Low-temperature damage at the seedling stage is one of the most significant natural obstacles to wheat’s growth. In domestic wheat breeding programs, the selection of cold-tolerant varieties is crucial for the development of superior wheat varieties. Traditionally, the extent of damage caused by freezing wheat is estimated through visual observation. In this study, we compared the RGB image analysis method with conventional visual evaluation and chlorophyll content analysis methods to determine if this method could accurately quantify the cold tolerance discrimination of wheat in the field. First, single-leaf-level RGB image analysis revealed a pattern similar to dead leaf ratio and chlorophyll content in three grades of freezing injury. Next, we compared the significance of plant-level RGB image analysis. The greenness index by RGB image analysis showed a higher correlation with dead leaf ratio by visual evaluation. Finally, 40 wheat varieties were planted in the field and wheat canopy images were collected at the seedling stage after wintering. There was a high correlation between the greenness index and the visual evaluation. However, there was no correlation between dead leaf ratio and visual evaluation or greenness index as determined by RGB image analysis. These findings suggest that using RGB image analysis rather than visual evaluation can be useful in assessing freeze damage in wheat fields.

This study was conducted to investigate the effect of starch properties on the texture of cooked noodles from Korean wheat. The genetic composition of GBSS I (granule bound starch synthase I, called waxy protein) and puroindoline, which affect the amylose content and kernel hardness, was also evaluated. Waxy wheats carrying Wx-1 null alleles showed clearly different starch properties, high swelling power, pasting viscosity, breakdown and paste clarity, unsuitable texture of cooked noodles, and low hardness and springiness. Two partial waxy soft wheats carrying single or double null alleles at the Wx-1 locus gene, and Pina-D1a and Pinb-D1a alleles exhibited a softer and higher elasticity texture of the cooked noodles than Korean wheats carrying wild-type Wx-1 null alleles. There were no significant differences in the starch properties and texture of cooked noodles according to the puroindoline composition. A principal component analysis showed a strong negative relationship between the amylose content and starch swelling power, and these traits also improved the springiness and cohesiveness of the cooked noodles prepared from non-waxy Korean wheat. Joongmo2012, a double null partial waxy wheat, showed higher starch swelling power and springiness of the cooked noodles than other non-waxy Korean wheats.