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ThesisItem Open Access Evaluation of selections and hybrids of Vetiver (Vetivena zizanieides (Linn ) Nash)(Department of Agricultural Botany, College of Horticulture, Vellanikkara, 1991) Radhakrishnan, G R; Viswanathan, T VThesisItem Open Access Genetic variability and path coefficient studies on fodder yield and its components in oats( Avena sativa. L.)(Department of Agricultural Botany, Rajasthan college of Agriculture, University of Udaipur, 1976) Sukumaran, Nair PThesisItem Open Access Induced chemical mutagenesis in Rose under in vitro culture(Department of Agricultural Botany, College of Agriculture,Vellayani, 1991) Uma, B; KAU; Krishnan Nair, NThe present investigation entitled “Induced chemical mutagenesis in rose (Rosa chinensis) under in vitro culture” was carried out in the Tissue Culture Laboratory attached to the Horticultural Department, College of Agriculture, Vellayani during 1989-90. The main objectives of the experiment were to standardize a suitable culture medium for the growth and development of axillary buds and to standardize a successful method of chemical mutagenesis in rose under in vitro culture using the most potent chemical mutagen, ethyl methane sulphonate. The standardization of hormone levels in the culture medium (ms) was done at three stages of explant development viz. culture establishment, axillary bud proliferation and in vitro rooting. Surface sterilization of axillary buds were standardized by using mercuric chloride selecting out three concentrations 0.06, 0.08 and 0.1 per cent and 3 periods of treatment 5, 10 and 15 minutes. The axillary buds used were of 4 maturity stages ie. Axillary buds at the time of flower harvest and 2, 4 and 6 days after flower harvest. The various concentrations of ethyl methane sulphonate tested include 0.125, 0.25, 0.375 and 0.5 per cent. Two methods of mutagen treatments were tried ie. direct treatment and cotton swab method. In the direct treatment the axillary buds were subjected to EMS treatment at different periods treating the buds at the time of culturing, 2 days after culturing, 4 days after culturing and 6 days after culturing. In the cotton swab method buds were treated with EMS in the plant itself at various stages ie. at the time of flower harvest and 2,4 and 6 days after flower harvest. Surface sterilization of axillary buds was found to be most successful with mercuric chloride at 0.08 per cent for 15 minutes of the various levels of hormonal combinations tested BAP 2 mg/1 +2.4-D 1 mg/1 was found to be the best for culture establishment and BAP 2 mg /1 +GA 1mg/1 for shoot proliferation. Maximum rooting was obtained in full strength MS medium supplemented with IAA 2 mg/1 of the two methods of mutagen treatments tried direct treatment of axillary buds with EMS was not found to be effective as the buds turned brown and no further development occurred. In the cotton swab method, lower concentrations of EMS (0.125 and 0.25 per cent) gave a better performance based on days taken for bud take multiple shoot production and rooting percentage. A decrease in survival percentage was noted with increase in mutagen concentration. Higher concentration of EMS (0.375 and 0.5 per cent) curbed multiple shoot production in buds excised at the time of flower harvest and delayed multiple shoot production in other stages. The percentage cultures showing rooting and the number of roots/shoot also decreased with increase in concentration of EMS. Increase in maturity of buds also delayed multiple shoot production and decreased rooting percentage of the 4 stages of buds used for in vitro culture, buds excised at the time of flower harvest was found to be the best. But mutagen treatment retarded their performance. For mutagen treatment buds excised 4 days after flower harvest was found to be best followed by buds excised 2 days after flower harvest. Buds excised 6 days after flower harvest showed a poor performance in the normal and treated populations. The experiment clearly demonstrated that induced mutagenesis in rose can be successfully done adopting in vitro culture techniques.ThesisItem Open Access Variety Sensitivity Analysis in Cucumis melo L. using Gamma Rays and Ethyl Methane Sulphonate(Department of Agricultural Botany, College of Agriculture,Vellayani, 1990) Nelson Lopez; KAU; Mercy, S TThe effect of gamma rays and 'EMS on ten Cucumis melo L. varieties was studied in the M1 generation. Germinability of seeds was not significantly affected by the different mutagen doses. However in general germination percentage decreased in varieties Panavalli, Attenganam local, Lucknow Sweet, Verma Surprise and Punthala local with gamma ray treatment while in Mudikode local, Pulliporan, Vellanad local and Co-1 germinability was better. EMS treatments in Mudikode local, Hara Madhu, Pulliporan, Puthala local and Co-1 resulted in decreased germination percentage. Significant delay in completion of germination compared to control was observed in different levels of gamma ray treatments in some of the varieties while early germination was noted in some others. Survival percentage, in general, was reduced with mutagen treatment in most of the varieties. Chlorophyll chimeras were noticed in both mutagen treatments. Morphological variations observed included leaf and fruit abnormalities. In general the lower doses of gamma rays resulted in early flowering of male flowers while 30 kR treatment resulted in delayed male flowering. Among EMS treatments, 1.0% and 2.0% treatments in general resulted in a delayed production of first male flower. In the case of appearance of first female flower a significant delay was observed in