Screening and identification of two strains of nitrogen-fixing bacteria from the silage maize rhizosphere and their roles in plant growth promotion

doi:10.11686/cyxb2023151

Abstract

Abstract:

The aim of this study was to screen for high-quality nitrogen-fixing bacteria and evaluate their growth-promoting effects on silage maize （Zea mays）. The dilution spread plate method with Ashby solid medium was used to screen and screen ten strains of nitrogen-fixing bacteria from the rhizosphere soil of silage maize. The nitrogen-fixation capabilities of the strains were analyzed. The results indicated that cultures of ZL-2 and ZL-13 exhibited strong nitrogen-fixing abilities （1.07 and 0.95 μg·mL^-1， respectively）. On the basis of their morphological characteristics， 16S rDNA sequence， and physiological and biochemical characteristics， ZL-2 was identified as Enterobacter cancerogenus， and ZL-13 was identified as Pantoea agglomerans. The growth-promoting characteristics of these two strains were analyzed， and both bacteria were found to secrete ammonium and siderophores， solubilize phosphate， and synthesize indole-3-acetic acid. In a pot experiment， compared with uninoculated silage maize plants， those inoculated with the nitrogen-fixing strains ZL-2 and ZL-13 showed significantly increased plant height， root length， aboveground and underground dry weights， and fresh weight （P<0.05）. In a field experiment， compared with uninoculated silage maize plants， those inoculated with one or both of the nitrogen-fixing strains showed significantly increased plant height， stem diameter， yield， crude protein content， and total phosphorus content （P<0.05）. Silage maize plants inoculated with these two nitrogen-fixing strains showed significantly increased expression levels of genes related to nitrogen metabolism and ammonia assimilation （ZmAMT-4， ZmAMTB， ZmGOGAT2， and ZmGS1-3）（P<0.05）. Therefore， these two nitrogen-fixing bacterial strains have favorable growth-promoting characteristics. Given their important role in enhancing the yield and quality of silage maize， they are valuable resources for the development of microbial agents.

Key words: silage maize, nitrogen-fixing bacteria, ammonium-secreting, growth-promoting function, gene expression

Chao-nan MENG, Yu-jie ZHAO, Jia-xin CHEN, Yi-lu ZHANG, Yan-jia WANG, Li-rong FENG, Yu-gang SUN, Chang-hong GUO. Screening and identification of two strains of nitrogen-fixing bacteria from the silage maize rhizosphere and their roles in plant growth promotion[J]. Acta Prataculturae Sinica, 2024, 33(3): 174-185.

