不同储存年限老芒麦种子种带真菌检测及致病性测定

对来自青海的5个不同收获年份的老芒麦种样进行了系统的种带真菌研究;测定了12种分离率大于1%的种带真菌对老芒麦种子萌发和幼苗生长的影响。结果表明,种样发芽率为56%~80%,S₂发芽率最高,达到80%,显著高于S₁和S₅(P<0.05);种样带菌率为24%~38%,随储藏时间延长呈下降趋势,S₅带菌率最高,达到38%,显著高于其他种样(P<0.05);共鉴定出老芒麦种带真菌15属17种,真菌分离率为0.25%~8.75%,其中青霉和曲霉是老芒麦最常见的种带真菌,在5个种样上均被分离得到;燕麦镰孢、串珠镰孢、镰孢菌1、离蠕孢和德氏霉5种真菌是老芒麦最主要的致病真菌,均显著地降低了老芒麦种子的萌发、抑制了幼苗的生长、降低了幼苗的生物量(P<0.05);细交链孢对种子的萌发没有显著抑制作用(P>0.05),但是显著地降低了幼苗的长度和干物质产量(P<0.05)。皮思霉、离蠕孢、曲霉3种真菌显著延长了老芒麦种子平均萌发时间,而燕麦镰孢则显著地缩短了种子平均发芽时间(P<0.05)。

Seed-borne fungi infection of Siberian wildrye: Effects on seed germination and seedling growth

We investigated seed-borne fungi in Siberian wildrye seed samples collected from Qinghai in five different harvest seasons (S₁ to S₅) and tested the effects of fungal infection on seed germination and seedling growth. Seed germination ranged from 56%to 80%. S₂ had the highest seed germination (80%), significantly higher than S₁ and S₅ (P<0.05).The fungal infection rate of seed samples varied from 24% to 38% and declined with the extension of storage time.S₅ had the highest infection rate of 38%, significantly higher than all other samples (P<0.05).17 fungal species from 15 genera were identified; the isolation rate ranged from 0.25% to 8.75%. Penicillium sp. and Aspergillus sp. were the most common seed-borne species found and were isolated in all seasons. Pathogenicity tests showed that Fusarium avenaceum,F. monilifome,Fusarium sp.1,Drechslera sp. and Bipolaris sp. were the most pathogenic fungi, significantly reducing seed germination and seedling growth (P<0.05). Alternaria alternata significantly reduced seedling growth but did not affect seed germination. Pithomyces sp.,Aspergillus sp. and Bipolaris sp. significantly prolonged the mean seed germination period, while Fusarium avenaceum significantly shortened it (P<0.05).