Relationship between SDS-Unextractable Glutenin Polymeric Protein and Mixograph Parameters Association Analysis for MixographProperties in Ningmai 9 and Its Derivatives Effect of Allelic Variation at Glu-1 and Glu-3 Loci on Insoluble Glutenin Content Analysis of Heat Resistance for Cultivars from North China Winter Wheat Region by Yield and Quality Traits