Quality differences between NILs of wheat variety Long 97-586 possessing HMW-GS 7+8 and 7

The high molecular weight glutenin subunits (HMW-GS) 7+8 were introduced into the Long 97-586 (1, 7, 2+12) wheat variety (Triticum aestivum) by 5 consecutive backcrosses with biochemical marker-assisted selection. Nearly isogenic lines (NILs) of HMW-GS 7 and 7+8 were obtained, and the NILs were planted in the experimental field at the Crop Breeding Institute of Heilongjiang Academy of Agricultural Science in 2004-2006. The field experiments were designed using the two-column contrast arrangement method with six replicates in 2004-2005 and four replicates in 2006. The result of three years experiments showed that the differences between NILs of Long 97-586 with subunit 7 and those with subunits 7+8 in the quality parameters of flour protein content and dry gluten content were negligible (P>0.1). However, the differences in some of the quality parameters were remarkably significant (P<0.01), including wet gluten content, ratio of wet gluten/dry gluten, gluten index, Zeleny sedimentation, ratio of sedimentation/dry gluten, and the farinogram parameters of water absorption, development time, stability, breakdown time and degree of softening. The difference between NILs with subunits 7+8 and subunit 7 was significant (P<0.05) on the alveogram W value and had a critical value (P=0.05) on the alveogram P value in 2006. The results show that HMW-GS 7+8 is far superior to HMW-GS 7 in terms of baking quality. The possibilities of using subunits 7+8 and subunit 7 in breeding strong and weak gluten wheat varieties are discussed in this paper.