Reference "Mapping QTLs associated with drought avoidance in upland rice"

Reference ID

7870

Title

Mapping QTLs associated with drought avoidance in upland rice

Source

Molecular Breeding, 2000, vol. 6, pp. 55-66

Authors (6)

Courtois-B	McLaren-G
Sinha-PK	Prasad-K
Yadav-R	Shen-L

Abstract

The identification of molecular markers linked to genes controlling drought
resistance factors in rice is a necessary step to improve breeding efficiency
for this complex trait. QTLs controlling drought avoidance mechanisms were
analyzed in a doubled-haploid population of rice. Three trials with different
drought stress intensities were carried out in two sites. Leaf rolling, leaf
drying, relative water content of leaves and relative growth rate under water
stress were measured on 105 doubled haploid lines in two trials and on a sub-
sample of 85 lines in the third one. Using composite interval mapping with a LOD
threshold of 2.5, the total number of QTLs detected in all trials combined was
11 for leaf rolling, 10 for leaf drying, 11 for relative water content and 10
for relative growth rate under stress. Some of these QTLs were common across
traits. Among the eleven possible QTLs for leaf rolling, three QTLs (on
chromosomes 1, 5 and 9) were common across the three trials and four additional
QTLs (on chromosomes 3, 4 and 9) were common across two trials. One QTL on
chromosome 4 for leaf drying and one QTL on chromosome 1 for relative water
content were common across two trials while no common QTL was identified for
relative growth rate under stress. Some of the QTLs detected for leaf rolling,
leaf drying and relative water content mapped in the same places as QTLs
controlling root morphology, which were identified in a previous study involving
the same population. Some QTL identified here were also located similarly with
other QTLs for leaf rolling as reported from other populations. This study may
help to chose the best segments for introgression into rice varieties and
improvement of their drought resistance.