PNABD246.pdf

*0488 Wu, L.C. 1968. Nitrogen mobilization in mung bean seedling infected
with Rhizoctonla solani. PLANT PHYSIOLOGY, v.43:S-9. [En] (REP.MB-1275)
MEETING: Annual Meeting of the American Society of Plant Physiology --
Amhert, MA, USA, Aug 20-23, 1968
It is well documented that external symptoms are the result of the
pathologically altered metabolism in the host plants. To approach this problem.
mungbean Rhizoctonia has been utilized as the host-parasite model in this
paper. Infection of mungbean by R. solani causes an increase in both reducing
sugar and amino acid fractions during the early stage of disease development
whereas the nucleic acid and protein contents are reduced as whole plants are
analyzed. When the determinations of free amino acid and protein are made with
cotyledon and root-shoot separately, protein content in root-shoot of infected
seedling becomes higher than that of healthy one as soon as the characteristic
symptom appears. Meanwhile, the reduction of cotyledon protein is lessened in
the infected seedling. Free amino acid contents in cotyledons of healthy and
infected seedlings are more or less the same, while, in root-shoot, free amino
acid content of infected seedling is less than that of healthy one. The
electrophoretic patterns of the soluble proteins are also shifted. These
results show the important role of nitrogen mobilization in mungbean seedling
for the establishment of disease development. [AS]
*0489 Beyries, A. ; Messiaen, C.M. 19b9. Virulence and specialization of
some strains of Rhizoctonia solani isolated from vegetable plants. ANNALES DE
PHYTOPATHOLOGIE, v.1(I):37-54. [FrJ [Fr En AbstJ (REP.MB-2406)
The strains of Rhizoctonia solani gathered in Southern France can be
tentatively classified in the following way: Group I - Strains showing an
optimal growth at 30 C, very virulent from 18 to 30 C towards beans (Phaseolus
vulgaris and Vigna radiata), lettuce, radish, cucumber, slightly on tomato and
potato stems. Group II - A heterogeneous collection of strains aggressive
towards a number of plants, but lacking virulence for lettuce or radish.
Temperature requirements are similar to thoge of group I for some strains, with
a better adaptation to growth at 10 C for others. Group III - Strains actively
growing at 10 C, and faster at 25 than at 30 C, highly virulent towards radish,
slightly virulent or not at all with other hosts. Group IV - Temperature
requirements similar to those of group III, strains virulent towards potato
stems and tubers from 10 to 25 C, slightly on tomato stems. Group V - Strains
which do not produce black, well differentiated scleroted sclerotia, like
groups I, II, III, IV, but have loose, white or light buff ones. Without any
virulence in the trials, they are probably secondary invaders on roots.
Implications of R. solani with diseases on beans, lettuce, crucifers, cucumber,
potato and tomato are discussed. The need of further studies with additional
hosts and criteria (basidial stages, C02 tolerance) is outlined. [AS]
*0490 Beyries, A. 1969. Efficacite de quelques fongicides systemiques
contre Rhizoctonia (corticium) solani Kuhn par traitements de semences de
haricot et de radis. PHYTIATRIE - PHYTOPHARHACIE, v.18(2):107-116. [Fr]
(REP .MB-2435)
Four systemic fungicides were compared with PCNB in laboratory and field
tests against Rhizoctonia on bean, blickgram and radish. Seed and soil
treatments were used. Oxathiin D.735 (carboxin) was the best. In view of its
low toxicity (LD5O, 3200 mg/Kg) it could be used in market gardening. [EMS]
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