Lodging Resistance of Different Winter Wheat Lines in a Sandy Fluvo-aquic Soil

Abstract

【Objective】 Lodging refers to the process that the crop shoots are displaced from their vertical stance. It is impacted by many factors including whether, crop varieties, soil type. The objective of this work is to experimentally study the variation of lodging between different winter wheat lines in a sandy fluvo-aquic soil in Henan province. 【Method】 The experiment was conducted in a field in which we compared 13 winter wheat lines. For each line, we measured the material properties and lodging resistance of its stems during the middle grain-filling stages under different agronomic managements. The relationship between the lodging resistance index (CLRI) of the second internode and nine culm properties was calculated using correlation, cluster and principal component analysis. 【Result】 Plant height and location of the gravitational center of the aerial parts had little impact on the lodging of the wheat in the middle grain-filling stage. The mechanical strength of the second internode of all lines was negatively correlated to the CLRI though not at a significant level. Plant height and the ratio of length of the second internode to plant height were both negatively correlated with the mechanical strength and the CLRI, both at significant level. The culm diameter, stem thickness and the ratio of stem thickness to culm diameter were all positively correlated with the mechanical strength and CLRI at significant level. Cluster analysis of Group I showed that reducing plant height and optimizing the second internode improved lodging resistance of the wheat, while the Group II analysis revealed that optimizing the traits of the second internode were equally effective. The result of Group III was that reducing plant height and increasing mechanical strength of the stems can also improve the lodging resistance. There were three principal component factors cumulatively contributing 83.72% of the principal component analysis, and the principal component factors (PCF) reflected 48.11% of the variation in the stem. Stem thickness, ratio of stem thickness to culm diameter and the mechanical strength were the major factors controlling PCF1, while plant height, dry density and location of the gravitational center were key determinants of PCF2. Stem thickness and location of the gravitational center were the main factors of PCF3. 【Conclusion】 Lodging resistance index (CLRI) is a parameter determined by a multitude of factors, but it can be estimated using the ratio of length of the second internode to the plant height, as well as stem thickness, culm diameter, the ratio of stem thickness to culm diameter. Breeding new genotypes to improve above crop traits are needed to enhance their lodging resistance when the crops are grown in the sandy fluvo-aquic soil in Henan province.

Keywords

• winter wheat lines
• sandy fluvo-aquic soil
• stem characterizes
• mechanical strength
• culm lodging resistant index (clri)