Taro is an important crop in parts of the world, especially in the Pacific Islands. Like all plants, it is also susceptible to virus infections that could result in diseases, which negatively affects the source of food and trade revenue. Understanding the biology of taro viruses could improve current knowledge regarding the relationship between viruses and taro, thus allowing for a better approach towards the management of the diseases that are associated with them. By compiling and discussing the research on taro and its four major viruses (Dasheen mosaic virus, Taro bacilliform virus, Colocasia bobone disease virus, and Taro vein chlorosis virus) and a relatively new one (Taro bacilliform CH virus), this paper explores the details of each virus by examining their characteristics and highlighting information that could be used to mitigate taro infections and disease management.

Begomovirus has become a potential threat to the agriculture sector. It causes significant losses to several economically important crops. Given this considerable loss, the development of tools to study viral genomes and function is needed. Infectious clones approaches and applications have allowed the direct exploitation of virus genomes. Infectious clones of DNA viruses are the critical instrument for functional characterization of the notable and newly discovered virus. Understanding of structure and composition of viruses has contributed to the evolution of molecular plant pathology. Therefore, this review provides extensive guidelines on the strategy to construct infectious clones of Begomovirus. Also, this technique’s impacts and benefits in controlling and understanding the Begomovirus infection will be discussed.

Hoya R.Br. is a genus of ornamental plants with an attractive flower shape and unique scents. Anatomical studies are required to understand their structure that produces, and stores, the metabolites released by plants. The present study was conducted to determine the type and position of floral glands in three Hoya species: Hoya cagayanensis C.M Burton, Hoya lacunosa Blume, and Hoya coriacea Blume. The investigations were carried out using light microscopy (LM), scanning electron microscopy (SEM), and histochemical staining tests. Secondary nectaries were present in the corona lobe portion, while simple trichomes (unicellular) were found in the petals’ adaxial epidermis of all the studied species. Conical trichomes were found in H. cagayanensis, cylindrical trichomes in H. lacunosa, and falcate trichomes in H. coriacea. In the cells of secondary nectaries, this study revealed proteins, lipids, polysaccharides, and starch grains; however, only lipids and proteins were observed in simple trichomes. Secondary nectaries and simple trichomes were described for the first time in all the studied species, contributing new insight into Hoya’s anatomical and micromorphological floral glands.

In Malaysia, peppers have a significant role in agricultural trade as they are planted on over 3,000 ha of land, generating around US$ 46 million annually (D.O.A. 2017). In May 2019, disease sympto...

In the tropics and subtropics, various ornamental plants have been cultivated for landscape decorations. The Bougainvillea species, a perennial flowering plant, is widely grown throughout Malaysia. Its beautiful floral colours made it a popular plant in the country, even dubbed the symbol flower for Ipoh, one of the major cities in Malaysia. In November 2018, disease symptoms including foliar chlorosis, vein-banding, and mottling were observed on bougainvillea plants growing in several residential colleges in the National University of Malaysia. Suspecting infection by a virus, samples from six different symptomatic plants were examined by transmission electron microscopy (TEM) after negative staining by uranyl acetate (Baranwal et al. 2010). Typical bacilliform virions of 120-150 nm x 25-35 nm in length were found randomly scattered in the cytoplasm of the phloem tissue of leaf veins of all the samples from the six plants. To confirm the identity of the virus, viral DNA was extracted from leaves of twelv...

Bacterial leaf streak (BLS) caused by bacterium Xanthomonas oryzae pv. oryzicola (Xoc) is one of the most prominent rice diseases. BLS causes a significant reduction in paddy yields. However, there are limited studies and a lack of information regarding the mechanisms and cells affected on leaf tissues severed from this disease. Therefore, in this study, sensitive paddy variety IR24 was inoculated against BLS, and the pathogen colonised mesophyll cells and some bundle sheath cells. The infection spreads rapidly towards the base and apex of the leaf, but rather slowly to the left and right sides of the leaf veins. Another experiment was performed to unravel anatomical characteristics in sensitive paddy varieties (TN1, IR24, IR5) and resistant paddy varieties (IR26, Dular, IR36) against BLS. Susceptible paddy varieties have less thick midrib and leaf lamina, a high number of bundle sheath cells at primary vascular tissue (midrib), one layer of sclerenchyma cells at the secondary vein, and more than two metaxylems at the primary vein. Resistant paddy varieties, on the other hand, consist of a relatively thickened midrib and leaf lamina, fewer bundle sheath cells at the primary vascular tissue (midrib), more than one sclerenchyma layers at the secondary vein, and two metaxylems at the primary vein. This study contributes new knowledge in identifying the level of infection in paddy fields, and helps breeders in producing resistant paddies to this disease.