Influence of packaging materials and storage conditions on root system architecture (RSA) of papaya (Carica papaya L.)

Aim: To evaluate the effects of packaging materials and storage conditions on root system architecture (RSA) of papaya (Carica papaya L.) seeds during prolonged storage, and identify optimal storage conditions for maintaining seedling vigour. Methodology: Seeds of four papaya cultivars (CO-8’, Vinayak, Shabnam, and Ameena) were packed in polythene packets or aluminium polypouches and stored under controlled conditions (5°C, 30% RH) or ambient conditions. RSA traits–total root length (cm), root surface area (cm²), root volume (cm³) and root average diameter (mm)–were assessed at 0, 3, 6 and 9 months of storage using WinRHIZO™ image analysis software, and inter–trait correlations were analysed using JMP statistical software. Data were evaluated using a factorial completely randomized design with Tukey’s test at p ≤ 0.05. Results: RSA traits declined progressively with storage duration, deteriorating by 9 months under ambient conditions. Aluminium polypouches under controlled conditions consistently preserved higher RSA traits than polythene packets under ambient storage. ‘Shabnam’ showed the best storability (0 to 9 months, controlled storage): total root length 68.94 to 55.30 cm, root surface area 10.23 to 6.61 cm2, root volume 0.130 to 0.100 cm3, and root average diameter 0.514 to 0.309 mm. 'Vinayak' in polythene packets under ambient conditions showed the sharpest decline: root length 32.13 to 18.49 cm, surface area 3.88 to 0.66 cm2, volume 0.045 to 0.021 cm3, and diameter 0.311 to 0.104 mm. All four RSA traits were strongly and positively correlated with each another. Interpretation: Aluminium poly pouches combined with controlled low-temperature storage effectively preserved RSA and seedling vigour in papaya during extended storage. The superior performance of the cultivar ‘Shabnam’ indicates inherent genetic variability in seed storability and ageing tolerance, offering useful insights for improving seed storage strategies and enhancing seedling establishment. Key words: Carica papaya, Packaging material, Root system architecture, Seed storage, Seedling vigour