| endopolygalacturonase, an extracellular pectic enzyme of rhizoctonia fragariae. | a pectolytic enzyme from culture filtrates of rhizoctonia fragariae was purified approx. 29-fold. the enzyme exhibited maximal depolymerizing activity on na-polypectate rather than pectin at ph 5.0 and was inhibited at different extent by divalent cations mg++, mn++, ca++. the analysis by paper chromatography of the products of enzyme hydrolysis suggested that the enzyme attacks the substrate by a random mechanism. the absorption spectrum of the chromogen formed by the hydrolysis products and th ... | 1977 | 16833 |
| endopolygalacturonase from rhizoctonia fragariae. purification and characterization of two isoenzymes. | an electrophoretically homogeneous preparation of endo-polygalacturonase (poly(1,4-alpha-d-galacturonide)glycanohydrolase, ec 3.2.1.15) from culture filtrates of rhizoctonia fragariae, a pathogenic agent in strawberry plants, was resolved into two isoenzymes when subjected to isoelectrofocusing in a narrow ph range. the isoelectric points of the two isoenzymes were 6.76 +/- 0.03 and 7.08 +/- 0.05. the two polygalacturonases exhibited similar substrate specificity, ph optimum and pattern of degra ... | 1977 | 884121 |
| comparison of pratylenchus penetrans infection and maladera castanea feeding on strawberry root rot. | the interaction of lesion nematodes, black root rot disease caused by rhizoctonia fragariae, and root damage caused by feeding of the scarab larva, maladera castanea, was determined in greenhouse studies. averaged over all experiments after 12 weeks, root weight was reduced 13% by r. fragariae and 20% by m. castanea. the percentage of the root system affected by root rot was increased by inoculation with either r. fragariae (35% more disease) or p. penetrans (50% more disease) but was unaffected ... | 2005 | 19262852 |
| effect of entomopathogenic nematodes and trichoderma harzianum on the strawberry black root rot pathogens pratylenchus penetrans and rhizoctonia fragariae. | the effects of inundative releases of entomopathogenic steinernema carpocapsae and s. feltiae infective juveniles and applications of the biological control fungus trichoderma harzianum t-22 (rootshield) on pratylenchus penetrans and strawberry black root rot caused by rhizoctonia fragariae were determined in field microplots and small plots. entomopathogenic nematodes were applied as a soil drench at rates of 7.4 or 14.8 billion per ha in may or august for 3 years. rootshield was applied as cro ... | 2002 | 19265955 |
| interaction of pratylenchus penetrans and rhizoctonia fragariae in strawberry black root rot. | a split-root technique was used to examine the interaction between pratylenchus penetrans and the cortical root-rotting pathogen rhizoctonia fragariae in strawberry black root rot. plants inoculated with both pathogens on the same half of a split-root crown had greater levels of root rot than plants inoculated separately or with either pathogen alone. isolation of r. fragariae from field-grown roots differed with root type and time of sampling. fungal infection of structural roots was low until ... | 2003 | 19265969 |
| effects of pratylenchus penetrans and rhizoctonia fragariae on vigor and yield of strawberry. | microplot and small field-plot experiments were conducted to determine the effects of pratylenchus penetrans on strawberry yield over several seasons and to evaluate the effects of nematode control on strawberry vigor and yield. pratylenchus penetrans alone or in combination with the black root rot pathogen, rhizoctonia fragariae, reduced strawberry yield in microplots over time. there were no differences in effects on yield among r. fragariae anastomosis groups a, g, or i. the interaction of th ... | 1999 | 19270914 |
| influence of rotation crops on the strawberry pathogens pratylenchus penetrans, meloidogyne hapla, and rhizoctonia fragariae. | field microplot, small plot, and greenhouse experiments were conducted to determine the effects of rotation crops on pratylenchus penetrans, meloidogyne hapla, and rhizoctonia fragariae populations. extraction of p. penetrans from roots and soil in microplots and field plots planted to rotation crops was highest for garry oat, lowest for triple s sorgho-sudangrass and saia oat, and intermediate for strawberry, buckwheat, and canola. isolation of r. fragariae from bait roots was highest for straw ... | 1999 | 19270931 |