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  • Author or Editor: Chee Kok Chin x
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Abstract

Asparagus officinalis L. was propagated by culturing single-node spear segments on Murashige and Skoog's medium. Incorporation of ancymidol in culture medium accelerated the production of plantlets, promoted development of stronger roots and shoots, and suppressed undesirable proliferation of callus.

Open Access

Abstract

Cut roses (Rosa hybrida L. cv. White Butterfly) pulsed with 14C-sucrose were analyzed for changes in total and labeled sucrose, glucose, fructose and starch after chases of various periods in either water or sucrose solution. Changes of 14C in an ethanol-insoluble fraction defined as the “cell wall fraction” were also studied. Changes in total amounts of each sugar did not correspond to changes in their respective labeled sugars, and these dissimilariteis in pattern indicated rapid turnover of each sugar in stems, and moderate turnover in leaves, with a general movement of 14C out of both leaves and stems. In flower heads, there was an initially short, overall incorporation of labeled sugars, followed by a gradual increase of 14C-glucose and 14C-fructose, but not 14C-sucrose. Starch turnover was appreciable in flower heads and in leaves, but not in stems. The leaves of roses held in the water chase showed the greatest turnover of starch. Incorporation of 14C into that portion of the ethanol-insoluble fraction designated “cell wall fraction” was greater in flower heads of roses chased in sucrose than those chased in water, but the type of chase solution used had little effect on incorporation of 14C into the “cell wall fraction” of leaf and stem tissue.

Open Access

Abstract

14C-sucrose, when taken up into the xylem, moved rapidly into leaves and flower heads of cut roses (Rosa hybrida L.) Outward lateral movement of 14C occurred rapidly along the entire length of stem at a uniform rate, regardless of l4C-sucrose concentration within the xylem and associated tissues. The quantity of 14C inverted sugars found in xylem tissue after uptake of 14C sucrose, and the rapid hydrolysis of sucrose passing through xylem of isolated stem segments suggests the involvement of invertase located in the xylem.

Open Access

Abstract

Labeling patterns of absorbed 14C sugars in petal discs of ‘Forever Yours’ rose (Rosa hybrida L.) revealed that most of the sucrose was absorbed undegraded indicating that inversion was not a prerequisite for absorption of sucrose by petal tissue.

Open Access

Abstract

Growth of ‘Bluecrop’ highbush blueberry (Vaccinium corymbosum L.) on Lloyd and McCown's woody plant medium was significantly unaffected by initial pH adjustments from 4.0 to 6.0 but was reduced significantly at pH 6.5. The expiants altered the pH of the medium during a 10-week culture period. A negative correlation between the final pH of the medium and growth was observed.

Open Access

Abstract

An effective dialysis extraction method was developed to extract gibberellinlike substances from cranberry plant tissue.

Open Access

Abstract

The temperature of the root zone can influence tomato growth (3) and yield (1). This probably occurs by altering root sink strength, which, in turn, influences photosynthesis by affecting the RuBP carboxylase activation state (2). Our data further indicated that within certain limits of air temperature (17°–25°C) the optimal root zone temperature for seedling growth is between 27° and 32° (3, 7). However, prolonged growth at 29° resulted in reduced yield (1).

Open Access

Abstract

Shoot growth of highbush blueberry (Vaccinium corymbosum L. cv. Bluecrop) in vitro was compared on various modifications of Murashige and Skoog (MS) medium containing Linsmaier and Skoog (LS) vitamins, Zimmerman’s Z-2 and Z-3 media, a modified Knop’s medium, and McCown and Lloyd’s woody plant medium (WPM). The WPM was found to produce best growth and highest number of shoots of 10 mm or longer. Shoots from Zimmerman’s half-strength medium (Z-3) yielded the highest percentage of rooting in sifted sphagnum peat.

Open Access

A protocol with a high rate of transformation and regeneration of `Hibush' eggplant (Solanum melongena L.) has been developed. This protocol used leaves of in vitro-grown seedlings as a source of explants. The shoot regeneration culture medium contained 0.1 μm thidiazuron (TDZ) combined with 10 to 20 μm N6-[isopentyl] adenine (2iP). Adding TDZ significantly improved regeneration efficiency and produced a mean of 15 buds and 3 to 4 shoots per explant. When explants were cocultivated with Agrobacterium tumefaciens strains Q10, Q20, Q30, Q40, Q201, Q202, Q203, or Q204 containing the native cryIIIB Bacillus thuringiensis (Bt), neomycin phosphotransferase (NPTII), and β-glucuronidase (uidA) genes, a callus/bud regeneration frequency of 38.8% was observed on the selection medium. Kanamycin at 50 μg·mL-1 was most effective in selecting for transgenic buds and shoots. Augmentin at 300 μg·mL-1 was used to eliminate A. tumefaciens. Augmentin also enhanced shoot proliferation. A transformation/regeneration efficiency of 20.8% was observed for shoot production. More than 400 putative transgenic plants have been produced with this method. From 50 putative transgenic plants, gene integration has been confirmed with Southern blot analysis and progeny tests.

Free access

Three constructs of a coleopteran toxic cryIIIB Bacillus thuringiensis gene were engineered and incorporated into eggplant (Solanum melongena L.). Southern blot analysis of the eight primary transformants and segregational analysis of their R, progenies indicated that the chimeric cryIIIB constructs in each of the transgenic plants were stably incorporated at a single locus or at multiple sites within the same linkage group and that they were regularly transmissible to the progeny. The results of Northern blot and RNase protection analyses demonstrated that transcription of the cryIIIB mRNA takes place in plant cells, but only a small amount of the expected entire length transcripts were produced. The amount of the 5' end mRNA fragment produced was at least 30 to 40 times more abundant than the amount of the 3' end mRNA fragment. This could be interpreted to mean that either the two ends of the mRNA are of different stability or that the transcription process is often interrupted and only a few mRNAs complete the entire process to the end. When the transgenic plant mRNA was reverse-transcribed, amplified by polymerase chain reaction, and hybridized to the cryIIIB probe, two smaller molecular weight mRNA species were identified. Thus, the preponderance of the cryIIIB mRNA in transgenic plants exists as a truncated species, a situation similar to that of cryI genes when expressed in transgenic plants. Seedlings from the eight independent transgenic plants were tested for Coleopteran insect resistance. However, they did not demonstrate any significant resistance to the first and second instar larvae of the Colorado potato beetle (Leptinotarsa decemlineata Say).

Free access