Figures/Tables 10

References 50

1	Nilahyane A， Islam M A， Mesbah A O， et al. Growth， water productivity， nutritive value， and physiology responses of silage corn to water stress. Agronomy Journal， 2020， 112： 1625-1635.
2	Zhao M， Feng Y， Shi Y， et al. Yield and quality properties of silage maize and their influencing factors in China. SCIENCE CHINA Life Sciences， 2022， 65（8）： 1655-1666.
3	Morugán-Coronado A， Linares C， Gómez-López M D， et al. The impact of intercropping， tillage and fertilizer type on soil and crop yield in fruit orchards under Mediterranean conditions： A meta-analysis of field studies. Agricultural Systems， 2020， 178： 10.
4	Acosta-Motos J R， Penella C， José A. Towards a sustainable agriculture： strategies involving phytoprotectants against salt stress. Agronomy， 2020， 10（2）： 194.
5	Dechorgnat J， Francis K L， Dhugga K S， et al. Tissue and nitrogen-linked expression profiles of ammonium and nitrate transporters in maize. BMC Plant Biology， 2019， 19（1）： 206.
6	Carpici E B， Kuscu H， Karasu A， et al. Effect of drip irrigation levels on dry matter yield and silage quality of maize （Zea mays L.）. Romanian Agricultural Research， 2017， 34： 293-299.
7	Castellano H A， Perez T V， Bedmar J E. Purple corn-associated rhizobacteria with potential for plant growth promotion. Journal of Applied Microbiology， 2018， 124： 1254-1264.
8	Thanh N C， Le V B， Minh T T H. Pseudomonas PS01 isolated from maize rhizosphere alters root system architecture and promotes plant growth. Microorganisms， 2020， 8（4）： 471.
9	Wang X M， Chen Z H， Li Y C， et al. Effects of different nitrogen forms and ratios on the growth of Phyllostachys edulis and Quercus glauca seedlings. Chinese Journal of Ecology， 2019， 38（9）： 2655-2661.
	王兴萌，陈志豪，李永春，等. 氮素形态及配比对毛竹和青冈实生苗生长特性的影响. 生态学杂志， 2019， 38（9）： 2655-2661.
10	Shen R F. Contribution of ammonium preference characteristics of corn revealed by Nanjing soil to its nitrogen use efficiency. Grain Oil and Feed Technology， 2019（5）： 45.
	沈仁芳. 南京土壤所揭示玉米铵偏好特性对其氮肥利用率的贡献. 粮油与饲料科技， 2019（5）： 45.
11	Adriana A， Fernando H S A， Heinzmann Júlia H， et al. Paenibacillus helianthi sp. nov.， a nitrogen fixing species isolated from the rhizosphere of Helianthus annuus L. Antonie van Leeuwenhoek， 2018， 111（12）： 2463-2471.
12	Li Q J， Cheng J J， Sun S X， et al. Isolation， identification and characterization of associative nitrogen-fixing endophytic bacterium Kosakonia radicincitans GXGL-4A in maize. Microbiology China， 2016， 43（11）： 2456-2463.
	李琼洁，程杰杰，孙帅欣，等. 玉米联合固氮菌Kosakonia radicincitans GXGL-4A的分离鉴定与固氮特性研究. 微生物学通报， 2016， 43（11）： 2456-2463.
13	Wang C， Ling J， Zhang Y Y， et al. Isolation， characterization and culture optimization of nitrogen-fixing and phosphate-solubilizing bacteria from rhizosphere sediments of Halophila ovalis. Acta Microbiologica Sinica， 2018， 58（5）： 817-829.
	王聪，凌娟，张燕英，等. 海洋固氮菌和解磷菌的分离鉴定及发酵条件优化. 微生物学报， 2018， 58（5）： 817-829.
14	Jiang Y， Wu Y， Wang G W， et al. Plant growth-promoting bacterium Variovorax sp. JX14 from calcareous alluvial soil： characterization and growth promotion on peanuts. Soils， 2015， 47（4）： 698-703.
	姜瑛，吴越，王国文，等. 一株固氮解磷菌的筛选鉴定及其对花生的促生作用研究. 土壤， 2015， 47（4）： 698-703.
15	Glickmann E， Dessaux Y. A critical examination of the specificity of the salkowski reagent for indolic compounds produced by phytopathogenic bacteria. Applied and Environmental Microbiology， 1995， 61（2）： 793-796.
16	Lin Q M， Zhao X R， Sun Y X， et al. Community characters of soil phosphobacteria in four ecosystems. Soil and Environmental Sciences， 2000， 9（1）： 34-37.
	林启美，赵小蓉，孙焱鑫，等. 四种不同生态系统的土壤解磷细菌数量及种群分布. 土壤与环境， 2000， 9（1）： 34-37.
17	Wang P， Dong B， Li F D， et al. Detection and determination of the siderophores produced by wheat rhizobacteria. Microbiology China， 1994（6）： 323-326.
	王平，董飚，李阜棣，等. 小麦根圈细菌铁载体的检测. 微生物学通报， 1994（6）： 323-326.
