin in differentiation media; the explants gradually turned white and died. The regeneration system established in this paper could be used for genetic transformation in strawberry.

In Vitro Regeneration through Direct Organogenesis from Protocorms of Oncidium tigrinum Llave & Lex. (Orchidaceae), an Endemic and Threatened Mexican Species

A protocol for in vitro propagation from protocorms of Oncidium tigrinum Llave & Lex., a threatened species distributed in Mexico and highly appreciated as an ornamental, was developed. Two different explants, entire protocorms and longitudinal halves of protocorms, were used. In addition, the effect of two different culture media, Murashige and Skoog (MS) and modified Knudson (KCm), supplemented with N6-benzyladenine (BA) (0, 0.5, 1, 2, 3, and 5 mg·L−1) and/or α-naphthaleneacetic acid (NAA) at 0, 0.1, and 0.5 mg·L−1 was investigated. Adventitious shoot formation by direct organogenesis was obtained in all treatments; in some cases, the formation of protocorm-like bodies was induced. Shoot formation was greater for entire protocorms; the best treatment was MS medium containing at BA 1 to 2 mg·L−1 in combination with at NAA 0.1 mg·L−1. The average height of shoots was three times greater in MS medium than in KCm medium. Subculturing individual shoots in MS medium without plant growth regulators, but with 1 g·L−1 activated charcoal, allowed further development and rooting. An ex vitro survival rate of almost 100% was achieved. This study represents a comprehensive application for propagation, conservation, and sustainable use of this valuable natural resource.

Micropropagation and Cormels Production in Gladiolus spp. Var. Oscar

Plant tissue culture techniques are used for the micropropagation of Gladiolus, Oscar variety, using axillary buds of the flower stalks, axillary buds of corms and cormels. It was aimed to design production program for micropropagation and cormels production all year round. This work included many experiments. The effect of Benzyl adenine (BA) and Kinetin (Kin) and the interaction between BA and Naphthalene acetic acid (NAA) on shoot proliferation, the effect of BA on shoot multiplication, the effect of NAA on rooting after 30, 40 and 50 days, were studied. The role of the composed (Peatmoss only, Peatmoss: sand, sand only) in plantlet survival during acclimatization was also studied. Results showed that BA supplemented to the medium at 2.0 mgl induced shoot proliferation from axillary buds of flower stalks, giving an average shoot height of 2.5 cm. while reached 7.4 cm. in shoots induced from axillary buds of corms on a combination of 0.05 mgl NAA and 0.4 mgl BA. In cormels, the best response occurred at concentration of 1.0 mgl Kin giving average shoot length of (6.5 cm.). Maximum average of shoot number and length at the multiplication stage occurred at 0.75 mgl BA in axillary buds taken from both flower stalks and corms, while at 0.5 mgl in cormels. NAA at 1.0 mgl achieved the highest response in root number and length for all studied explants. Rooting percent, number and root length increased over time. Cormels formed 50 days after rooting reaching 100% cormels formation on all plantlets regenerated from the different explants under investigation. Peatmoss was found the best among the three tested media in sustaining plantlets survival.

The Effects of Litter Cover on the Early Growth of Manchurian Wild Rice (Zizania latifolia)

ABSTRACT The effects of a standing layer of litter on the shoot emergence and subsequent growth of Zizania latifolia were evaluated by removing the litter layer in three plots. Three other plots were kept as controls with litter layer. Shoot emergence and growth parameters were observed for seven months. Light incidence through the litter layer was measured. New shoots emerged about a month earlier in the plots without litter than in the plots with litter layer. The maximum shoot density in the plots where the litter layer was removed was 590 m−2 at the time when average shoot height was 61 cm, whereas the shoot density was 316 m−2 with an average shoot height of 71 cm in the control plots. Maximum shoot density was reached three weeks later in the plots with litter. Although removal of standing litter significantly increased initial shoot density, plant growth was essentially comparable regardless of the presence or absence of accumulated litter.

Effects of salinity and cutting on the development of Phragmites australis

The effects of increased salinity and cutting the above ground biomass on the growth of Phragmites australis were evaluated by investigating four experimental reed stands grown in outdoor tanks. Two stands were treated with 30‰ salinity and the other two stands with freshwater; one stand of each treatment was cut to 20 cm during the second growing season. Growth conditions were observed until all the plants were dead at the end of the second year. The number of shoots emerged from the freshwater-treated stand was about 70% higher than that of the saltwater-treated stand. The number of shoots emerged from cut plant stands were markedly lower than uncut stands. The average shoot height was negatively affected by salinity and shoots that emerged after cutting further decreased in height. The average number of leaves on a shoot was not significantly affected by salinity, but reduced by cutting in both treatments. Leaf length, width and the distance between leaves were decreased by both salinity and cutting. In the freshwater-treated uncut stand more than 50% of the shoots formed panicles, but this proportion was reduced to 6% by salinity, to 15% by cutting, and to 0% by the combination of salinity and cutting. This study showed again that salinity reduces the growth of aboveground components. The growth, however, was most severely retarded by cutting combined with salinity, which has many implications for better management of P. australis stands.

