Efficiency of RAPD, ISSR, iPBS, SCoT and phytochemical markers in the genetic relationship study of five native and economical important bamboos of North-East India.

10 primers each of random amplified polymorphic DNA (RAPD), inter-simple sequence repeats (ISSR), inter primer binding site (iPBS) and start codon targeted (SCoT) were used to analyze genetic polymorphism and relationship between 50 genotypes of 5 economical important native bamboos (Bambusa cacharensis, B. mizorameana, Dendrocalamus manipureanus, D. hamiltonii and D. sikkimensis) of North-East India. The 40 different primers generated 111, 115, 116 and 138 polymorphic bands for RAPD, ISSR, iPBS and SCoT markers respectively. The comparative analysis of 4 marker systems based on polymorphic information content (PIC), effective multiplex ratio (EMR) and marker index (MI) values showed SCoT to be more informative with higher discriminating power than the other three markers. The correlation value (r) as determined by the Mantel test ranged from 0.60 (SCoT and RAPD) to 0.83 (iPBS and ISSR) indicating a high positive correlation between the markers. The close correspondence between the genetic matrices of RAPD, ISSR, iPBS and SCoT markers revealed the effectiveness of each marker system in determining the genetic relationship between bamboos. UPGMA (Unweighted Pair Group Arithmetic Mean Method) dendrograms generated from DNA marker analysis demonstrated species-specific clustering of different bamboo genotypes. Except for RAPD, the dendrograms of ISSR, iPBS and SCoT markers also showed a close association of bamboo genotypes based on geographical origin. Principal coordinate analysis (PCoA) revealed the distribution of different bamboo genotypes in accordance with the cluster analysis. The cluster grouping based on phytochemical study not only discriminated the different bamboo species but also illustrated a location-specific grouping of the genotypes. The bamboo clustering pattern derived from phytochemical analysis matched closely with the dendrograms generated by the DNA markers. The present investigation established the possibility of using a combined molecular and phytochemical marker approach to determine the genetic relationship between 5 native bamboos of North-East India with high precision.

Evaluation of genetic relationship between 15 bamboo species of North-East India based on ISSR marker analysis.

The classification of bamboos based on floral morphology and reproductive characters is very hard due to erratic flowering behavior and unusually long reproductive cycle. The application of reliable and effective DNA molecular markers is highly essential to address this problem. In the present investigation, inter-simple sequence repeats (ISSR) markers were employed to study phylogenetic relationship of 15 different bamboos of North-East India. The 10 ISSR primers generated 116 polymorphic loci or scorable bands with average of 11.6 bands per primer. The genetic similarity coefficient ranged from 0.41-0.76 showing high genetic polymorphism among different bamboo species. The phylogenetic tree constructed based on genetic similarity matrix revealed genetic proximity of endemic Bambusamizorameana to other five Dendrocalamus species by clustering into a single group, while Dendrocalamus manipureanus segregated from the cluster indicating its genetic divergent character. Except for Schizotachyum fuchsianum, the three Schizotachyum species viz., S. dullooa, S. pergracile and S. munroi exhibited close genetic affinity by grouping into a single minor clade. Principal coordinates analysis (PCoA) showed distribution of different bamboos species in the plot in accordance to unweighted pair-group method with arithmetic average (UPGMA) cluster analysis. Genetic relationship of 15 different bamboos as revealed from the dendrogram and PCoA analysis reasonably conformed to traditional system of classification though slight disagreement existed. This is the first report on the successful use of ISSR markers in the phylogenetic and genetic variation studies of 15 important bamboos of the region including the endemic bamboo species of B. mizorameana, B. manipureana, D. sikkimensis and D. manipureanus.

ISSR Marker Based Population Genetic Study of Melocanna baccifera (Roxb.) Kurz: A Commercially Important Bamboo of Manipur, North-East India.

Melocanna baccifera (Roxb.) Kurz is an economically important bamboo of North-East India experiencing population depletion in its natural habitats. Genetic variation studies were conducted in 7 populations sampled from 5 districts of Manipur using ISSR molecular markers. The investigation was carried out as a primary step towards developing effective conservation strategies for the protection of bamboo germplasm. ISSR marker analysis showed significant level of genetic variation within the populations as revealed by moderately high average values of Nei's genetic diversity (H 0.1639), Shannon's diversity index (I 0.2563), percentage of polymorphic bands (PPB 59.18), total genetic variation (Ht 0.1961), and genetic diversity within population (Hs 0.1639). The study also divulged a high genetic variation at species level with Shannon's diversity index (I), Nei's genetic diversity (H), and percentage of polymorphic band (PPB%) recorded at 0.3218, 0.1939, and 88.37, respectively. Genetic differentiation among the populations (Gst) was merely 19.42% leaving 80.58% of genetic variation exhibited within the populations. The low genetic diversity between populations was consistent with AMOVA. The low genetic differentiation among populations coupled with existence of significantly high genetic diversity at species level indicated the urgent necessity of preserving and protecting all the existing natural bamboo populations in the region.