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Theses

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1980 - 198521
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Subject: Agriculture × Author: KAU × End date: 1985 × Start date: 1980 × Thesis Type: M.Sc ×
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    ThesisItemOpen Access
    Estimation of induced variability in chillies
    (Department of agricultural botany , College of agriculture Vellayani, Trivandrum., 1985) Lekha Rani, C; KAU; Krishnan Nair, N
    The mutagenic effect of Co-gamma rays and Ethylmethane sulphonate on three different chilli varieties have bean studied in detail in generation U3 ing two moderate doses of gamma rays <20 and 30 kR) and two concentrations of ISMS (0.5 and 1*0 par cent)* The presence and extent of chimeras and their relation to induced variability was assessed by raising branch-wise progenies in ^ generation* The experiment was conducted during 1982-84 at the Department of Agricultural Botany# College of Agriculture, Vellayani* The generation was laid out in RBD and in splitplot design with proper randomisation and replications* The crop wa3 raised and maintained following the Package of Practices recommended. The polygenic traits analysed in a, generalisen include plant height, number of branches per plant, fruit yield per plant and length and weight of fruits. The data collected were statistically analysed for proper interpretation of tho results obtained. It has been observed in almost all the polygenic traits that the extent of variability created vary depending on the genotypes, mutagen and their dosos and character under observation. The mean values wer« found to shift both in negative and positive directions to control values• significant shift in mean values depending on the type of branch category clearly demonstrates that there exists the mechanism of diplontlc selection in this particular crop variety# when exposed to mutagens. But the extent of selection varies depending on the mutagen and their doses and the genotypes concerned. a significant negative shift in mean Value was noted only in the case of fruit weight under both the concentrations of EM3 and 20 kR gamma rays whereas a positive or negative insignificant shift was noted in all other characters under both the mutagens, when under EM3 and in gansna rays showed a negative shift* positive shift in mean value wes noted in majority of the cases for number of branches per plant. Fruit length and weight and number of seeds per fruit showed a negative shift in majority of the cases analysed# but fruit number and yield per plant showed a reverse trend. The shift in mean value under the different branch categories varied depending on the varieties# mutagens and their doses and also the character under study. The phenotypes were found toAdistributedboth in negative and positive directions to control group in all the characters analysed. The frequency distribution whether negative or positive varied depending on the mutagen and their doses# the genotypes and character under study. In majority of tha cases the maximum frequencies of positive variants under both the concentrations of EMS and under 0.5 per cent for negative variants were found to be in the early formad branches when it was in the later ones is tha case of negative variants under 1.0 per cent EMS. in the case of gamma rays this general trend was not observed* The data analysed clearly demonstrate the existence of diplontic selection and promises wide scope for positive selection response either in negative or positive directions.
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    ThesisItemOpen Access
    Pollination studies in cashew
    (Department of Agricultural Botany, College of Horticulture, Vellanikkara, 1985) Elsy, C R; KAU; Narayanan Namboodiri, K M
    Investigation on the various aspects of pollination viz., flower opening, fruit set and fruit drop under natural pollination and assisted pollination, effect of pollinating agents and intensity of pollen in the atmosphere were undertaken at the Cashew Research station, Madakkathara and Department of Agricultural Botany, College of Horticulture, Vellanikkara during 1983-84, on six year old BLA-139/1 trees (air layers) under uniform cultural and manurial conditions. The data were subjected to various statistical analysis. The results have shown that the period of flower opening in both male and hermaphrodite flowers was same, starting after 23 hr and extending upto 15 hr next day. The peak period of flower opening for male flowers was between 7 and 9 hr and for hermaphrodite flowers between 9 and 11 hr. Climatic factors such as temperature, sunshine hours, relative humidity and wind velocity have not shown any significant influence on the magnitude of flower opening. Type BLA-139/1 has a relatively low sex-ratio of 1: 2. 83 resulting a higher percentage of hermaphrodite flowers. There is variation in sex-ratio even within the panicles of the same tree. When compared to natural pollination, assisted pollination resulted in significantly higher initial fruit set indicating the inefficiency or inadequacy of pollinating agents. But the higher initial fruit set was not fully reflected in the percentage of fruits harvested since a major portion of the set fruits dropped at different stages of development. In both cases of natural and hand pollination, fruit droop was more in early stages of nut development. This necessitates the need for improving the initial fruit set and more over reducing post fertilization drop for higher yields in cashew. In completely bagged panicles no fruit was set, confirming the cross pollinated nature of cashew. The failure of fruit set in water sprayed panicles rules out the possibility of water as a pollinating agent. Wind plays a significant role in cashew pollination along with insects like red and black ants, honey bees and butterflies which frequently visit cashew inflorescence. The intensity of pollen grains on the atmosphere was 20 times higher than that of hermaphrodite flowers in a unit area.
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    ThesisItemOpen Access
    Genetic variability and correlation studies in cocoa (Theobroma cacae L.)
    (Department of Agricultural Botany, College of Horticulture, Vellanikkara, 1983) Gregory Zachariah; KAU; Kumaran, K
    Investigation 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.
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    ThesisItemOpen Access
    Estimation of genetic parameters in green gram (Phaseolus aureus Roxb.)
