6种药剂处理对西葫芦种子表面微生物群落的影响

Effects of six chemical treatments on surface microbial communities of zucchini seeds

采用六种药剂处理西葫芦种子后,测定西葫芦出苗率、茎粗、株高、叶片数、叶面积、冠根比等生长发育指标,并利用Illumina MiSeq测序技术分析西葫芦种子表面微生物群落。结果表明,药剂处理后西葫芦的各项生长发育指标均明显高于对照,其中70%甲基托布津可湿性粉剂和3%中生菌素水剂处理种子后变化最为显著(P<0.05)。微生物群落中,共检测出13门38纲53目105科231属细菌,其中优势门为变形菌门Proteobacteria(78.7%),其次为厚壁菌门Firmicutes(19.0%)和拟杆菌门Bacteroidetes(1.28%);共检测出3门17纲49目90科133属真菌,其中优势门为子囊菌门Ascomycota(83.55%),其次为担子菌门Basidiomycota(5.41%)和接合菌门Zygomycota(0.38%)。不同药剂处理种子表面微生物群落多样性及丰富度存在差异,与对照相比,2%春雷霉素水剂处理后种子表面细菌群落丰度和多样性最低,3%中生菌素水剂处理后种子表面真菌群落丰度和多样性最低。处理后Pectobacterium、Ralstonia、Gibellulopsis和Fusarium菌群群落相对丰度均明显下降,差异极显著(P<0.001)。根据处理后种子表面微生物的群落丰度,将6种药剂分为三类,70%代森联水剂和40%百菌清悬浮剂为一类,2%春雷霉素水剂和22.5%啶氧菌酯悬浮剂为一类,70%甲基托布津可湿性粉剂和3%中生菌素水剂为一类。3%中生菌素水剂为处理西葫芦种子的最佳药剂,其次为70%甲基托布津可湿性粉剂。研究结果将为筛选用于种子处理的有效药剂提供数据支持,进而为种子处理技术的开发和应用提供参考。

Growth indexes of seedling and diversity of surface microbial communities of zucchini seeds were tested after six chemical treatments.The results showed that the seedling emergence rate,plant height,stem thickness,numbers and area of leaves,crown-root ratio increased obviously after chemical treated.Growth indexes of seedling treated by 70%thiophanate-methyl WP and 3%mesomycin AS increased more significantly(P<0.05).A total of 13 phyla,38 classes,53 orders,105 families and 231 genera bacteria were detected where Proteobacteria(78.7%),Firmicutes(19.0%)and Bacteroidetes(1.28%)were the dominant phyla.A total of 3 phyla,17 classes,49 orders,90 families,133 genera fungi were detected where Ascomycota(83.55%),Basi-diomycota(5.41%)and Zygomycota(0.38%)were the dominant phyla.The diversity and relative abundance of surface microbial communities were different among treatments.Compared with the control,the diversity and relative abundance of bacterial communities were lowest by 2%kasugamycin AS treatment while the lowest fungi communities were observed by 3%mesomycin AS treatment.The relative abundances of Pectobacterium,Ralstonia,Gibellulopsis and Fusarium decreased significantly after treated(P<0.001).According to the relative abundance of surface microbial communities of seeds,6 chemicals were clustered into three groups:one group including 70%metiram AS and 40%chlorothalonil SC,another group including 2%kasugamycin AS and 22.5%picoxystrobin SC,and the third group including 70%thiophanate-methyl WP and 3%mesomycin AS.Among the six chemical treatments,3%mesomycin AS was the best seed treatment,followed by 70%thiophanate-methyl WP.The results helped choose effective seed chemical treatments and provided scientific basis for development and application of seed treatment technology.