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1983 - 198911990 - 19941
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Subject: Plant Physiology × Author: KAU × End date: 1996 × Type: Thesis × Thesis Type: M.Sc ×
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    ThesisItemOpen Access
    Physiological and biochemical basis of degeneration in Root (Wilt) affected coconut palm
    (Department of Agricultural Botany, College of Agriculture, Vellayani, 1983) Sheela Cherian; KAU; Abraham, A T
    Several studies on the physiological and biochemical aspect of the root (wilt) disease have been carried out and conclusions have been drawn. A recent study comprising o f the estimation of protein non protein amino acids and cytokinin from the leaf, root and developing nut o f healthy# apparently healthy and root (wilt) affected coconut palm was carried out in tills, laboratory (unpublished). The chlorophyll content of leaves was also estimated. The present study comprised o f estimation o f gibberellin s and abscissic acid from the leaf# root and nut of healthy apparently healthy and five different intensities of root (wilt) affected coconut palms. The results of the biochemical analysis show that in the root (wilt) affected coconut palms there are alterations or deviations in normal metabolic activities from that o f healthy palms. Earlier work done has shown a reduction in cytokinin content in the root(wilt) affected palm in addition to protein and chlorophyll content. The present study has revealed a deficiency of gibberellins another important growth regulator and an accumulation of the growth inhibitor abscissic acid in the root(wilt) affected palms. The site s of synthesis and / interconversion o f gibberellins are damaged together with the impairment o f the translocation system. Increased respiration lowered CO2 fixation and severe damage o f the shoot system in the later stages are in brief the in tern al and external expressions o f the root (wilt) syndrome. Thus the shoot and root system which are interdependant are unable to function in harmony leading to a failure in their growth and development. An accumulation of ABA along with a reduction in gibberellin level might be the reason for the stunting syndrome seen in root(wilt) affected palms.
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    ThesisItemOpen Access
    In vitro propagation of malabar white pine (Vateria indica L.) through tissue culture
    (Department of tree physiology and breeding, College of Forestry, Vellanikkara., 1994) Ashok B Divatar; KAU; Vijayakumar, N K
    The present investigation was carried out at the Department of Tree Physiology and Breeding, College of Forestry, Vellanikkara, during 1992-94, to standardise the in vitro technique for multiplying Vateria indica which is commonly known as Malabar white pine. This being the first attempt of micropropagation in this tree species, the methodology was to be standardised from the initial stage itself. Nodal and intermodal segments as well as leaf segments collected from seedling maintained in the College of Forestry were used as explants. Different routes like enhanced release of axillary buds, organogenesis and embryogenesis were attempted for this species. It was found that nodal segments of size 0.5 to 1.5 cm was ideal as the explants. Prophylactic spray of seedlings with a mixture of Bavistin and Indofil M-45 combined with surface sterilization of explants with 0.1 per cent mercuric chloride for 5 minutes for nodal explants and 4 minutes for leaf explants, could control culture contamination to the greatest extent. Seasonal variation was observed for the fungal interference and the period from February to May was identified as the best season for establishing the cultures of Vateria indica. Half strength MS medium was noted to be suitable for primary culture establishment for both nodal and leaf segments. Out of the various growth regulator combinations tried for bud break and shoot elongation in vateria, 2-ip and IBA could support bud break and shoot production. Among the various media additives tried, CCC had less effect on bud break in half MS medium and silver nitrate had moderate effect on bud break in WPM medium. Casein hydrolysate, adenine sulphate, cobalt chloride and coconut water were the other additives, tried without having any beneficial effect on bud culture of Malabar white pine. Moderate callusing could be induced from leaf and intermodal segments on MS and half strength MS media supplemented with growth regulators 2-ip + 2,4-D (in MS media) and 2-ip + IBA (in half strength MS) with a callus index ranging from 35.7 to 100.0 The calli did not respond to organogenesis but growth units of callus were obtained. The morphology and growth rate varied according to the growth regulator combinations tried. The results of the present study being first of its kind in Vateria indica would have significance to disentangle the in vitro response of this species for micropropagation. Since this species is recalcitrant in nature, much more regulated efforts are to be made for standardising the protocol for micropropagation of Vateria indica.