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ThesisItem Open Access Collection cataloguing and evaluation of rouwolfia spp.(Department of Agricultural Botany, College of Horticulture,Vellanikkara, 1993) Narayanan, A K; KAU; Luckins Babu, CA study on 'Collection, cataloguing and evaluation of Rauwolfia spp' was conducted in the Department of Agricultural Botany, College of Horticulture, Vellanikkara during 1991-93, with the objectives of understanding the distribution pattern of various species of Rauwolfia in Kerala, detailed descriptive study of the morphological and anatomical characters of the different species of Rauwolfia and a preliminary comparative evaluation study for the total alkaloids in roots and the chlorophyll content of aerial parts. Survey of 10 geographic locations of Kerala from North to South was conducted and four species of Rauwolfia were collected. Nine ecotypes of R. Serpentina and four ecotypes of R. tetraphylla were also collected. Different species were compared based on 60 morphological characters, 15 anatomical characters and three characters of pollen grains. Evaluation for total root alkaloids was done using chloroform as solvent and determination of total chlorophyll content was done using acetone as solvent. The study on distribution aspects showed that R. serpentina was widely distributed in Kerala but the frequency of occurrence was low, while R. tetraphylla was widely distributed in non-forest areas only, with a higher frequency of occurence. R. densiflora and R. beddomei are in a state of near extinction while R. micrantha was almost disappeared from Kerala. Morphological and antomical characters and the morphology and viability of pollen grains showed wide variability among different species of Rauwolfia. Characters in addition to that available in the literature, for identifying the four species of Rauwolfia are suggeated. It is seen that chances are there for the occurence of higher ploids of the same species having higher alkaloid content, in Rauwolfia. Total alkaloid content of roots, chloroform extract and total chlorophyll content of aerial parts varied with different species and ecotypes of Rauwolfia. The conditions for the higher root alkaloid production in R. sepentina may not be favourable for the alkaloid production in R. tetraphylla. The chloroform extract and total chlorophyll content of aerial parts were negatively correlated to the total root alkaloid content in all the species of Rauwolfia. The relationship between these was found to be “Total root alkaloid content= 2.047 – 0.016 x chloroform extract of aerial parts =2.304–1.434 x total chlorophyll content of aerial parts” The relationship can be effectively utilized in the estimation of root alkaloid, in Rauwolfia spp., even at the early stages of growth, without uprooting the plants.ThesisItem Open Access Artifical induction of polyploidy in Cucumis sativus L(Department of Agricultural Botany, College of Agriculture, Vellayani, 1993) Girish Kumar, KG; KAU; Chandramony DAn investigation entitled “Artifical induction of polyploidy in Cucumis sativus L. was carried out as two separate experiments. Experiment I, was (in-vivo study) was carried out at the College of Agriculture, Vellayani during the period September 1991 to February 1991. Experiment II (in-vitro study) was carried out at the Tissue culture laboratory attached to Department of Pomology, College of Horticulture, Vellanikkara during the period January 1991 to july 1991. The main objective of Experiment I was to study the effect of colchicine for inducing polyploidy in seed, seedling and apical bud treatments. Objectives of Experiment II were to standardise a suitable medium for embryo culture and to study the effect of colchine on proembryos, mature embryos and dry seed embryos under in - vitro conditions. Experiment I was laid out in RBD with two replications. Experiment II was carried out in CRD with three replications. The two varieties of Cucumis sativus used for the present study were Seethal and Delila. The abstract of results is given below. Experiment I Survival of plants in both Seethal and Delila was significantly affected by increasing colchicine concentration 0.2 to 0.4 per cent and with increasing period of treatment from two to six hours. Survival was significantly low in apical bud treatment. Maximum survival was noticed in seed treatment of colchicine 0.2 per cent for a period of four hours. At early growth stage significant reduction was noticed in length of vine, number of branches per plant and number of leaves per plant along with the increase in colchicine concentrations, from 0.2 to 0.4 per cent, and period of treatment, from two to six hours. Seed treatment gave maximum value for these parameters in both varieties except number of leaves in Delila. These variations seen during early growth stages were found to be diminishing at later growth stage (60 days growth stage). Delay in both male and female flower opening along with significant reduction in number of male and female flowers was noticed in higher colchicine concentrations and in lower period of treatments. Mode of treatment did not exert any significant influence on number of days taken for flower opening and total number of flowers produced per plant in both varieties except on number of days taken for female flower opening in Seethal in which by apical bud treatment maximum delay was noticed. With increasing colchicine concentration from 0.2 to 0.4 per cent and period of treatment from two to six hours significant increase in stomatal length was noticed in both varieties. Mode of treatment exerted no significant influence on stomatal length. All the fruit characters ie. Number of fruits