TY  - BOOK
AU  - Sheela Paul T 
AU  - James Mathew(Guide)
TI  - Biochemical and Biological Bases of Resistance in Solanaceous Vegetables Against Bacterial Wilt Incited By Ralstonia Solanacearum (Smith) Yabuuchi et al
U1  - 632.3 
PY  - 1998///
CY  - Vellanikkara
PB  - Department of Plant Pathology, College of Horticulture 
N2  - An investigation on biochemical, biological 
and nutritional bases of resistance in solanaceous 
vegetables against bacterial wi1t incited by Ralstonia 
solanacearum (Smith) Yabuuchi et al., has been attempted. 
The pathogen R. solanacearumwas isolated from 
respecti ve hosts and characterised by various morphological, 
cultural, biochemical and physiological tests upto biovar 
level. 
The three isolates were cross inoculable, and 
were sensitive to AmDistryn and Streptocycline. Based on 
these studies the tomato and chilli isolates were identified 
as Ralstonia solanacearum race I biovar III and that from 
brinjal as R. solanacearum race I biovar V. 
The study on toxigenic property of the 
bacterial isolates revealed that the toxic metabolites were 
not host specific. 
Out of the 43 varieties / lines screened , 
12 varieties / lines were selected, one each from resistant, 
moderately resistant, moderately susceptible and susceptible 
 
categories. The varieties / lines selected were LE 79-5, 
BT-IO, LE 470 and Pusa Ruby for tomato; Swetha, Composite-2, 
BB-7 and Pusa Purple Long for brinjal and Ujwala, Manjari, 
Jwalasakhi and Pusa Jwala for chilli. 
The studies on biochemical, biological and 
nutritional factors in tomato, brinjal and chilli showed 
considerable variation between crops, between varieties/ 
lines, and between plant parts. However the root being the 
primary foci of infection by R. solanacearum the biochemical 
reactions in root is considered more important than other 
plant parts. Among the biochemical factors, the OD phenol 
and specific activity increased due to infection and the 
content was higher in the resistant genotype (LE 79-5) both 
under heal thy and diseased condition in tomato. In brinj al, 
the polyphenol oxidase activity, specific activity and 
peroxidase activity increased due to infection and were 
higher in resistant genotype (Swetha) both under healthy 
and diseased condition. In chilli, total phenol and OD 
phenol, increased due to infection and were higher in 
resistant plants (Ujwala) under healthy and diseased 
condi tions. The soluble sugar content and specific activity 
were also higher in resistant plants both under healthy and 
diseased condition even though a decrease was observed due 
to infection . 
 
In tomato, the resistant genotype showed a 
higher content of OD phenol, polyphenol oxidase activity, 
specific activity and alkaloids under healthy condition; and 
total phenol, OD phenol, soluble protein, specific activity 
and peroxidase activity under diseased condition. In 
brinjal, the resistant genotype recorded higher content of 
total phenol, OD phenol, soluble sugars, amino acids, soluble 
protein, polyphenol oxidase activity, specific activity and 
peroxidase activity under healthy condition; and polyphenol 
oxidase activity, specific activity and peroxidase activity 
under diseased condition. In chilli, the resistant genotype 
recorded higher total phenol, OD phenol, soluble sugars and 
specific acti vi ty under heal thy condition; and total phenol, 
OD phenol, soluble sugars, specific activity and peroxidase 
activity under diseased condition. 
Among the biological factors, the total 
microflora (fungi and actinomycetes), Pseudomonads and 
parasitic nematodes increased due to infection in resistant 
genotype whereas beneficial microbes recorded a decrease in 
population in resistant genotype by infection. 
In tomato the resistant genotype recorded 
higher nematode population under heal thy condi tion and higher 
total microflora, virulent Ralstonia and avirulent 
 

 
Pseudomonas 
 

under diseased condition. 
 

In brinjal the 
 
	
resistant genotype recorded higher population of fungi, 
avirulent Pseudomonas, mycorrhiza and saprophytic nematodes 
under heal thy condition, and fungi, virulent Ralstonia, 
avirulent Pseudomonas and nematodes under diseased condition. 
In chilli, the resistant genotype recorded higher populations 
of avirulent Pseudomonas, mycorrhiza and nematodes under 
heal thy condition and fungi, avirulent Pseudomonas and 
mycorrhiza under diseased condition. 
Among the nutritional factors, in tomato the 
resistant genotype recorded higher content of potassium and 
calcium under heal thy condition and iron, zinc and manganese 
under diseased condition. In brinjal the resistant genotype 
recorded higher content of nitrogen, calcium, magnesium and 
zinc under heal thy condition; and potassium, magnesium, iron 
and zinc under diseased condition. In chilli, the resistant 
genotype recorded higher content of phosphorus, calcium and 
iron under heal thy condition; and nitrogen, potassium 
magnesium and zinc under diseased condition. 
Thus the study revealed that it was not 
possible to arrive at common bases for resistance to 
bacterial wilt in tomato, brinjal and chilli taken together. 
However it was possible to outline the important parameters 
that conditions resistance in individual crops. 


UR  - https://krishikosh.egranth.ac.in/handle/1/5810101561
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