Pre-breeding for waxy proso millet by phenotyping and marker-assisted selection

Proso millet (Panicum miliaceum L.) is important in some Kazakhstan food, this research objective was to develop pre-breeding waxy proso millet resource for breeding new varieties by using phenotyping and marker-assisted selection. The amylose content of the endosperm starch in a collection of 18 proso millet cultivars widely used in northern Kazakhstan were evaluated and ranged from 14.6% to 34.8%. The introduced glutinous millet accessions of PI436626 (Lung Shu 18), PI436625 (Lung Shu 16) were selected to cross with local cultivars (Saratovskoe 6 and Pamyati Bersieva). The potassium iodide (KI) staining method and PCR analysis using the 9bF/15delRB primer were used to identify the waxy trait for selection of the F-2-F-3 generation. Seeds staining dark blue to black were scored as wild type, while waxy seeds were stained as pinkish or amber to reddish-brown color. The hybridological analysis of inheritance of the "waxy" trait suggested that the segregation ratios for waxy endosperm in the F-2 and F-3 populations was close to 15:1 of the caryopses with blue and brown colors. PCR analysis with the 9bF/15delRB primer confirmed that this specific primer flanks a 123 bp fragment in amylose samples, while in glutinous samples, this primer promotes the amplification of 108 bp long PCR product (15 nucleotides deletion). Finally, the waxy lines were obtained and could be used for further testing.