1. KAUTIR (Kerala Agricultural University Theses Information and Retrieval)
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Item Investigaiton on extraction of starch from cassava (Manihot esculenta Crantz) stem(Department of Plant Biotechnology, College of Agriculture, Vellayani, 2019) Hasmi Sulain, K K; Saravanan RajuThe study entitled “Investigation on extraction of starch from cassava (Manihot esculenta Crantz) stem” was carried out at the Division of Crop Utilization, ICAR- Central Tuber Crops Research Institute, Sreekariyam, Thiruvananthapuram during the year 2018- 2019. Cassava stem starch is an ideal source to increase the availability of starch without using additional land, water and fertilizers. Hence understanding the structural and functional properties of stem starch is an important aspect before substituting with root starch because there is a lack of knowledge of starch properties when compared to root starch. In this study, starch from cassava stem were extracted by four different methods such as extraction using water, extraction using chemicals such as Sodium hydroxide and sodium meta bi sulphate, microwave assisted extraction and ultra sound assisted extraction. The cassava genotypes suitable for extraction of starch from stem and functional properties of this stem starches were investigated. In the present study, the physiological characters of such as stem length, stem girth, stem fresh weight and stem dry weight and stem moisture content were measured in the selected genotypes of cassava. The results showed that stem length of cassava ranges from 100-300cm and the stem girth ranges from 2.5-8cm. The fresh weight and dry weight of cassava stem ranges from 0.4-2Kg and 0.2-0.7Kg respectively.The moisture content of cassava stem varies from 62-72% but the moisture content was less than 2% in all stem starches. The swelling volume was same for all the stem starches (15ml) and the solubility was less than 10%. Starches with high swelling volume and solubility and low gelatinization temperature has various applications in food industry. The water binding capacity varied from 46.09% to 77.50% for different cassava stem starches. The in vitro starch digestibility of cassava stem starches ranges from 0.1-0.3 g/g. The starch yield from cassava stem ranges from 17% to 30% and the starch content was found to be 38-55% on dry weight basis. The starch yield was found to be maximum for H-1687 and minimum for Quintal. 64 The peroxidase content in cassava stem starches ranges from 0.05-0.13ng/mg and the poly phenol oxidase content ranges from 10-30mg/g. Both this enzyme content was found to be lowest in Black Thailand and maximum for Sree Swarna and Quintal. It was found that extraction using ultra sound and micro wave assistance could increase the extractability of starch from cassava stem and the genotypes H1687 and H-226 was found to be high starch yielding varieties and thus it could be used for the extraction of starch from cassava stem. Cassava stem contain more than 30% of starch (dry mass), hence the wasted cassava stem starch can be utilized for both food and non-food applications. More over cassava can increase both food and fuel resources where cassava roots are for food and stems for fuel and even reduce poverty without using additional land.Item Genetic diversity analysis of indigenous rice varieties in Kerala using molecular markers(Department of Plant Pathology, College of Agriculture, Vellayani, 2019) Ajith, M K; Jayalekshmy, V GThe present study entitled “Genetic diversity analysis of indigenous rice varieties in Kerala using molecular markers “was carried out in the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, Thiruvananthapuram during 2017-2018. The study was conducted with the objective to analyze the genetic diversity of traditional rice varieties in four agro climatic zones of Kerala using RAPD and SSR markers. Five varieties were collected from the each agro climatic zones viz., hill areas of Wayanad, rice growing tract of Palakkad, saline soils of Pokkali and Kuttanad soils. The DNA was isolated and RAPD analysis with 10 Operon primers and SSR analysis was done with ten RM primers. In the RAPD analysis the ten operon primers produced 88 amplicons with an average polymorphism 82%. Resolving power OPC-07 (15.4) had the highest value but its Polymorphism Information Content and Effective Multiplication Ratio (EMR) were considerably low. Considering all the three parameters together primer OPF-06 is found to be the best RAPD primer with considerably high polymorphism information content, resolving power and effective multiplication ratio. The dendrogram constructed based on the RAPD scoring showed that varieties Pokkali and VTL-2 had maximum similarity. These two were from Pokkali rice tract. PTB 12 from Pattambi was found to be unique and it clustered with others only at 30% similarity.The clustering of the genotypes did not show any correlation with the geographic origin. ABL 12 and VTL- 2 showed 70 % similarity but those two were from Wayanad Hills and Pokkali tract respectively. Vellakuttadan from Moncombu clustered with PTB 2 from pattambi at 72% a similarity. Kochuvith and Vellakuttadan from Moncombu clustered at 67 %. All the SSR markers produced two alleles except RM 210 and RM 204 which produced four alleles and one allele respectively. All the alleles of all the markers were polymorphic except that of primer RM204. The polymorphism information content of the SSR primers used in the study ranged from 0 to 0.88. In this study the highest PIC value of 0.88 was reported by RM 210 followed by RM 567 (0.85). The resolving power and EMR was also highest for RM 210. The dendrogram constructed based on the SSR markers could give a clustering of genotypes more correlated with the geographic origin. Genotypes Kochuvithu and Vellakuttadan showed 100 % similarity both where from Kuttanad. But Karavalakochuvith, T.virippu, and PTB 2 also showed 100% similarity but these three were from Moncompu, Pokkali and Palakkad respectively. At around 90 % similarity AMB 14, AMB 22 from Wayanad, Pokkali andVTL-2 from Pokkali, PTB 13 and PTB 8 from Palakkad clustered showing more correlation to the Geographic origin. SSR markers being sequence specific and flanking the repeat sequence which has more role in evolution, are more reliable in predicting the Genetic diversity based on origin. Since both of them could not give a clear-cut clustering based on geographic origin an analysis using both the markers together was done. This gave a better picture of the clustering as it involved more number of variables. But here also the varieties from Wayanad A1 to A5 were scattered in different clusters. Only A 14 and A15 (AMB 14 and AMB 5) clustered at 60 percentage similarity. The accessions from moncompu (A6-A10) clustered at around 50 % similarity. In the accession from Pokkali tract (A11-A15) only T.virippu to VTL-2 clustered at 78 % similarity. Accession from central zone Pattambi (A16-A20) was scattered into different clusters. PTB 12 was unique from other accessions. This molecular diversity analysis of the traditional rice genotypes from four different agro climatic zones could find that the maximum similarity was 78% and that too only between two accessions. The diversity among the genotypes was 64% as all the genotypes clustered at 36% similarity. The clustering of the genotypes did not show any correlation with the geographic origin. Exchange of varieties between the farmers and some amount of natural crossing would have led to the mixture of populations of rice genotypes in different agro climatic zones.Item Marker assisted selection for bacterial leaf blight resistance genes in the backcross progenies of prathyasa variety of rice(oryza sativa L)(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2019) Govinda Rai Sarma; Jayalekshmy, V G