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1997 - 19982
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End date: 1999 × Start date: 1997 × Thesis Type: Ph.D. ×
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    ThesisItemOpen Access
    Genetic analysis of certain clones, hybrids and inbreds in cocoa
    (Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 1998) Rose Mary Francies, KAU; Achamma Oommen
    Genetic studies in cocoa (Theobroma cacao L.) using various population viz., clones, biclonal crosses, biclonal pair crosses and inbreds were undertaken in College of Horticulture, Kerala Agricultural University, Thrissur, during 1994-97. The study assessed variability, association of yield attributes and relative importance of these attributes for yield variation using multiple regression and path analysis. Selection indices, inbreeding depression and limits to genetic diversity for heterosis were also worked out. Wide spectrum of variability existed in the populations studied. The highest variability was observed in yield of dry beans/tree and precocity of bearing (pods/tree - 5 years from planting), whereas, traits pod width and bean width showed low variability. Clones GI 10.2, S 27.16, GI 14.17 of Clonal base population, hybrids H'8 (GI 5.9 x GII 23.3), H2 (M 13.12 x GI 5.9) of Series IV biclonal crosses and hybrids H4 (M 16.9 x GII 19:5), H3 (M 16.9 x GII 20.4) of Series 11 biclonal crosses, exhibited superior yield - performance. Yield however, recorded only moderate heritability and therefore moderate expected genetic advance. Strong correlation was observed for yield with pod weight, dry weight/bean and efficiency index but not with precocity of bearing, chlorophyll contents and net photosynthesis rate. Multiple regression and path analysis revealed the importance of dry weight/bean, bean size and efficiency index in determining the yield in cocoa. High correlation exhibited by many traits was due to indirect effects. Selection index for yield, based on the above traits viz., dry weight/bean, bean length, bean thickness and efficiency index recorded a relative efficiency of 150.35 per cent over direct selection. Inbreeding depression was observed for growth traits. The rate of depression was more in the second inbred generation as compared to that in the first inbred generation. Number of hybrids exhibiting relative heterosis in desirable direction ranged from one (eg. pod width, bean length and thickness) to seventeen (number of beans/pod). Considerable genetic divergence among clonal genotypes was evident. Results indicated that the chances for occurrence of a high frequency of heterotic crosses and high values of heterosis are more, when the parental divergence is moderate.
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    ThesisItemOpen Access
    Evaluation of growth in Penaeus Monodon Fabricius by incorporation of selected nonhormonal growth promoters in the diet
    (Department of Aquaculture, College of Fisheries,Panangad, 1997) Vinodh, M P; KAU; Susheela, Jose
    The effect of three growth promoters viz. Chitin, chitosan and glucosamine each at three levels (0.25, 0.5 and 1g per 100g diet) were evaluated in P.monodon early juvenile for a period of 70 days. The three growth promoters at three level were tested with 3 replicates for each treatment. The growth promoters were incorporated into a soyflour clam meal based practical diet containing 40% protein and fed to the shrimps adlibitum. The results showed that the overall growth was not affected by dietary inclusion of chitin though the growth rate at 0.25g chitin per 100g diet was comparatively better than that of the control diet. Chitin does not seem to have any effect on specific growth rate of the juveniles although incorporation at 0.25g/100g diet improved the food conversion of the animal significantly over the control. Percentage survival values were also not significant at any level of incorporation. It does not seem to improve protein efficiency ratio and productive protein value too. Incorporation of chitosan at 0.25 and 0.5g/100g diet significantly improved the weight gain, specific growth rate, food conversion ratio, protein efficiency ratio and productive protein value. However inclusion of chitosan at 1g/100g diet did not have any effect on growth though it significantly improved food conversion ratio, protein efficiency ratio and productive protein value. None of these treatments had any effect on survival of the animal. Incorporation of glucosamine into the diet at 0.25g/100g diet was found to be the most efficient amongst the different treatments as evidenced by various growth parameters. It was significantly different from all other treatments in terms of growth, productive protein value and protein efficiency ratio. However it was not significantly different from glucosamine incorporation at 0.5g/100g diet in terms of specific growth rate and food conversion ratio. Enhancement of glucosamine level to 1g/100g diet was found to give poor result compared to the control. The survival rate of shrimps were not significantly different among the treatments. Hence in the present study, glucosamine was found to be superior to chitin and chitosan as a growth promoter and the optimum level was identified as 0.25g/100g diet for P.monodon juveniles