per plant, length of fruit, girth of fruit and weight of fruit studied, were not significantly influenced by the treatments tried. In both varieties pollen size and sterility increased considerably with increasing colchicine concentration. Apical bud treatment gave significantly high values for pollen size and pollen sterility in Delila. Seed treatment recorded minimum pollen size and pollen sterility. Cytological studies were conducted in the root tips of colchicine treated seeds and metaphase and anaphase stages were obtained in the normal diploid cells. But the enlarged colchicine affected cells showed very poor stainability. Eepeiment II Standardisation of a suitable medium was carried out by using MS medium as the basal medium. MS medium supplemented with 0.1 mg/L of IAA was found suitable for embryo culture. Three types of embrayo viz., pro-embryo, mature embryo and dry seed embryo were used for embryo culturing. Embryogenesis was delayed significantly with increase in colchicine concentration from 0.02 to 0.04 per cent in both varieties. When pro-embryos were used for inoculation significant delay was noticed for embryogenesis in both varieties. Regeneration of calli was reduced significantly with increase in colchicine concentration. Pro-embryos gave lowest and dry seed embryo gave highest regeneration percentage in both varieties. Length of plantlet and number of leaves produced per plantlet in culture tubes were reduced significantly in the higher levels of colchicine concentration. Pro-embryos gave lowest and dry seed embryos gave highest values with respect to these parameters. Plantlets from pro- embryo showed lowest survival under green house conditions in both varieties. Colchicine concentration exerted no significant influence in Seethal. But in Delila with increasing colchicine concentration from 0.02 to 0.04 percent, survival of plants in green house reduced significantly. Day of treatment had no significant influence in all the parameters studied. On the basis of present study it can be concluded that different concentrations of colchicine, different periods of treatment and different modes of colchicine treatment can induce significant changes in the survival of plants, cytomorphological characters of the plants and pollen sterility. With increasing colchicine concentration and period of treatment the variations increased progressively. But considering the lethal effects as reflected on the survival of plants, 0.2 per cent colchicine application for two hours by seed treatment is desirable under in-vivo condition. Under in-vitro condition use of dry seed embroyo is best for embryo culture which can be successfully carried out by using MS medium modified with 0.01 mg/L of IAA. Colchicine 0.02 per cent can be used for the induction of polyploidy under in-vitro conditions. Since it is effective in producing variations with minimum deleterious effects.ThesisItem Open Access Evaluation of kacholam (kaempferia galanga L.) types for morphological variability and yield(Department of Agricultural Botany, College of Horticulture, Vellanikkara, 1994) Latha, E V; KAU; Viswanathan, T VAn investigation on the evaluation of Kacholam (Kaempferia galanga L.) types for morphological variability and yield was undertaken at the College of Horticulture, Vellanikkara during 1993-94. The experiment was aimed at studying the extent of morphological variability and yield contributing characters in the local collection of Kaempferia and to identify types with high yield potential for large scale cultivation. It was also aimed to compare the performance of the types under open and as intercrop in coconut garden. The salient results of the investigation are abstracted below. There was considerable amount of variability for the characters, number of leaves, leaf area index, days to flowering, spread of flowering, plant spread, number of main and secondary zhizomes, frash rhizome yield, dry rhizome yield, biological yield and oil percentage both under open and shaded condition. Under coconut garden in addition to the above characters, length and width of leaves and number of suckers per plant showed variability. There was difference in the performance of the types under open and shaded conditions. Fresh rhizome yield was more under open condition whereas dry rhizome yield was comparable which indicates that Kacholam can be grown as an intercrop in coconut garden. Ponnukkara can be considered as a stable type which performed well under both the conditions. Vellanikkara Seln. Br was found to be a shade sensitive type and the performance of Palakkad was poor under open and shaded conditions. Regarding oil yield Vellanikkara Selections were the superior types both under open and shaded conditions. Rhizome yield and oil yield were found to be two independent characters. This necessitates separate selection criteria for types with high rhizome yield and oil yield. Under open condition number of leaves, leaf area index, days to flowering and spread of flowering had high correlation and direct effect on yield with moderately high heritability and appreciable genetic advance. So selection will be effective for these characters. For the crop under shade, selection will be effective for the characters, number of leaves 5 months after planting, leaf area index and spread of flowering. Under shade plant spread was an important character which had high correlation and direct effect on yield. But the character recorded moderately high heritability but low genetic advance. No morphological character was found to be correlated with oil yield. So independeant selection has to be made for identifying varieties with high oil content per unit area.ThesisItem Open Access