2.2 Plant materials and temperature treatment
The high-quality rice (Oryza sativa L. ) variety Wuyujing 3 (W3) was used as the plant material for its sensitivity of the quality formation to the increased temperature and the large area of cultivation in the experimental region. In order to evaluate the individual and co-impact effects of the increased temperature, field treatments were conducted as follows: (i) normal temperature (CK); (ii) elevated temperature (ET). Temperature treatment was carried out with the free-air temperature enhancement system (FATE) from full heading (80% of the rice in the field starts the heading stage). Each treatment was designed with 3 replications and 80cm intervals and protection lines were set up between the treatment blocks to ensure the independence of the experiment. Rice cultivation methods were adopted by seedling raising and artificial transplanting. Field management measures including fertilization, wet-dry alternate irrigation, prevention of pests and weeds were carried out according to the local high-yielding cultivation measures.