Sterols and polysaccharides of green alga Caulerpa lentillifera grown under laboratory conditions and in mariculture and polysaccharides of green alga C. sertularioides grown under natural conditions were studied. The sterol fraction consisted of C 27 -C 29 steroidal alcohols with Δ 5 -unsaturation in the steroid core regardless of the growth conditions. The dominant (79.9%) steroid component of the sterol fraction was clionasterol. The water-soluble fraction of C. lentillifera grown under laboratory conditions was a mixture of 1,4-α-and 1,3-β-D-glucans and protein. The same fraction isolated from C. lentillifera grown in mariculture contained only protein. The water-soluble fraction of C. sertularioides grown under natural conditions contained 1,3;1,6-β-D-galactan sulfated at C2. The principal components of the base-soluble polysaccharide fractions from all algae samples were 1,4-α-D-glucans.

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In addition to traditional methods, advanced biotechnologies, especially CRISPR/Cas9-mediated genome editing, have emerged as effective tools for improving important agronomic traits in rice. However, the critical step for utilizing these systems is to develope an effective system for rice transformation and regeneration. This study was performed to establish procedures for Agrobacterium-mediated transformation and regeneration of rice cultivar Khang Dan 18 (KD18) – a popular indica variety in the North of Vietnam. The tissue cultures procedure with optimized medium compositions showed high frequencies of callus induction and shoot regeneration, at 94.7% and 45.3% respectively. We found that 30 mg/L of hygromycin was an effective concentration for transgenic KD18 selection. Light-yellow friable calli were used as the starting material for transformation mediated by A. tumefaciens strain AGL1 harbouring pHUE411 vector containing gus intron and hygromycin resistance gene (hptII). Important factors related to transformation procedure had been optimized in this study. The high transformation frequency (12.8%) was achieved by using the optimized procedure for KD18 cultivar. In which, bacterial density (OD600), infection time and co-cultivation period were performed at 0.1, 20 minutes and 3 days, respectively. PCR analysis using specific primers and the histological GUS staining demonstrated the presence of hptII and gus genes in transgenic rice lines. This result provides a potential protocol to transfer genes of interest into KD18 as well as other indica rice cultivars.

In this study, morphogenesis and anatomy of adventitious roots and hairy roots of Ngoc Linh ginseng (Panax vietnamensis Ha et Grushv.) were compared. Adventitious roots were derived from four different samples (leaf, petiole, root and callus) in vitro cultured on medium SH supplemented with 5 mg/L IBA. Hairy roots were derived from callus infected with Agrobacterium rhizogenes strain ATCC 15834. The results showed that there were significant differences in morphogenesis and anatomy, the pathway of secondary roots formation, culture medium between adventitous roots and hairy roots. The hairy roots strongly grew and branched on the free-plant growth regulator medium. The secondary root of the hairy root was formed in two pathways: (1) The secondary root formation began at the vesicles system of main root; (2) The secondary root formation was independent of the vesicles system of main root; it kept developing in length and connected to the vesicles system of main root. On the other hand, growing adventitous roots only grew on the environment with exogenous auxin supplementation; also their branching ability were low. The secondary root formation of the adventitous root was started at the vesicles of the main roots and there was only one secondary root that was formed at an location of adventitous root. The results that obtained in this study will be the reference to identify two types of root.