Variability of biological nitrogen fixation traits and yield components in blackgram(Department of Agricultural Botany, College of Horticulture, Vellanikkara, 1994) Siby, Thomas; KAU; Sreekumar, S GA research programme was carried out at the Department of Agricultural Botany, College of Horticulture, Vellanikkara, Trichur during October – March 1993 -94, with the objectives of assessing the genetic variability for biological nitrogen fixation traits and yield components in blackgram as a preliminary step to develop high yielding varieties with good biological nitrogen fixation capacity. Thirty three varieties of blackgram were evaluated, adopting a randomised block design with two replications. Data on thirteen characters were collected and subjected to analysis of variance. The genotypic and phenotypic coefficients of variation, heritability, genetic advance and genotypic and phenotypic correlations were estimated. Analysis of variance revealed significant differences among the varieties for all the characters except number of pods, number of seeds per pod and harvest index. High heritability coupled with high genetic advance was recorded for weight of nodules in the secondary roots and number of secondary roots suggesting the reliability of these characters during selection programmes for the improvement of the nitrogen content of this crop. Grain yield recorded high positive genotypic correlation with most of the yield components, biological yield and harvest index ; and negative genotypic correlation with nitrogen content in the plant at 50 per cent flowering. High positive genotypic correlation of number of pods per plant and number of seeds per pod with grain yield per plant, indicating that selection based on one or more of the above components may result in the improvement of grain yield. Weight of nodules in the secondary roots, which had high variability, heritability, genetic advance and genotypic correlations with nitrogen content in the plant at 50 per cent flowering and harvest index may be considered during selection programmes for identifying blackgram genotypes having high nitrogen fixation capacity.ThesisItem Open Access Cytogenatic analysis in kacholam(Department of Agricultural Botany, College of Horticulture, Vellanikkara, 1993) Rekha, K; KAU; Viswanathan, T VThe present study on cytogenetics of Kaempferia galanga L. in relation to seed set was undertaken at the Department of Agricultural Botany, College of Horticulture, Vellanikkara during the period 1991-93. A local selection ‘Vellanikkara’ grown under garden of AICRP on Medicinal and Aromatic Plants was used for the study. The major objectives were to confirm the existing reports on chromosome numbers, to determine the nature of pliody based on meiotic studies and to find out reasons for seedlessness in the crop in cytology and floral biology. The procedure for karyotype studies in Kaempferia was standardized. Pre-treatment of the roots in – bromonaphthalene for hours at 40C followed by fixation in Carnoy’s fluid for 24 hours and staining overnight in Snow’s carmine were effective in getting best cytological preparations. Mitotic studies revealed that this species is a polyploid and with all probability a pentaploid with 2n = 5x = 55. This somatic chromosome number is being reported for the first time in Kaempferia galanga L. The karyotype was found to be a symmetric one and belonged to ‘1a’ group of Stebbins (1958) classification. Meiotic studies revealed the presence of associations involving three, four, five and six chromosomes in addition to the bivalents and univalent. However, the number of multivalents were much less than expected and later meiotic abnormalities were rather almost absent. Pollen grains also exhibited reasonable fertility and viability. Based on both mitotic and meiotic studies it was indicated that Kaempferia galanga L. is a segmental allopolyploid with five sets of genomes designated as A1A2A2A2A2. Studies on floral morphology and artificial pollinations to induce seed set led to the conclusion that seedlessness in the crop is mainly due to the incompatibility factors in the style and stigma. The spiny stigma does not permit the proper adherence and germination of the pollen grains and the pollen tube growth attained was not sufficient to surpass the lengthy style and to reach the ovary. Attempts to induce seed set by hand pollination and stub pollination also failed.ThesisItem Open Access Comparative evaluation of selected types of Piper longum (Linn.) in coconut plantations(Department of Agricultural Botany, College of Horticulture, Vellanikkara, 1994) Jaya Manuel; KAU; Viswanathan, T VComparative evaluation of five selected types of piper longum (Linn.) namely Cheematippali, Panniyur, Mala, Pattambi and Kaanjur was carried out in the Department of Agricultural Botany, College of Horticulture, Vellanikkara during the year 1990-92 with the objective to select the best type of piper longum in order to recommend for large scale cultivation after evaluating economic characters and active principles. Experiment was laid out in Randomised Block Design with five replications. Observations were recorded for twenty three vegetative characters, nine productive characters and total alkaloidal content in dried spikes of piper longum for all the five types. The study revealed that the five types of piper longum differed for eleven vegetative characters namely length of the longest stem, number of vegetative branches per stem, length of leaf, width of leaf, legth of petiole, spread of the plant, internodal length of main stem, number of spike bearing branches per stem and angle of insertion of spike bearing branch and for three productive characters