Influence of Host Condition on the Performance of Rhopalomyia n. sp. (Diptera: Cecidomyiidae), a Biological Control Agent for Scentless Chamomile, Tripleurospermum perforatum

Abstract The gall midge Rhopalomyia n. sp. has been used as a biological control agent for the weed scentless chamomile, Tripleurospermum perforatum (= Matricaria perforata ), in Canada since spring 1999. A series of three experiments was carried out in 1996 and 1997 to investigate the effect of three nutrient and two water levels on T. perforatum, on the performance of Rhopalomyia n. sp., and on the interaction between scentless chamomile and the gall midge. The hypotheses were that (1) the performance of Rhopalomyia n. sp. is favored when larvae develop on fertilized, well-watered plants of scentless chamomile (vigor hypothesis) and that (2) fertilized plants compensate for gall midge attack. Two different seed origins of tetraploid T. perforatum, Canadian or European, which resulted in two different phenostages, rosettes or bolting/flowering plants, respectively, were used. Weekly application of nutrients resulted in a 64–85% increase in the nitrogen level of plants and in increased plant vigor. On rosettes, the addition of nutrients did not influence gall midge performance, whereas on bolting/flowering plants, more galls were induced, and potential fecundity of females was increased by 17–19%. Within the low nutrient level, reduced water supply increased the nitrogen concentration of plants in one of the experiments, but decreased plant vigor. The potential fecundity of gall midge females was reduced by water shortage in one of the experiments. The results of this study generally support the vigor hypothesis. The height of the main shoot was always reduced in midge-attacked compared to unattacked plants, irrespective of nutrient treatment, whereas the impact of Rhopalomyia attack on average shoot height and on the number of shoots produced per plant varied with nutrient treatment. We recommend the release of Rhopalomyia n. sp. preferentially onto scentless chamomile plants at nutrient-rich, moist sites.

Micropropagation of yellow cedar (Chamaecyparis nootkatensis)

Mature yellow cedar (Chamaecyparis nootkatensis (D. Don) Spach) embroys were exposed to a range of N6-benzyladenine concentrations in a variety of culture media generally used for conifer caulogenesis. All seven media supported the induction of adventitious shoots but Schenk & Hildebrandt medium was the best. The best cytokinin level of N6-benzyladenine was 0.35 mg 1-1. This resulted in an average of 4–5 large adventitious shoots per explant. Shoots arose primarily from the cotyledons regardless of whether they were in contact with the medium or not. Embryos from seeds stratified four weeks at 21°C and eight weeks at 5°C were more caulogenic than unstratified controls. An additional four weeks at 5°C caused a change in the pattern of shoot induction in that shoots arose from the hypocotyl as well as the cotyledons. Shoots elongated on basal Schenk & Hildebrandt medium. The best rooting response was obtained under non-sterile greenhouse conditions where approximately 60% of the shoots formed roots. Over a 12-month period the average shoot height ranged between 10–13.9 cm with a stem diameter of 2.29–2.68 mm. These propagules are still being grown under forest nursery conditions.

Interactions between vesicular-arbuscular mycorrhizal fungi and asparagus

The vesicular-arbuscular mycorrhizal (VAM) fungus,Glomus versiforme increased significantly the growth ofAsparagus officinalis under controlled conditions using Turface as the growth medium. The growth responses, including increases in root fresh weight, numbers of shoots, shoot dry weight, and shoot height follow a pattern similar to other mycorrhizal systems. Indigenous VAM fungi appeared to have negative effects on average shoot fresh and dry weight, number of shoots per pot and average shoot height on one year oldA. officinalis seedlings obtained from the field and grown under controlled conditions. These results may be due either to the high levels of soluble phosphate present in the soil or the ineffectiveness of the particular indigenous fungi as mycorrhizal fungi in asparagus. Indigenous mycorrhizal fungi overwinter in asparagus root crown as vesicles and as external and internal hyphae. Soil obtained from the same fields as the one year old crowns was a good source of mycorrhizal inoculum for sterile seedlings.

Influence of Temperature on the Yield and Chemical Composition of Five Forage Legume Species1

AbstractOne‐year‐old plants of ‘Vernal’ alfalfa, ‘Lakeland’ red clover, ‘Common’ alsike clover, ‘Empire’ birdsfoot trefoil, and ‘Goldtop’ biennial sweetclover were grown to first flower in four temperature regimes: (a) 32 C, day/27 C night, (b) 27/21 C, (c) 21/15 C, and (d) 15/10 C. Flowering was delayed as temperatures decreased, except for trefoil and sweetclover where flowering occurred first in (b). Herbage, root, and total plant dry matter yields increased as temperatures decreased, except for trefoil in (a) where maturity was delayed and yields were as large as in (d). Average shoot height of red and alsike clovers and sweetclover increased as temperatures decreased, but changed little with trefoil. Shoot height of alfalfa was greatest in (b). Numbers of shoots were not affected by temperature, except in alsike clover where they increased as temperature decreased. Influence of temperature on chemical composition of the herbage and on carbohydrate storage in the roots is discussed. It was noteworthy that K concentration was very low in the herbage grown at the coldest temperatures (d) where the average for all species was 1.4% as compared with 2.3% in the herbage from (b).

The Effect of Casein Hydrolysate on the Growth In Vitro of Immature Hordeum Embryos

The Effect of Casein Hydrolysate on the Growth In Vitro of Immature Hordeum Embryos