Culm anatomy revealed association of vascular bundle number and silicon content with lodging behaviour in Kodo millet (Paspalum scrobiculatum L.).

In dry lands, small millets such as kodo millet contribute to regional food security to some extent. It is normally harvested using paddy combine harvester due to labour scarcity. However, the current varieties are not amenable for mechanized harvesting as they lodge at grain filling and maturity stages, thus resulting in heavy grain loss in terms of quality and quantity. In this context, we studied the anatomical features of culm and elemental composition in relation to lodging behaviour in kodo millet (Paspalum scrobiculatum L.), which is one of the important yield limiting factors in this crop. The strong culm genotype, Adari had higher culm thickness, thicker mechanical tissue, more lignin deposition and more number of vascular bundles per cross section when compared to the weaker counterpart, Aamo10. However, not all the genotypes with thicker culm were lodging resistant. Sel21 which recorded the highest culm thickness (1283.4 µm) among the genotypes lodged heavily as higher culm thickness in Sel21 was not supported by an increased number of vascular bundles. Interestingly, TNPsc183 which had a moderate culm thickness of 782.82 μm exhibited a low degree of lodging and had more number of vascular bundles per cross section than Sel21. Hence, 'number of vascular bundles per unit area' appears to be an important trait in contributing lodging resistance in kodo millet. SEM-EDX studies for silicon and potassium contents in culm implicated the role of silicon, but not potassium in imparting culm strength in kodo millet. However, more potassium content in parenchymatous cell wall suggests its role in imparting strength to the non-lignified cells of the culm. [ABSTRACT FROM AUTHOR]