Indian Society of Genetics & Plant Breeding

Evaluation of rice germplasm for multiple disease resistance under artificial inoculation conditions

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One thousand and eighteen rice germplasm lines were
evaluated against the prevalent pathotypes viz., PbXo-7
and PbXo-10 of Xanthomonas oryzae pv. oryzae causing
bacterial blight, brown spot and sheath blight diseases
under artificial inoculation conditions. Virulence/
avirulence of the two pathotypes to Xa/xa genes indicated
that all the pathotypes were virulent on the most of
bacterial blight resistant single Xa/xa gene (s). Pathotype
PbXo-7 was virulent to known Xa genes namely Xa 1, Xa
3, Xa 4, xa 5, Xa 7, xa 8, Xa 10 and Xa 11 and cultivars PR
114, PR 116 and PR 118 growing in Northern regions of
India. PbXo-10 was virulent on all these genes including
newly identified gene Xa38. None of the single gene is
effective against the pathotypes prevalent in Punjab.Two
years data revealed that 46 lines (5.4%) showed resistant
reaction to pathotype PbXo-7 and 30 lines (2.9%) showed
resistance to newly emerged pathotype PbXo-10. Twenty
two lines showed resistant reaction to both the pathotypes.
Most of the entries which were resistant to PbXo-10 also
showed resistant to the PbXo-7. Germplasm line IC
No.346207 showed resistant reaction and IC Nos. 114315
and 320826 showed moderately resistant reaction to brown
spot. None of the germplasm line showed resistance to
sheath blight. These resistant entries can either be
released as new varieties or further utilized as donors in
multiple disease resistance breeding programmes.

Keywords: Oryza sativa, bacterial blight, brown spot, pathotype, resistance, Xanthomonas oryzae pv. oryzae


Year: 2014
Volume: 74
Issue: Supplementry Issue
Article DOI: 10.5958/0975-6906.2014.00908.0
Print ISSN: 0019-5200
Online ISSN: 0975-6906



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