Exploring genetic variation for salinity tolerance in chickpea using image-based phenotyping

Abstract

Soil salinity results in reduced productivity in chickpea. However, breeding for salinity tolerance is challenging because of limited knowledge of the key traits affecting performance under elevated salt and the difficulty of high-throughput phenotyping for large, diverse germplasm collections. This study utilised image-based phenotyping to study genetic variation in chickpea for salinity tolerance in 245 diverse accessions. On average salinity reduced plant growth rate (obtained from tracking leaf expansion through time) by 20%, plant height by 15% and shoot biomass by 28%. Additionally, salinity induced pod abortion and inhibited pod filling, which consequently reduced seed number and seed yield by 16% and 32%, respectively. Importantly, moderate to strong correlation was observed for different traits measured between glasshouse and two field sites indicating that the glasshouse assays are relevant to field performance. Using image-based phenotyping, we measured plant growth rate under salinity and subsequently elucidated the role of shoot ion independent stress (resulting from hydraulic resistance and osmotic stress) in chickpea. Broad genetic variation for salinity tolerance was observed in the diversity panel with seed number being the major determinant for salinity tolerance measured as yield. This study proposes seed number as a selection trait in breeding salt tolerant chickpea cultivars.

Plant phenotyping relevance

画像ベース表現型解析を用いて塩ストレス下の成長速度を高スループットに測定し、圃場性能との関連も検証しており、表現型取得が研究の主要な方法的要素である。

Code and data availability

The paper describes image-based phenotyping of 245 chickpea accessions at The Plant Accelerator, but provides no public deposit of its phenotype data, RGB images, or analysis code. The only URL mentioned (plantphenomics.org.au/services/accelerator/) is the facility's website, not a paper-specific data/code repository.

No evidence-backed public reproduction asset is currently recorded.