Root and shoot traits responses to phosphorus deficiency and QTL analysis at seedling stage using introgression lines of rice.
Phosphorous (P) deficiency is a major restraint factor for crop production and plants have developed several mechanisms to adapt to low P stress. In this study, a set of 271 introgression lines (ILs) were used to characterize the responses of seedlings to low P availability and to identify QTLs for root traits, biomass, and plant height under P-deficiency and P-sufficiency conditions. Plant height, total dry weight, shoot dry weight, and root number were inhibited under P-deficiency, whereas maximum root length (MRL) and root-shoot ratio (RS) were induced by P-deficiency stress. Relative MRL (RMRL, the ratio of MRL under P-deficiency to MRL under P-sufficiency condition) and relative RS (RRS) were used to evaluate P-deficiency tolerance at the seedling stage. A total of 24 additive QTLs and 29 pairs of epistatic QTLs were detected, but only qRN4 was detected in both conditions. This suggested that different mechanisms may exist in both P supply levels. QTLs for adaptive traits (RMRL, RRS, RRV, and RRDW) and qRN4 consistently expressed to increase trait stability may contribute to P-deficiency tolerance. Twelve intervals were cluster regions of QTLs for P-deficiency tolerance, and one QTL (qRRS8) showed pleiotropic effects on P-deficiency tolerance and drought tolerance. These interesting QTLs can be used in marker-assisted breeding through the target ILs.
Li
Junzhou
J
Key Laboratory of Crop Genomics and Genetic Improvement of Ministry of Agriculture and Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, China.
Xie
Yan
Y
Dai
Anyong
A
Liu
Lifeng
L
Li
Zichao
Z
D007178:Inbreeding; D012275:Oryza / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D010758:Phosphorus / Q000172:deficiency*; D018517:Plant Roots / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D018520:Plant Shoots / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D040641:Quantitative Trait Loci; D036226:Seedlings / Q000235:genetics / Q000254:growth & development / Q000378:metabolism
D010758:Phosphorus