the higher doses of gamma ray treatments in Co-1 and Attenganam local while a significantly early appearance of first female flower was noted with lower doses of gamma ray treatments in Mudikode local, Lucknow Sweet and Pulliporan. The 1.5 % and 2.0% EMS treatments in general produced first female flower earlier than control and 1.0% treatment. In most of the varieties the EMS treatments in general resulted in the apperance of the first male flower at lower nodes compared to control. EMS treatment induced appearance of first female flower at lower nodes than gamma ray treatment. Increase in sex ratio (male to female) due to some of the EMS treatments was observed in some varieties while a decrease was observed in others. Irradiation with higher doses of gamma rays caused decreased sex ratio in Panavalli, Lucknow Sweet, Hara Madhu, Pulliporan and Punthala local. In general in all varieties there was reduction in pollen and seed fertility with increase in dose of gamma rays and EMS except 10 kR gamma ray treatment and 1.5% EMS treatment where a slight increase in seed fertility was noticed. Different varieties showed differential response to different levels of gamma rays and EMS for number of fruits produced per plant and also for lenght and girth of fruit. Higher doses of gamma rays in Mudikode local, Co-1 and Pulliporan recorded greater fruit weight compared to control while 30 kR treatment in Panavalli and Punthala local recorded lower fruit weight compared to control. In Mudikode local, Panavalli, Vellanad local and Co-1 irradiation of gamma ray in general resulted in significantly lower yields than their control while in Attenganam local gamma ray irradiation resulted in significantly increased yield compared to control. Significantly lower fruit set compared to control occured in 20 kR treatment in Panavalli, Punthala local, Pulliporan and Co-1 whereas 10 kR treatment in Lucknow Sweet and Vellanad local resulted in a significant increase in fruit set. Lower levels of EMS treatments in Hara Madhu, Co-1, Pulliporan and Panavalli induced significantly lower fruit set compared to control. Irradiation with gamma rays resulted in significantly lower number of seeds compared to control in Mudikode local and Punthala local while in Pulliporan greater number of seeds than control was produced due to gamma ray treatment. In Co-1 and Attenganam local, 2.0% EMS treatment resulted in a significant reduction in 100 seed weight while lower levels of EMS treatments in Lucknow Sweet resulted in a significant increase in 100 seed weight compared to their control. The 10 kR treatment of all varieties in general resulted in slight decrease in mean length of main vine compared to control whereas the higher levels of gamma rays resulted in slight increase in mean length of main vine. In general the 2.0% EMS treatment of most of the varieties induced slight reduction in mean length of main vine while the lower levels of EMS resulted in slight increase in mean length of main vine compared to control.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 Cytotoxic and clastogenic effects of some insecticides in allium cepa, L(Department of Agricultural Botany, College of Horticulture, Vellanikkara, 1983) Jayaprakash Naik, B; KAU; Vijayakumar, N KIn the present investigation, the cytotoxic and clastogenic effects of three very commonly used insecticides, namely, aldrin, carbofuran and phorate were tested in Allium cepa, L., a test system. Four concentrations of each insecticides were used for the study. These concentrations were fixed taking into consideration of their field dose of application in insect control. The treatment periods fixed were 12, 24 and 48 hours. The mitotic index was computed from 4000 cells and indices of each division phases were also computed. The chromosome abnormalities were scored from about 100 to 150 cells of each phases in each treatments. Aldrin was found to be drastically mitodepressive compared to carbofuran and phorate. While phorate increased mitotic index in the lowest dose, carbofuran showed only marginal reduction. However, both the compounds reduced mitotic index in higher doses and the field doses. Aldrin exhibited a dose and period responsiveness, while carbofuran and phorate could not with regard to mitotic index. The study also revealed that aldrin is an effective toxicant on both genetic material and proteins. The various chromosome abnormalities noticed were stickiness, bridges, laggards, blurred chromosome borders, chromatin bridge, micronuclei, non-orientation of metaphase, precocious movement in anaphase, chromatin bodies, irregular anaphase, star metaphase, strays, beaked nuclei, break, C-metaphase and unequal nuclei in their decreasing order of occurrence. Unlike aldrin, carbofuran and phorate could not induce anomalies to a significant level in the lowest doses tried, 0.0075 and 0.02 per cent respectively. Chromosome bridge being the most frequent abnormality found in carbofuran, which was followed by stickiness and laggards. The frequency of abnormalities found in field and higher doses were more or less same. Phorate, on the other hand showed linear relationship in inducing chromotoxicities with respect to concentrations and period of treatment. The major types of abnormalities recorded were bridges, breaks and stickiness. The results showed that all the insecticides tried were capable of affecting the genetic material as well as protein, but to different degrees depending on concentrations. It can be tentatively concluded that they cannot be considered completely safe at the field dose of application on the cellular constituents of the organism. The results call for extensive testing of