Lecture on Fabaceae Family

Fabaceae Family Overview

• Fabaceae (Leguminosae): A family common in many parts of the world, notable for producing legumes.

Sub-families of Fabaceae

• Mimosoidea: Characterized by monadelphous stamens and flower arrangements in spherical heads.
• Faboidea: Known for zygomorphic flowers; includes a variety of legumes.
• Caesalpinoidea: Features distinct floral structures and is often less economically significant compared to others.

Flower Characteristics

• Unique and diverse floral structures within Fabaceae.
• Example: Strongylodon macrobotrys shows drastic variations among flower shapes.

Fruit Structure of Legumes

• Legume: A fruit that develops from the ovary, typically containing several seeds.
• Anatomical Features:
  • Calyx: Outer whorl of sepals.
  • Ovary Wall (Pericarp): The wall structure of the pod; varies among species.
  • Seeds: Usually contain two cotyledons in legumes.

Types of Legume Pods

• Diverse shapes and structures. This can include various pod types, like flat, curved, or coiled.
• Medicago orbicularis and Pterocarpus indicus as examples of diverse pod types.

Germination of Legumes

• Process: Involves the seed coat breaking, allowing the embryonic plant to emerge.
• Key Parts:
  • Cotyledons: Initial leaves providing nutrients to the young plant.
  • Hypocotyl: The stem of the seedling; crucial for pushing through the soil.
  • Radicle: The embryonic root that will develop into the primary root.

Growth Stages of a Bean Plant

• Begins with cotyledons and develops into a foliage leaf split into three leaflets.
• Growth includes establishing root nodules, which are essential for nitrogen fixation.

Types of Legume Crops

• Grown as:
  • Grain/Vegetable: e.g., beans and lentils.
  • Ornamentals: These can include flowering types appreciated for aesthetics.
  • Forage: Grown primarily for animal feed.

Nutritional Value of Pulses

• Pulses are high in protein and fibers, important for a balanced diet.

Symbiotic Relationships

• Rhizobium Bacteria: Crucial for nitrogen fixation; live in root nodules of legumes, enhancing soil fertility.

Pollination in Legumes

• Mechanisms involved in the reproduction and fertilization of legumes, including both self-pollination and cross-pollination.

Specific Legume Examples

• Soya (Soybean): Its cultivation involves knowledge of pollination and growth patterns.
• Broad Bean: A popular variety, distinguished by its robust growth and pod structure.
• Peas (Pisum sativum): Includes varieties like garden peas and field peas for different culinary uses.