Detection Of QTLs For Salt Tolerance In Rice At The Seedling Stage By Using The Jiucaiqing/IR26 RILs

It is estimated that at least 20ï¼…of plowlands are affected by saline soils to various extentsAccumulation of salt in the soil not only restrains the growth and development of crops, butalso causes decrease of production and quality of crops. Rice is one of the most importantfood crops, and also a moderate sensitive plant to salt. Breeding and extending the elite ricevarieties with a high level of salt tolerance will be helpful to use akalin soil, and enlargearable lands and improve the crop production.To explore genetic mechanism of tolerance to salt stress in one Japonica varietyJiu-cai-qing from Taihu lake region it was detected QTLs for salt tolerance in rice atseedling stage using a RILs population from the cross of Jiucaiqing/IR26 in this study.With a RILs population from the cross of Jiucaiqing/IR26, with the genetic linkagemap of 110 pairs SSR markers, the QTLs for root dry weight(RDW), root Na/K(RN/K),shoot dry weight(SDW), shoot Na concentration(SNC), shoot K concentration(SKC), shootNa/K(SN/K) and salt tolerance rate(STR) were detected under 0.5ï¼…NaCl treatment and0.7ï¼…NaCl, respectively. The result showed that 16 QTLs special for salt tolerance. Therewere 11 QTLs under 0.5ï¼…NaCl treatment. The qRN/K-11m, qSKC-1m, qSN/K-11m,qSN/K-12m and qSTR-11m, could explain larger phenotypic variance, with 13.3ï¼…, 15.9ï¼…,23.2ï¼…, 10.4ï¼…and 19.8ï¼…of total phenotypic variance, respectively. There were 5 QTLsunder 0.7ï¼…NaCl treatment. The qSNC-12h and qSN/K-12h, could explain largerphenotypic variance, with 18.0ï¼…and 13.2ï¼…of total phenotypic variance, respectively.Addtionally, the qSTR-1m and qSDW-8m were found to locate in the similar region asqSTR-1 and qDWS-8 in the previous study, while qSN/K-11m might be similar to Knalpreviously detected in wheat. The qRN/K-3c and qRN/K-3m, qSDW-8c and qSDW-Sm werelocated in the same regions of the chromosomals both in the control and salt treatment,respectively, so they might be the same QTLs, respectively. The correlation analysisshowed that QTLs for correlated traits were always mapped in the same chromosomalregions, such as qSN/K-11m and qSTR-11m, qSNC-12h and qSN/K-12h, and so on.It was thought that the lower SN/K was an important trait for salt tolerance in wheat inprevious research, while in our study we found that Jiucaiqing with higher SN/K representlower STR higher. Therefore, rice, as a moderate salt sensitive crop, a better assignmentand separation of salt enter in rice was possibly more adaptive to only maintain lowerNa/K.