Thumbnail Image

Theses

Browse

1997 - 19994
Reset filters
Subject: Plant Breeding × Author: KAU × End date: 1999 × Start date: 1997 × Thesis Type: M.Sc ×
Reset filters

Search Results

Now showing 1 - 4 of 4
  • Thumbnail Image
    ThesisItemOpen Access
    Diallel analysis in rice bean(Vigna umbellata( Thunb.) ohwi & ohashi)
    (Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 1999) Preeti, S V; KAU; Radha Devi, D S
    A diallel analysis in ricebean (Vigna umbellata (Thunb.) Ohwi and Ohashi) was carried out in the Department of Plant Breeding and Genetics, during 1997 - '98. The experimental material consisted of six parental lines and 30 F I hybrids, laid out in Randomised Block Design with three replications. The six parents were 3 LG, 5 LG, 6 LG, 8 LG, 9 LG, and 100 LG obtained from the germ plasm collection maintained at NBPGR, Thrissur. The observations were recorded on yield and yield attributing characters. Significant differences were detected among the mean performance of the genotypes, for all the characters studied. The combining ability analysis carried out by Method I, Model I of Griffing's approach (1956), revealed that the parent, 8LG was the best general combiner for most of the yield attributing traits. Among the crosses, 8LG x 3 LG exhibited outstanding sea for seed yield per plant. The crosses involving 8 LG were found to be good specific combiners. The combinations involving 3 LG and 6 LG also gave good specific combining ability effects. The numerical analysis by Hayman's approach indicated overdominance for almost all characters, which was confirmed by graphical analysis. The dominance of decreasing alleles in the parents was indicated by the negative value of F for all characters except, plant height, length of pods and number of seeds per pod. An almost equal distribution of genes with positive and negative effects was indicated by the ratio of H2 to 4H} for all the characters. The regression coefficient of covarince between parents and their offsprings in each array (Wr) on variance of all progenies in each parental array (Vr) did not- differ from unity, for plant height, length of pods, seed yield, 100 seed weight, days to maturity and protein content, indicating that assumption of non-allelic interaction was satisfactory for these characters. The Vr - Wr graph indicated that the parents were genetically divergent for days to first flowering, number of pods per plant, number of seeds per pod, 100 seed weight, days to maturity, root weight and nodule weight. Manifestation of heterosis was seen for all the characters studied. Among the hybrids, 8 LG x 3 LG was the most outstanding for yield and yield related characters. The crosses, 8 LG x 9 LG, 8 LG x 100 LG, 6 LG x 9 LG, 100 LG x 8 LG and 6 LG x 3 LG also performed better in yield and yield attributing characters. In general, hybrids involving 8 LG and 6 LG were found to be heterotic.
  • Thumbnail Image
    ThesisItemOpen Access
    Reproductive biology and enzyme studies in ocimum
    (Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 1997) Fancy, Parameswaran; KAU; Presannakumari, K T
    The present study on "Reproductive biology and enzyme studies in Ocimum spp." was undertaken at the Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara during the period 1994-1996 with a view to make a comparative evaluation of the reproductive biology and phosphorylase enzyme activity of different species of Ocimum. The four species of Ocimum viz. O. tenuiflorum, o. gratissimum, o. canum and o. basilicum collected and maintained in the Department were used for the study. The different species of Ocimum varied significantly in the time taken for inflorescence development, completion of anthesis in an inflorescence, number of flowers per inflorescence and distance between verticils. Species level variations were also observed in seed moisture content, seed density, l000-seed weight and seed dormancy period. Flowers of the four selected species were identical in basic structure although there existed variation in size, colour, hairyness and shape of floral parts. Anthesis occurred earlier in o. canum than the other three species. Pollen grains of Ocimum were hexacolpate and reticulate. However, species level difference existed in the size, shape and fertility of pollen grains. No self incompatibility mechanism existed in the four species studied. The floral morphology and protandrous nature makes the species adapted to cross pollination. Insects and ants are the main agents of pollination. Comparison of Sanctum and Basilicum groups revealed that Sanctum group which includes o. tenuiflorum and O. gratissimum required longer time for inflorescence development than Basilicum group which includes o. canum and O. basilicum. Verticils were closer in the inflorescence of Sanctum group than Basilicum group. Sanctum group produced less conspicous flowers with sessile bracts and yellow pollen grains. In this group anther dehiscence occurred in bud stage. Basilicum group produced conspicous flowers with pedicellate bracts and white pollen grains. Anther dehiscence was after flower opening in this group. Dormancy break was sudden in Sanctum group and gradual in Basilicum group. Moisture content of Ocimum seeds was positively related to phosphorylase enzyme activity. Phenol content was negatively related to both moisture content and phosphorylase enzyme activity of the seeds.
  • Thumbnail Image
    ThesisItemOpen Access
