Intra-genotypic variation of morpho-anatomical and biochemical traits for lodging resistance in oat (Avena sativa L.)

Abstract

Oat (Avena sativa L.) is prone to stem lodging under field conditions that negatively affect productivity. The present study aimed to determine the association between lodging resistance with culm morphological, anatomical and biochemical traits. The experiment was laid out in randomized block design in Rabi season of 2020–21 and 2021–22 using eight recently released oat genotypes (OL-1769-1, RO-11-1, OL-13, OL-1896, JHO-822, OL-15, OL-14 and OL-12) to evaluate the impact of stem lodging on oat genotypes. Dendrogram analysis depicted that Cluster I genotypes (OL-1769-1, RO-11-1, OL-13) proved to be more efficient in overcoming lodging stress as compared to Cluster III (OL-15, OL-14, OL-12) and Cluster II (OL-1896, JHO-822) genotypes. Cluster I had lower lodging scores plus lower percent reduction in thousand grain weight, lignin content, dry matter yield of lodged plants and higher breaking strength (BS), culm lodging resistance index (CLRI) than Cluster III. Increased lodging also had a negative impact on biomass partitioning. The correlation analysis depicted a negative association of CLRI with second internode length (− 0.841**) while significant positive correlation with second internode diameter (0.808*) and BS (0.949**). Water-soluble carbohydrates (WSC) and starch content varied significantly with lodging. Increased vascular bundle area and xylem tissue contributed towards lodging resistance. This study provides the direct estimation of the differential behavior of oat genotypes towards stem lodging and its effect on morpho-anatomical and biochemical characters. Genotype RO-11-1 showed resistant behavior while OL-15 showed susceptible behavior towards lodging. Our findings demonstrate the potential of using commercially viable genotypes to achieve high and stable yield under field conditions and to identify lodging tolerant genotypes to support future breeding programs.