Abstract
The acrylamide gel electrophoretic band patterns of proteins from young or fresh and old, senescing leaves or petals of roses, carnations, chrysanthemums, and snapdragons showed generally that with aging the initial and prominent, distinct bands near the origin became less distinct and were located at a distance thus indicating the presence of a more heterogeneous admixture of apparently smaller molecular weight protein units. There was also less protein in the senescing tissues. Kinetin treatment tended to maintain the electrophoretic pattern of leaf proteins similar and comparable to proteins from fresh leaves.
.) for the plant material. This work was supported in part by a grant from the Florida Department of Agriculture and Consumer Services. Mention of any trade names does not imply endorsement of the products named or criticism of similar ones not named. The
University of Florida, Institute for Food and Agricultural Sciences, Center for Aquatic and Invasive Plants, 7922 NW 71st St., Gainesville, FL 32653. Published as Journal Series Number R-10420 of the Florida Agriculture Experiment Station. This
Abstract
Shoot tips of Nicotiana aiata Link & Otto, N. forgetiana Sander and N. sanderae W. Wats seedlings were established on modified Murashige and Skoog (MS) salts and vitamins medium to provide leaf material as the cell source for protoplasts. Viable protoplasts (8.0 × 105 to 1.5 × 106/ml per g fresh weight) were enzymatically isolated from N. alata in 2.5% Driselase plus 4.0–4.7% mannitol or sorbitol in cell protoplast wash solution (CPW). An enzyme mixture of 1.0% Driselase, 1.0% Macerozyme R-10, 1.0% Cellulase R-10, 0.5% potassium dextran sulfate and 4.0% mannitol in CPW released 4.0 × 105 to 1.0 × 106 and 7.6 × 105 to 8.5 × 105/ml protoplasts per g leaf tissue respectively from N. forgetiana and N. sanderae. Only 4 of 13 tested culture media, also exhibiting species selectivity, promoted sustained cell division of protoplasts to the macroscopic callus stage in 28-35 days. Optimum plating efficiency ranged from 15 to 37% when the protoplasts were cultured at 5.0 × 104/ml in Cool White light. Plating efficiency did not increase when cultures were placed under Gro-Lux light. Macroscopic callus was readily regenerated to shoots in 2 months on MS medium + 1.0 mg/liter zeatin (Z) or MS + 2.0 mg/liter idoleacetic acid (I A A) + 1.0 mg/liter benzy lamino purine (BA). Rhizogenesis occurred in hormone-free MS medium. Regenerated plants flowered in the greenhouse and exhibited minor variation in flower form and pigmentation.
Abstract
A 20% dichlorvos impregnated polyvinyl chloride (PVC) resin strip (6.3 × 15.9 × 0.7 cm) per 28.3 m3 interior room significantly reduced the number of mealybugs (Phenacoccus solani Ferris) 48 hour posttreatment. Greenpeach aphid (Myzus persicae Sulzer) and twospotted spider mite (Tegranychus urticae Koch) populations were not suppressed. Exposure of pests to a stake label with an attached dichlorvos impregnated PVC strip produced the same effects as the room fumigation test. Placement of a 20% dichlorvos PVC resin strip per 25.4 × 70 cm polyethylene bag with infested plant material for 12 or 24 hr reduced populations of M. persicae, P. solani and T. urticae, however, 3 exposures at 7-day intervals were more effective in maintaining low populations. Fumigation in bags produced phytotoxic effects with specific plants.
