Indian Society of Genetics & Plant Breeding

Marker aided improvement of Pusa 6B, the maintainer parent of rice hybrid Pusa RH10, for resistance to bacterial blight

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The present study was under taken to transfer two
bacterial blight resistance genes, xa13 and Xa21 into
Pusa6B, the maintainer parent of Pusa RH10 (PRH 10),
the first superfine grain aromatic rice hybrid. Marker aided
foreground selection for genes xa13 and Xa21 was carried
out using a CAPS marker RG136 and STS marker pTA248,
respectively. Forty Six STMS markers polymorphic
between Pusa 6B and Pusa1460 providing genome wide
coverage were used for background selection for
recovering recurrent parent genome. Marker aided
selection was combined with phenotypic selection for
agronomic, grain and cooking quality traits to hasten the
breeding process. In each backcross generation, based
on background selection, a single plant positive for genes
xa13 and Xa21 was selected for further backcrossing/
selfing. The extent of recurrent parent genome recovery
in the 9 BC
2F2 plants, carrying both the genes in
homozygous condition, ranged from 92.3% to 95.6%. All
the plants of BC2F3 families were found highly resistant to
BB on artificial inoculation with the most virulent Kaul
isolate of Xoo. The improved lines of Pusa 6B showed
highly resistant reaction with susceptibility index (SI)
ranging from 0.5 to 1.5 as compared to 1.2 of donor parent
Pusa 1460 and 9.2 of recurrent parent Pusa 6B. The
agronomic performance, grain and cooking quality
attributes of majority of the BC2F3 plants were similar to
Pusa 6B. However, some plants showed improvement in
spikelet fertility, aroma, grain length and L/B ratio. Some
of the BC
2F3 families matured a few days earlier than the
recurrent parents, which will be useful in synchronization
of parental lines in hybrid seed production.

Keywords: Foreground selection, Background selection, Bacterial Blight, STS & CAPS


Year: 2009
Volume: 69
Issue: 1
Article DOI: N/A
Print ISSN: 0019-5200
Online ISSN: 0975-6906


M. Nagarajan info_circle
T. Mohapatra info_circle

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