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- Author or Editor: Lincoln C. Peirce x
Abstract
Lastrucci (2) has stated: “Since the whole purpose of scientific research is to add to man’s store of verified knowledge, communication among scientists is a vital link in the whole chain of research effort.” The need for communication among scientists is really the basis for existence of professional societies. Knight (1), in discussing the history of scientific progress, ascribes a prominent role to communication and to the philosophical and, later, the professional societies organized to discuss and report science. Today, opportunities abound for disseminating research data or ideas or techniques. Our individual abilities to convey these data, ideas, and techniques in an understandable way are another matter. C.J. Sindermann’s book, Winning the Games Scientists Play (3), gives a tongue-in-cheek discussion of such matters as writing and reviewing manuscripts and presenting oral papers. My concern in this discussion, however, is not our ability to communicate but rather the avenues provided by our Society to get the job done.
Several cinnamic acids have been identified as principal toxic components of asparagus (Asparagus officinalis L.) root autotoxin and have been shown to synergize Fusarium infection of asparagus. The basis for this synergism was studied by exposing asparagus seeds and radicles from pregerminated seeds to ferulic (FA), caffeic (CA), or methylenedioxycinnamic (MDA) acids alone and in combinations of two or three of these acids. After treatment, seeds were placed in pots of peat-lite mix, and, depending on the experiment, all or half were inoculated with F. oxysporum (Schlecht) f. sp. asparagi (Cohen). Seedling emergence from each pot was used as a measure of toxicity. All cinnamic acids at 1% suppressed emergence compared with the control. Solutions combining FA and CA (0.5%/0.5%, v/v) were substantially more toxic than 1% solutions of either alone. Exposure of radicles (early postgermination) for 10 minutes to combined FA/CA before planting decreased emergence from pots, whereas emergence following a 10-minute exposure to 1% CA or FA alone did not differ from the controls. The 2-hour exposure to FA or to FA/CA and the 24-hour exposure to CA, FA, or FA/CA decreased emergence, with toxicity progressing as follows: CA < FA < FA/CA. Root tip squashes showed fewer mitotic figures in treated than in untreated radicles, and scanning electron microscopic (SEM) examination of the radicle epidermis revealed damage to the surface of epidermal cells and precocious root hair development, the extent of which paralleled treatment toxicity.
Abstract
Ten enzymes of asparagus (Asparagus officinalis L.) were examined on both starch and Polyacrylamide gels to identify polymorphic loci useful as genetic markers. Two polymorphic loci were discovered, one a root peroxidase (PER-1) and the other a stem shikimic acid dehydrogenase (skd-1). Electrophoretic analysis of 17 totipotent calli derived from anthers that were heterozygous for PER-1 showed 14 to be heterozygous somatic clones and three to be homozygous doubled haploids. The procedure described represents a significant improvement in efficiency over the current method of sexing and progeny testing for the recovery of gametic genotypes from asparagus anther culture.
Abstract
Asparagus (Asparagus officinalis L.) root filtrate (RF) depressed asparagus seedling emergence in a sterile peat–vermiculite medium. In a medium inoculated with Fusarium oxysporum f. sp. asparagi (FO), the effect was magnified. The response to RF dose, regardless of level of FO infestation, was quadratic. Comparisons with a sucrose solution of the same percentage of soluble solids as the RF suggested that reduced emergence may have been due in part to enhancement of FO growth by the energy source added to the medium. However, after germinating seeds in RF until radicle emergence, then rinsing and transferring them to FO-inoculated medium, emergence was reduced relative to controls. Therefore, depression of emergence apparently related both to an autotoxin somehow predisposing young radicles and/or hypocotyls to increased FO infection and to stimulation of FO in the rhizosphere by the soluble solids content of the root exudate. Infection was confirmed to be the only role of FO: sterilization of the spore suspension by Millipore (0.2 µm) filtration eliminated pathogen toxicity.
Abstract
HortScience will undergo some changes that the Publications Committee and the publications staff believe will increase interest and expand usefulness of this publication. The first of these changes—the reorganization of the currently combined Reports & Notes section into 2 separate sections—will begin with the Feb. 1985 issue.
A potential allelochemical was isolated and identified from methanol extracts of asparagus (Asparagus officinalis L.) fresh root tissue. Fractions were collected by cellulose column chromatography and tested for inhibition by an asparagus seed germination bioassay. The fraction showing the greatest inhibition contained caffeic acid, as identified by melting point, thin-layer chromatography, and infrared spectrum analysis. Seed germination bioassays and greenhouse pot tests showed depression of seedling emergence when asparagus seeds were exposed to various dosages of crude filtrate, a methanol extract from crude filtrate, and caffeic acid.