Introgression of Xa4, Xa7 and Xa21 for resistance to bacterial blight in thermosensitive genetic male sterile rice (Oryza sativa L.) for the development of two-line hybrids

Issue Date

2-2008

Abstract

Bacterial blight (BB) of rice caused by X. oryzae pv. oryzae is a major production constraint in commercial hybrid rice production in the Philippines because most of the parental lines used in hybrid production do not carry resistance genes against the pathogen. In this study, three bacterial blight resistance genes, Xa4, Xa7 and Xa21, were introgressed to a temperature- sensitive genetic male sterile (TGMS1) line. A three-way cross of AR32-19-3-3/TGMS1//IRBB4/7 (PR36944) was made to produce 1,364 F2 plants carrying various combinations of Xa4, Xa7 and Xa21. Individual plants were characterized for reaction to bacterial blight PXO61 (race 1), PXO86 (race 2), PXO99 (race 6) and pollen sterility. Of 144 F2 plants demonstrating resistance against PXO61, PXO86 and PXO99, 22 exhibited highly resistant phenotypes with mean lesion lengths ranging from 0.37-2.97 cm. Analysis of disease reaction identified 20 potential TGMS F2 plants containing Xa4, Xa7 and Xa21 while 78 plants with Xa4 + Xa7. Phenotypic and polymerase chain reaction (PCR) analyses confirmed PR36944-450, PR36944-473 and PR36944-700 as homozygous for Xa7 and Xa21 and highly resistant to all three Xoo races. Fertility of PR36944-450 and PR36944-700 was restored at permissive temperature in a growth chamber. BB-resistant TGMS lines should facilitate breeding two-line hybrids in the tropics. © 2008 Springer Science+Business Media B.V.

Source or Periodical Title

Euphytica

ISSN

142336

Volume

164

Issue

3

Page

627-636

Document Type

Article

Language

English

Subject

Bacterial blight, Disease resistance, Hybrid rice, Marker-aided selection

Identifier

https://doi.org/10.1007/s10681-008-9653-1

Digital Copy

YES

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