OPTIMIZATION OF CRYOPRESERVATION FOR STERCULIA CORDATA ZYGOTIC EMBRYOS USING VITRIFICATION TECHNIQUES

Vitrification is a physical process by which a concentrated aqueous solution solidifies into stable amorphous glass at a sufficiently low temperature. This process eliminates the potentially damaging effect of intra- and extracellular crystallization in cryopreservation of plants and animal cells. Sterculia cordata embryos were cryopreserved using a vitrification technique. The embryos were precultured for three days on MS media supplemented with sucrose (0.35, 0.55 and 0.75 M) and treated with loading solution (LS) and plant vitification solution 2 (PVS2) for one to three hours before storing in liquid nitrogen. Their germination was assessed before and after cryopreservation. Multiple logistic regression analysis showed that the sucrose pregrowth medium, LS and PVS2 pretreatments were not detrimental to the germination of embryos. However, sucrose and LS pretreatments alone were not sufficient for successful cryopreservation in contrast to the high germination (≥ 80%) achieved with PVS2 treatment. Vitrifikasi merupakan proses mengubah larutan akues pekat menjadi kaca amorfus yang stabil pada suhu rendah. Proses ini mengelak kerosakan yang terjadi akibat pengkristalan intrasel dan luar sel semasa krioawetan sel tumbuhan dan haiwan. Embrio Sterculia cordata dikrioawet menggunakan teknik vitrifikasi. Embrio tersebut diprakultur selama tiga hari pada medium MS yang ditambah sukros (0.35, 0.55 dan 0.75 M) dan dirawat dengan larutan muatan (LS) serta larutan vitrifikasi tumbuhan (PVS2) selama satu hingga tiga jam sebelum disimpan dalam nitrogen cecair. Percambahan embrio dinilai sebelum dan selepas krioawetan. Analisis regresi logistik berganda menunjukkan bahawa prarawatan media sukros, LS dan LVS2 tidak memudaratkan percambahan embrio. Bagaimanapun, prarawatan sukros serta LS tidak menunjukkan keputusan krioawetan yang baik berbanding dengan rawatan PVS2 yang menghasilkan percambahan tinggi melebihi 80%.