these chemicals in other test systems also.ThesisItem Open Access Genetic variability and correlation studies in cocoa(Department of Agricultural Botany, College of Horticulture, Vellanikkara, 1983) Gregory, Zachariah; KAU; Kumaran, KInvestigation on the generic variability and correlation studies in cocoa were undertaken in the Department of Agricultural Botany, College of Horticulture, Vellanikkara during the period from July 1980 to August 1981 in a well established cocoa garden at Alpara in Trichur district, to elucidate information on the extent of variability and the degree of association existing among the 26 important plant, pod and bean characters, in a group of 135 cocoa tress, variety Forastero. Considerable variability was noted among all the characters of the sexually reproduced population of cocoa trees. Number of flowers per unit length on the trunk, number of pods per tree per year, weight of pod, volume of pod and wet weight of beans per pod showed maximum variability. Shell percentage and seed index manifested considerable variability among the bean characters. Phenotypic coefficient of variation (P.C.V.), genotypic coefficient of variation (G.C.V.) and heritability were estimated for 7 pod and bean characters. Both (P.C.V.) and (G.C.V.) were highest for attributes such as thickness of pod husk, number of beans per pod and weight of pod. Moderately high heritability was observed for weight of pod, thickness of pod husk and number of germinated beans. Volume of beans showed the lowest heritability. Yield from trees was found to be positively correlated with 6 of the characters studied, while number of germinated beans per pod and pod value were negatively correlated with yield. Out of the eight characters, pod value had the maximum contribution to yield. Number of pods per tree per year was found strongly associated with yield. Seed index and trunk girth also were positively and significantly correlated with yield. Phenotypic (rp) correlations among seven characters indicated that number of beans per pod was positively correlated with weight of pod. Positive correlations were also established between volume of beans and wet weight of beans per pod. Among the seven characters observed for genetypic (rg) correlations, wet weight of beans showed positive correlation with diameter of the pod and pod weight. Positive phenotypic as well as genotypic correlations were established in the case of wet weight of beans per pod with number of beans per pod and volume of beans. Number of beans per pod in turn, showed positive correlation with weight of pod at both levels. From the present studies it was evident that characters like diameter of pod, wet weight of beans per pod, number of beans per pod, number of germinated beans per pod, volume of pod, volume of bean, pod value, number of cushions on trunk, trunk girth, number of pods per tree per year and seed index have direct influence on the yield of cocoa. These traits can be considered while selecting cocoa trees for using in breeding programmes.ThesisItem Open Access Chromosome behaviour and pollen analysis in anthurium sp(Department of Agricultural Botany, College of Agriculture, Vellayani, 1992) Bindu, M R; KAU; Mercy, S TChromose behaviour and pollen characters had been studied in five commercially important varieties of Anthurium andreanum viz. Honeymoon Red, White (album), Lady Jane (Pink), Chillired and Pink. Some morphological characters were also recorded. The varieties show distinct differences in morphological characters. They can be identified from one another even in the absence of their typical spadices. All the varieties have a somatic chromosome number of 30+2B. The basic chromosome number is x=15. Two B chromosomes are present irrespective of the varietal type. The B chromosomes are either acentric or telocentric and round or rod shaped. Their size is always smaller than the smallest A chromosome. The karyotype of all the five varieties was analysed. On the basis of total chromosome length (TCL), average chromosome length (ACL) and arm ratio (r), the variety Pink appears to be most advanced. When the relative chromosome length (RCL) was taken in to consideration, the variety Chillired is found to be most advanced. With regard to the character, chromosome asymmetry, Lady Jane appears to be most advanced. When the karyotype asymmetry as a whole is considered, all the varieties are falling in the '3B' category which represents a high position in evolution. During meiosis, all the varieties exhibited a wide range of abnormalities like univalent formation, unequal seperation, presence of laggards, micronuclei etc. This point out the hybrid nature of the species. All the varieties are found to be protogynous with distinct interphase. This is an adaptation for natural cross pollination. However, natural crossing is occuring only to a limited extent. The pollen production capacity of the varieties varies significantly. The varieties Honeymoon Red and Pink produce the highest amount of pollen. All the varieties have round pollen with a single germ pore. The pollen size among the varieties does not vary significantly. However, the variety Lady Jane has the largest pollen. Pollen fertility is very low, when it was tested by acetocarmine staining and in vitro pollen germination methods. The latter is found to be more reliable in estimating the pollen fertility. All the varieties have paracytic type of stomata. But the varieties vary widely in their size and distribution. Morphological variations, karyotypic differences, meiotic abnormalities, high pollen sterility and the wide variability in stomatal characters point out the basic hybrid nature of the species.