Belly Button appearance in sweet orange is the character of | Agrigyan

• Malus asiatica $\rightarrow$ (I) Diploid ($2n = 2x = 34$): Chinese pearleaf crabapple is diploid, characterized by regular bivalent pairing and high sexual fertility.
• Malus sikkimensis $\rightarrow$ (II) Triploid ($2n = 3x = 51$): Native to Sikkim and the eastern Himalayas, maintains triploid genetic stability through facultative or obligate apomixis.
• Malus sargentii $\rightarrow$ (III) Tetraploid ($2n = 4x = 68$): Sargent's crabapple is a dwarf ornamental crabapple exhibiting apomictic tetraploid cytotypes.
• Malus sieboldii $\rightarrow$ (IV) Pentaploid ($2n = 5x = 85$): Toringo crabapple possesses polyploid series extending up to pentaploid cytotypes ($2n = 5x = 85$) sustained via apomixis.
• Correct Combination: (A) - (I), (B) - (II), (C) - (III), (D) - (IV), matching Option 2.

Correct option: (2) (A) - (1), (B) - (I), (C) - (ll), (D) - (IV).

• Navel Group Sweet Oranges (Citrus sinensis): Characterized by the development of a small, secondary rudimentary fruit embedded at the apex (stylar end) inside the primary fruit.
• Belly Button Appearance: The stylar scar enclosing this small secondary fruit produces a prominent indented, concentric opening resembling a human belly button or navel (e.g., Washington Navel, Cara Cara).
• Comparative Sweet Orange Groups:
• Mosambi: Common commercial sweet orange of western/central India with faint circular apical ring and mild, low-acid juice.
• Malta: Common acid-sweet orange of North India (e.g., Malta Blood Red).
• Tanjore / Sathgudi: Smooth-skinned tight orange of Andhra Pradesh/Tamil Nadu.
• Correct Option: Option 3 (Navel group).