Analysis of Factors Determining the Sterility of Lower Spikelets of Six-Rowed Barley

• Published in: Japanese Journal of Crop Science Vol. 94; no. 3; pp. 219 - 229
• Main Authors: SHIMAZAKI, Yumi, IKENAGA, Sachiko, SEKI, Masako
• Format: Journal Article
• Language: Japanese
• Published: CROP SCIENCE SOCIETY OF JAPAN 05.07.2025
• Subjects: Barley; Cumulative temperature; Ear development; Maximum number of spikelet primordia; Spikelet; Spikelet survival rate; Sterility of lower spikelets
• ISSN: 0011-1848; 1349-0990
• DOI: 10.1626/jcs.94.219

In the Hokuriku region of Japan, sterile spikelets of barley are known to occur in the lower part of the ear, and this is considered one of the reasons for the reduced yields in this region. The ear formation period in barley begins during winter. In areas subject to snowfall, the environment during ear formation varies greatly depending on the presence or absence of snow cover. This study aimed to confirm that the ear characteristics of barley plants grown in different environments differ at maturity and to examine the factors involved in sterile spikelet formation, focusing on the maximum number of spikelet primordia and the spikelet survival rate. The test was conducted in fields in the cities of Joetsu and Morioka over three cropping seasons. Ears of barley grown in the six different environments differed significantly in spike morphology, such as in the total numbers of spikelets and lower sterile spikelets and the maximum number of spikelet primordia. The number of lower sterile spikelets was higher in Joetsu than in Morioka in all three years. The maximum number of spikelet primordia was significantly positively correlated with the cumulative temperature in the spikelet-differentiation period and negatively correlated with the rate of spikelet differentiation. The spikelet survival rate was negatively correlated with the maximum number of spikelet primordia. Higher temperatures during the ear-formation period increased the maximum number of ear primordia but decreased the spikelet survival rate, resulting in the formation of ears with greater numbers of lower sterile spikelets.