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  • Author or Editor: M. L. Brenner x
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Abstract

The age of computer literature searches is upon us. On a time-share basis, a computer can be used to search for specific topics, titles, and authors. It is now possible to search Biological Abstracts, Chemical Abstracts, the CAIN Data base as well as other citation listing services. To be assured that articles published in our two horticultural journals have maximum exposure we should institute the use of identifying key words. Presently the main agricultural citation system compiled by the National Agricultural Library only uses titles and authors' names. It is too costly for the National Agricultural Library to scan articles for key words. Thus, we are forced to heavily rely upon the selected wording of titles to provide maximum recognition of our published work. By listing key words for each article the probability of our publications having maximum visibility would be increased. I urge such a policy to be instituted as soon as is practical.

Open Access

Abstract

Lilium longiflorum Thunb. cv. Nellie White shoots rapidly emerged and flowered when bulbs were given a 4.5°C/40 day treatment. However, GA levels in the bulbs did not increase during the 4.5°C/40 day cold storage, but increased afterwards in the greenhouse with a GA maximum 30 days past storage. ABA activity patterns were similar to GA. Bulbs first treated at 4.5°C/30 days and then followed by 21°C/30 days had higher GA activity and their shoots were slower to emerge and flower than those of bulbs first treated at 21°C/30 days then given 4.5°C/30 days. Bulbs from 4 harvest dates had greater GA activity in the inner scales while ABA activity was greater in the outer scales.

Open Access

Abstract

Individual flowers from Rhododendron L. ‘Prize’ inflorescences were used at various stages of development for quantitative analysis of endogenous free abscisic acid (ABA) content by gas-liquid chromatography with electron capture detection. A decrease of endogenous ABA levels was observed in bud scale, petal, and gynoecium tissue during 6 weeks of cold treatment (9°C) given for release of floral bud dormancy. However, plants which received no cold treatment flowered as rapidly as plants exposed to 6 weeks of 9°. Therefore, a relationship between endogenous ABA levels and the capacity of azalea floral buds for continued development after a cold treatment could not be shown. Regression models of endogenous ABA content on respective morphological measurements of flower bud parts were computed to illustrate the relationship between destructive hormonal determinations and defined morphological changes over time.

Open Access

Abstract

Corms of Freesia hybrida Bailey ‘Moya’ and F. hybrida ‘Maria’ were stored at 2°, 13°, or 30°C immediately after harvest and sampled at 0, 6, or 13 weeks for fresh weight, sprouting ability, free indoleacetic acid (IAA), free abscisic acid (ABA) and conjugated ABA (conj-ABA). High performance liquid and gas-liquid chromatography methods were used for identification and quantification of the extractable IAA, ABA, and conj-ABA. Shoots from corms planted immediately after harvest emerged in 33 to 57 days. It is suggested that freshly harvested F. hybrida corms exhibit physiological dormancy for not more than 4 to 6 weeks and subsequently enter a state of imposed dormancy in storage at 30° or 2°. Physiological dormancy was released more rapidly and corm shoots emerged more rapidly during imposed dormancy when stored at 30° versus 2°. The 30° treatment did not appear to be mandatory for shoot emergence since corms stored at 2° or 13° for 6 weeks emerged within 5 or 20 days, respectively. Extended storage at 13° promoted pupation whereas storage at 30° and 2° prevented pupation. Pupated corms did not emerge when planted. The IAA, ABA, and conj-ABA levels in the corms during storage did not correspond with growth inhibition but rather appeared to relate to the formation of the new corm during pupation.

Open Access

Abstract

Freesia hybrida Bailey ‘Moya’ corms were analyzed for extractable indole-3-acetic acid (IAA), abscisic acid (ABA) and conjugated ABA (conj.-ABA) before and after 13 weeks of storage at 30°C. After 13 weeks of 30° storage, which is required for emergence, IAA levels did not change in the apical node + bud; however, there was a decrease in ABA and no statistically significant change in the conj.-ABA levels. IAA level increased (0.5 to 14 ng/g fresh weight) in the lateral buds after 13 weeks of heat while the ABA and conj.-ABA did not statistically change. Over the same period, IAA increased slightly (3 to 7 ng/g fresh weight) in the remaining corm tissue while ABA and conj.-ABA levels remained statistically constant.

Open Access

Abstract

Corm, shoot, and flower development in seed grown Freesia hybrida Bailey cv. Super Emerald Mixture were compared with levels of endogenous indoleacetic acid (IAA), abscisic acid (ABA) and conjugated ABA (conj-ABA) in the developing corm tissue. Lowering the forcing temperature to below 15°C stimulated floral initiation and corm filling. IAA levels decreased midway through corm filling in 1977 whereas in 1978 the decrease was not statistically significant. During the period of rapid corm filling, ABA levels increased as the temperature decreased below 15° suggesting an association between temperature, corm filling, and ABA.

Open Access

Abstract

Correlative inhibition of axillary shoot growth is one aspect of apical dominance that has been extensively investigated, but we still have a limited understanding of how this interesting process is controlled (2). Substantial evidence indicates that auxin, especially IAA synthesized in the apical portion of the plant, can inhibit axillary shoot growth (see refs. 2, 14, and 15) and that the inhibitory effect of IAA is most likely exerted indirectly (see ref. 10). In general, when apical dominance is released by surgical removal of the apical portion of a young plant, release of suppressed growth of axillary buds is detectable within 6 to 12 hr. There are three phases of growth, an initial slow phase, a second accelerated growth phase (see ref. 2) and a subsequent slow phase. There is also considerable information indicating that factors from roots, especially cytokinins, may be important for promotion of axillary shoot growth (12).

Open Access