Early Generation Selection of Gluten Strength in Common Wheat

Most of the Chinese wheat(Triticum aestivum L.) cultivars are characterized by weak gluten strength,which are not suitable for Chinese main food including dry white Chinese noodles and steamed bread using mechanized methods.The major objective for quality wheat breeding currently in Northern China is to improve the protein quality.The parents,F_1,F_2 and F_(2:3) progenies of five crosses between Zhongyou 9507 with strong gluten strength and five cultivars with different gluten strength from strong to weak,namely Annong 91168,Gaoyou 503,Ji 5099,Jinmai 45 and Lumai 5,were used to analysze the frequency distribution for SDS sedimentation value and mixograph mixing time,heritability and response to selection for SDS sedimentation value.The percentages of F_2 and F_(2:3) progenies with higher sedimentation value than that of Zhongyou 9507 in the number calculations in crosses of both parents with strong or medium to strong gluten strength like Zhongyou 9507/Annong 91168,Zhongyou 9507/Gaoyou 503,and Zhongyou 9507/Ji 5099,were 53%,30%,30% and 74%,41%,53%,respectively,and that in F_(2:3) family with longer mixograph mixing time were 76%,39%,and 27%,respectively,the progeny number varied by crosses.Narrow-sense heritability estimates for SDS sedimentation value was high with 43%70%,indicating that this trait was suitable for early generation selection.The actual response to selection did not differ significantly between 5% and 10% selection intensities for all crosses,suggesting 10% selection intensity should be used.The cross of Zhongyou 9507 and Annong 91168,both with strong gluten strength,showed good selection response for protein properties,indicating that parents with strong or medium to strong gluten strength should be used first at all in the crosses with the main wheat breeding objective being to improve protein quality.It also indicated that SDS sedimentation value in F_2 and mixograph parameters such as mixing time in F_(2:3) should be used in early generation selection to improve wheat gluten strength.