Seedling

Seedling Development:

• Seedling is a young sporophyte developing from a seed embryo.
• Typical seedling consists of radicle, hypocotyl, and cotyledons.
• Monocots have one cotyledon, while dicots have two.
• Gymnosperms like pine seedlings may have up to eight cotyledons.
• Some flowering plants have acotyledon seedlings.

Seedling Physiology:

• Light-grown dicot seedlings have short hypocotyls and open cotyledons.
• Dark-grown seedlings have long hypocotyls and closed cotyledons.
• Seedlings protect the shoot apical meristem during skotomorphogenesis.
• Light receptors like phytochrome and cryptochrome sense light for seedling development.
• Seedlings photosynthesize, grow roots and shoots, and mature with true leaves replacing cotyledons.

Pests and Diseases:

• Seedlings are vulnerable to pests and diseases.
• Damping off is a common disease affecting seedlings.
• Pests like cutworms, pillbugs, slugs, and snails can damage seedlings.

Transplanting Seedlings:

• Seedlings are transplanted when true leaves appear.
• Shade may be needed for arid or hot environments during transplanting.
• Vitamin hormone concentrate can be used to prevent transplant shock.
• Process of transplanting seedlings is known as ‘pricking out’ in the UK.

Research and Resources:

• Research studies on seedling growth, including effects of temperature, light intensity, carbon dioxide enrichment, and nitrogen supply.
• Publications on pests, diseases, and garden plant disorders.
• Sources for gardening techniques, including pricking out seedlings and seedling potting.
• Relevant publications, reports, and resources for seedling care, maintenance, and optimal growth.

Seedling Data Sources