ABSTRACT
Deep root in relation to grain yield and plant height of waxy maize

Yaoxiang Ge1, Xiaohu Hu1, Xingyan Li1, Wenying Zhang2, Cai Zhang1, Zhuoxuan Wu1, Caihong Bai1*, and Ping Deng1*
 
Waxy maize (Zea mays L. Ceratina Group Kuleshov) genotypes with enhanced root development demonstrate an improved capacity for nutrient and water acquisition, potentially leading to higher grain yields. To investigate the relationships between grain yield, plant height, and root traits, 65 waxy maize lines were evaluated under field conditions in 2020 and 2021. The 65 genotypes exhibited significant variation in yield, plant height, and root traits across both years. Furthermore, all yield, height, and root traits were significantly affected by the Genotype × Year interaction, with the exception of dry grain yield. Root dry weight in the 40-100 cm soil layer exhibited a stronger positive effect on dry grain yield compared to that in the 0-40 cm soil layer in both years. This positive effect was more pronounced in 2020, a relatively dry year, than in 2021, which experienced higher rainfall. Deep root traits (40-100 cm), including root dry weight, root length density, and the deep root ratio, played a crucial role in achieving high grain yields, particularly under dry conditions. Significant correlations between root traits (root dry weight, root length density, and deep root ratio) and plant height were observed only in deeper soil layers in 2021, but not in 2020, suggesting that the relationship between root traits and plant height may be environment-dependent. These findings provide valuable insights for the breeding and cultivation of waxy maize, particularly with respect to improving root development to enhance grain yield under varying environmental conditions.
Keywords: Deep root, height, waxy maize, yield, Zea mays L. Ceratina Group Kuleshov.
1Yulin Normal University, College of Agronomy, Guangxi 537000, China.
2Dryland Farming Institute, Hebei Academy of Agricultural and Forestry Science, Hengshui 053000, China.
*Corresponding authors (caihong_bai@ylu.edu.cn; d_p@nwafu.edu.cn).