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ThesisItem Open 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 SA 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.ThesisItem Open Access Induction of polyploidy in kacholam(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 1996) Ajithmohan, N K; KAU; Pushkaran, KA trial on induction of polyploidy in Kaempferia galanga L. was undertaken at the Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, during the period 1994-'95. A local selection Vellanikkara collected from the genetic stock maintained at AICRP on M & AP was used for the study. The objective was to create variability in kacholam by developing polyploids. The rhizomes of the crop were treated with colchicine for inducing polyploidy. Five concentration of colchicine viz., 0.05, 0.15, 0.25, 0.35 and 0.45 per cent (C2 to C6, C1 being control i.e., 0%) was tried for two time durations viz., four hours and six hours (T1 and T2), the same treatment being repeated on two consecutive days. Two methods of treatment were tried the first (M1) being chemical application in a hole drilled close to the sprouting bud and the second (M2) being the ordinary cotton swab method. Rhizomes with two different stages of bud sprouting were used: (1) with just emerging buds (S1) and (2) buds at an advanced stage of sprouting (S2). The treated rhizomes were planted in the field and their growth was examined. In the end of the crop season, 18 variant plants were identified and they were put to detailed morphological and cytological study in the next growing season. Mitotic study of the parent material confirmed that the chromosome number of kacholam is 55. Of the 18 variants identified one was found to contain 110 chromosomes in the somatic cells. As kacholam is proposed to be a pentaploid the induced polyploid must be a decaploid. The polyploid was obtained from the treatment combination S1M1T1C6. It was characterised by small plant size and reduced vigour. The leaves were thick with reduced size. Stomatal size increased conspicuously with their numbers reduced. The rhizome development was found retarded and the per plant yield was also less. The rhizome morphology was on par with the normal plants. The plant flowered neither in the first season nor in the second. In addition to the polyploid, there other stable variants were obtained from the experiment. They were also characterised by reduced vigour and yield.ThesisItem Open Access Reproductive biology and enzyme studies in ocimum(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 1997) Fancy, Parameswaran; KAU; Presannakumari, K TThe 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.ThesisItem Open 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, AStudies 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.ThesisItem Open Access Induced mutations in interspecific hybrids of abolmochus(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 1996) Animon, G; KAU; Gopimony, RThe F1 seeds of the cross between Abelmoschus esculentus cv Kiran and the semi- wild species, Abelmoschus manihot were exposed to four different doses (10, 20, 30 and 40 KR) of gama rays and their effects in the first generation were studied. The percentage of seed germination decreased with increasing doses of gamma rays. The treated hybrids have shown delyed germination compared to the control. The survival of plants was found to decrease with increase in dose of the mutagen. The rate of growth of plants and plant height were found to decrease by the treatment with gamma rays. Various chlorophyll and morphological varients were observed in the irradiated population. An increase in pollen fertility was noticed in the irradiated hybrids. But the increased pollen fertility did not show any effect on the seed set. Irradiation delayed the formation of flowers and fruiting. The mean values for number and weight of fruits did not differ significantly among irradiated treatments and was on par with the control F1. The treated hybrids were found to be on par with the control F1 for yellow vein mosaic disease incidence and the important diseases affecting bhindi. The hybrids irradiated at higher doses had become more susceptiable to fruit borer incidence. The hybrids represented more towards the semi-wild parent and have shown considerable heterosis over the cultivated parent and semi-wild parent for most of the economic characters. The hybrids were vigorous in growth habit compared to the parents. The hybrid treatments exhibited significant positive heterosis for days taken to first flowering and last fruiting over the cultivated parent. The hybrids treatments exhibited significant positive heterosis for number of flowers, number of fruits and weight of fruits over both the parents. Significant negative heterosis over the cultivated parent was shown for fruit length by the hybrid treatments. Significant negative heterosis over the cultivated parent for fruit borer incidence was shown by the control and the hybrids irradiated at 10 and 20 KR. All the hybrid treatments manifested significant negative heterosis over the cultivated parent for YVMD incidence. The mutagenic effectiveness in inducing chlorophyll mutations was found to increase with increase in dose of the gamma rays. The mutagenic efficiency estmated on the basis of lethality and injury increased with increase in dose of gamma rays. On sterility basis, the 30 KR treatments was the most efficient.ThesisItem Open Access Genetic make up of yield and yield attributes in a six parent dialiel cross of tomato(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 