Asparagus Seeds Research Articles

Comparison of Technique for Eliminating Contaminants from Asparagus Seeds

Abstract Thirteen seed treatments were compared to determine the optimal method to produce asparagus (Asparagus officinalis L. cv. Viking) seeds suitable for axenic culture. Treated seeds were examined for microbial contamination by culture on an agar medium and for percent germination by incubation on moistened paper. All treatments that included benomyl in acetone (2.5%, w/v) with 20% household bleach (0.1% sodium hypochlorite) were superior to the other treatments in eliminating bacterial and fungal contaminants without decreasing seed germination. Ethanol (70%) and hydrogen peroxide also decreased contamination levels, but ethanol decreased germination significantly. No evidence of internal contamination was detected when aseptic seeds were germinated and cultured on agar medium. Chemical names used: methyl(1-[(butylamino)carbonyl]-1H-benzimidazol-2-yl] carbamate (benomyl).

Asparagus virus. III: A new member of potexvirus from asparagus.

A potexvirus which had not been described previously, was isolated from Asparagus officinalis in Japan and the name asparagus virus III (AVIII) is proposed. AVIII infected 26 species from 8 families by sap inoculation, out of 37 species from 11 families tested. Artificially infected asparagus plants did not show any distinct leaf symptoms in the greenhouse for 2 years. The virus was not transmitted by aphids and through seeds of infected asparagus. Sap from infected Nicotiana megalosiphon was infective after heating for 10 min at 55 C but not at 60 C, after dilution to 2×10-4 but not 10-4, and after 21 days but not 23 days at 20 C. The virus particles were elongated flexuous rods, with a modal length of 580nm×13nm. Ultraviolet absorption spectrum of purified virus preparation was characteristic of that of nucleoprotein with an A 260/280 ratio of 1.18-1.19. The titer of the antiserum against the virus was 1/1024 in ring interface precipitin test. This antiserum reacted positively with AVIII but not with potato virus X(PVX) in SDS-agar gel immunodiffusion test. In tests with immune electron microscopy using the antibody decorating technique, the virus reacted with antisera against cactus virus X and narcissus mosaic virus but not with antisera against white clover mosaic virus, PVX, clover yellow mosaic virus and tulip virus X. All of the properties described are consistent with AVIII being a distinct member of potex-virus group.

Effects of allelopathic substances produced by asparagus on incidence and severity of asparagus decline due toFusarium crown rot

The effects of toxic components isolated from asparagus tissue onFusarium spp. and other soil microorganisms and their effects on the susceptibility of asparagus toFusarium crown rot was investigated to determine what role allelopathic substances may play in the asparagus ecosystem and in asparagus crown rot decline. Dried sterilized asparagus crown and root tissues were incorporated into pots of 3-month-old asparagus seedlings with and withoutFusarium inoculum. Root tissue alone and treatments in which crown and root tissues were combined with theFusarium inoculum showed significant reduction of plant growth over nontreated controls. Root and crown tissues were partitioned with polar and nonpolar solvents and bioassayed on pregerminated asparagus and cress seeds. Inhibition of radicle growth was confined to the polar fractions. Further separation with paper chromatography gave several fractions that were inhibitory to radish, cress, tomato seed germination as well as inhibitory to growth of pregerminated asparagus seeds. Crude extracts from roots and crown residues were bioassayed on many different fungal isolates on Petri plates and were found to inhibit the growth of oomycetous fungi. Extracts from the roots were found to be more active than extracts from other portions of the asparagus plants.

Etude des polysaccharides de réserve de deux graines de liliacées: Asparagus officinalis L., et Endymion nutans dumort

The seeds of Asparagus officinalis and Endymion nutans contain large quantities of NaOH-soluble polysaccharides. These hemicelluloses are linear molecules consisting of β-glucose and β-mannose 1→4 linked with α-galactose as a terminal group. The seeds of Asparagus are containing only one type of glucomannan (for which the ratio mannose/glucose=1) whereas those of Endymion seem to have at least two kinds of polysaccharide, differentiated by the mannose/glucose ratio.

Development of the Seed of Asparagus officinalis

In a study2 having to do with methods of hastening the germination of common asparagus seeds, it became necessary to determine the stages in the development of certain seed structures. This investigation was later extended, and the results are here presented. The seed of common asparagus arises from an anatropous ovule, two ovules normally being borne in each of the three locules of the ovary. The seed coat is black, finely rugose, and somewhat brittle. The embryo is a slender, threadlike structure completely imbedded in the hard, horny endosperm, the walls of which are hemicellulose. The structure of the mature seed of asparagus is briefly described and figured by HARZ. His descriptions and figures, however, show certain errors, which undoubtedly were due to his failure to follow through the changes which the seed structures undergo in their development. For example, he regards the structureless membrane just beneath the seed coat as the epidermis of nucellus, whereas developmental studies show this to be of integumentary origin. Both paraffin sections and sections of fresh seeds were employed. The latter were found to be particularly helpful. All drawings were made with a camera lucida. Integument At the time of pollination, the inner integument of the ovule consists of two cell layers, and the outer integument of from five to ten layers (figs. I-3) . The line of demarcation between the integuments I Contribution from the Division of Botany, College of Agriculture, University of California. 2 BORTHWICK, H. A., Factors influencing the rate of germination of the seed of Asparagus officinalis. Calif. Agric. Exp. Sta., Tech. Paper i8. I925. 3 HARZ, C. D., Landwirtschaftliche Samenkunde. i885. 4 In all the figures of this paper the following indicators are used: de, disintegrating endosperm cells; e, endosperm; em, embryo; gr, stem growing point; I, hilum; ii, inner integument; m, micropyle; n, nucellus; oi, outer integument; pe, pitted, thick walled endosperm; pm, pectic membrane; r, root tip; rc, root cap; s, seed coat; sac, embryo sac; sm, suberized membrane; su, suspensor; te, thin walled endosperm cells. Botanical Gazette, vol. 8o] [426