Reference "RFLP analysis of genomic regions associated with cooked-kernel elongation in rice"

Reference ID

Title

RFLP analysis of genomic regions associated with cooked-kernel elongation in rice

Source

Theoretical and applied genetics, 1993, vol. 87, pp. 27-32

Authors (4)

Ahn-S-N	Bollich-C-N
McClung-A-M	Tanksley-S-D

Abstract

As a result of earlier breeding efforts, portions of the genome of ''Basmati
370'' have been introgressed into a rice breeding line, B8462T3-710. Cooked-
kernel elongation was increased in this breeding line to a level equal to that
of ''Basmati 370''. The objective of this study was to identify and locate
quantitative trait loci (QTLs) associated with cooked-kernel elongation in an F3
population derived from a cross between B8462T3-710 and the reduced-elongation
recurrent parent variety, Dellmont. DNA from the parental lines and ''Basmati
370'' as a control, were screened for RFLPs using 170 clones chosen to cover the
rice genome at intervals of 8 cM on average. Eighteen markers identified RFLPs
common to Basmati 370 and B8462T3-710, but different from Dellmont, suggesting
possible associations with kernel elongation. The B8462T3-710/Dellmont F3
population was analyzed for segregation of those RFLPs and for kernel
elongation. Analysis of variance of the kernel elongation ratio revealed that
two markers, 14.6 cM apart on chromosome 8, are significantly associated with
this trait (RZ323 P less-than-or-equal-to 0.005, RZ562 P less-than-or-equal-to
0.05). Interval mapping suggests a single QTL with a close proximity to RZ323.
This QTL was tested in F6 lines derived from the same cross and the presence of
the B8462T3-710 segment detected by RZ323 caused a highly significant increase
of the kernel elongation ratio (P less-than-or-equal-to 0.04). In addition, the
QTL for kernel elongation and a gene for aroma, which are major components of
the grain quality characteristics of Basmati-type rices, showed linkage. The
availability of linked markers to the QTL may facilitate early selection for
kernel elongation in rice breeding programs. [References: 19]