18	Dong X Z， Cai M Y. Handbook for the identification of common bacterial systems. Beijing： Science Press， 2001.
	东秀珠，蔡妙英. 常见细菌系统鉴定手册. 北京：科学出版社， 2001.
19	Zhang Y. Screening plant growth promoting rhizobacteria resources and their promotion mechanisms from rhizosphere of four forages in Ali Alpine grassland of Tibet. Lanzhou： Gansu Agricultural University， 2013.
	张英. 西藏阿里高寒草原四种牧草根际促生菌资源筛选及促生机理研究. 兰州：甘肃农业大学， 2013.
20	Li Y Z， Redmann R E， Zhu T C， et al. Nitrogen fixation in Leymus chinensis grassland in Northeast China. Acta Agrestia Sinica， 2002， 10（3）： 164-166.
	李玉中， Redmann R E，祝廷成，等. 羊草草原豆科牧草生物固定量研究. 草地学报， 2002， 10（3）： 164-166.
21	Buchanan R E， Gibbons N E. Bergey’s manual of determinative bacteriology. Beijing： Science Press， 1984.
	Buchanan R E， Gibbons N E. 伯杰细菌鉴定手册. 北京：科学出版社， 1984.
22	Kocagöz T， Yilmaz E， Ozkara S， et al. Detection of Mycobacterium tuberculosis in sputum samples by polymerase chain reaction using a simplified procedure. Journal of Clinical Microbiology， 1993， 31（6）： 1435-1438.
23	Weatherburn M W. Phenol-hypochlorite reaction for determination of ammonia. Analytical Chemistry， 1967， 39（8）： 971-974.
24	Leveau J H J， Gerards S. Discovery of a bacterial gene cluster for catabolism of the plant hormone indole 3-acetic acid. FEMS Microbiology Ecology， 2008， 65（2）： 238-250.
25	Zhang X S. Analysis of the factors affecting the available P content in the fermentation liquid of P bacteria determined by Mo-Sb colorimetry. Journal of Anhui Agricultural Sciences， 2008， 36（12）： 4822-4823.
	张祥胜. 钼锑抗比色法测定磷细菌发酵液中有效磷含量测定值的影响因素分析. 安徽农业科学， 2008， 36（12）： 4822-4823.
26	Xie Z L， Yang M J， Gu K D， et al. Spectrophotometric method for the determination of bacterial liquid concentration of ralstonia solanacearum. Journal of Xichang University （Natural Science Edition）， 2022， 36（2）： 13-16.
	谢祯璐，杨梦婕，顾康蝶，等. 分光光度计法测定不同分离源青枯雷尔氏菌菌液浓度. 西昌学院学报（自然科学版）， 2022， 36（2）： 13-16.
27	Liu J J， Wei Z， Li J H. Effects of copper on leaf membrane structure and root activity of maize seedling. Botanical Studies， 2014， 55（1）： 1-6.
28	Liu M Y， Lei C Y， Li J J， et al. Differential physiological and biochemical responses of cucumber to the feeding by Bemisia tabaci B and Q biotypes. Scientia Agricultura Sinica， 2016， 49（13）： 2514-2523.
	刘明杨，雷彩燕，李静静，等. 黄瓜对B型和Q型烟粉虱取食的不同生理生化反应. 中国农业科学， 2016， 49（13）： 2514-2523.
29	Bochinnock X H. Methods for biochemical analysis of plants. Jing J H， Ding Z R， translated. Beijing： Science Press， 1981.
	Bochinnock X H. 植物生物化学分析方法. 荆家海，丁钟荣，译. 北京：科学出版社， 1981.
30	Liu Y Q， Wang Y H， Kong W L， et al. Identification， cloning and expression patterns of the genes related to phosphate solubilization in Burkholderia multivorans WS-FJ9 under different soluble phosphate levels. AMB Express， 2020， 10（1）： 1-11.
31	Lu K， Song Z G. Effects of different sprayed nanomaterials on the phosphorus content in rice seedlings. Journal of Agro-Environment Science， 2020， 39（1）： 28-36.
32	Wang J， Han J L， Yang M， et al. Study on the nitrogen uptake and metabolism in different nitrogen efficient maize varieties. Journal of Nuclear Agricultural Sciences， 2020， 34（12）： 2800-2812.
	王健，韩金玲，杨敏，等. 不同氮高效玉米品种对氮素的吸收转运和代谢研究. 核农学报， 2020， 34（12）： 2800-2812.
33	Li H M， Han G M. Analysis of the ammonium transporter gene family in maize inbred line B73. Journal of Anqing Normal University （Natural Science Edition）， 2018， 24（1）： 73-77.
	李红梅，韩国民. 玉米自交系B73铵转运蛋白基因家族分析. 安庆师范大学学报（自然科学版）， 2018， 24（1）： 73-77.
34	An Y， Yang X X， Zhang L， et al. Alfalfa MsCBL4 enhances calcium metabolism but not sodium transport in transgenic tobacco under salt and saline-alkali stress. Plant Cell Reports， 2020， 39（8）： 997-1011.
35	Wang H， Wu Y J， An T T， et al. Lateral root elongation enhances nitrogen-use efficiency in maize genotypes at the seedling stage. Journal of the Science of Food and Agriculture， 2022， 102（12）： 5389-5398.
