Journal of Integrative Agriculture ›› 2021, Vol. 20 ›› Issue (8): 2077-2089.DOI: 10.1016/S2095-3119(20)63346-9

所属专题: 玉米遗传育种合辑Maize Genetics · Breeding · Germplasm Resources 玉米耕作栽培合辑Maize Physiology · Biochemistry · Cultivation · Tillage

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  • 收稿日期:2020-01-19 出版日期:2021-08-01 发布日期:2021-07-20

Lignin metabolism regulates lodging resistance of maize hybrids under varying planting density

LI Bin, GAO Fei, REN Bai-zhao, DONG Shu-ting, LIU Peng, ZHAO Bin, ZHANG Ji-wang   

  1. State Key Laboratory of Crop Biology, Ministry of Science and Technology/College of Agronomy, Shandong Agricultural University, Tai’an 271018, P.R.China
  • Received:2020-01-19 Online:2021-08-01 Published:2021-07-20
  • Contact: Correspondence ZHANG Ji-wang, Tel/Fax: +86-538-8241485, E-mail: jwzhang@sdau.edu.cn
  • Supported by:
    The authors gratefully acknowledge the earmarked fund for China Agriculture Research System of MOF and MARA (CARS-02), the National Key Research and Development Program of China (2017YFD0300304) and the National Natural Science Fundation of China (31671629).

摘要:

夏玉米品种及其种植密度是影响玉米抗倒伏能力的主要因素。本试验从木质素代谢的角度来探究不同玉米品种的抗倒伏能力及其种植密度调控。研究结果表明,抗倒伏夏玉米品种登海605 (DH605)具有较低的重心和良好的茎秆形态特征,这是其抗倒伏能力显著高于浚单20(XD20)的原因之一。DH605的木质素积累量、木质素合成途径关键酶活性以及G、S和H型木质素单体含量均显著高于XD20。随着种植密度的增加,两种品种的茎秆机械强度、木质素积累量和木质素合成途径关键酶活性均显著降低,G型木质素单体含量呈现先减少后保持稳定的趋势,S型木质素单体含量呈下降趋势,H木质素型单体含量呈上升趋势。相关性分析表明,倒伏率与植株性状及木质素代谢显著相关。因此,抗倒伏能力强的玉米具有木质素积累量高、木质素合成途径关键酶活性高、S型单体含量高、重心低、茎穿刺强度高、皮质厚度高、维管束面积小等特点,同时,高种植密度降低了茎秆木质素的积累、酶活性和机械强度,进而导致倒伏率提高


Abstract:

Hybrids and planting density are the main factors affecting maize lodging resistance.  Here, we aimed to elucidate the mechanism of the regulation of maize lodging resistance by comparing two hybrids at various planting densities from the perspective of lignin metabolism.  Our results showed that compared to lodging-susceptible hybrid Xundan 20 (XD20), lodging-resistant hybrid Denghai 605 (DH605) showed a lower center of gravity and culm morphological characteristics that contributed to the higher lodging resistance of this hybrid.  Lignin content, activities of key lignin synthesis-related enzymes and G-, S- and H-type monomer contents were significantly higher in hybrid DH605 than in hybrid XD20.  Stalk mechanical strength, lignin accumulation and enzyme activity decreased significantly with increasing planting density in the two hybrids.  While G-type monomers first decreased with increasing planting density but then remained stable, S-type monomers showed a decreasing trend, and H-type monomers showed an increasing trend.  Correlation analysis showed that lodging rate was significantly correlated with plant traits and lignin metabolism.  Therefore, maize hybrids characterized by high lignin accumulation, high lignin synthesis-related activities, high S-type monomer content, low center of gravity, high stem puncture strength, high cortical thickness, and small vascular bundle area are more resistant to lodging.  High planting densities reduce stalk lignin accumulation, relevant enzyme activities and mechanical strength, thereby, ultimately increasing the lodging rate significantly.

Key words: summer maize ,  lignin metabolism ,  stem morphological characteristics ,  lodging resistance