namely number of spikes per spike bearing branch, yield of green spike and yield of dry spike at one or all of the stages for which observations were recoeded. Of the above characters for which the five types differed significantly eight characters showing high and significant correlation with yield were chosen for carrying out studies on intercorrelation among yield components and path analysis. Correlation studies and path analysis revealed that angle of insertion of spike bearing branch, number of stems per hill, number of spikes per spike bearing branch and number of spike bearing branches per stem and yield green spike were the most important characters influencing dry spike yield. The studies on the total alkaloidal content in dried spikes of piper longum revealed that though Panniyur recorded the maximum alkaloidal content in percentage, with respect to total alkaloidal out put from an unit area of land Cheematippali was found to be superior to Panniyur since dry spike yield per hectare of Cheematippali was significantly superior to Panniyur. Mala recorded the minimum alkaloidal content in the dried spikes. Cheematippali showed constistency superior performance for all the important characters at all the stages and could be recommended for large scale cultivation after multilocational trials. Kaanjur can also be considered as a promising type since only in a very few characters it failed to establish its superiority over Cheematippali. The type Mala was found to be consistently inferior to all other five types of piper longum for all the vegetative and productive characters studied.ThesisItem Open Access Somatic embryogenesis in cocoa (Theobroma cacao L.)(Department of Agricultural Botany, College of Horticulture, Vellanikkara, 1993) Jolly Antony; KAU; Achamma OommenInvestigation on somatic embryogenesis in cocoa (Theobroma cacao L.) were carried out at the college of Horticulture, Kerala Agricultural University, Vellanikkara during the period 1989-91, with the objective of studying the developmental potential of somatic embryos and its differentiation into plantlet by means of in vitro techniques. Stem and leaf segments, cotyledons and enbryonic axes of embryos collected from four typical genotypes of cocoa namely criollo, Amelonado, Amazon-forastero and Trinitario were used as explant. Cotyledons and embryonic axes of immature embryos (100 days pot anthesis) when incubated on MS basal semisolid medium supplemented with NAA 2 mg/1, thiamine 1 mg/1, casein hydrolysate 0.2 per cent (W/V) and coconut water 15 per cent (v/v) under dark for seven weeks resulted in high frequency and intensity of embryogenesis. Stem segements remined recalcitrant without embryoid regeneration, while leaf segments had a little potential. Auxins conditioned the culture for embryogenic competence while cytokinins had an inhibitory effect. The effect of NAA 2ppm was not replaceable by other auxins such as IAA, 2, 4-D. 2,4-D was a poor quantitative and qualitative stimulant of embryogenesis. Studies on auxincytokinin interaction revealed the counteracting effect of cytokinin on auxin. Fully mature embryoids germinated in hormone-free liquid medium consisting of half the salt concentration of MS and 5 per cent sucrose when incubated at 3000 lux (16 hours) for two weeks. De-cotyledonisation of embryoids and its rinsing with sterile distilled water and dessication, each for three minutes, enhanced the differentiation into plantlet. Shoot growth was stimulated by exogenous supply of NAA, GA3 and coconut water. In vitro rooting was promoted by reducing the salt concentration of MS medium to half strength and supplementing with IBA and activated charcoal. Germination and regeneration of embryoid into plantlet was dependent on its size. Sizes ranging from 0-4 mm were sub-optimal for germination and differentiation. Larger embroids (4-6 mm) had greater potential for differentiation. Quantitative and qualitative differnces were expressed by cocoa genotypes. Amelonado was found to be superior to Criollo and Amazon types for the induction of embryogenesis from cotyledons. Trinitario was the least efficient. Embryogenic potential of Amazon embryonic axes was superior to Criollo and Amelonado types. Trinitario embryonic axes remained recalcitrant. Plantlets were derived from embryoids within a time span of 13 weeks in Amelonado, Criollo and Amazon types.ThesisItem Open Access Radiosensitivity analysis in Cucumis sativus L.(Department of Agricultural Botany, College of Agriculture, Vellayani, 1994) Raju, K M; KAU; Mercy, S TThe effect of five doses of gamma rays viz. 10, 20, 30, 40 and 50 kR in ten Cucumis sativus L. varieties was studied in M1 generation. Enhanced germination was observed in some varities in laboratory condition whereas in field condition a reduction in germination percentage was noticed in all treatments compared to control. Reduced survival percentage as a result of gamma irradiation was noticed on 40th day after sowing. Morphological abnormalities such as leaves with short petioles, half leaf blade only and chlorophyll deficient patches were obtained as a result of gamma irradiation. Increased sex ratio as a result of gamma irradiation was noticed in the present study. No variation was noticed on floral morphology. Variations in fruit morphology, reduced fruit weight and mean yield per plant were observed in certain treatments. Gamma irradiation increased pollen sterility. Cytological aberration were not observed in the present investigation. Different varieties of Cucumis sativus L. showed differential response to gamma rays. The characters studied in the M1 generations indicate the scope for selection of beneficial mutants in the segregating generations.
