Soft wheat quality traits in Jiangsu province and their relationship with cookie making quality

The objectives of this study were to investigate soft wheat quality traits with fertilizer management practice in southern region of the Huaihe river in Jiangsu province, and to suggest quality selection parameters in soft wheat breeding. Fifteen high quality soft wheat varieties or advanced lines were grown at three environments with the combination of location and year. High-molecular-weight glutenin subunits (HWM-GS) of tested genotypes were identified. Kernel hardness, grain and flour protein content, wet gluten content, ash content, Zeleny sedimentation value, parameters of farinograph, mixograph, and rapid viscocity analysis (RVA), solvent retention capacity (SRC), gluten protein quantification, and cookie quality were investigated. No sample met the national soft wheat quality standard (GB/T 17320-2013, GB/T 17893-1999) for protein content, wet gluten content, and farinograph stability, few samples met the standard for sedimentation value, and all samples exceeded the standard for kernel hardness and farinograph absorption. Kernel hardness, ash content, and RVA parameters were not significantly associated with cookie quality parameters. Zeleny sedimentation value, absorption and stability of farinograph, peak time and right of peak slope of mixograph, water SRC, sodium carbonate SRC, lactic acid SRC, glutenin/gliadin ratio, unextractable polymeric protein (UPP), and %UPP were significantly correlated with cookie diameter, with r = –0.657, –0.601, –0.617, –0.659, –0.676, –0.857, –0.726, –0.616, –0.546, –0.541, and –0.637, respectively (r ≤ –0.520, P < 0.05; r ≤ –0.652, P < 0.01). One multiple regression model only with water SRC as a variable could explain 73.76% of the total variation of cookie diameter, and the other regression model with both water SRC and kernel protein content as variables could explain 83.90% of the total variation. Based on the selection of grain hardness and protein content, reducing gluten strength and general water holding capacity is the main targets in soft wheat breeding program, and water SRC, lactic acid SRC and mixograph parameters are the most important selection parameters.