Comparative assessment of genetic diversity among Indian bamboo genotypes using RAPD and ISSR markers.

Bamboo is one of the important plant for pulp, paper and charcoal industries. After China, India is the second largest bamboo reserve in Asia. Around the globe, wide genetic diversity of bamboo is present which serves as the base for selection and improvement. DNA based molecular markers appears to be a striking substitute for systematic assessment of the genetic diversity in conservation and genetic improvement of plants. DNA based molecular markers such as RAPD and ISSR were used to assess the genetic diversity in 13 bamboo genotypes. Total 120 RAPD and 63 ISSR primers were tested, of which only 42 polymorphic primers (30 RAPD and 12 ISSR), gave reproducible amplification profile and were used in this study. 30 RAPD primers yielded total 645 amplified fragments, of which 623 were polymorphic, and 20.76 polymorphic bands per primer were observed across 13 genotypes. 12 ISSR primers produced 246 amplified fragments, of which 241 were polymorphic, and 20.08 polymorphic bands per primer was observed across 13 different genotypes. The Jaccard's coefficient of RAPD, ISSR and pooled RAPD and ISSR dendrograms ranged from 0.26 to 0.83, 0.23 to 0.86 and 0.26 to 0.84 respectively. The present study found the large genetic diversity present between different elite genotypes of bamboo. Such investigation can deliver a well understanding of the available genotypes, which might be further exploited for the paper industry.

Assessment of genetic fidelity of micropropagated date palm (Phoenix dactylifera L.) plants by RAPD and ISSR markers assay.

RAPD (Random Amplified Polymorphic DNA) and ISSR (Inter-Simple Sequence Repeats) markers assay were employed to validate the genetic stability of date palm (Phoenix dactylifera L.) plants multiplied through somatic embryogenesis with upto forty two in vitro subcultures. Out of the 160 RAPD and 21 ISSR primers screened, 30 RAPD and 12 ISSR primers produced a total of 347 (246 RAPDs + 101 ISSRs) clear, distinct and reproducible amplicons, which were monomorphic across all micropropagated plants (27) studied. Thus, a total 8592 bands (number of plants analysed x number of amplicons with all the primers) were generated which exhibited homogeneous banding patterns with both RAPD and ISSR markers. These results indicate that the micropropagation protocol developed by us for rapid in vitro multiplication is appropriate and suitable for clonal propagation of date palm and corroborated the fact that somatic embryogenesis can also be used as one of the safest modes for production of true-to-type plants.

Phoenix phylogeny, and analysis of genetic variation in a diverse collection of date palm (Phoenix dactylifera) and related species.

Date palm (Phoenix dactylifera), one of the most ancient crops, is grown commercially in >30 countries. Using whole plastome assemblies, phylogenetic analyses revealed that cultivated date palm accessions share the same clade with P hoenix sylvestris, P hoenix pusilla and P hoenix acaulis, which are native to the Indian subcontinent, and Phoenix caespitosa that is native to the Arabian Peninsula and the deserts of Somalia. Analysis of genetic diversity and genetic relationships among date palm accessions from 13 producing countries involved 195 date palm accessions that were genotyped at 19 microsatellite loci. Extensive genetic diversity was observed, with many accessions heterozygous for most markers in this clonally propagated crop. The average number of alleles per locus (42.1), expected heterozygosity (0.8), observed heterozygosity (0.47) and fixation indices (FST = 0.42) demonstrated substantial genetic diversity and population structure. Iraqi accessions were found to have the richest allelic diversity, and the most private alleles. The model-based Bayesian method indicated that these accessions could be broadly divided into two structure groups, one group with predominantly African accessions and another predominantly Asian. Some germplasm, especially from Tunisia and Iraq, deviated from this generalization. Many accessions in the STRUCTURE-derived groups were found to be genetic admixtures, with gene flow between Asian and African groups. Indian and Pakistani date palms were found to be most closely related to North African germplasm.

Evaluation of Clonal Fidelity of Micropropagated Date Palm by Random Amplified Polymorphic DNA (RAPD).

Date palm is a fruit-bearing tree commonly found in arid and semiarid regions. It is a dioecious plant, producing fruit on female plants and a limited number of basal offshoots for propagation. To produce large numbers of uniform plantlets, tissue culture techniques are required. It is highly advisable to detect genetic variation that may occur through micropropagation techniques as it may lead to phenotypic alterations. Random amplified polymorphic DNA (RAPD) is a simple and PCR-based molecular marker technique which can be employed to check the somaclonal variation. Screening of markers requires repeated confirmation of the pattern obtained in individual samples.