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Browsing Theses by Subject "Agricultural Biochemistry"

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    ThesisItemOpen Access
    Decomposability and Mineralisation Pattern of Coirpith in Latosols
    (Department of soil science and agricultural chemistry, College of horticulture,Vellanikara, 1993) Jothimani, S; KAU; Sushama, P K
    An investigation on the decomposability and mineralisation pattern of coirpith in latosols was carried out at the Department of Soil Science and Agricultural Chemistry, College of Horticulture, Vellanikkara, Thrissur during the period 1990 – 92. The experimental soil was laterite and the various treatments for mixing with the soil comprised of coirpith raw as well as enriched with Pleurotussajorcaju, urea and rockphosphate. The individual and different combinations of these factors were compared with Glyricidiamaculata applied to the soil. The study involved and incubation experiment and field trial. In order to measure the decomposition of coirpith compared to glyricidia in laterite soil under incubation, the measurement of CO2 evolution was carried our for a period of six months. A field experiment was conducted to study the influence of additives such as microbe, rockphosphate and urea on decomposition of coirpith. The fertility value of the resulting compost was evaluated by estimating pH, organic carbon, cation exchange capacity, available N, P and K of the soil at monthly intervals for a period of one year. Humic and fulvic acid contents of soil were estimated one year after the incorporation of treatments in the soil. The mineralisation of lignin rich coirpith was found to be accelerated due to the addition of both Pleurotussajorcaju and mineral N in the form of urea. With all the treatments and treatment combinations the rate of Co2 evolution was found to be the highest at the second day of incubation and appreciable changes were associated in general, up to 48th day of incubation. There after it declined and attained almost equilibrium values at the end of sixth month. Due to the incorporation of either the glyricidia or coirpith with the without the various adjunctants a steady state of acidic reaction was maintained in the soil. Even with the application of coirpith alone, there was only slight reduction in soil pH. There was not much variation between glyricidia and coirpith treatments on organic carbon content of the soil. Both the microbe and urea enrichment to coirpith reduced the organic carbon content due to faster decomposition whereas it was slightly improved by the addition of rockphosphate. Though there was hike in the CEC of the soil immediately after the addition of organic materials, the values tended to decrease at the end. There was progressive increase in the available nitrogen contents of the soil with the advancement of period of incubation due to the mineralization of glyricidia and coirpith. Among the coirpith treatments, the maximum value was noticed when coirpith was enriched with all the additives. The addition of organic materials also favoured an improvement in available P content of the soil. The contents of available P in the soil increased when coirpith was incorporated with urea. Regarding the release of available K from the soil, the glyricidia incorporation always showed a better performance as compared to coirpith treatments. The microbial inoculation seemed to decrease the humic and fulvic acid contents from their original levels due to decrease in organic carbon content of the soil. This was noticed one year after incorporation of treatments into the latosols.
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    ThesisItemOpen Access
    Morpho-molecular characterization of cluster bean(cyamopsis tetragonoloba(L.) taub.)
    (College of Agriculture, Vellayani, 2011) Divya, Lekshmanan; KAU; Abdul, Vahab M
    The present study entitled “ Morpho- molecular characterization of cluster bean [Cyamopsis tetragonoloba (L.) Taub.] was conducted at the Departments of Olericulture and Plant Biotechnology, College of Agriculture, Vellayani during 2010-2011. The objectives were to assess the genetic diversity of the cluster bean germplasm both at morphological and molecular level. One hundred genotypes of cluster bean were evaluated for yield and yield related characters in randomised block design with two replications. Analysis of variance revealed significant differences for fourteen out of sixteen characters studied. The significant characters include plant height, primary branches, internodal length, pod clusters per plant, pods per plant, pods per cluster, yield per plant, pod weight, pod length, pod girth, seeds per pod, 100 seed weight, protein content and shelf life High vales of PCV and GCV were recorded for primary branches followed by pod weight, yield per plant, pods per cluster and pod clusters per plant. High heritability coupled with high genetic gain was observed for primary branches, clusters per plant, pods per cluster, yield, pod weight, pod length and pod girth. Vegetable pod yield showed high positive genotypic correlation with the characters pod weight, pod length, pod girth, pods per plant, plant height, pod clusters per plant and 100 seed weight. Plant height, pods per plant and pod length showed positive direct effect on yield. In genetic divergence analysis 100 accessions were grouped into five clusters. Maximum number of genotypes were in cluster I and most of the genotypes in this cluster were low yielders. The highest yielders stood in the fifth cluster. On the basis of selection index CT 72 (a local collection from Tamil Nadu) recorded highest index value followed by Pusa Naubahar and CT 81 (a local collection from Tamil Nadu). These were identified as genetically superior. In molecular characterization, 12 accessions were selected from different clusters formed by morphological analysis. Out of thirty primers screened, eleven primers viz., OPA-14, E-14, E-15, E-1, E-3, OPA-9, E-4, OPB-8, OPP-16, E-12, E-6 were selected for DNA amplification. They generated 62 scorable bands out of which 41 were polymorphic and 21 monomorphic showing 66.12 per cent polymorphism. Resulted amplified products ranged in the size of 100- 1200 bp. The similarity coefficient values ranged from 0.375 to 0.894. At 0.73 per cent similarity level, 12 accessions were divided into 5 clusters. CT 22 constituted first cluster, CT 41 and CT 60 in second, CT 12 and CT 17 in third, CT 8 and CT 27 were included in fourth and CT 3, CT 79, CT 38 and CT 81 and CT 72 in fifth. CT 79 and CT 38 showed maximum relatedness with each other. The accessions CT 17 and CT 12 and CT 38, CT 81 and CT 72 were closely placed in dendrograms generated by both morphological and molecular analysis. Clustering of other accessions used in the molecular study was not in full agreement with the morphological clustering pattern. This may be due to the influence of environment in modifying the expression of characters. The present study using morphological characters and RAPD markers have shown considerable variability in cluster bean genotypes. Two local accessions viz., CT 72 (non branching type) and CT 81 (branching type) were identified as superior for yield and quality. These genotypes may be progressed to further confirmatory studies, CYT and multilocational trials. The study also revealed the reliability of molecular techniques compared to morphological methods in the characterization of cluster bean. Further studies on morphological and agronomic traits and analysis of accessions with more number of primers and reliable DNA markers may be helpful in getting accurate result.