1998) Siby Varghese, KAU; Chadramony, DAn experiment in tomato (Lycopersicon esculentum Mill.) was carried out at the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani during 1995-96, with the objective of estimating the combining ability of parents, and gene action involved in the inheritance of different yield attributes. The study was conducted in a diallel model, using three bacterial wilt resistant varieties and three popular varieties. The three bacterial wilt resistant varieties were Sakthi, Arka Alok and Arka Abha. The three popular varieties were LE 79-5, LE 373 and PKM 1. These six parental varieties and fifteen hybrids were planted in the field in Randomised Block Design., with three replications. Observations recorded were plant height, number of branches per plant, spread of the plant, number of leaves per plant, number of days taken for first flowering, number of days taken for first harvest, duration of harvest, single fruit weight, fruit size, number of fruits per plant, fruit yield per plant, pericarp thickness, locules per fruit, number of seeds per fruit, reaction to pests and diseases, colour at collar of fruits and fruit cracking. Analysis of variance revealed highly significant differences among the genotypes for all the characters except for number of locules per fruit. Both g.c.a. and s.c.a. were significant for all these characters. The additive to \1 \3«;6 • dominance variance ratio indicated a preponderance for non-additive gene action in the characters such as spread of the plant, number of days for first flowering, number of days for first harvest and duration of harvest, and a preponderance for additive gene action in the remaining characters. Combining analysis showed that Sakthi and PKM 1 were good general combiners with respect to fruit yield and other yield attributes whereas LE 79-5 and LE 373 ",!ere good general combiners for the different vegetative characters such as plant height, branches and leaves per plant. Among the fifteen hybrid combinations, significant S.C.a. and heterosis were observed in the hybrids such as Arka Alok x PKM 1, Arka Abha x PKM 1, Sakthi x Arka Alok, Sakthi x Arka Abha and LE 79-5 x LE 373. Among these hybrids Arka Alok x PKM 1 showed significance for fruit yield, individual fruit weight, size of fruit, plant height, leaves per plant spread of the plant and also showed resistance to mosaic, fruit rot and fruit borer. The hybrid Arka Abha x PKM 1 showed significance for fruits per plant, fruit yield per plant, plant height, leaves per plant and spread of the plant. The combinations Sakthi x Arka Alok and Sakthi x Arka Abha showed high s.c.a. and heterosis for fruit weight, fruits per plant and fruit size and also high heterosis for fruit yield per plant. LE 79-5 x LE 373 exhibited high s.c.a. for fruit yield per plant and heterosis for fruit number and fruit yield. Therefore, these hybrids can be utilized for further crop improvement programme.ThesisItem Open 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 VThe 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.ThesisItem Open Access Gametocidal properties of certain chemical in rice(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 1996) Manjula, M; KAU; Ibrahim, K KA pot culture experiment was conducted at Instructional Farm, College of Horticulture, Vellanikkara, Kerala during summer 1995 to study the gametocidal properties of three chemicals viz., ethrel, maleic hydrazide and streptomycin in two varities of rice. The study aimed at induction of variable levles of male sterility using these chemicals, with minimum interactions with other factors viz., stage, concentration and variety and also without adversely affecting spikelet fertility and plant growth characters like panicle exsertion. The chemicals were sprayed at concentrations of 4000, 6000 and 8000 ppm at stage-1 (spiketet differentiation stage) or stage-2 (pollen mother cell formation stage) in Annapurna, a short duration variety and Athira, a medium duration variety. The pollen spikelet sterility were observed in main and subsequent panicles. Pollen sterility differed with chemical, concentration and variety in main panicle and with all factors including stage of application in subsequent panicles. The effect of a chemical interacted significantly for pollen sterility with other factors viz., concentration and variety in main panicle and concentration and stage in subsequent panicles. The treatments involving maleic hydrazide were the most effective inducing pollen sterility upto 99.3 per cent. Ethrel was moderately effective in inducing maximum pollen sterility of 48.9 per cent in Annapurna with 4000 ppm at stage-1. Streptomycin failed to induce pollen sterility irrespective of stages and concentrations. Maleic hydrazide produced male sterility in a dose dependent manner. It caused more sterility in main panicle in Annapurna but in susequent panicles in Athira. Pollen sterility to a large extent was due to deformed anthers containing low or no pollen production in MH treated plants. High pollen sterility induced by the chemical was aasociated with high sterility of spikelets (upto 99.7%). Besides, it adversely affected plant height, panicle emergence and panicle exsertion. MH at 4000 ppm appeared to be the most ideal treatment for population improvement programme considering its effects on not only pollen sterility but also other important characters including spikelet sterility. On the other hand, in hybrid rice programme that require almost complete male sterility, MH at 8000 ppm at stage-1 or at 6000 ppm at stage-2 appeared to be more suitable.