36	Wu Y G， Wang H X， Zhang Z， et al. The effect and promotion prospect of bio-organic fertilizer containing super-efficient nitrogen-fixing bacteria instead of chemical fertilizer. Rural Economy and Science-Technology， 2020， 31（20）： 23-24.
	武玉国，王洪祥，张振，等. 含超高效固氮菌的生物有机肥替代化肥的效果与推广前景. 农村经济与科技， 2020， 31（20）： 23-24.
37	Zhang T， Yan L Y， He S， et al. Involvement of the ammonium transporter AmtB in nitrogenase regulation and ammonium excretion in Pseudomonas stutzeri A1501. Research in Microbiology， 2012， 163（5）： 332-339.
38	Delaporte Q P， Lovaisa N C， Rapisarda V A， et al. The plant growth promoting bacteria Gluconacetobacter diazotrophicus and Azospirillum brasilense contribute to the iron nutrition of strawberry plants through siderophores production. Plant Growth Regulation， 2020， 91（2）： 15.
39	Islam M R， Sultana T， Joe M M， et al. Nitrogen-fixing bacteria with multiple plant growth-promoting activities enhance growth of tomato and red pepper. Journal of Basic Microbiology， 2013， 53（12）： 1004-1015.
40	Huang S C， Hou D， Yue H Z， et al. Effects of three growth promoting bacteria and their mixed microbial agents on growth and quality of lettuce. Acta Agriculturae Zhejiangensis， 2021， 33（7）： 1212-1221.
	黄书超，侯栋，岳宏忠，等. 三株促生菌及其混合微生物菌剂对莴笋生长和品质的影响. 浙江农业学报， 2021， 33（7）： 1212-1221.
41	Lelapalli S， Baskar S， Jacob S M， et al. Characterization of phosphate solubilizing plant growth promoting rhizobacterium Lysinibacillus pakistanensis strain PCPSMR15 isolated from Oryza sativa. Current Research in Microbial Sciences， 2021， 2（2）： 100080.
42	Zhao W S， Guo Q G， Yu W Q， et al. Phosphate solubilizing characteristics of Bacillus amyloliquefaciens PHODB35 and its growth-promoting effect on tomato. Acta Microbiologica Sinica， 2020， 60（7）： 1370-1383.
	赵卫松，郭庆港，于稳欠，等. 解淀粉芽胞杆菌PHODB35的溶磷特性及其对番茄的促生作用. 微生物学报， 2020， 60（7）： 1370-1383.
43	Liu Y P， Teng S S， Zhao L. Identification of a siderophore-producing bacterium Pseudomonas putida A3 and its growth-promoting effects on cucumber seedings. Journal of Plant Nutrition and Fertilizers， 2011， 17（6）： 1507-1514.
	刘艳萍，滕松山，赵蕾. 高产嗜铁素恶臭假单胞菌A3菌株的鉴定及其对黄瓜的促生作用. 植物营养与肥料学报， 2011， 17（6）： 1507-1514.
44	Khare E， Arora N K. Effect of indole-3-acetic acid （IAA） produced by Pseudomonas aeruginosa in suppression of charcoal rot disease of chickpea. Current Microbiology， 2010， 61（1）： 64-68.
45	Ham S H， Yoon A R， Oh H E， et al. Plant growth-promoting microorganism Pseudarthrobacter sp. NIBRBAC000502770 enhances the growth and flavonoid content of Geum aleppicum. Microorganisms， 2022， 10（6）： 1241.
46	Zhang X， Tong J， Dong M， et al. Isolation， identification and characterization of nitrogen fixing endophytic bacteria and their effects on cassava production. PeerJ， 2022， 25（10）： e12677.
47	Xu X P， Fu X D， Liao H. Advances in study of ammonium assimilation and its regulatory mechanism in plants. Chinese Bulletin of Botany， 2016， 51（2）： 152-166.
	徐晓鹏，傅向东，廖红. 植物铵态氮同化及其调控机制的研究进展. 植物学报， 2016， 51（2）： 152-166.
48	Hou S Q， He S， Dou Y T， et al. Molecular cloning and functional analysis of ammonium transporter encoding genes amtB in associative nitrogen-fixing bacterium Pseudomonas stutzeri A1501. Journal of Nuclear Agricultural Sciences， 2007， 21（6）： 572-576.
	侯胜强，何升，窦岳坦，等. 固氮斯氏假单胞菌铵载体amtB基因的功能和结构分析. 核农学报， 2007， 21（6）： 572-576.
49	Li Y B， Li Y L， Zhang H W， et al. Diazotrophic Paenibacillus beijingensis BJ-18 provides nitrogen for plant and promotes plant growth， nitrogen uptake and metabolism. Frontiers in Microbiology， 2019， 10（10）： 1119.
50	Brambilla S， Soto G， Odorizzi A， et al. Spontaneous mutations in the nitrate reductase gene napC drive the emergence of eco-friendly low-N₂O-emitting alfalfa rhizobia in regions with different climates. Microbial Ecology， 2020， 79（4）： 1044-1053.

