Abstract
Wheat (Triticum aestivum L.) grain hardness is determined mainly by variations in puroindoline genes (Pina-D1 and Pinb-D1), which are located on the short arm of chromosome 5D. This trait has a direct effect on the technological properties of the flour and the final product quality. The objective of the study was to analyze the mutation frequency in both Pin genes and their influence on grain hardness in 118 modern bread wheat cultivars and breeding lines cultivated in Poland, and 80 landraces from Poland. The PCR products containing the Pin gene coding sequences were sequenced by the Sanger method. Based on detected the SNPs (single-nucleotide polymorphisms) we designed CAPS (cleaved amplified polymorphic sequence) markers for the fast screening of Pinb alleles in a large number of genotypes. All analyzed cultivars, breeding lines, and landraces possess the wild-type Pina-D1a allele. Allelic variation was observed within the Pinb gene. The most frequently occurring allele in modern wheat cultivars and breeding lines (over 50%) was Pinb-D1b. The contribution of the remaining alleles (Pinb-D1a, Pinb-D1c, and Pinb-D1d) was much less (approx. 15% each). In landraces, the most frequent allele was Pinb-D1a (over 70%), followed by Pinb-D1b (21% frequency). Pinb-D1c and Pinb-D1g were found in individual varieties. SKCS (single-kernel characterization system) analysis revealed that grain hardness was strictly connected with Pinb gene allelic variation in most tested cultivars. The mean grain hardness values were significantly greater in cultivars with mutant Pinb variants as compared to those with the wild-type Pinb-D1a allele. Based on grain hardness measured by SKCS, we classified the analyzed cultivars and lines into different classes according to a previously proposed classification system.
Highlights
In Europe, common wheat (Triticum aestivum L.) is cultivated on almost 61 million hectares of land, and, in Poland, on 2.416 million hectares, which accounts for about 31% of all cereals cultivated in Poland [1]
Grain hardness is primarily controlled by two puroindoline genes, Pina and Pinb
The allelic variation of Pina and Pinb was determined by Sanger sequencing
Summary
In Europe, common wheat (Triticum aestivum L.) is cultivated on almost 61 million hectares of land, and, in Poland, on 2.416 million hectares, which accounts for about 31% of all cereals cultivated in Poland [1]. One of the most important technological traits, is considered as significant as gluten protein composition [3]. It has a direct effect on the grinding and baking characteristics, flour particle sizes, and water absorption. Grain hardness is primarily controlled by two puroindoline genes, Pina and Pinb. Both genes are intronless, with a 447 bp coding sequence and are located in locus Ha on the short arm of chromosome 5D [5]. PIN proteins exhibit a tryptophan-rich domain, which consists of five tryptophan residues in PINA and three residues in PINB [5]. Increased grain hardness is the result of mutations within one or both wild-type
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
