1. KAUTIR (Kerala Agricultural University Theses Information and Retrieval)

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    Comparative evaluation of selected types of Piper longum (Linn.) in coconut plantations
    (Department of Agricultural Botany, College of Horticulture, Vellanikkara, 1994) Jaya Manuel; Viswanathan, T V
    Comparative 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.
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    Somatic embryogenesis in cocoa (Theobroma cacao L.)
    (Department of Agricultural Botany, College of Horticulture, Vellanikkara, 1993) Jolly Antony; Achamma Oommen
    Investigation 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.
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    Radiosensitivity analysis in Cucumis sativus L.
    (Department of Agricultural Botany, College of Agriculture, Vellayani, 1994) Raju, K M; Mercy, S T
    The 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.
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    Induced mutations in cowpea
    (Department of Agricultural Botany, College of Agriculture, Vellayani, 1989) Mini, V; Vijayagopal, P D
    Seeds of cowpea ( vigna unguiculata) cultivar kuruthola-payar were subjected to induced mutagenesis using four doses of gamma rays (10 to 40 krad) and four doses of EMS (0.5 to 2.0 per cent) and their effects in the M1 and M2 generations were studied. The germination percentage was observed to decrease prgogressively with the increase in dose of both mutagens although the reduction was more drastic with EMS. Reduction in survival percentage was observed with increase in the dose of gamma rays and EMS. The growth of shoot and root and plant height were reduced by both the mutagens, although gamma rays showed greater shoot inhibition and EMS showed greater root inhibition. The pollen fertility as well as seed fertility decreased linearly with increase in doses of both the mutagens. Chlorophyll chimeras were observed only in the 30 krad and 40 krad gamma ray treatments. Morphological variations noticed included plants with alterations in the number, size and shape of leaflets. The chlorophyll mutation frequency estimated on M2 progeny row basis showed an increase with increasing doses of gamma rays, except in the 40 krad treatment, which showed a slight decrease. In the case of EMS, maximum mutants were observed at the lowest dose. The chlorophyll mutation frequency estimated on M2 seedling basis showed dose-dependence. The frequencies of the different types of chrolophyll mutants did not show any dose-relationship. The segregation ratio of chlrophyll mutants was higher for EMS than gamma irradiation. The viable mutation frequencies did not show any definite relationship with the doses in both the mutagen treatments. The mutagenic effectiveness in inducing chlrophyll mutations was high at the lowest dose of both mutagens. On the basis of lethality, 20 krad of gamma rays was the most efficient, while on the basis of injury and sterility, 10 krad was the most efficient. With EMS, the 0.50 per cent treatment was the most effective as well as the most efficient treatment on the basis of lethality, injury and sterility. The mutagenic efficiency in inducing chlorophyll mutations was higher for gamma rays with respact to lethality and injury, while on the basis of sterility, EMS proved to be more effcient than gamma rays.
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    Induced mutagenesis in rose under in vivo and in vitro culture
    (Department of Agricultural Botany, College of Agriculture, Vellayani, 1993) Wilson, D; Krishnan Nair, N
    Investigations were carried out at the Department of Agricultural Botany and Tissue Culture Laboratory attached to the Department of Horticulture, College of Agriculture, Vellayani during the period from 1989-1993 on “Induced mutagenesis in rose under in vivo and in vitro culture. Induced mutagenesis adopting in vivo method was carried out with three rose cvs. Alliance, Suraga and Folklore belonging to Hybrid Tea group. The cv. Folklore alone was utilized for induced mutagenesis adopting in vitro culture. The budwoods of three selected cultivars were collected at three different stages of growth and exposed to Gamma rays at 20, 30, 40, 50 and 60 Gy, and budded on rooted stock plants and effect of gamma rays on morphological attributes were recorded. In vitro culture conditions were standardized for cv. Folklore. Budwoods were collected at five different growth stages and exposed to gamma rays at 20, 30, 40 and 50 Gy, before culturing. The in vitro variations in terms of culture establishment, shoot proliferation and rooting efficiency were studied. Multiple shoots were also subjected to gamma irradiation to study their in vitro variations. Gamma irradiation of bud woods induced inhibition and reduction in sprouting and survival. Growth retardation exhibited in the form of reduction in plant height and number of branches. The cultivars showwed no significant interaction with different doses of gamma rays for sprouting and survival. The ED50 was estimated as 38Gy. One reddish yellow mutant was isolated from cv. Folklore from 30 Gy treated population and one mutant for increased number of petals from 40 Gy treated population of the same cultivar. In addition, gamma exposure induced variation in size and shape of leaves at 30 and 40 Gy. The treatment of mercuric chloride 0.08 per cent for 12 minutes had the minimum contamination rate for shoot tip and axillary bud explants, and 0.06 per cent for 12 minutes was most effective in the case of internodal segments and leaf disc explants. Axillary buds of 1.0 cm length for enhanced release of axillary bud, internodal segments of 0.5 cm and leaf discs of 1.0 cm with a petiole portion for callus induction were identified as the most suitable explants. Axillary buds excised 4 days after flower opening had the best