    Cytological and Biochemical Changes in Aged and Osmoprimed Seeds of Chilli
    (Department of Planting Breeding and Genetics, College of Horticulture,Vellanikkara, 1999) Thara Manohar; KAU; Nandini, A
    Studies Oil seed quality aspects in storage or chilli variety Jwalasakhi and Ujwala were undertaken in the Department of Plant Breeding and Genetics, College of Ilort icult urc, Vel lanikkara during 1997 to 1998 to study the di fferent types of cytological and biochemical changes in aged seeds or chilli, to investigate the effects of osmopriming in chilli seeds and to study the feasihility of osmopriming in overcoming physiological and genetic deterioration of stored seeds. The germination studies conducted during the ten months of storage period revealed that chilli seeds lost viability completely from the nineth month of storage onwards in amhient conditions. Hydroprimed seeds germinated to the tune of 13 and 20 per cent in Jwalasakhi and Ujwala respectively. Under this conditions osmopriming with chemicals PI':(; and Na Cl significantly improved this germination per cent to 40 as observed during the tenth month of storage. The chemical Na Cl with concentration 1.5 MPa and 48 hours duration was found the hest. Among the varieties Ujwala responded bcuer compared to Jwalusukhi. Irrespective of the chemical all osmopriming treatments produced uniform seedlings compared to control and the germination was completed within seven days under ideal conditions. In general vigour index and root shoot ratio also expressed similar results to that of germination. Studies 011 biochemical characteristics revealed a progressive loss of activity of mitochondrial dehydrogenase and soluble protein with ageing. The electrical conducuvity of seed leachate also increased with period of storage revealing the loss of mcmbrune integrity resulting ill leakage of cell contents outside the cell membrane. . Osmopriming treatments were ahle to repair this membrane damage to a good extend and increase the level of dehydrogenase activity and soluhle protein content compared to _ control. In hoth varieties sodium chloride with - 1.5 MPa was found the hest treatment. Among varieties Ujwala responded hetter than lwalasakhi. Cytological studies revealed u reduction in mitotic index values during storage irrespective of the variety. Osmopriming was found to improve the mitotic index values over hydropriming and untreated control. Any type or chromosomal aberration was not detected during the ten months of ageing period. l lere also sodium chloride with I. S M 1 'a was found to be superior. It can be concluded that I. The loss of viability in chilli seeds is mainly due to biochemical lesions '") Osmopriming was found beneficial after two months of storage in chilli seeds, because chilli seeds could retain the innate capacity to germinate and produce quality seedl ings up to two months of storage period. 3. PHI-ooon and Na Cl C<.I1l be used as an osmoticum for post storage priming treatments in aged chilli seeds. Na Cl can be advocated more economically compared to PLG.
  • Thumbnail Image
    ThesisItemOpen Access
    Genetic divergence and selection parameters in basmati rice
    (Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 1999) Sreejaya, K C; KAU; Radhakrishnan, V V
    The research project 'Genetic divergence and selection parameters in Basmati rice was carried out in the College of Horticulture, Kerala Agricultural University, Vellanikkara, Thrissur during the period 1995-'97. The major objectives of the study were to study the genetic divergence among advanced breeding lines of Basmati rice evolved at various rice research centres in India and to select high yielding quality Basmati rice genotypes adopted to Kerala ecosystem. The study, about components of heritable variation revealed that the range of variation is high for height of plant at harvest, total number of tillers, numbers of panicle bearing tillers, number of panicles/ m2 , number of spikelets/panicle, pubescence, awnness, num- ber of grains/panicle, aroma, overall acceptability, amylose content, kernel elongation after cooking, elongation ratio and yield. Heritability studies revealed that pH of raw grain, LIB ratio, kernel breadth and taste showed the maximum broad sense heritability among the qualitative characters; number of days to panicle initiation also had high heritability among the quantitative characters. Cluster analysis revealed that there was no parallelism between geographical distribu- tion and genetic diversity. The 38 genotypes were grouped into seven clusters. Correlation studies revealed that the principal yield determining components in Basmati rice are number of days to panicle initiation, number of days to 50% flowering, height of plant at harvest, number of panicle bearing tillers, number of paniclesl/m2 ,1000 grain weight, aroma, kernel length before and after cooking, alkali value and awnness. While selecting genotypes for higher yield potential, emphasis should be given for compara- tively long vegetative period, short period from panicle initiation to 50 percent flower- ing and dwarf plant type. A selection model was formulated consisting of the characters namely. Yield/ha, num- ber of days to panicle initiation, height of plant at harvest, number of panicles/m2 , alkali value and elongation ratio. Basmati culture 385 and UPR-BS-92-4 are identified as superior genotypes among the entries studied.