Menu Close

March 2021, Vol. 104 No. 1

Philippine native pigs are commonly found in the backyards of rural households in several regions in the Philippines. They are predominantly black with long face, long snout, short and lowset body conformation, erect ears, small size, with an average mature body weight of 40kg only (Bondoc and Ramos 1998). With the goal to improve the performance of The Philippine native pigs, the National Swine and Poultry Research and Development Center (NSPRDC) in Tiaong, Quezon developed the Black Tiaong pigs through selective breeding of native pigs from Kalinga, Marinduque and Quezon. Researches are also conducted on the establishment of nutrient requirements of the pigs.

{Photographs courtesy of Mary Arnel D. Garcia, Deparment of Animal Science, College of Agriculture, Benguet State University, La Trinidad, Benguet, and Rommel C. Sulabo, Animal Nutrition Division, Institute of Animal Science, College of Agriculture and Food Science, University of the Philippines Los Baños, College, Laguna}


Maximum Entropy (MaxEnt) Modeling of the Potential Distribution of Aspidiotus rigidus Reyne (Hemiptera: Diaspididae) in the Philippines
Ireneo B. Pangga, Arnold R. Salvacion, Nikka H. Hamor and Sheryl A. Yap

Received: 27 February 2020/ Revised: 4 February 2021/ Accepted: 8 February 2021

The coconut scale insect (CSI) Aspidiotus rigidus Reyne (Hemiptera: Diaspididae) poses a significant threat to coconut production in the Philippines as shown by recent outbreaks. Ecological niche modeling using Maximum Entropy (MaxEnt) was used to determine the effects of environmental factors on the infestation of A. rigidus, and map its potential distribution in the Philippines to assess the risk of future outbreaks. The influence of bioclimatic variables on A. rigidus infestation was determined using MaxEnt modeling using the location data of A. rigidus occurrence confirmed using molecular markers. Rainfall and temperature variables were important for A. rigidus distribution with rainfall being more important than temperature. Annual rainfall and precipitation seasonality were the first and second most important variables determining A. rigidus infestation with 47.9% and 30.7% permutation importance, respectively. The final A. rigidus MaxEnt model showed an area under the curve (AUC) value of 0.93 indicating a very good predictive power; hence, the potential distribution map can be used to assess the risk of A. rigidus outbreaks in the Philippines.

The Role of α-Tocopherol in Mitigating the Effect of Elevated CO2 Concentrations Emitted from the AL-Hunay Power Plant Main Station on the Glycine max L Plants
Mohammed Abdulrahman Almuwayhi

Received: 29 June 2020/ Revised: 14 December 2020/ Accepted: 4 January 2021

Soybean (Glycine max L.), belonging to Leguminosae, is an essential food in Asian countries. It has become a necessity to study the long-term effects of elevated concentrations of CO2 on plant growth and development. Climate change may be affected by the increment of CO2 and higher temperatures on crops. Elevated concentrations of atmospheric CO2 can negatively affect the yield as well as the quality of the field crops. Alpha-tocopherol is the major vitamin E compound found in leaf chloroplasts. This antioxidant deactivates photosynthesis-derived reactive oxygen species and prevents the propagation of lipid peroxidation by scavenging lipid peroxyl radicals in thylakoid membranes. AL-Hunay is an electrical power plant main station located in the Al-Hofuf agricultural area in Saudi Arabia. The role of α-Tocopherol in mitigating the effect of CO2 emitted from AL-Hunay on the morphological and physiological traits of soybean has been investigated in this study by selecting a site of 100 meters apart from the station. The results revealed a negative effect of elevated concentrations of CO2 on the morphological traits of soybean such as plant height, leaf area, and number of leaves. Furthermore, it also negatively affected the physiological traits such as the contents of P and K, mono- and disaccharides, chlorophyll a and b and the activity of catalase, and superoxide dismutase. The results showed an obvious role of α-Tocopherol in mitigating the effect of elevated CO2 on soybean plants through regulating the growth, stimulating photosynthesis, protecting the cell membrane and chloroplasts, and tolerating oxidative stress. The current study provides proof for the positive role of α-Tocopherol in mitigating the effect of elevated CO2 emitted by the AL-Hunay power plant main station on the morphological and physiological traits of Glycine max L. plants.