Abstract
The influence of P applications on the growth of Berberis x mentorensis L. M. Ames, Juniperus chinensis ‘Keteleeri’ Cornman, and Taxus x media ‘Hicksii’ Rehd., was studied for 2 growing seasons. During one summer P was applied at varying rates to plants grown in containers and the growth and P content of various plant parts were determined. The following spring the roots of these dormant plants were washed free of the growing medium and the plants were grown in solution culture at varying levels of P labeled with P32. The spring growth, the P content of all plant parts, and the % P coming from the solution into all plant parts during the spring were determined. Phosphorus applied during the summer caused little growth response except with young Taxus plants receiving a high P level. There were several significant growth responses during the spring due to P applications the previous season. A high P concentration during the spring increased the growth of some plants, but Taxus plants with a high internal P status showed little response. The P coming into the new spring growth from solution varied from 0 to 86% depending on the plant species used and the concentration around the roots. In Berberis the majority of the rest of the P moving into new growth originated from reserve P in the roots. In Juniperus the majority of the internally redistributed P came from the foliage and in Taxus both the foliage and roots were important sources of reserve P.
Abstract
N, N-dimethyl-2, 2-diphenylacetamide (diphenamid) and α, α, α,- trifluoro-2, 6-dinitro-N, N-dipropyl-p-toluidine (trifluralin) caused no injury to transplanted petunias (Petunia hybrida Vilm.) or marigolds (Tagetes patula L.) when incorporated in a mulch. Satisfactory broadleaf and grass weed control as denoted by indicator crops was achieved with both of these herbicides. Dichlobenil, 2,6-dichlorobenzonitrile, caused severe injury to both petunia and marigold transplants when applied in the herbicide-mulch combination. Control of broadleaf and grass indicator weeds with dichlobenil was excellent at all rates. Dimethyl tetrachloro terephthalate (DCPA) resulted in no visible injury to the marigold or petunia transplants when used in the herbicide-mulch combination, but control of grass and broadleaf indicator weeds was poor. When diphenamid and dichlobenil at the same rates were incorporated on peat moss, licorice root, pine bark or sugar cane mulches, no differences were observed among the mulches in regard to their ability to control weed growth.
On established nursery stock, 2-chloro-4, 6-bis (ethylamino)-s-triazine (simazine) plus DCPA, simazine plus diphenamid, and 3-(3, 4-dichlorophenyl)-1, 1-dimethylurea (diuron), applied directly to the soil surface performed better than the herbicide-mulch combination at the lower rates. At higher rates, both the direct spray on the soil surface and the herbicide-mulch combination performed satisfactorily.
Abstract
No appreciable signs of phytotoxicity were observed for 4 days following fumigation of plants (including begonias, petunias, snapdragons) with ozone of up to 80 parts per hundred million (pphm) or sulfur dioxide of up to 400 pphm for 2 hr. Thereafter, there was considerable necrosis, particularly on begonias fumigated with the highest concn of the pollutants. Growth suppression was reflected in reduced shoot and flower wt, and to a lesser degree in reduced flower number. Overall, begonias and petunias were the most sensitive. Coleus and snapdragons were moderately sensitive, while marigold, celosia, impatiens and salvia were tolerant. ‘White Tausendschon’ was the most sensitive begonia cultivar while blue-flowered ‘Capri’ was the most sensitive petunia. Mixed color petunias exhibited varying degrees of tolerance. ‘Scarlet Rainbow’ coleus was more sensitive than ‘Pastel Rainbow’. Measurements of growth alterations in plants were found very useful in determining latent forms of air pollutant injury.
Abstract
Hardwood bark was used in combination with other materials as media for forsythia and juniper plants in containers with various growing procedures, bark sources, and fertility practices. Based on dry wt, the most rapid growth of forsythia was obtained in a bark and fine sand medium; whereas, the least growth was obtained in soil, peat, and perlite. However, pfitzer juniper plants under 2 different fertility regimes grew most rapidly in a bark, soil, and peat medium, slowest in a bark and torpedo #2 sand medium, and at an intermediate growth rate in soil, peat, and perlite. The standard mix (soil, peat, and perlite) was more acidic than the experimental mixes containing bark and sand. Chlorotic plants were more numerous in acidic mixes. Leaf tissue analyses from the plants grown in the peat amended bark and standard mix had higher Fe and Mn concn than plants grown in a bark-sand mix.