Multi-environment screening of 2579 linseed accessions from the National Genebank of India was undertaken to identify novel donors imparting resistance to Alternaria lini causing blight disease of linseed. Alternaria blight incidence showed a differential genotypic response in the degree of disease severity across different location-year environments. The comparative analysis of disease incidence across two locations revealed that the mean leaf blight was higher at Raipur (∼81%) compared to Kanpur (43.83%), while mean bud blight was comparatively higher (up to 14.86%) at Kanpur than Raipur (∼4%). Leaf and bud blight scores across multiple environments revealed only 3.41% of the tested germplasm (4 resistant and 84 moderately resistant accessions) showed resistance to A. lini infection. Based on pooled disease incidence scores, a small and representative ‘Reference Set for Alternaria blight resistance’ (RSAB) comprising 256 genotypes was assembled and validated for confirmation of resistance. Overall, one genotype, a selection from IC0591124 was identified as resistant and 14 genotypes (selections from germplasm accessions having National IDs – IC0526066, EC0718850, IC0526032, IC0498580, IC0499140, IC0523800, EC0718852, IC0305053, IC0597268, IC0420772, EC0041481, IC0526017, IC0498549 and IC0597274) were found moderately resistant against all the three isolates of A. lini (Rpr, Knpr and Dli) in up to seven environments including artificial epiphytotic conditions in an environment-controlled glass house. A critical examination of the different quality evaluation criteria revealed that the assembled RSAB effectively captured the representativeness of the whole collection for disease resistance. The RSAB germplasm and novel broad-range resistant genotypes identified in the present study offer valuable insights for breeding programs aiming to develop blight resistant linseed varieties for sustainable disease management. In addition, these genetic resources will be crucial in identifying genes/genomic regions underlying blight resistance through genome-wide association studies and mapping resistance-linked QTLs.

中文翻译：

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开采遗传资源以稳定抗性亚麻籽链格孢枯病 （Linum usitatissimum L.）


对来自印度国家基因库的 2579 份亚麻籽种质进行了多环境筛选，以确定对导致亚麻籽枯萎病的 Alternaria lini 产生抗性的新颖供体。链格孢菌枯萎病发病率在不同地点年份环境中疾病严重程度的基因型反应存在差异。对两个地点病害发病率的比较分析表明，赖布尔的平均叶枯病 （∼81%） 高于坎普尔 （43.83%），而坎普尔的平均芽枯病相对高于赖布尔 （∼4%）（高达 14.86%）。多种环境下的叶枯病和芽枯病评分显示，只有 3.41% 的受试种质 （4 个抗性种质和 84 个中度抗性种质） 对 A. lini 感染表现出抗性。根据汇总的疾病发病率评分，组装了一个包含 256 个基因型的小型且具有代表性的“链格孢菌枯萎病抗性参考集”（RSAB） 并进行了验证，以确认耐药性。总体而言，一种基因型（从 IC0591124 中选择的基因型被鉴定为抗性，14 种基因型（从具有国家 ID 的种质种质中选择 - IC0526066、EC0718850、IC0526032、IC0498580、IC0499140、IC0523800、EC0718852、IC0305053、IC0597268、IC0420772、EC0041481、IC0526017、IC0498549 和 IC0597274）在多达七种环境中（包括人工附生条件）中度抗性环境控制的玻璃屋。对不同质量评价标准的严格检查表明，组装的 RSAB 有效地捕捉了整个系列在抗病性方面的代表性。 本研究中鉴定的 RSAB 种质和新的广谱抗性基因型为旨在开发抗枯萎病亚麻籽品种以实现可持续疾病管理的育种计划提供了有价值的见解。此外，这些遗传资源对于通过全基因组关联研究和绘制抗性相关 QTL 来识别枯萎病抗性的基因/基因组区域至关重要。