Variation for amylose content in wheat [Triticum aestivum] cultivars carrying different null alleles at the Wx loci
1998
Araki, E. (Obihiro Univ. of Agriculture and Veterinary Medicine, Hokkaido (Japan)) | Miura, H. | Watanabe, N. | Sawada, S.
The wheat Wx proteins, controlling amylose synthesis in the endosperm, are the product of the Wx genes at a triplicate set of single-copy homoeoloci located on chromosomes 7A (Wx-A1), 4A (Wx-B1) and 7D (Wx-D1). Using a range of cultivars carrying the different null alleles at the Wx loci, variation for amylose content was investigated to determine the effects of each null allele on changing the content. Amylose content varied from 20 % to 25 % (100 mg starch base). A highly significant correlation was detected between the field-grown and growth chamber materials, indicating that amylose content is genotype-dependent. Genetic variation was mostly attributable to the differences between the five allele types at the Wx loci, indicating that the cultivar difference in amylose content is primarily under control of the Wx loci. It was confirmed that the effect of the null Wx-B1b on reducing amylose content is largest among the three null Wx alleles. Five cultivars carrying the Wx-B1b allele showed a significant variation by about 2 % of amylose content, suggesting that a part of amylose synthesis is affected by genes located on background chromosomes. It appeared that a combined effect of the null Wx-B1b with Wx-A1b on reducing amylose content was not additive and led to lower content than the expected one
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