An integrated study on Dendrocalamus hamiltonii, concerning its distribution, diversity and relationships, has been carried out. Field work was undertaken in the natural bamboo forests of the Khasi and Naga Hills, in the northeastern parts of India. Culm parameters were recorded and leaf samples collected.
The distribution study involved consulting ecological literature and herbarium voucher specimens, and the extraction and analysis of climatic and edaphic data from thematic maps. Through modelling of extracted parameters using Geographic Information Systems recorded and potential distribution maps of D. hamiltonii were generated. From the baseline data the ecological requirements of the species were characterized in terms of altitude, mean annual rainfall, dry period and soils.
The diversity study involved a survey and sampling of I 20 D. hamiltonii clumps in six populations. Seven commercially important parameters were recorded and analysed. The study found statistically significant variation in six parameters, which could be grouped into two components. Principal components analysis of populations based on morphological parameters differentiated Khasi Hills populations from the population in
Naga Hills. This variation between the two regions could be explained by the variables culm wall thickness and internode length. No clear population structure was detected in the Khasi Hills populations, where some degree of overlapping among populations was observed.
The genetic analysis of populations involved DNA extractions and generation of amplified fragment length polymorphism markers (AFLPs) for the 120 clumps belonging to six populations surveyed during the field study. The genetic diversity and structure analysis with 434 AFLP markers from two primer sets revealed moderate diversity (Ht = 0.221) and moderate differentiation ( ΦPT = 0.122) in D. hamiltonii. The genetic diversity (He) within Khasi Hills populations ranged from 0.180 to 0.236, however the populations had a weak structure (ΦPT= 0.037).
The genetic relationships study involved ten putative Dendrocalamus taxa and five allied taxa from Bambusinae. 470 AFLP markers from five primer sets were used to assess phenetic and phylogenetic relationships among the included taxa. The study revealed three clusters/clades within Dendrocalamus. Dendrocalamus hamiltonii was found closest to Bambusa balcooa, whereas D. strictus was found genetically distant from the three clusters/clades containing Dendrocalamus taxa. The implications of the findings for the circumscription of Dendrocalamus and Bambusinae are discussed.