Developing Blast Disease Resistance of Jasmine Rice by Phenotypic-Genotypic Simultaneous Selection

Breeding for resistant varieties of rice is known to be the most preferable way of controlling blast disease (Pyricularia oryzae). Identification and introduction of resistance genes into elite rice lines has become possible by the use of molecular markers. KD2-1 line is an isogenic line of KDML105 carrying four resistance genes on chromosome 2, 3, 8 and 12 from IR64 variety. The objective of this research was to transfer blast disease resistant genes from KD2-1 line into RD15 variety by using phenotypic and genotypic selections by the aid of markers. In this study, the four resistance genes were transferred from KD2-1 rice line into a blast susceptible rice variety, RD15. The study resulted in the breeding of four elite rice lines with four resistance genes by phenotypic and foreground selection. The genome-wide SSR marker analysis of the lines showed more than 86.5% background genome recovery of RD15. Pathogenicity assays of the four selected lines exhibited a resistant reaction to all 13 isolates, with agronomic and yield performance, and cooking and eating quality characteristics similar to that of RD15. The phenotypic-genotypic (foreground and background) simultaneous selection strategy is very useful to introduce multiple resistance genes in rice as it is a fast and economical way for identification of anticipated recombinant lines with desired genes

Potential usage of biosynthesized zinc oxide nanoparticles from mangosteen peel ethanol extract to inhibit Xanthomonas oryzae and promote rice growth

In recent decades, the biosynthesis of nanoparticles using biological agents, such as plant extracts, has grown in popularity due to their environmental and economic benefits. Therefore, this study investigated into utilizing ethanol crude extract sourced from mangosteen peel for the synthesis of zinc oxide nanoparticles (ZnO NPs) and assessing their efficacy against the rice blight pathogen (Xanthomonas oryzae pv. oryzae) through antibacterial evaluations. Additionally, the effects of the synthesized ZnO NPs on rice plant growth was investigated. The X-ray diffraction analysis revealed the production of wurtzite ZnO NPs under specific synthesis conditions, exhibiting a crystallite size of 38.71 nm (or 387.122 Å) without any contamination. Analysis of the ultraviolet–visible optical absorption spectrum indicated a characteristic absorption peak at 363 nm, suggesting a calculated band gap energy of 2.88 eV for the ZnO NPs. Furthermore, Fourier transform infrared spectroscopy analysis confirmed the presence of active compounds functional groups from mangosteen peel in the synthesized ZnO NPs. These biosynthesized ZnO NPs demonstrated significant inhibition of X. oryzae pv. oryzae growth, exhibiting an in vitro 50 % inhibitory concentration (IC50) value of 1.895 mg/mL and a minimum inhibitory concentration (MIC) value of 4 mg/mL. The ZnO NPs treatments at two-fold IC50 values significantly enhanced root length, dry biomass, and chlorophyll a content in rice plants. Consequently, the results demonstrated the potential application of biosynthesized ZnO NPs from mangosteen peel extract in green agriculture, as an alternative to excessive antibiotic use, for combating bacterial plant diseases, and for enhancing plant growth