Santhoshkumar, A VMobin, K MKAU2020-11-042020-11-042014173422https://krishikosh.egranth.ac.in/handle/1/5810154303PGThe research work entitled “Enhancement of storage life of synthetic seeds of cocoa (Theobroma cacao L.) through germination inhibition, desiccation and low temperature treatments” was carried out at Plant Tissue Culture Laboratory, College of Forestry, Vellanikkara, during the period 2012-2014. The objectives of the research work were to enhance the longevity of synthetic cocoa seeds through the application of different concentrations of chemical inhibitors/osmotica, desiccation at different RH for varying durations and low temperature treatment under refrigerated conditions and hence to prepare a storage protocol for synthetic cocoa seed. Synthetic seeds using calcium alginate encapsulation technique were prepared from embryonic axes of cocoa containing ¼ cotyledon. The experiments revealed that, presence of different chemical inhibitors in storage medium significantly influenced radicle emergence of synthetic seeds of cocoa. ABA at 10 -3 M and 10 -4 M level did not inhibit the radicle emergence of synthetic cocoa seeds and seed mortality were observed by 20 th and 25 th day respectively in both the concentrations. All synthetic seeds stored in higher concentrations of coumarin (10 -2 M) and CCC (1 M) containing ½ MS basal medium were found mortal on 10 th and 15 th day respectively. The presence of lower levels of coumarin (10 -3 M) or CCC (10 -1 M) in the storage medium helped to extend the longevity of synthetic cocoa seeds for 60 days without complete loss of viability. The combination of 10 -3 M coumarin and 10 -1 M CCC in the storage medium extended the longevity of the cultures for 67 days. Low levels of osmotica in the storage medium (100 mM sorbitol and 5% PEG) did not inhibit the germination of synthetic cocoa seeds whereas, higher levels (500 mM sorbitol and 15% PEG) had a negative influence on the cultures. Among the different osmotic treatments, 250 mM sorbitol fortified medium was found to be best as it could arrest radicle emergence in 42.97 % cultures. Longevity of more than 40 days were observed for synthetic seeds subjected to desiccation treatment: 85.3% RH (36 hours), 78.6% RH (24 hours and 36 hours) and 46.6% RH (18 hours and 24 hours). A longevity of only 15 days were obtained for synthetic seeds subjected to low temperature treatment in refrigerated conditions at 4ºC. The synthetic seeds stored in 10 M CCC and 10 -3 M coumarin added storage medium, when transferred to ½ MS basal medium after 60 days showed a maximum storage life of 98 days and 92 days respectively. The study was able to enhance the storage life of synthetic cocoa seeds by 9 days compared to a previous study by Shiran, (2012). Based on the results of the experiments conducted, a protocol for short and medium term storage of cocoa seed was developed.EnglishThesis