Taxonomic Microbiome Profiling and Abundance Patterns in the Cacao (Theobroma cacao L.) Rhizosphere Treated with Arbuscular Mycorrhizal Fungi and Bamboo Biochar
Angelbert D. Cortes, Nelly S. Aggangan, and Rina B. Opulencia 

Received: 20 August 2020/ Revised: 12 December 2020/ Accepted: 16 December 2020

Biochar and arbuscular mycorrhizal fungi (AMF) are agricultural interventions adopted by farmers to improve the growth of crops in nutrient-deficient acidic soil, which relatively influence the biological properties in the rhizosphere. This greenhouse study investigated the changes in prokaryotic diversity in the rhizosphere of cacao plants grown in acidic soil with AMF and bamboo biochar (BB) for 15 months under nursery conditions. Metagenomic analysis of the V3-V4 region of the 16S rRNA gene of the rhizosphere with AMF, 15% BB, and AMF + 15% BB revealed that the addition of AMF and BB reduced the sample’s diversity, but the treatments increased the overall plant growth. Of all Operational Taxonomic Units (OTUs) recovered, the top three abundant phyla in the treated soils were: Proteobacteria, Acidobacteria, and Actinobacteria. The relative abundances of Proteobacteria and Acidobacteria increased with the treatments, whereas that of Actinobacteria was decreased. Biochar increased the unclassified genera under Order Acidobacteriales and Chromatiales. In contrast, AMF increased the abundance of an unclassified genus under Order Xanthomonadales. The genus Rhodoplanes was the most dominant in AMF + 15% BB-treated soil with a relative abundance of 9.4%. The four samples shared only 4.9% of the total OTUs; apparently, the microbial communities across samples were separated and distinct. Most of the increased genera have been reported to play essential roles in nutrient cycling, which may contribute to cacao growth promotion.

Postharvest Salicylic Acid and Melatonin Dipping Delay Ripening and Improve Quality of ‘Sensation’ Mangoes
Mohamed A. Awad and Adel D. Al-Qurashi 

Received: 14 October 2020/ Revised: 05 February 2021/ Accepted: 08 February 2021

Freshly harvested mature-green ‘Sensation’ mangoes were dipped for 10 min in 2 mM salicylic acid (SA) and 0.2 mM melatonin (MT) alone or in combination and stored at 23±1°C and 60–70%RH. SA or MT delayed ripening measured as higher green peel color (lower a* values), firmness, titratable acidity (TA) and membrane stability index (MSI) and lower weight loss, total soluble solids (TSS), TSS/TA ratio and hydrolytic enzyme activities (polygalacturonase, xylanase and α-amylase) compared to that of untreated fruit. Total phenolic content (TPC) in peel of treated fruit increased with fluctuations during ripening and was higher than the control. In pulp, TPC decreased up to 6 days but increased thereafter, and was higher in treated fruit than the control. Total flavonoid content (TFC) in the peel decreased while that in the pulp increased with fluctuations during ripening and was higher in treated fruit than the control. Vitamin C content decreased during ripening and was not affected by the treatments. DPPH radical scavenging capacity (RSC) in peel decreased during ripening and was higher in treated fruit than the control. However, RSC in pulp increased during ripening and was not affected by treatments, except for SA plus MT treatment that gave higher RSC than the control after 6 and 10 days. Polyphenoloxidase (PPO) activity increased during ripening and was lower in treated fruit than the control. Peroxidase (POD) activity increased during ripening and was higher in treated fruit than the control. SA and MT combination treatment provided no additional positive effects on most parameters. It is concluded that postharvest dipping in 2 mM SA or 0.2 mM MT delayed ripening and improved quality of ‘Sensation’ mangoes via inhibiting hydrolytic enzymes and enhancing antioxidant system of fruit and are suggested as natural alternative to synthetic chemicals.

Morphological and Microsatellite-Based Molecular Characterization of Locally Collected Sugarcane (Saccharum officinarum L.)
Carl F. Libayao, Ma. Carmina C. Manuel, Eureka Teresa M. Ocampo, and Antonio G. Lalusin

Received: 06 March 2020/ Revised: 02 February 2021/ Accepted: 08 February 2021

Fifty-three sugarcane accessions from Aklan, Iloilo, Cagayan, Nueva Vizcaya, Isabela, and Bohol were characterized using forty-two morphometric parameters and forty microsatellite markers. Twenty-six morphological characters using the Shannon-Weaver diversity index showed high variability (H’ = > 0.76) and were able to characterize the fifty-three sugarcane accessions. Cluster analysis of morphological traits based on sequential agglomerative hierarchical test and Euclidean distance revealed two groupings at 0.3 coefficient of dissimilarity. The clustering of some accessions was irrespective of their geographical origin indicating a high degree of phenotypic similarity in some accessions. Out of the forty microsatellite markers, twenty-five (63%) have a PIC value greater than 0.5 with Sach 53 showing the highest at 0.89. This implies that these markers are suitable for sugarcane genetic diversity studies as they can detect a high number of discernable alleles. Molecular cluster analysis generated using Unweighted Pair Group Method with Arithmetic Mean (UPGMA) and Jaccard distance showed two clusters at 0.4 coefficient of dissimilarity. In cluster I, twenty-one accessions from Aklan and Iloilo grouped indicating genetic similarity. Aklan and Iloilo provinces are both located in the same geographic island in Western Visayas, hence, the observed grouping in cluster I. On the other hand, thirty-two sugarcane accessions from Northern Luzon (Cagayan, Nueva Vizcaya, and Isabela), Iloilo, Aklan, and Bohol were grouped in cluster II. The observed clustering of accessions from different regions implies the extensive distribution of sugarcane germplasm to the different parts of the Philippines.

