George, T ESheela K BKAU2019-05-152019-05-151998171388http://krishikosh.egranth.ac.in/handle/1/5810103167PhDInvestigation on 'Genetic improvement of bird pepper (Capsicum frutescens L.) by selection' was undertaken at the Department of Olericulture, Kerala Agricultural University, Vellanikkara, during 1993-97. The main objectives of the study were estimation of variability and genetic diversity, study of floral biology, improvement of the selected lines through single plant and mass selection methods, analysis of biochemical constituents and morphological and biochemical characterization of bird pepper. Eighty six accessions of bird pepper collected from different locations were characterized based on IBPGR descriptor list for Capsicum. Wide variability was observed for morphological and biometric characters. Twenty five selected accessions were further evaluated for two seasons for quantitative characters. Variability, heritability, genetic diversity and association of various characters was studied. e Accessions CF 5, CF 10, CF 19, CF 23, CF 36 and CF 103 having consistent high yield and better fruit size were advanced by single plant and mass selection for three generations. Single plant selection was more effective in improving fruit size and yield. Genetic gain was realised for fruit characters and yield under both the methods of selection. The peak period of anthesis and anther dehiscence in bird pepper was between 9 am to lOam. Stigma was receptive 24 hours before and after anthesis. Significant variation was observed among 25 selected accessions for ascorbic acid, capsaicin, oleoresin and carotenoid content. The highest content of ascorbic acid, capsaicin, oleoresin and carotenoids in mature fruits were registered in accessions CF 15 (77.6 mg 100 g-1), CF 5 (1.57%), CF 23 (14.25%) and CF 138 (0.5%) respectively. These constituents registered a significant increase with ripening. A comparison of C. frutescens and C. annuum accessions with respect to fatty acid, nucleic acid and protein content, enzyme activities and flavour components were made. Biochemical characterization of C. frutescens was done by studying the electrophoretic pattern of the enzyme peroxidase. Accession CF 19 with high yield (185.38 g per plant) and better fruit size (24.26 cm2) and CF 5 and CF 10 with high capsaicin content (1.57 and 1.41 % respectively) were identified for further improvement.ennullThesis