STUDIES ON PHYSIOBIOCHEMICAL CHANGES, VIRUSVECTOR RELATIONSHIP AND MANAGEMENT OF RICE TUNGRO DISEASE
KrishiKosh
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Title |
STUDIES ON PHYSIOBIOCHEMICAL CHANGES, VIRUSVECTOR RELATIONSHIP AND MANAGEMENT OF RICE TUNGRO DISEASE
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Creator |
SHYAM KISHOR PATEL
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Contributor |
RAJESWARI, B
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Subject |
PHYSIOBIOCHEMICAL, CHANGES, VIRUSVECTOR, RELATIONSHIP, MANAGEMENT, RICE, TUNGRO, DISEASE
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Description |
Rice tungro disease (RTD) is a major constraint in production of rice (Oryza sativa L.) not only in India but in all South and Southeast Asia. In Andhra Pradesh, rice tungro disease (RTD) has been reported to occur in almost all the popular rice cultivars grown in Khammam, East Godavari, Ranga Reddy, West Godavari, Medak, Nalgonda, Nellore, Chittoor and Prakasam districts. Keeping this in view, a detailed study on host range, virus vector relationship, physiological and biochemical changes and insecticides management of rice tungro disease and its vector was conducted at Department of Plant Pathology, College of Agriculture, ANGRAU in collaboration with Directorate of Rice Research (DRR), Rajendranagar, Hyderabad, Andhra Pradesh, India during the year 2013-2014. Out of twenty weed host species tested through forced feed inoculation with viruliferous leaf hoppers (Nephotettix virescens), thirteen weed host species were found positive reaction for tungro disease viz., Cynodon dactylon, Digitaria sanguinalis, Echinocloa colonum, E. crusgalli, Leptochloa chinensis, Panicum repens, Cyperus rotundus, Fimbrystylis miliaceae, Dinebra aratica, Brachiaria ramosa, Paspalum dilatum, Leersia hexandra and Paspalum hydrophilum and exhibited leaf yellowing, stunting, reduction in number of tillers and interveinal chlorosis with typical symptoms of tungro disease as expressed in rice crop. The virus was also recovered from the seven virus infected weed host species viz., E. colonum, E. crusgalli, Panicum repens, C. rotandus, Paspalum dilatum, P. hydrophilum and Leersia hexandra. Weed hosts viz., Paspalum dilatum and Paspalum hydrophilum exhibited prominent symptoms of the tungro disease. Physiological and biochemical changes were found to be induced in rice leaves due to infection by rice tungro disease. Significant differences in chlorophyll ‘a’, chlorophyll ‘b’, total chlorophyll (a+b), chlorophyll a/ b ratio and carotenoide content were observed in different rice cultivars and at different days after inoculation (10, 20, 30 and 40). In general in the uninoculated control plants of all the nine rice cultivars, the contents of photosynthetic pigments were increased with the advancement of the crop age. In the inoculated plants of susceptible rice cultivars showed highest reduction in photosynthetic pigments with the advancement of the plant age as compared to moderately resistant and resistant rice cultivars. Among the nine rice cultivars tested, the decrease in photosynthetic pigments was highest in T(N)1 (82.5 %), and least in resistant rice cultivar Vikramarya (5.58 %) at 40 days after inoculation, respectively as compared to all the rice cultivars tested. The carbohydrate fraction viz., reducing sugars, non reducing sugars, total sugars and starch content were significantly differed in RTD inoculated and uninoculated plants irrespective of the rice cultivars. In general in the uninoculated control plants of all the nine rice cultivars, the contents of reducing sugars were increased with the advancement of the crop age irrespective of the rice cultivars and days after inoculation. The inoculated plants of susceptible rice cultivars showed highest increase in carbohydrate fractions with the advancement of the plant age as compared to moderately resistant and resistant rice cultivars. Among the nine rice cultivars tested, the increase in carbohydrate fractions were found high in susceptible rice cultivar T(N)1 74.5 %, 69.6 %, 71.7 % and 55.5 % at 40 days after inoculation. The quantities of the phenol contents in healthy plants generally increased with the age of the plants of all the nine rice cultivars tested. The healthy plants of moderately resistant and resistant cultivars recorded higher amount of total phenols than the susceptible cultivars. Total phenol content were decreased in susceptible rice cultivar T(N)1 (22.9%, 45.3% and 60.5%), CO 39 (21.1%, 41.0% and 59.3%) and MTU 1010 (19.2%, 37.5% and 53.7%) at 20, 30 and 40 DAI, respectively. But in moderately resistant and resistant cultivars, total phenol were increased at different days after inoculation. The maximum decline in phenol content was noticed in susceptible rice cultivar T(N) 1 (60.50%) samples analysed at 40 DAI. Biochemical parameters viz., reducing sugars, non reducing sugars, total sugars and starch content were found high in susceptible rice cultivars (T(N)1, CO 39 and MTU 1010) as compared to moderately resistant (IR 64, RPBIO 226 and MTU 7029) and resistant rice cultivars (Vikramarya, Utrirajapan and Nidhi). The phenol content of susceptible rice cultivars (T(N)1, CO 39 and MTU 1010) was observed to be decreased over moderately resistant and resistant rice cultivars. In case of virus- vector and host relationship, resistant rice cultivars (10 -15 days), moderately resistant cultivars (11-13 days) and susceptible cultivars ( |
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Date |
2016-09-12T10:27:16Z
2016-09-12T10:27:16Z 2014 |
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Type |
Thesis
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Identifier |
http://krishikosh.egranth.ac.in/handle/1/76401
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Language |
en
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Relation |
D9678;
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Format |
application/pdf
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Publisher |
ACHARYA N.G. RANGA AGRICULTURAL UNIVERSITY, RAJENDRANAGAR, HYDERABAD
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