response in culture establishment. MS basal medium supplemented with BAP 2.5 mg/1+2,4-D 0.5 mg/1 recorded bud break percentage of 80 per cent within 4 days. Early multiple shoot induction and highest number of shoots/culture observed in medium supplemented with kinetin 2.0 mg/1 + GA3 1.0 mg/1. Addition of BAP 2.0 mg/1+ GA3 0.75 mg/1 was the best for getting highest percentage of cultures with multiple shoots. Flower bud initiation was observed in combination of BAP 2.0 MG/1 + GA3 0.5 MG/1. The best medium for in vitro rooting was found to be IAA and NAA 1.0 mg/1 each, along with activated charcoal 500 mg/1. Successful hardening and ex vitro establishment of plantlets were achieved by surface inoculation of germinated spores of mycorrhizae (VAM) in liquid suspension. Highest survival rate of 66.67 per cent was observed by inoculation with Glomus etunicatum against no plants in the untreated lot. Minimum number of days to flowering (105) was taken in plantlets inoculated with G. etunicatum BAP 0.5 mg/1 + NAA 2.0 mg/1 +2, 4-D 0.5 mg/1 was the best combination for callus induction and BAP 0.5 mg/1 + NAA 0.1 mg/1 + ascorbic acid 5 mg/1 had the highest callus proliferation. In vitro rhizogenesis obtained from internodal and leaf calli in MS medium supplemented with BAP 0.5 mg/1 + NAA 2.5 MG/1 + 2, 4-D 0.5 mg/1. Gamma irradiation of axillary buds delayed bud break, reduced percentage of bud break, multiple shoot production and rooting efficiency and also induced morphological variations in leaf and growth pattern. The estimated value for ED50 was 33 Gy under in vitro culture. Exposure of multiple shoots to gamma rays induced several morphological abnormalities and reduced the shoot production and rooting efficiency.
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    Anther culture in cocoa
    (Department of Agricultural Botany, College of Horticulture, Vellanikkara, 1992) Sunil, K P; Achamma Oommen
    Investigations on anther culture of cocoa (Theobroma cacao L.) were carried out at the College of Horticulture, Kerala Agricultural University, Vellanikkara, during 1990-'92 with the objective of studying the amenability of cocoa anther under in vitro conditions for the production of haploids. The fertility and viability of pollen grains of cocoa were found to be 35 and 61 per cent respectively. Anthers at tetrad stage (bud length 1.75 mm) were subjected to a two-stage culture procedure involving incubation and subculture (after 4 weeks) on modified H3 basal medium supplemented with 1 mg 1-1 NAA and 0.1 mg 1-1 2-iP for 50 days (stage 1) and subsequent weekly transfer to ½ Ms basal media supplemented with 0 to 1 mg 1-1 2-iP and 0 to 3 mg 1-1 GA3 (stage II). Proembryoids were obtained in stage 1 medium via callus within 45 days of culture, only when anthers derived from Criollo, Trinitario and H2 were cultured. Serial subculturing of embryoids in stage II media led to formation of shootlets and rootlets. With four sub- cultures in stage II in a span of one month, the embryoids could be germinated into plantlets of size 2.5 cm with two leaflets and one rootlet. This is the first report of plantlet recovery from cocoa anthers via indirect embryogenesis. The plantlets were dried up after an elapse of 3 months. The most favourable combination for root development was Ms medium supplemented with 2 mg 1-1 2-iP, 0.1 mg 1-1 NAA and 126 mg 1-1 PG. The factors influencing anther callus induction were: stage of anther development, minimum temperature in the field of donor plants, type and strength of basal medium, type and concentration of auxins and cytokinins, carbohydrate source, sucrose level, presence of CW and PG, physical environment and gamma and UV rays. Anther callus multiplication was influenced by type of basal medium; type and concentration of growth regulators; carbohydrate source; sucrose level; presence of amino acids; organic supplements; ethylene releasing and inhibiting chemicals; adenine and its derivatives; unusual regulants.; gibberellins and growth inhibitors; light and gamma rays. The factors influencing indirect embryo- genesis were found to be stage of anther development and light. Hybrid genotype (H2 and H1) responded more favourably to callus induction, callus multiplication, callus rhizogenesis and were stable with respect to seasonal changes. However, they took more number of days for callus initiation. Criollo took minimum period for callusing. Chlorine water treated for 3-4 min was the best chemical identified for surface sterilization of flower buds of cocoa. A single auxin or cytokinin alone in the basal medium could not initiate anther callusing. Thermic shock pre-treatments were ineffective for callus induction. Light had no role in callus induction. UV rays had no role in altering anther callus growth. Time of subculturing in cell suspension culture was found to be 15 days. Calloids developed in cell suspensions were not amenable to organogenesis or embryogenesis. Isolated microspore culture was unsuccessful.
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    Ergonomic influence of plant morphology on yield in sesamum
    (Department of Agricultural Botany, College of Agriculture, Vellayani., 1990) Ganga Rani, B R; Gopakumar, K
    The study is basic and appears new to its type. A prototype model to assess meritwise ergonomics in morphologically diverse seed propagated field crop communities in which seeds make the produce proper is presented. The approach seems to promise greater scope for varietal/genetic improvement of crops of the category as against the conventional multivariate methods that are being widely practiced. Trust is on the elaboration of the source and the flow of a part of it to make the sink. Hypothetical views on the influence of plant morphology on yield factor are expressed and their validity tested. Relevant aspects are discussed in detail. Cultivated sesamum represents the material studied.