Reference "QTLs underlying rice tolerance to low-potassium stress in rice seedlings"

Reference ID

7921

Title

QTLs underlying rice tolerance to low-potassium stress in rice seedlings

Source

Crop Science, 1998, vol. 38, pp. 1458-1462

Authors (3)

Luo-A-C	Ni-J-J
Wu-P

Abstract

Potassium is an important nutrient in plant growth and development of rice
(Oryza sativa L.), but K availability may be seriously limited in developing
countries. Genotypic variation in tolerance to low-K stress has been shown.
This study was conducted to investigate the genetic basis for tolerance to low-
K stress in rice and to identify the quantitative trait loci (QTLs) that
provide this tolerance. On the basis of preliminary tests, seedlings of 123
double haploid (DH) lines and their parents (which differed in response to K
supply) 'IR64', an indica cultivar and 'Azucena', a Japonica variety, were
grown in a hydroponic greenhouse study at adequate and at stress levels of K in
August, 1995, at Zhejiang Agricultural University, Hangzhou, China. Plants were
sampled after 4 wk in culture solution and measurements were made for plant
height, shoot and root dry matter, K concentration in plant tissue, K uptake,
and K use efficiency. Relative changes of the parameters from K-sufficient to
K-stress culture were calculated to evaluate the genotypic variation in
tolerance to K-stress. IR64 was more tolerant to low-K stress than Azucena. A
total of 175 molecular markers mapped on all 12 chromosomes of rice was used to
detect QTLs underlying tolerance to low-K stress. These QTLs individually
explained about 8 to 15% of the variations in relative changes of the
parameters from K-sufficient to K-stress culture across the population. The
differences in the changes of the parameters between Azucena and IR64 at the
marker loci linked to the QTLs detected were from 16 to 39% above the overall
means of the population. The identification of QTLs underlying the tolerance of
low-K stress may be useful in.