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<abstract> <p>Callogenesis and embryogenesis are integral parts of many tissue culture procedures for genetic manipulation in rice. However, the efficiency of both processes is largely dependent on the media constituent especially the plant growth regulators (PGRs) due to the genotype-dependent nature of <italic>in vitro</italic> culture protocols. Therefore, this study investigates the effect of two PGRs; 2, 4-dichlorophenoxyacetic acid (2, 4-D) and kinetin (Kin) on callus growth and somatic embryogenesis of an important Malaysian rice cultivar (<italic>Oryza sativa</italic> L. cv. MARDI Siraj 297). Mature rice seeds explants were inoculated in Murashige &amp; Skoog (MS) medium supplemented with different combinations of 2, 4-D (0 to 3.5 mg/L) and Kin (0 to 0.5 mg/L) to induce callogenesis. Parameters for callus growth such as fresh weight (FW), callus induction frequency (CIF), embryogenic callus frequency (ECF), regeneration frequency (RF), number of plantlets per callus (PPC), callus texture and callus color were observed after 35 days of inoculation. The results show that the maximum callus growth was achieved in MS medium supplemented with combination of 2.0 mg/L 2, 4-D and 0.2 mg/L Kin, represented by the highest FW (211 mg), CIF (95%), ECF (90%), RF (100%) and PPC (22 plantlets); along with friable callus texture. Low concentration of 2, 4-D (0 to 0.5 mg/L) in the presence or absence of Kin promotes root growth instead of callus, while high concentrations (above 3.0 mg/L) retard the callus formation. The embryogenic calli from this optimized PGRs combination were successfully formed shoots in MS medium supplemented with 2 mg/L BAP and 1 mg/L NAA, followed by rooting in PGRs-free MS medium. This finding provides an efficient protocol for callogenesis and somatic embryogenesis of MARDI Siraj 297, since this is the first published report regarding somatic embryogenesis induction of this cultivar.</p> </abstract>

The vanilla orchid is one of the high value and most favorite culinary crops in the world. The aroma or flavor of vanillin make the plant as an important economic crop in the food and beverage industry. Nevertheless, the production of vanilla is hindering by two main factors which are the propagation and diseases. Devastating disease has cause losses in bean production as it can infect the vines at any times and at all stages of the plant growth. As a result, it is cause the losses of quality and quantity of pod production. Some of important diseases associated with fungal and viral on vanilla such as Fusarium root and stem rot, anthracnose, black rot, sclerotium rot, rust, mosaic and stem necrosis are discussed in this review paper.

Drought is a major abiotic constraint on rice (Oryza sativa L.) production in Malaysia. Malaysian Agricultural Research and Development Institute (MARDI) has released more than 50 indica rice genotypes so far. However, little has been studied about their drought tolerance. The study aimed to evaluate the germination and early seedling growth performances of 15 rice genotypes under polyethylene glycol (PEG) 6000-induced drought stresses. Four osmotic potentials of PEG 6000 (0, -0.3, -0.6, -0.9 MPa) were used in the study denoted as control, low, moderate and severe stresses respectively. Data on seed germination percentage, germination index, germination energy, germination rate, seedling height, seedling vigor I and II, fresh and dry weight of seedlings were measured. Studied parameters varied greatly among genotypes with different osmotic stresses. The findings suggested most of the rice genotypes showed an apparent reduction in germination and growth traits, while MR211 showed less reduction under all of the stresses. The Multivariate clustering grouped genotypes into five different clusters, where cluster V (MR220, MR269, MR253, MR297, MR303 and MR284) incorporated six genotypes showed better germination and growth under different osmotic potentials, followed by cluster IV (MR211 and MR307). Cluster II incorporated one genotype MARDI WARNA98 which had minimal germination and growth attributes. Principal component analysis (PCA) was performed to identify the maximum contributing variables for diversity, revealed maximum variation by first two components (81.8% and 7.7%) respectively. Therefore, PEG 6000 can be used as an efficient tool for discrimination and identification of drought tolerance in rice.