Browsing by Author "Bandupriya, H.D.D."

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    Androgenic potential in coconut (Cocos nucifera L.)
    (2008) Verdeil, J.L.; Hocher, V.; Perera, P.I.P.; Yakandawala, D.M.D.; Bandupriya, H.D.D.; Weerakoon, L.K.
    Conditions for induction of androgenesis in coconut cv. Sri Lanka Tall were studied. Anthers collected from inflorescences at four maturity stages were given heat (38 C) or cold (4 C) pretreatments for 1, 3, 6 and 14 days, either prior to or post inoculation. Three different basal media and different anther densities were also tested. Androgenesis was observed only in anthers collected from inflorescences 3 weeks before splitting (WBS) and after a heat pretreatment at 38 C for 6 days. Modified Eeuwens Y3 liquid medium supplemented with 100 lM 2,4-dichlorophenoxyacetic acid (2,4-D), 0.1% activated charcoal and 9% sucrose was effective in inducing an androgenic response. The lowest anther density tested, 10 per petri plate, was found to be the optimal density. When androgenic calli or embryos were subcultured to Y3 medium containing 66 lM 2,4-D, followed by transfer to Y3 medium without plant growth regulators and finally to Y3 medium containing 5 lM 6-benzyladenine (BA) and 0.35 lM gibberellic acid (GA3), plantlets regenerated at a frequency of 7%. Histological study indicated that the calli and embryos originated from the inner tissues of the anthers. Ploidy analysis of calli and embryos showed that they were haploid. This is the first report of successful androgenesis yielding haploid plants from coconut anthers
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    Androgenic potential in coconut (Cocos nucifera L.)
    (2008) Perera, P.I.P.; Hocher, V.; Verdeil, J.L.; Yakandawala, D.M.D.; Bandupriya, H.D.D.; Weerakoon, L.K.
    Conditions for induction of androgenesis in coconut cv. Sri Lanka Tall were studied. Anthers collected from inflorescences at four maturity stages were given heat (38 C) or cold (4 C) pretreatments for 1, 3, 6 and 14 days, either prior to or post inoculation. Three different basal media and different anther densities were also tested. Androgenesis was observed only in anthers collected from inflorescences 3 weeks before splitting (WBS) and after a heat pretreatment at 38 C for 6 days. Modified Eeuwens Y3 liquid medium supplemented with 100 lM 2,4-dichlorophenoxyacetic acid (2,4-D), 0.1% activated charcoal and 9% sucrose was effective in inducing an androgenic response. The lowest anther density tested, 10 per petri plate, was found to be the optimal density. When androgenic calli or embryos were subcultured to Y3 medium containing 66 lM 2,4-D, followed by transfer to Y3 medium without plant growth regulators and finally to Y3 medium containing 5 lM 6-benzyladenine (BA) and 0.35 lM gibberellic acid (GA3), plantlets regenerated at a frequency of 7%. Histological study indicated that the calli and embryos originated from the inner tissues of the anthers. Ploidy analysis of calli and embryos showed that they were haploid. This is the first report of successful androgenesis yielding haploid plants from coconut anthers.
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    Changes in Soluble Sugars, Sugar Profile, Starch and Proline in Developing Coconut (Cocos nudfera L.) Inflorescences
    (2008) Bandupriya, H.D.D.; Weerakoon, L.K.; Ranasinghe, C.S.; Fernando, W.P.K.K.
    Changes in soluble sugars, sugars profile, starch and proline levels in inflorescence rachill; from individual coconut palms were investigated during inflorescence development with the aim determining a possible correlation between these characters and morphogenic potential inflorescence tissues. Rachillae for analysis were collected from unopened inflorescences of-1 to -] stages (considering the youngest open inflorescence as 0 stage) in decreasing order of maturity (-stage is the most mature stage whereas -13 is the most immature stage). Important differences amoi the maturity stages were observed for total sugars. In very tender inflorescences (-13 and -12), tl total sugar content was very low whereas a gradual increase was observed from -11 to -7 stages, wi -7 stage having the highest level. The total sugar content in more mature inflorescences w; relatively low, with the exception of -2 stage, which had a high total sugar content. In regard sugar profiles, sucrose, fructose and glucose were the main soluble sugars present in cocon inflorescence and sucrose was the most abundant sugar hi -5 to -9 maturity stages. Total solub sugars and sucrose in maturity stages from -5 to -9 showed a very similar variation and significant higher levels of sucrose were observed in -6 to -8 stages. The proline content in the mature stages, to -3, was significantly lower than in the other stages with no significant variation in the stages -4 -11. The pattern of variation in starch content was similar to that of proline which decreased wi increasing maturity of inflorescence. In view of the results obtained, the higher accumulation < "sucrose and total sugars in -6, -7 and -8 stages may have some significance in morphogenesi especially as an energy source. The 10 cm length inflorescence that responds better for callusing fal within this range. Thus total sugar and sucrose content may be possible biochemical markers fi asses sing the morphogenic potential of inflorescence explants.