基因名称 Gene name	正向引物序列 Forward primer sequence （5′→3′）	反向引物序列 Reverse primer sequence （5′→3′）
铵转运蛋白基因 ZmAMTB	CTACTGGGTAACTGCTGTCT	AACCCATCCACACGAGA
谷氨酰胺合成酶基因 ZmGS1-3	CTTCTGTATCCCTGAATCTACC	GTTACCGCATCATTGTCC
谷氨酸合成酶基因 ZmGOGAT2	TAGTGTTCCAACCTCTTTCC	AACACACCTTCCACGTTAG
铵转运蛋白基因 ZmAMT-4	TGACCTAATTGGTCGTGC	ATGGGGTCGCAAAGG
内参基因 GADPH	TGGGCCTACTGGTCTTACTACTGA	ACATACCCACGCTTCAGATCCT

基因名称 Gene name	正向引物序列 Forward primer sequence （5′→3′）	反向引物序列 Reverse primer sequence （5′→3′）
铵转运蛋白基因 ZmAMTB	CTACTGGGTAACTGCTGTCT	AACCCATCCACACGAGA
谷氨酰胺合成酶基因 ZmGS1-3	CTTCTGTATCCCTGAATCTACC	GTTACCGCATCATTGTCC
谷氨酸合成酶基因 ZmGOGAT2	TAGTGTTCCAACCTCTTTCC	AACACACCTTCCACGTTAG
铵转运蛋白基因 ZmAMT-4	TGACCTAATTGGTCGTGC	ATGGGGTCGCAAAGG
内参基因 GADPH	TGGGCCTACTGGTCTTACTACTGA	ACATACCCACGCTTCAGATCCT

指标 Index	菌株 Strains
指标 Index	ZL-2	ZL-13
甲基红 Methyl red	－	＋
伏普 Voges-proskaue	＋	＋
吲哚 Indole	＋	＋
葡萄糖 Glucose	＋	－
柠檬酸盐 Citrate	＋	＋
接触酶 Catalase	＋	＋
淀粉水解 Starch hydrolysis	＋	＋
硫化氢 H₂S	－	－
明胶液化 Gelatin liquefaction	－	－
脲酶 Urease	＋	－
革兰氏染色 Gram stain	－	－

指标 Index	菌株 Strains
指标 Index	ZL-2	ZL-13
甲基红 Methyl red	－	＋
伏普 Voges-proskaue	＋	＋
吲哚 Indole	＋	＋
葡萄糖 Glucose	＋	－
柠檬酸盐 Citrate	＋	＋
接触酶 Catalase	＋	＋
淀粉水解 Starch hydrolysis	＋	＋
硫化氢 H₂S	－	－
明胶液化 Gelatin liquefaction	－	－
脲酶 Urease	＋	－
革兰氏染色 Gram stain	－	－

