Marker-assisted backcrossing is a powerful method for developing new cultivars. To develop genomic-wide markers, genotyping-by-sequencing (GBS) can be an efficient method. However, unrefined low-quality markers and missing data between markers can contribute to hampering the marker selection process, particularly in multi-way crosses. In this study, we aimed to calculate the recovery rate of offspring individuals and minimize errors that occur among a large number of markers. Initially, missing data were imputed by comparing samples using the k-nearest neighbor (k-NN) algorithm. Thereafter, low-quality single-nucleotide polymorphisms (SNPs) were corrected by applying the graphical representation method based on the k-NN algorithm in order of the SNPs in a chromosome designed for a multi-parental population. Four-way cross and double-backcrossed tomato BC₁F₁ (230 lines) and BC₂F₁ (96 lines) populations were genotyped by GBS. The genotype of samples of the BC₁F₁ and BC₂F₁ populations was determined based on the parental haplotype. Thus, the method of visualizing the genotype of offspring individuals, generated via crosses of multiple parents, not only improves estimation of the recovery rate but also facilitates easier selection in breeding programs.

Yellow alkaline noodles were prepared with various Korean wheat cultivars including different protein and amylose contents and made from two types of noodle machines. Korean food companies and restaurants generally used noodle machine made in Korea, whereas research institutes mainly practiced with noodle machine made in Japan. Noodle dough sheet from Korean machine showed 5% higher water absorption and 30 min shorter resting period than the noodle dough from Japanese machine because of the difference of size and weight of roller in two types of the machines. In 15 Korean wheat cultivars, thickness of noodle dough sheet was positively correlated with protein content and mixograph water absorption regardless of both types of the machines. Cooked noodles from Korean machine showed higher hardness and lower springiness than noodles from Japanese noodle machine, but difference in cohesiveness of cooked noodles was not found between two different noodle machines. In the three Korean wheat cultivars with different protein content, thickness of noodle dough sheet was also positively correlated with protein content, SDS sedimentation volume and mixing time of mixograph in both types of the machines. The more protein content increased, the more hardness of cooked noodles increased regardless of both types of the machines. However, springiness and cohesiveness of cooked noodles were not significantly correlated with protein content. In waxy and partial waxy wheat cultivars, lightness of noodle dough sheet from Korean noodle machine positively correlated with amylose content. Amylose content and setback in pasting properties were positively correlated with hardness, springiness, and cohesiveness of cooked noodles while both damaged starch and breakdown were negatively correlated with those.

Mixolab is suitable to evaluate mixograph and farinograph for testing dough rheology and amylopgraph for properties of starch pasting with a view to analyze protein and starch quality at the same time. Mixolab analysis revealed that water absorption and dough development time of Korean wheat cultivars were similar to it of soft wheats and flour while dough stability and protein weakening of Korean wheat cultivars were similar to it of hard wheat and strong flour. Also, starch properties of Korean wheat cultivars showed similar properties of hard wheats. There was a significantly positive correlation between mixolab and mixograph in the water absorption of dough, whereas no correlation was observed between them in dough development time and stability. Furthermore, maximum viscosity of starch and breakdown in amylopgraph were correlated to stabilities of pasting and cooking and setback in mixolab. Resultantly, in mixolab, properties of dough and protein highly and positively correlated to loaf volume, hardness of noodles, and size of cookies i.e. diameter. Moreover, positive correlation was identified between viscoelasticity of noodles and properties of protein, pasting, and setback in mixolab.

This study was executed to establish a basis of evaluation of starch properties of Korean wheat cultivars e.g. damaged starch, swelling, and pasting properties for Korean wheat breeding program. Damaged starch is critical evaluation factor for flour milling related industry because it influences water absorption and color of dough for processing quality and preference of end-use products. The present results revealed that there was significantly high positive correlation between the results of damaged starch analysis by amperometric (SD-matic) and enzymatic (Megazyme assay) methods. Evaluation of damaged starch must be considered as one factor to evaluate properties of starch due to its accuracy and a stable efficiency for the wheat breeding program. Properties of swelling and pasting of dough were important for cooking time and texture. Nevertheless, it was impossible to evaluate starch extracted from flour in the wheat breeding program i.e. small amount of flour or small number of spikes Comparison of results of evaluation of properties of swelling and pasting with starch or flour, the evaluation using flour positively correlated with the other evaluation using starch. In addition, swelling evaluation must be considered to apply for the wheat breeding program because the result of evaluation of swelling property, which possible to evaluate with low efficiency, and the quantity of a sample is highly under positive correlation with paste peak viscosity. In the future, studies using NIR (Near Infrared) analysis must be necessary to evaluate starch properties with grains in early generation lines for improvement of wheat breeding program.