• Production of Near-Isogenic Lines (NILs):
• Repeated Backcrossing: Traditional standard method where a donor segment is introgressed into a recurrent parent across 6–8 backcross generations.
• Selfing from Heterogeneous Inbred Families (HIFs): Selecting heterozygous progeny at advanced generations ($F_5/F_6$) and selfing to derive pairs of NILs differing only at the target locus.
• Residual Heterozygotes Selection: Identifying lines segregating at a single target region.
• Fast-Neutron Deletion Mutagenesis / Transformation: Generating isogenic pairs differing by a single mutation or insertion.
• Conclusion: Methods (A), (B), (C), and (D) can all be used to generate NILs. (Correct answer: Option 3)

• Wallace-Itakura Rule for Primer Melting Temperature ($T_m$):

$$T_m = 2(A + T) + 4(G + C)$$

• Forward Primer: TCTATTACGATGCCACCGC (19 nt):
• Count: $A = 4$, $T = 5 \implies A + T = 9$
• Count: $G = 4$, $C = 6 \implies G + C = 10$

$$T_m = 2(9) + 4(10) = 18 + 40 = 58^\circ\text{C}$$

• Reverse Primer: GGCAATTCATGTCGAGGTG (19 nt):
• Count: $A = 4$, $T = 5 \implies A + T = 9$
• Count: $G = 6$, $C = 4 \implies G + C = 10$

$$T_m = 2(9) + 4(10) = 18 + 40 = 58^\circ\text{C}$$

• Conclusion: Both forward and reverse primers have a theoretical melting temperature of 58 °C. (Correct answer: Option 2)

• Statement (I) is True: Collinearity (synteny) refers to the conservation of linear gene or molecular marker order along homologous or homeologous chromosomal segments within the same genome or across related divergent species (e.g., conserved syntenic blocks among grass genomes).
• Statement (II) is True: In Genomic Selection (GS), when predicting Genomic Estimated Breeding Values (GEBVs), high collinearity (multicollinearity) among adjacent dense molecular markers leads to severe variance inflation and unstable coefficient estimates; hence, low collinearity among independent marker predictors ensures more reliable and robust marker effect estimates.
• Conclusion: Both Statement (I) and Statement (II) are true (Option 1).

Correct option: (1) Both Statement (|) and Statement (II) are true.

• Statement (I) is True: During induction of somatic embryogenesis, a synthetic auxin—most commonly 2,4-dichlorophenoxyacetic acid ($2,4\text{-D}$)—is added to the induction medium to promote dedifferentiation of somatic cells and trigger embryogenic competency.
• Statement (II) is True: For somatic embryo maturation, development, and subsequent plantlet conversion, embryos are subcultured onto a development/germination medium either lacking auxins or supplemented with low auxin/cytokinin levels and abscisic acid (ABA) to allow polarized cotyledonary and root-shoot axis expansion.
• Statement (III) is True: Somatic embryogenesis recapitulates the zygotic developmental trajectory through recognizable morphological stages: globular, heart-shaped, torpedo, and cotyledonary stages in dicotyledons.
• Conclusion: Statements (I), (II), and (III) are all true (Option 3).

Correct option: (3) Statements (I), Statement (Il) and Statement ({Il) are true