Derivation of seed viability constants ( C W, K E) and predicting seed longevity for jute mallow ( Corchorus capsularis and C. olitorius )

Genebanks support long-term germplasm conservation and ensure availability of viable seeds to users. The improved seed viability equation enables prediction of longevity by combining species-specific moisture content constants ( C W , K E ) with universal temperature constants ( C H = 0.0329; C Q = 0.000478). While the number of genebank collections of jute mallow ( Corchorus capsularis and C. olitorius ) has significantly increased in recent years, such constants are lacking to support management. To derive C W and K E and predict longevity, seeds of both species were equilibrated to five moisture content levels (7.5-12.2%) and subjected to experimental storage at 60°C for 25 or 35 days for C. olitorius and C. capsularis , respectively. The viability constants were then estimated as C W = 6.80 and K E = 10.78 for C. capsularis and C W = 6.21 and K E = 10.06 for C. olitorius . The validation of the derived constants indicated good agreement between predicted and observed viability at high viability levels in both species, with increasing divergence as seeds deteriorated. The predicted seed longevity under genebank conditions indicated that C. capsularis seeds live longer than C. olitorius . The derived constants provide a practical tool for genebanks to optimise germplasm regeneration cycles and minimise the risk of genetic erosion.