    (Department of Agricultural Botany, College of Agriculture, Vellayani, 1980) Presanna Kumari, K T; KAU; Mary, K George
    Biometric studies on fifteen divergent green gram varieties (Phaseolus aurreus Roxb. syn. Vigna radiata (L.) wilzeck.) was conducted at the College of Agriculture , Vellayani , during November- January, 1979-80, to estimate the important genetic parameters like mean, range, genotypic and phenotypic coefficientsof variation , heritability, genetic advance and genetic gain and to find out the direct and indirect contributions of various component characters on yield by path coefficient analysis. There were significant differences among the varieties for all characters studied. Genotypic coefficient of variation was maximum for number of branches per plant followed by 100 seed weight and minimum for days to 50 per cent flowering . High heritability estimates were observed for pod length , 100 seed weight, plant height, number of seeds per pod days to 50 per cent flowering and number of pods per plant. Genetic gain was maximum for number of branches per plant followedby 100 seed weight and minimum for days to 50 per cent flowering. The number of branches per plant 100 seed weight, number of pods per plant and pod length had high heritability and genetic gain indicating the presence of additive gene action and hence they can be relied upon in selection programmes.
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    ThesisItemOpen Access
    Effect of herbicides of cell division sterility and yield in rice
    (Division of Agricultural Botany, College of Agriculture, Vellayani, 1981) Kishore Kumar, K; KAU; Mercy, S T
    Herbicides have become a very important tool for weed control and research in this line has been progressing ever since their invention. Studies on the possible damages which herbicides cause at the chromosomal level have been undertaken under laboratory conditions by many workers. But only a few studies have been on this aspect under field conditions. This study was done with the aim of finding the extent of chromosomal aberrations and consequent deterioration of yield attributes in rice caused by the application of five selective herbicides. Observations on the herbicidal influence on weed population have also been taken. From this study it has been found that herbicides do cause chromosomal changes during cell division. Pollen mother cell studies revealed that highest number of chromosomal abnormalities occur in 2,4-D and nitrofen treatments when applied at a dose of 1kg and 1.5 kg a.i. per hectare, eighteen days after transplanting. Such abnormalities caused pollen sterilityand consequent spikelet sterility leading to reduction in yield . These parameters showed significant positive correlation.
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    ThesisItemOpen Access
    Induction of mutations in cowpea (Vigna unguiculata (L.) Walp.)
    (Department of Agricultural Botany, College of Agriculture, Vellayani, 1980) Sunny, K Oommen; KAU; Gopimony, R
    Studies were undertaken to obtain precise information on the effects of six doses of gamma rays (5-30 krads) and seven concentrations of ethyl methanesulphonate (0.1-0.7 per cent) in cowpea, using the variety ' New Era'. The effectiveness and efficiency of different doses of the two mutagens in inducing chlorophyll mutations were estimated. (1) The germination of cowpea seeds was not affected by green rays even at the highest dose employed , whereas ethyl methanesulphonate inhibited germination and the reduction in percentage was progressive with increasing doses. (2) The survival of plants based on the number of seeds sown was reduced by both mutagens. Post germination mortality occured to a certain degree with gamma irrediation, whereas it did not occur to any considerable extent with ethyl methanesulphonate treatment. (3) A differential effect on the growth of shoot and that of root was observed with both mutagens in the present study. The growth inhibition was more for the shoot with gamma rays ,while ethyl methanesulphonate produced a higher degree of inhibition for the growth of root than for shoot.
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    ThesisItemOpen Access
    Selection parameters in tapioca (Manihot esculenta Crantz)
    (Department of Agricultural Botany, College of Agriculture, Vellayani, 1980) Radhakrishnan, V V; KAU; Gopakumar, K
    During a biometrical study conducted on 20 divergent types of tapioca (Manihot esculenta Crantz) in the premises of Central Tuber Crops Research Institute at Trivandrum, as a postgraduate programme of the Kerala Agricultural University, useful informations on the selection parameters become available. Accordingly, it was found that harvest index should be the best reliable criterion for effecting selection in favour of a desirable genotype from among others in a genetically heterogenic base population. Further, it is proposed that potentially high tuber yielders in the crop could be identified among relatively short statured ones with more number of large sized leaves that have become completely developed sufficiently early during development of the shoot. In addition , a tendency for relatively more number of leaves to become abscissed towards the time of harvest should also be considered as a positive sign of high tuber yield
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    ThesisItemOpen Access
    Selection index in horse gram (Dolichos biflorus L.)
    (Department of Agricultural Botany, College of Agriculture, Vellayani, 1980) Suraiya, D; KAU; Mercy, S T
    The present biometric study was carried out in the College of Agriculture, Vellayani during the year 1979-80 with fifteen varieties of horse gram (Doliches biflorus L.) to formulate a suitable selection index for yield. The observation plants were studied individually for the following characters. (1) Seed yield per plant (2) Number of pods per plant (3) Number of seeds per pod (4) 100-seed weight (5) Pod length (6) Days to 500 flowering (7) Height of plant (8) Number of branches (9) Days to maturity (duration). The data obtained in the study were subjected to statistical analysis viz. estimates of mean for all the different varieties, analysis of variance in respect of the nine selected characters, estimates of components of variances, genotype, environmental and phenotypic coefficients of variations, heritability, genetic advance and studies of discriminant function and path coefficient analysis.
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    ThesisItemOpen Access
    Correlation and path coefficient analysis in guinea grass (Panicum maximum Jacq.)
    (Department of Agricultural Botany, College of Agriculture, Vellayani, 1983) Sreenivasan, E; KAU; Kamalam, N
    A study was undertaken at the Department of Agricultural Botany, College of Agriculture, Vellayani, to determine the character association for yield and quality of green fodder and their degree of association and relative influence on yield in guinea grass. Twenty four diverse varieties of guinea grass were selected for the study and laid out in randomised block design with three replications. Observations were made on nine morphological characters and four chemical attributes and the data collected were subjected to variability studies and correlation analysis. Five morphological characters which showed highly significant genotypic correlation with green fodder yield were considered for path coefficient analysis in order to separate the total correlation of these characters with green fodder yield into direct effects and indirect effects via. other characters.