H. annuus

A second polysaccharide fraction (Sample 3) was isolated from the filtrates by concentration and following precipitation with ethanol (1 3). The yield and characteristics of the obtained polysaccharides (Samples 2 and 3) are given in Table 1. It is evident that the sum of the yields for Samples 2 and 3 is almost equal to the yield for Sample 1. The polyuronic content data are also well balanced. This fact indicates that the suggested method is suited for fractional isolation of the polysaccharides from the spent culture medium of H.annuus 1805 cell suspension. As can be seen from Table 1, the main part of the exopolysaccharide was in fraction I. 

The objective of this research was to follow the course of growth of H.annuus 1805 cell suspension in parallel with the changes in the amount of cell walls, as well as the course of biosynthesis and secretion of the enzymes polygalacturonase and pectinmethylesterase and the... 

H.annuus 1805 cell suspension was cultivated on a shaker (11.6 rad/s) at 26-28 °C in the dark in 1/5 net volume flasks. Duration of growth was different from 5 days for obtaining the inoculum to 10 days for studying the course of growth, the course of changes in the cell walls and the courses of biosynthesis and secretion of the enzymes polygalacturonase and pectinmethylesterase as well. For inoculation 20 % (v/v) five-day cell suspension, containing 9 g/L dry cell biomass, was used. 

Extracellular Enzyme Activities. The protein, carrier of the polygalacturonase and pectinmethylesterase activities, was salted out from the H.annuus 1805 culture medium by adding ammonium sulphate to 70 % saturation. The precipitate was separated by centrifugation (30 min, 4500 xg), diluted with 0.1 M phosphate buffer (pH 7.0) and dialyzed for 12 hours against distilled water. After dilution to the required volume with the same buffer, both enzyme activities under study were determined in the solution. 

Course of growth of H.annuus 1805 cell suspension and of changes in the cell walls. 

Fig. 3 Time course of biosynthesis and secretion of pectinmethylesterase from H. annuus 1805.

Name given to a H. annuus H H. tuberosus hybrid Shoemaker, 1927... 

The sectional name Atrorubens has replaced Divaricati of Schilling and Heiser (1981) due to priority (Anashchenko, 1974). Species in the sections Agrestes and Helianthus are annuals. The section Helianthus includes H. annuus and around 10 other species, which are confined largely to the western part of the U.S. and are diploid (2n = 34) (Heiser, 1995). The Jerusalem artichoke and around 30 other members of the section Atrorubens are perennials. They are geographically concentrated in the eastern and central part of the U.S. and include diploid, tetraploid, and hexaploid species. Jerusalem artichoke is a hexaploid species (2n = 102). 

PI 458544 — German origin. H. annuus x H. tuberosus hybrid, with reportedly high tuber yields. 

Cauderon, Y., Analyse cytogenetique d hybrides entre Helianthus tuberosus et H. annuus. Consequences en matiere de selection, Am. Amelior. Plant, 15, 243-261, 1965. 

Witrzens, B., Scowcroft, W.R., Donnes, R.W., and Larkin, P.J., Tissue culture and plant regeneration from sunflower and interspecific hybrids (II. tuberosus and H. annuus), Plant Cell Tissue Organ Cult., 13, 61-76, 1988. 

The following is a brief overview of the biology of several of the more important insect species, based largely on data gathered from infestations of H. annuus, that have been reported to feed on H. tuberosus. 

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