The era of the green revolution has significantly improved rice yield productivity. However, with the growing population and decreasing arable land, rice scientists must find new ways to improve rice productivity. Although hundreds of rice yield-related QTLs were already mapped and some of them were cloned, only a few were utilized for actual systematic introgression breeding programs. In this study, the major yield QTLs Grain Number 1a (Gn1a) and Wealthy Farmer’s Panicle (WFP) were introgressed and stacked in selected NERICA cultivars by marker-assisted backcross breeding (MABB). The DNA markers RM3360, RM3452, and RM5493 were used for foreground selection. At BC₃F₄ and BC₃F₅ generation, a combination of marker-assisted selection and phenotypic evaluation were carried out to select lines with target alleles and traits. Further, genotyping-by-sequencing (GBS) was conducted to validate the introgression and determine the recurrent parent genome recovery (RPGR) of the selected lines. The Gn1a and/or WFP introgression lines showed significantly higher numbers of spikelets per panicle and primary branching compared to the recurrent parents. In addition, lines with Gn1a and/or WFP alleles were comparatively similar to the recurrent parents (RP) in most yield-related traits. This study demonstrates the success of utilizing yield QTLs and marker-assisted selection to develop and improve rice cultivars.

Annually, the Philippines is burdened by a high number of infections and deaths due to Dengue. This disease is caused by the Dengue virus (DENV) and is transmitted from one human host to another by the female Aedes aegypti mosquito. Being a developing country, most of the high-risk areas in the Philippines are resource-limited and cannot afford equipment for detection and monitoring. Moreover, traditional clinical diagnoses of DENV infection are costly and time-consuming and require expertise. Hence, it is important to establish effective vector control and surveillance measures. In this study, we developed a DNA-based nanobiosensor for the colorimetric detection of Dengue virus serotype 2 (DENV-2) synthetic target DNA (stDNA S2) using gold nanoparticles (AuNPs). We successfully functionalized dextrin-capped gold nanoparticles with the designed DENV-2 oligonucleotide probes. The detection of the complementary stDNA S2, indicated by the pink-colored solution, was successfully performed within 15 min using 0.40 M NaCl solution. We were able to detect up to 36.14 ng/μL of stDNA S2 with some cross-reactivity observed with one non-complementary target. We believe that our study offers a basis for developing nanobiosensors for other DENV serotypes.

Each plant species is regarded to substantially influence and thus, select for specific rhizosphere microbial populations. This is considered in the exploitation of soil microbial diversity associated with important crops, which has been of interest in modern agricultural practices for sustainable productivity. This study used PCR-DGGE (polymerase chain reaction - denaturing gradient gel electrophoresis) in order to obtain an initial assessment of the bacterial and fungal communities associated in bulk soil and rhizospheres of different mungbean genotypes under natural field conditions. Integrated use of multivariate analysis and diversity index showed plant growth stage as the primary driver of community shifts in both microbial groups while rhizosphere effect was found to be less discrete in fungal communities. On the other hand, genotype effect was not discerned but not inferred to be absent due to possible lack of manifestations of differences among genotypes based on tolerance to drought under non-stressed environment, and due to detection limits of DGGE. Sequence analysis of prominent members further revealed that Bacillus and Arthrobacter species were dominant in bacterial communities whereas members of Ascomycota and Basidiomycota were common in fungal communities of mungbean. Overall, fungal communities had higher estimated diversity and composition heterogeneity, and were more dynamic under plant growth influence, rhizosphere effect and natural environmental conditions during mungbean growth in upland field. These primary evaluations are prerequisite to understanding the interactions between plant and rhizosphere microorganisms with the intention of employing their potential use for sustainable crop production.

As global demand for bananas rises, the threat of banana bunchy top disease (BBTD), caused by banana bunchy top virus (BBTV), poses a significant constraint to sustainable banana production. To circumvent this, it is critical to fast-track the development of BBTV-resistant banana cultivars. In a dataset of differentially expressed genes between BBTV-resistant and susceptible bananas, six RLK genes involved in plant defense against pathogens were exclusively upregulated in the BBTV-resistant wild Musa balbisiana compared to the BBTV-susceptible Musa acuminata cv. ’Lakatan’. Here, two genic variants of RLKs , single nucleotide polymorphisms (SNPs) and simple sequence repeats (SSR), were identified in 10 banana accessions representing major genomic groupings. Nine gene-specific markers were developed using three marker systems: SSR, allele-specific PCR, and tetra primer amplification refractory mutation system PCR markers. Six of these were polymorphic and successfully discriminated 117 Musa genotypes at the NPGRL-IPB ex situ germplasm, with an average polymorphism information content of 0.36 for SNP markers and 0.49 for SSR marker, both of which are moderately informative. These markers facilitated the construction of a dendrogram using the Unweighted Neighbor-Joining (UNJ) method with 1000 bootstrap iterations, identifying four major clades: M. acuminata spp. and other Musa spp. (I), wild M. balbisiana (BBw) and other accessions with high-proportion of B-genome (II & III), hybrid bananas (triploids and tetraploids) (IV), which revealed the genetic diversity and relationships among Musa accessions. Ultimately, this genomic resource will aid in positioning the Philippines as a key player in banana disease resistance breeding towards a food-secure banana industry.