Thumbnail Image

Theses

Browse

1983 - 198911990 - 19973
Reset filters
Subject: Plant Physiology × End date: 1999 × Thesis Type: M.Sc ×
Reset filters

Search Results

Now showing 1 - 4 of 4
  • Thumbnail Image
    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nut o f healthy# apparently healthy and root (wilt) affected coconut palm was carried out in tills, laboratory (unpublished).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.
  • Thumbnail Image
    ThesisItemOpen Access
    Provenance evaluation in the seedling characters of neem (Azadirachta indica A. Juss)
    (Department of tree physiology and breeding, College of Forestry, Vellanikkara., 1997) Vinod, S; KAU; Vijayakumar, N K
    A study was conducted at College of Forestry, Vellanikkara, Trichur on provenance evaluation in the seedling characters of neem (Azadirachta indica A. Juss) for a period of one year from 1995 to 1996. The experiment was laid out in a completely randomised design. A total of eight provenances were used in this study they are Dindigul, Nagarcoil, Coimbatore, Trichur, Srivelliputhur, Palghat, Ghatti Subramanya and Molakalmur. In respect of various seed characters studied Nagarcoil was the best performer in characters like 100 seed weight, seed breadth and germination percentage. Trichur was the best performer in seed length and seed length breadth ratio and Srivelliputhur was the best performer in thickness of pericarp. In terms of various seedling characters studied Coimbatore was the best performer in height, leaf number, leaf area, stem dry weight, leaf dry weight, and shoot dry weight. Palghat provenance was superior with respect to root dry weight, and root shoot ratio; Nagarcoil was the best in terms of collar girth and Dindigul in total dry weight. Nevertheless, Coimbatore provenance was found to be the best performer in most of the seedling character studied. Isozyme banding pattern for peroxidase showed two bands PRX-1 and PRX-3 in common. Eight provenances were grouped in to two based on the presence or absence of PRX-2. No significant variation was observed in terms of chlorophyll - A, Band total chlorophyll content between provenances. Number of stomata per square centimetre was maximum in Coimbatore provenance. For the genetic characters studied 100 seed weight and germination percentage recorded maximum GCV and PCV for seed characters and shoot weight and shoot root ratio for seedling characters. Maximum heritability and genetic gain were recorded in germination percentage and height and collar girth in seedling characters. Application of Mahalanobis' D2 statistics and Tocher's method of clustering resolved eight provenances in to four distinct clusters. Cluster I comprising of three provenances (Dindigul, Palakkadu and Ghatti Subramanya). Cluster II comprising of only one cluster (Coimbatore), cluster III comprising of again only one cluster (Molakalmur) and cluster IV comprising of three provenances (Nagarcoil, Trichur and Srivelliputhur). Incidence of pests was not noticed during the entire period of investigation. All provenances were found affected by sooty mold caused by Capnodium sp. during the rainy seasons with out affecting the growth of the seedlings.
  • Thumbnail Image
    ThesisItemOpen Access
    Parasitic interference of sandal (Santalum album Linn.) on common agricultural crops from the homesteads
    (Department of tree physiology and breeding, College of Forestry, Vellanikkara., 1997) Saju Varghese; KAU; Ashokan, P K
    Experiments were conducted at College of Forestry. Kerala Agricultural University. Vellanikkara. Thrissur during 1995-96 to elucidate the various aspects of parasitisation behaviour of sandal (Santalum album Linn.). Parasitisation behaviour of sandal on selected agricultural crops occurring in the homesteads of Kerala. response of selected sandal-host combinations to manures and fertilizers and uptake and translocation of nutrients and photosynthates by sandal-host associations were the principal aspects investigated. Pot culture experiments involving a number of hosts like coconut, cashew, banana, black pepper, jack, mango, rubber, casuarina, erythrina and redgram were conducted as part of the study. The results indicated that, growth parameters of the sandal seedling like total dry weight and number of haustoria varied significantly depending on the host associated with sandal. Maximum growth of sandal was observed in association with the host - Casuarina equisetifolia. No significant decrease was observed in the growth of any of the hosts consequent to the parasitisation by sandal. Host is the principal factor governing the growth of sandal and fertilizer levels tried in this experiment had not caused any significant influence on the growth of sandal seedlings. In, view of the favourable influences by the host complex of a good and bad host together ie., casuarina + erythrina, on sandal's growth, the possible competitive/complementary effects of multiple host combinations on sandal's growth, need be investigated in greater detail. Sandal plants can take up elements like calcium, sulphur and phosphorus directly from soil and a small fraction of these are also obtained from host. Carbon compounds also are translocated between sandal and hosts. The same host differed in its ability to supply different elements to sandal ie., in the supply of phosphorus to sandal casuarina was better while carbon compounds were optimally supplied by erythrina. So instead of providing a single host to sandal, a variety of good hosts should be provided in the field for ensuring a more optimal growth of sandal. Anatomical studies showed that, sandal roots can establish direct vascular connections with host roots through haustoria.
  • Thumbnail Image
    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.