Guava was introduced in India during the century? | Agrigyan

• Tunica-Corpus Theory: Proposed by A. Schmidt (1924) to describe the structural organization of the shoot apical meristem (SAM) in angiosperms, recognizing two distinct tissue zones:
• Tunica: The outer peripheral mantle characterized predominantly by anticlinal cell divisions (perpendicular to surface), maintaining discrete sheet-like cell layers and facilitating surface growth.
• Corpus: The inner central core characterized by multidirectional divisions (anticlinal, periclinal, and oblique) giving rise to the central ground tissue and provascular strands.
• Layers of the Tunica (L1 and L2): In angiosperms, the tunica typically comprises two distinct layers: L1 and L2:
• L1 Layer: Outermost single layer; gives rise strictly to the epidermis of leaves, stems, and floral organs.
• L2 Layer: Subepidermal cell layer; divides anticlinally to contribute to the subepidermal mesophyll, outer cortex, and reproductive gametes (germ cells).
• L3 Layer: Belongs to the corpus proper, forming the vascular cylinder, pith, and deep internal tissues.
• nalysis: The tunica is strictly constituted by L1 and L2 only (Option 3).

Correct option: (3) L1 and L2 only

• Origin and Domestication of Guava (Psidium guajava): Guava is native to tropical America (stretching from southern Mexico through Central America to northern South America).
• Introduction into India: Guava was introduced into the Indian subcontinent by Portuguese explorers and traders during the 17th century (early 1600s).
• Naturalization and Spread: Following its 17th-century arrival, guava adapted rapidly across diverse agro-climatic zones, making India the world's leading producer with premier cultivars like Allahabad Safeda, Sardar (L-49), and Lalit.
• Correct Option: Option 3 (17th century).