Nuzhat Bano, Naseer Mohammad, Shamim Akhtar Ansari
Among the studied populations, the Odisha teak population exhibited the highest allelic richness (P% = 88.78%, Na = 1.92, I = 0.32), whereas the Kerala teak population displayed the highest genetic diversity indices (Na (rar) = 1.16, Ne = 1.33, Ho = 0.15, and uHe = 0.20), identifying it as a key hotspot of genetic variation. Structural analysis based on the Pritchard model revealed three gene pools in Indian teak, providing novel genetic evidence that extends beyond the previously recognized two-tier population framework comprising southern and central Indian lineages. The third, previously undetected, hidden gene pool may represent an introduced lineage and is hypothesized to have originated from Myanmar. The high inbreeding coefficient of the third gene pool (FIS = 0.47-0.57) is consistent with the hypothesis that this lineage may have experienced population bottlenecks, genetic isolation, and restricted gene flow. AMOVA revealed that the majority of the genetic variation was captured within the subpopulations/genetic clusters (62.29%), and the remainder was among the subpopulations/genetic clusters (35.73%), with significant genetic differentiation (FST = 0.38, P < 0.001).
INTRODUCTION: Teak (Tectona grandis L. f.) is one of the world's most valuable tropical timber-producing tree species, and understanding its genetic diversity and population structure is fundamental for sustainable breeding, conservation, and plantation management. In the investigation, we employed next-generation single nucleotide polymorphism (SNPs) markers to investigate the genetic diversity and population structure of Indian teak.
METHODS: A total of 98 SNPs derived from three lignin biosynthesis gene and transcription factors were utilized to estimate the genetic diversity and population structure of teak collected from 10 agro climatic states and maintained at NTGB, Chandrapur, India.
RESULTS: Among the studied populations, the Odisha teak population exhibited the highest allelic richness (P% = 88.78%, Na = 1.92, I = 0.32), whereas the Kerala teak population displayed the highest genetic diversity indices (Na (rar) = 1.16, Ne = 1.33, Ho = 0.15, and uHe = 0.20), identifying it as a key hotspot of genetic variation. Structural analysis based on the Pritchard model revealed three gene pools in Indian teak, providing novel genetic evidence that extends beyond the previously recognized two-tier population framework comprising southern and central Indian lineages. The third, previously undetected, hidden gene pool may represent an introduced lineage and is hypothesized to have originated from Myanmar. The high inbreeding coefficient of the third gene pool (FIS = 0.47-0.57) is consistent with the hypothesis that this lineage may have experienced population bottlenecks, genetic isolation, and restricted gene flow. AMOVA revealed that the majority of the genetic variation was captured within the subpopulations/genetic clusters (62.29%), and the remainder was among the subpopulations/genetic clusters (35.73%), with significant genetic differentiation (FST = 0.38, P < 0.001).
DISCUSSION: These findings reveal a previously unrecognised genetic lineage in Indian teak, providing new insights into its population structure. Accurate documentation of native and introduced gene pools will support the identification of genetic diversity hotspots. The majority of Indian teak belongs to central Indian teak lineage; greater utilization of genetically diverse southern Indian teak could broaden the genetic base and enhance long-term sustainability.