Reference "Inheritance of resistance to rice tungro spherical virus in a near-isogenic line derived from Utri Merah and in rice cultivar TKM6"

Reference ID

7024

Title

Inheritance of resistance to rice tungro spherical virus in a near-isogenic line derived from Utri Merah and in rice cultivar TKM6

Source

Euphytica, 2001, vol. 122, pp. 91-97

Authors (5)

Azzam-O	Imbe-T
Ikeda-R	Nath-P-D
Coloquio-E

Abstract

Resistance to rice virus diseases is an important requirement in many Southeast
Asian rice breeding programs. Inheritance of resistance to rice tungro spherical
virus (RTSV) in TW5, a near-isogenic line derived from Indonesian rice cultivar
Utri Merah, was compared to that in TKM6, an Indian rice cultivar. Both TKM6 and
Utri Merah are cultivars resistant to RTSV infections. Crosses were made between
TKM6 and TN1, a susceptible cultivar, and between TW5 and TN1, and F3 lines were
evaluated for their resistance to RTSV using two RTSV inoculum sources and a
serological assay (ELISA). In TKM6, the resistance to the mixture of RTSV-V +
RTBV inoculum source was controlled by a single recessive gene, whereas in TW5,
the resistance was controlled by two recessive genes. A single recessive gene,
however, controlled the resistance in TW5 when another RTSV variant, RTSV-VI,
was used, suggesting that the resistance in TW5 depends on the nature of the
RTSV inoculum used. RT-PCR, sequence, and phylogenetic analyses confirmed that
RTSV-VI inoculum differs from RTSV-V inoculum and accurate phenotyping of the
resistance to RTSV requires the use of a genetic marker.