Modification of the Oligidic Medium for Axenic Culture of Aphelenchoides rutgersi

Aphelenchoides rutgersi was axenically cultured in modified Soytone, yeast extract, lyophilized chick embryo extract medium (3% ST:2% YE:20% CEE-L, w/v:w/v:v/v). Earlier formulations used 10% CEE, v/v, before the manufacturer changed the preparation. After reestablishing A. rutgersi in medium that permitted continuous subcultivadon and reproduction, a second medium was tested that contained 0.5% sucrose and 0.5% Lipid Concentrate. The commercially available Lipid Concentrate made it possible to incorporate nonaqueous soluble chemicals into the medium. In addition, 0.1% Fast Green #3 was added to both media to visually demonstrate active ingestion of nutriment.     

Molecular Analysis of Plant Defense Responses to Plant Pathogens

A number of inducible plant responses are believed to contribute to disease resistance. These responses include the hypersensitive reaction, phytoalexin synthesis, and the production of chitinase, glucanase, and hydroxyproline-rich glycoproteins. Because of the coordinate induction of these responses, it has been difficult to determine whether they are functional defense responses, and if they are, how they specifically contribute to disease resistance. Recent developments in molecular biology have provided experimental techniques that will reveal the specific contribution of each response to disease resistance. In this paper, we describe a strategy to determine if the hypersensitive reaction is a functional plant defense mechanism.     

DNA radiation damage and asymmetric somatic hybridization: Is UV a potential substitute or supplement to ionising radiation in fusion experiments?

Recent reports have revealed that the asymmetric nature of the nuclear genome of somatic hybrids, produced following the irradiation of one of the parents with X- or gamma rays, is generally much less than had been anticipated. As a consequence, we have begun to investigate whether UV radiation might be used as an alternative or indeed a supplement to the presently-used ionising radiation techniques in such experiments. Cell culture studies have revealed that UV radiation induces the desired physiological effects in sugar beet ( Beta vulgaris ) protoplasts, namely, a prevention of cell division without immediate cytotoxicity. Preliminary studies using denaturing and pulsed field gel electrophoresis have shown that UV can also induce substantial physical fragmentation of DNA. When using the same techniques, less breakdown was observed following gamma radiation. All results were highly reproducible. Such results augur well for the potential use of UV in asymmetric somatic cell fusion experiments.     

Optimum Initial Inoculum Levels for Evaluation of Resistance in Tomato to Meloidogyne spp. at Two Different Soil Temperatures

The effects of Meloidogyne incognita or M. javanica at five initial inoculum levels of 20, 100, 200, 1,000, and 2,000 eggs and infective juveniles per seedling on ''Floradade,'' ''Nemarex,'' ''Patriot,'' and ''PI 129149-2(sib)-5'' tomatoes maintained at 25 or 32.5 C were studied. The number of egg masses on roots of the susceptible cultivar Floradade was similar for both species of root-knot nematodes at either 2.5 or 32.5 C soil temperatures. At 25 C, very low numbers of egg masses were produced by both species of root-knot nematodes on Nematex, Patriot, and Lycopersicon peruvianum PI 129149-2(sib)-5. At 32.5 C, the best inoculum level for assessing resistance in these tomato genotypes was 200 eggs and infective juveniles per seedling. With 28 days of incubation, this temperature and inoculum level produced quantitative differences in resistance for both species of Meloidogyne.     

Influence of Meloidogyne incognita on the Content of Amino Acids and Nicotine in Tobacco Grown Under Gnotobiotic Conditions

Seedlings of Meloidogyne incognita-resistant (N.C. 95) and -susceptible (McNair 30) tobacco cultivars were grown aseptically for 55 days inside isolator chambers in autoclaved soil infested with 0 or 3,000 axenized eggs of M. im ognita per 500 cc of soil. Healthy and infected plants were compared. Dry root weights of infected plants of resistant and susceptible cultivars were 16% and 84%, respectively, less than the controls. Sixteen amino acids, including those precursors for nicotine, and nicotine, increased significantly in infected roots of both cultivars. Increases in amino acids in infected roots ranged from 28% for valine to 103% for tyrosine in the resistant N.C. 95, and from 30% for leucine to 148% for tyrosine in lhe susceptible McNair 30. Nicotine content (dry weight basis) increased 42% and 62% in infected roots of resistant and susceptible cultivars, respectively. Nematode infection increased nicotine by 112% in leaves of N.C. 95, and decreased it by 56% in leaves of McNair 30. Root damage by M. incognita probably decreased nicotine movement into leaves of McNair 30. In N.C. 95, nicotine movement into leaves apparently was not adversel b affected due to lack of significant root damage.     

Molecular weight and amino acid composition of purified spinach beet phenolase

The purification of spinach beet phenolase has been modified to include equilibration of the crude macerate with 0.5% cetyl-trimethylammonium bromide a     

Interaction of Four Soybean Cultivars with Subsoiling and a Nematicide

Yields of four soybean, Glycine max, cultivars were increased with subsoiling under the row and application of the nematicide, DBCP i 1,2-dibromo-3-chloropropane) in Tiflon sandy loam heavily infested with the root-knot nematode Meloidogyne incognita. These cultivars represent four maturity groups: very early (V), "Essex'', early (VI), "Davis'': medium (VII), ''Ransom''; and late (VIII), '' Hutton ''. The average increase for the four cullivars was about the same for subsoiling or DBCP. When the treatmcnts were used together, the increase was greater than when either was used alone, but the effects were not additive. Increased yields were obtained with subsoiling and DBCP for the most nematode resistant cultivar, Hutton, as well as for the most susccptiblc, Davis. Subsoiling reduced root-knot galling in nonfumigated plots but did not affect it in fumigated plots. On 12 September, M. incognita larvae were most numerous at the 0- to 20 cm depth, intermediate at 20 to 33 cm depth and least numerous at 33 to 46 cm depth, Subsoiling did not affect larval populations at the three levels.     

An Imported Case of Cystic Echinococcosis in the Liver

A 25-year-old Uzbek male presented with right upper abdominal pain for 20 days. On radiologic studies, a huge cystic mass was noticed in the right liver which was suspected as parasitic. The patient received right hepatic segmentectomy (segment 7), and the surgically resected mass was confirmed as cystic echinococcosis (CE), measuring 10.5 cm in its diameter. The inner surface of the cyst was bile-stained. The patient was discharged on the 8th hospital day, and was rechecked 6 months after the surgical intervention without any evidence of recurrence. The present report describes findings of an imported case of CE which represented ultrasound images of the ''ball of wool''.     

Adenine nucleotide content and energy charge in dry cells and cysts of Azotobacter vinelandii

Abstract The levels of intracellular adenine nucleotides, energy charge, oxygen consumption and poly-β-hydroxybutyric acid stored, have been investigated in dry vegetative cells and cysts of Azotobacter vinelandii . The data show that under desiccation conditions the cysts retain viability at energy charge values of 0.20 and an ATP/ADP ratio of 0.24, whereas under the same desiccation conditions, vegetative cells die at energy charge values <0.5 and an ATP/ADP ratio of <0.6.