【摘要】 【目的】建立科学简便的水稻穗发芽抗性鉴定体系以及评价标准，以批量筛选穗发芽抗性种质资源，为抗穗发芽品种选育提供技术支撑。【方法】以16个水稻试验品系为材料，优化穗发芽抗性鉴定方法和取样时间，采用优化后的抗性鉴定方法对2023—2024年在南京正季种植的360份水稻材料进行人工穗发芽鉴定试验，结合聚类分析评价其穗发芽抗性，并与熟期特性及大田穗发芽情况进行关联分析。【结果】（1）16个水稻试验品系在开花后20～50 d取样条件下的穗发芽表现显示，在水稻开花后35 d取样，供试材料整穗相对含水量比较稳定，既能保证相似的成熟度，也更有利于区分不同材料间的穗发芽抗性差异；相比于籽粒发芽法，整穗发芽法能反映不同材料穗发芽抗性，且省工省时；（2）360份水稻材料整穗发芽试验的平均发芽率呈现正态分布，2年的变化趋势类似，且在试验第4天品种间差异显著（P<0.05），第6天后差异缩小；（3）利用K-均值聚类分析法，对2年人工整穗发芽试验的平均发芽率进行归一化处理并聚类，将360份供试水稻材料按照穗发芽抗性等级划分为高抗穗发芽类型（聚类I）、中抗穗发芽类型（聚类Ⅱ）和易穗发芽类型（聚类Ⅲ）3类；（4）分析熟期与穗发芽试验结果发现，在南京正季种植的水稻，8月5日—8月15日期间开花的水稻平均穗发芽率较大，更易发生穗发芽；（5）将2年的人工穗发芽试验结果与当年大田穗发芽表现进行比较，建立穗发芽抗性评价标准：高抗穗发芽类型整穗发芽试验第4天发芽率<15%，第6天发芽率<25%；易穗发芽类型整穗发芽试验第4天发芽率>20%，第6天发芽率>50%。【结论】在水稻开花后35 d取整穗，进行人工整穗发芽试验，根据试验第4天和第6天的发芽率即可鉴定水稻穗发芽类型，该方法为水稻抗穗发芽品种的选育提供技术参考。更多还原

【Abstract】 [Objective]This study aims to establish a scientific and convenient evaluation system for identifying pre-harvest sprouting(PHS)resistance in rice and screening PHS-resistant germplasm resources,thereby providing technical support for breeding PHS-resistant varieties.[Method]16 rice experimental lines were used as research material to optimize the evaluation methodology and sampling timing for PHS-resistance.Subsequently,the optimized protocol was applied to conduct artificial panicle sprouting tests on 360 rice accessions grown under normal seasonal conditions in Nanjing during 2023-2024. Cluster analysis was performed to assess PHS resistance levels,followed by correlation analyses with heading date characteristics and field sprouting performance.[Result]The study demonstrated that:(1)Evaluation of 16 rice test lines sampled at 20-50 days after flowering(DAF)revealed that panicles collected at 35 DAF exhibited stable relative water content while maintaining consistent maturity,thereby better differentiating PHS-resistance among materials.Compared with the grain germination method,the whole-panicle germination method reflected more effectively varietal differences in PHS-resistance with improved labor efficiency and time efficiency.(2)The average germination rates from whole-panicle sprouting tests of the 360 rice accessions followed a normal distribution,showing similar variation trends between the two years. Significant differences(P<0.05)in preharvest sprouting(PHS)rates among varieties were observed on day 4, and the differences diminished after day 6.(3)The daily average germination rates from the artificial whole-panicle sprouting tests conducted in 2023and 2024 were normalized separately and subsequently analyzed using K-means clustering. Based on this analysis,the 360 tested rice accessions were classified into three pre-harvest sprouting(PHS)resistance categories:highly PHS-resistant(Cluster I),moderately PHS-resistant(Cluster Ⅱ),and PHS-susceptible(Cluster Ⅲ).(4)Statistical analysis of the correlation between heading dates and PHS test results demonstrated that rice accessions flowering from August 5 to 15 under conventional cultivation conditions in Nanjing exhibited significantly elevated panicle sprouting rates(P<0.05),suggesting their inherent susceptibility to PSH.(5)By comparing the artificial PHS test results from 2023-2024 with the actual field PHS performance in the corresponding years,the following PHS resistance evaluation criteria was established as following:For the high spike germination-resistant type,the germination rate was less than 15% on the 4th day and less than 25%on the 6th day in the whole spike germination test;for the spike germination-prone type,the germination rate was more than 20% on the 4th day and more than 50% on the 6th day in the whole spike germination test.[Conclusion]For the whole panicles collected at 35 DAF,the artificial whole-panicle germination test can be used to classify rice PHS resistance types based on the germination rates recorded on day 4 and day 6.This method provides a technical reference for breeding PHS-resistant rice varieties.更多还原