Sankar S Mukesh, Singh S P, Prakash G, Satyavathi C Tara, Soumya S L, Yadav Yashpal, Sharma L D, Rao A R, Singh Nirupma, Srivastava Rakesh K
Division of Genetics, ICAR-Indian Agricultural Research Institute, New Delhi, India.
Division of Plant Pathology, ICAR-Indian Agricultural Research Institute, New Delhi, India.
Front Plant Sci. 2021 May 17;12:656158. doi: 10.3389/fpls.2021.656158. eCollection 2021.
Once thought to be a minor disease, foliar blast disease of pearl millet, caused by , has recently emerged as an important biotic constraint for pearl millet production in India. The presence of a wider host range as well as high pathogenic heterogeneity complicates host-pathogen dynamics. Furthermore, environmental factors play a significant role in exacerbating the disease severity. An attempt was made to unravel the genotype-by-environment interactions for identification and validation of stable resistant genotypes against foliar blast disease through multi-environment testing. A diversity panel consisting of 250 accessions collected from over 20 different countries was screened under natural epiphytotic conditions in five environments. A total of 43 resistant genotypes were found to have high and stable resistance. Interestingly, most of the resistant lines were late maturing. Combined ANOVA of these 250 genotypes exhibited significant genotype-by-environment interaction and indicated the involvement of crossover interaction with a consistent genotypic response. This justifies the necessity of multi-year and multi-location testing. The first two principal components (PCs) accounted for 44.85 and 29.22% of the total variance in the environment-centered blast scoring results. Heritability-adjusted genotype plus genotype × environment interaction (HA-GGE) biplot aptly identified "IP 11353" and "IP 22423, IP 7910 and IP 7941" as "ideal" and "desirable" genotypes, respectively, having stable resistance and genetic buffering capacity against this disease. Bootstrapping at a 95% confidence interval validated the recommendations of genotypes. Therefore, these genotypes can be used in future resistance breeding programs in pearl millet. Mega-environment delineation and desirability index suggested Jaipur as the ideal environment for precise testing of material against the disease and will increase proper resource optimization in future breeding programs. Information obtained in current study will be further used for genome-wide association mapping of foliar blast disease in pearl millet.
曾经被认为是一种小病的珍珠粟叶瘟病，由[病原体名称未给出]引起，最近已成为印度珍珠粟生产的一个重要生物限制因素。宿主范围广泛以及高致病性异质性使宿主 - 病原体动态变得复杂。此外，环境因素在加剧病害严重程度方面起着重要作用。通过多环境试验试图揭示基因型与环境的相互作用，以鉴定和验证对叶瘟病稳定抗性的基因型。一个由从20多个不同国家收集的250份种质组成的多样性群体在五个环境的自然流行条件下进行了筛选。共发现43个抗性基因型具有高且稳定的抗性。有趣的是，大多数抗性品系成熟较晚。对这250个基因型的联合方差分析显示出显著的基因型与环境相互作用，并表明存在交叉相互作用以及一致的基因型反应。这证明了多年和多地测试的必要性。前两个主成分分别占以环境为中心的瘟病评分结果总方差的44.85%和29.22%。遗传力调整后的基因型加基因型×环境互作（HA - GGE）双标图分别恰当地将“IP 11353”和“IP 22423、IP 7910和IP 7941”鉴定为具有对该病稳定抗性和遗传缓冲能力的“理想”和“优良”基因型。在95%置信区间的自展验证了基因型的推荐。因此，这些基因型可用于未来珍珠粟的抗性育种计划。大环境划分和优良性指数表明斋浦尔是针对该病精确测试材料的理想环境，并将在未来育种计划中提高资源的合理优化。当前研究中获得的信息将进一步用于珍珠粟叶瘟病的全基因组关联图谱分析。