[1]	Hai-wang YUE, Jian-wei WEI, Guang-cai WANG, Peng-cheng LIU, Shu-ping CHEN, Jun-zhou BU. Comprehensive evaluation of silage maize hybrids in the Huanghuaihai plain based on mega-environments delineated using envirotyping techniques [J]. Acta Prataculturae Sinica, 2024, 33(3): 120-138.
[2]	Jia-hui CHEN, Wen-xian LIU. Construction and application of a graphic visualization tool for important forage omics data [J]. Acta Prataculturae Sinica, 2024, 33(2): 57-67.
[3]	Cong-ze JIANG, Na SHOU, Wei GAO, Ren-shi MA, Yu-ying SHEN, Xian-long YANG. A multivariate evaluation of production performance and nutritional quality of different varieties of silage maize in the dry plateau area of Longdong [J]. Acta Prataculturae Sinica, 2023, 32(7): 216-228.
[4]	Jin GUAN, Yi-di GUO, Ling-yun LIU, Shu-xia YIN, Ke TENG. An efficient protocol for Zoysia japonica mesophyll protoplast isolation and transformation， and its application in subcellular localization and protein interaction analysis [J]. Acta Prataculturae Sinica, 2023, 32(7): 61-71.
[5]	Li-li ZHU, Ye-meng ZHANG, Wan-cai LI, Ya-li ZHAO, Xiang LI, Zhi-guo CHEN. Adaption to the Plateau climate in Qinghai of 39 silage maize varieties cultivated in different ecological regions of China [J]. Acta Prataculturae Sinica, 2023, 32(4): 68-78.
[6]	Mu-ye LIU, Li-zhu GUO, Yue-sen YUE, Ju-ying WU, Xi-feng FAN, Guo-zeng XIAO, Ke TENG. Physiological and antioxidant enzyme gene expression differences between female and male Buchloe dactyloides plants under drought stress [J]. Acta Prataculturae Sinica, 2023, 32(10): 93-103.
[7]	Hao-yu XU, Ying ZHAO, Qian RUAN, Xiao-lin ZHU, Bao-qiang WANG, Xiao-hong WEI. Resistance of quinoa seedlings under different salt-alkali stress levels [J]. Acta Prataculturae Sinica, 2023, 32(1): 122-130.
[8]	Ying-zheng LI, Yu-lin CHENG, Lu-lu XU, Wan-song LI, Xu YAN, Xiao-feng LI, Ru-yu HE, Yang ZHOU, Jun-jun ZHENG, Xing-yu WANG, De-long ZHANG, Ming-jun CHENG, Yun-hong XIA, Jian-mei HE, Qi-lin TANG. A comparative study of silage quality characteristics of whole-plant， whole-ear and whole-straw silage of different maize varieties （lines） [J]. Acta Prataculturae Sinica, 2022, 31(8): 144-156.
[9]	Ling-shuang ZENG, Pei-ying LI, Zong-jiu SUN, Xiao-fan SUN. Analysis of antioxidant enzyme protection systems and gene expression differences in two Xinjiang bermudagrass genotypes with contrasting drought resistance [J]. Acta Prataculturae Sinica, 2022, 31(7): 122-132.
[10]	Li-juan GAO, Zheng-she ZHANG, Yu WEN, Xi-fang ZONG, Qi YAN, Li-yan LU, Xian-feng YI, Ji-yu ZHANG. Genome-wide identification and expression analysis of the bHLH transcription factor family in Cenchrus purpureus [J]. Acta Prataculturae Sinica, 2022, 31(3): 47-59.
[11]	Li-qing ZHAO, Zhi-gang HAO, Xiao-yan CUI, Xiang-yong PENG. Effects of gibberellin and its inhibitors on growth and gene expression in Poa pratensis [J]. Acta Prataculturae Sinica, 2022, 31(3): 85-91.
[12]	Guo-xiang ZHANG, Wei-leng GUO, Ming-yu BI, Li-shuang ZHANG, Dan WANG, Chang-hong GUO. Identification of CAX gene family and expression profile analysis of response to abiotic stress in alfalfa [J]. Acta Prataculturae Sinica, 2022, 31(12): 106-117.
[13]	Ning ZHAO, Hui-ling MA, Ran ZHANG, Jin-qing ZHANG, Yi SHI. Regulatory effects of butanediol on the expression level of endogenous hormones and related genes in creeping bentgrass under heat stress [J]. Acta Prataculturae Sinica, 2022, 31(12): 118-132.
[14]	Na WEI, Yan-peng LI, Yi-tong MA, Wen-xian LIU. Genome-wide identification of the alfalfa TCP gene family and analysis of gene transcription patterns in alfalfa （Medicago sativa） under drought stress [J]. Acta Prataculturae Sinica, 2022, 31(1): 118-130.
[15]	Xin-ming WU, Zhi-hong FANG, Hui-wu CHI, Hui-li JIA, Jian-ning LIU, Yong-hong SHI, Xue-min WANG. Comparison of 30 maize （Zea mays） varieties for food and feed in the Yanmenguan area [J]. Acta Prataculturae Sinica, 2022, 31(1): 205-216.