Morphomolecular characterization and evaluation of pandanus spp.

Abstract

Investigation on “Morphomolecular characterization and evaluation of Pandanus spp.” was undertaken at College of Agriculture, Vellayani during 2002-2004 with the view of estimating the genetic diversity among 30 genotypes of Pandanus selected from different locations of Kerala and Tamil Nadu based on morphological, anatomical and molecular markers. Variability and divergence studies between 22 male genotypes of P. fasicularis, standardization of different propagation techniques and leaf curing technology were also undertaken. Morphological characters viz., stem, leaf and spine growth characters and leaf anatomical characters such as leaf thickness and number of stomata revealed significant variability among the 30 genotypes of Pandanus. In RAPD analysis, the four primers such as OPB-11, OPB-12, OPB-18 and OPB-20 produced the highest number of intense and polymorphic bands. A total of 41 scorable RAPD markers were amplified by the four primers and out of these, 35 were polymorphic and six were monomorphic. The UPGMA based dendrogram generated through RAPD analysis grouped the 30 genotypes into eight clusters and each cluster consisted of similar morphotypes. In variability and divergence studies, the genotypic and phenotypic coefficient of variation (GCV and PCV), heritability and genetic advance showed highest values for most of the characters. Inflorescence yield per plant had high significant positive phenotypic and genotypic correlation with leaf length, width, weight, inflorescence length, girth and inflorescence weight. It had significant negative correlation with spine length.

D2 analysis grouped the 22 male genotypes of Pandanus into six clusters. The major characters contributed towards divergence were inflorescence yield and number of inflorescence per plant. The selection of best genotypes for leaf purpose based on the leaf characters viz., number of leaves, leaf length, width, weight and thickness indicated that, the genotype PF 21, PF 22 (grayish green leaf type) and PF 25 (long dark green and short spiny type) identified from Chavara and Karunagapally areas of Kollam respectively are the superior ones. Selection based on the inflorescence yield and related characters revealed that, the genotypes PF 10, PF 19 and PF 25 are the best. The selection for oil content and its fragrance showed that long spiny yellow inflorescence types are good. Genotype PF 18 had the highest oil content of 0.21 per cent. The effect of different physical and chemical seed treatments on the germination and growth performance of Pandanus seedlings indicated that, the treatment T6 (soaking the seeds in diluted cow urine), T7 (cow urine + cowdung slurry) and T8 (cow urine + GA3 100 ppm) were the superior while considering the germination and other growth parameters. Different vegetative propagation materials viz., terminal cuttings with crown (T1), stem cuttings without crown (T2), aerial suckers (T3) and ground suckers (T4) were evaluated for their growth characters such as establishment percentage, number of days taken for the establishment, plant height, girth, number of leaves, length of leaf, width of leaf, leaf yield, number of suckers and number of prop roots. Terminal cuttings with crown showed significant influence on all growth characters invariably at all stages of growth and it was followed by ground suckers. In micro propagation for the initial establishment of shoot tip cultures, the treatment combination involving BA 1 mg l-1 and NAA 0.4 mg l-1 (T7) was found to be the best. For the induction of axillary buds the treatment combination with BA 4 mg l-1 and NAA 1 mg l-1 (T9) was considered as the best. The treatment combination involving 0.6 per cent activated charcoal along with the growth hormones viz., NAA 2 mg l-1 and IBA 2 mg l-1 (T6) produced the highest number of roots per shoot (11.0). The in vitro raised plantlets showed 70 per cent survival in the field. The effect of different leaf curing treatments on the quality attributes of the Pandanus mats were assessed in terms of colour, texture, eye appeal, durability and overall acceptance. Treatment T9 (boiling and sun drying of leaves + colouring with synthetic dyes) and T3 (boiling and sun drying of leaves) obtained highest score values for almost all the quality attributes except texture. With regard to texture treatment T5 (soaking in water for 48 hours + sun drying) excelled the other treatments.