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    Cryopreservation as a Tool for the Management of Coconut Germplasm
    (2011) Malaurie, B.; N'Nan, O.; Bandupriya, H.D.D.; Borges, M.; Verdeil, J.L.; Tregear, J.
    We present hereafter a review of different collaborative research studies carried out on the cycopreserntion of coconut plumules excised from the zygotic embryo. Plumule (shoot apical meristem and leaf primordia) tissues have shown different degrees of success in cropresen ation depending on th combination of alginate encapsulation and osmotic or evaporative dehydration used. The percentage of regrowth was progressi\\ Cly impro\\ ed from vitrification (0%), to osmoprotection (10%), and subsequently the encapsulation-dehydration technique allowed 20% regrowth level into leafy shoots. Addition of abscisic acid (20 to 40 JI:\\I) boosted recovery growth after freezing (up ta 40%). Histological studies have clearly shown that the addition of lower amounts of ABA (10 JIM) allows cells to maintair. the structural characteristics of control cells for immersion into liquid nitrogen without dehydration. The effect of plant material conditioning, for transport from collecting site to laboratories, was studied to identify possible effects of unc( ntrolled factors on tissue tolerance to cryopreservation. Three conditioning methods lemb o set in endosperm core (ALB); emb,·yo transferred onto of solidified agar (5W); emb, o immersed into KCI solution (KCI)I were u~ed. 5W performance is clearl~ more efficient when combined with dehydration and freezing. giving 40% recovc . These results are interesting as they show that the medium surrounding the ~mb 1 (endosperm or medium supply) can be replaced by agar alone. without nutritive factors. This approach should also facilitate germrlasm exchanf e. As a result of the absence of phloem vascular bundles in the plumular tissues, the approach described here should increase the scope for obtai.ling material free of pathogenic agents, an essential prerequisite for the conserntion and exchange of germ plasm. This approach should be a strong point in the fight lIgainst Lethal Yellowing Disease. the most serious disease affecting coconut plantations.
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    Efficient Method of Transporting Coconut (Cocos nucifera L.) Zygotic Embryos for Cryopreservation of Plumules by Encapsulation/Dehydration
    (2014) Bandupriya, H.D.D.; Fernando, S.C.; Verdeil, J.L.; Malaurie, B.
    Coconut is both socially and economically important crop in tropical and subtropical countries, thus the conservation of existing diversity of its germplasm is vital to maintain biodiversity, sustain crop production and utilisation of germplasm for crop improvement strategies. The recalcitrant storage behavior and large size of the coconut seed make it impossible to use as a germplasm storage material. Cryopreservation is an ideal means of long-term storage of germplasm which offers long-term storage capability with minimal storage space and maintenance requirements. The coconut embryo has been now adapted by various researchers for the purpose of germplasm exchange and it is now being routinely applied in germplasm collection and exchange activities with sufficient germination rates. The aim of the present study was to determine the effect of different coconut embryo transport! storage methods [as solid endosperm plugs under cold temperature, embryos cultured in Solidified Agar Medium (SAM) or KCI solution under room temperature] on cryopreservation of plumules using encapsulation/dehydration method. The results revealed that plumules excised from embryos transported/ stored in SAM and pretreated with 1.0M sucrose could be cryopreserved with 71.8% survival and 56% recovery rates. The survival and recovery could be further increased up to 77.5% and 65% respectively by supplementation of I.OM sucrose with 20 uM ABA.
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    Expression of Aintegumenta-like Gene Related to Embryogenic Competence in Coconut Confirmed by 454-pyrosequencing Transcriptome Analysis
    (2015) Bandupriya, H.D.D.
    A member of the Aintegumenta sub-family of Apetala gene family encoding two APETALA2 (AP2) domains was isolated and termed as Cocos nucifera Aintegumenta like gene (CnANT). The deduced amino acid sequence of the conserved domains shared a high similarity with AintegumentaLike (ANT like) genes in Arabidopsis thaliana, Elaeis guineensis, Oryza sativa. Comparison of transcriptomes in different tissues revealed that CnANT transcripts were high in mature zygotic embryo (12 months after pollination; 12ME). Quantitative R T-PCR results confirmed the higher CnANT transcript accumulation in mature zygotic embryos while transcripts were rarely detected in vegetative tissues such as leaf The expression data and global transcriptome data were therefore consistent across the embryo maturity stage and showed that CnANT could play a role in embryogenesis.