Standardized Ileal Digestibility of Amino Acids in Nacedero (Trichanthera gigantea (Humboldt & Bonpland.) Nees) Foliage, Copra Expeller, and Soybean Meal Fed to Growing Philippine Native Pigs (Sus scrofa domesticus Erxleben, 1777)
Mary Arnel D. Garcia and Rommel C. Sulabo 

Received: 10 December 2019/ Revised: 04 February 2021/ Accepted: 10 February 2021

The experiment was conducted to determine the apparent ileal digestibility (AID) and standardized ileal digestibility (SID) of amino acids (AA) in nacedero (Trichanthera gigantea Humboldt & Bonpland.) Nees; NAC) foliage, copra expeller (CE), and soybean meal (SBM) fed to growing Philippine native pigs (Sus scrofa domesticus Erxleben, 1777). Eight barrows of Black Tiaong strain (initial BW of 36.44 ± 1.59 kg; 132 to 135 d) installed with a T-cannula at the distal ileum were housed individually in metabolism cages and randomly allotted to a replicated 4 × 3 Youden square design with four diets and three periods. One diet contained 30% soybean meal (SBM) and two diets were formulated with 20% SBM and 30% (as-fed basis) NAC or CE. The last diet was a N-free diet used to measure basal endogenous losses of crude protein (CP) and AA. The SID of CP and all indispensable AA in CE were less (P<0.001) than in SBM, while NAC foliage were similar to those in SBM. However, the amount of SID CP and AA in NAC were remarkably lower (P < 0.001) than in CE and SBM. To our knowledge, this is the first time the AID and SID of AA in NAC have been determined in Philippine native pigs. Results of this experiment indicate that NAC foliage has good palatability and AAs are well digested by growing Philippine native pigs at a rate similar with SBM. However, when NAC is fed fresh, the SID concentration of CP and AA (g/kg) were the least (P < 0.001) compared with CE and SBM. Drying and processing of NAC foliage into a meal may be considered to increase AA concentrations in the diet.

Phenotypic Characters and Expression of Cytokinin oxidase 2 (OsCKX2) Gene in Rice Genotypes with Enhanced Grain Filling Traits
Cielo Luz C. Mondejar, Maria Genaleen Q. Diaz, Teresita H. Borromeo, Tonette P. Laude, Arlen A. Dela Cruz and Roel R. Suralta

Received: 07 November 2020/ Revised: 22 February 2021/ Accepted: 26 February 2021

Poor grain filling is still a major problem in rice production. Recent attention in crop varietal improvement is focused on heritable delayed foliar senescence, enhanced root system, and fast-synchronous grain filling pattern. Nine genotypes were characterized for these three enhanced grain-filling traits to determine the role of these traits on grain yield. Based on heritable delayed foliar senescence, NSIC Rc436 and NSIC Rc512 were characterized as Type A, while PSB Rc18 and NSIC Rc514 as Type B. These genotypes had a significantly higher yield than IR64, owing to their high spikelets number. Data suggested a positive correlation between the delayed foliar senescence and grain number. NSIC Rc480, Arabon, Biniding (IR68), NSIC Rc512, Cuevas, and NSIC Rc436 were characterized with phenotypically superior root characters than IR64. A tendency of direct association was observed between the root characters and the percentage of filled grains and 500-grain weight. Only NSIC Rc480 was characterized with a fast-synchronous pattern, and its percentage of filled grains was significantly higher than the other tested genotypes. Integrating these enhanced grain filling traits in the selection criteria may improve poor grain filling in rice, which is a major constraint in improving the rice yield potential. Preliminary work on the expressions of Cytokinin oxidase 2 (OsCKX2), a gene implicated in the regulation of rice grain yield, was likewise conducted. Differences in the OsCKX2 expression was observed, which may entail a positive note on the exploration at the molecular level to identify the possible role of cytokinin in the gene regulation during rice grain filling.

Research Notes

16S rRNA Gene Sequence Analysis of Acetic and Lactic Acid Bacteria Isolated from Philippine Sugarcane Wine (Basi)
John Russel G. Sevilla, Michael Angelo S. Esteban, Honey Bhabes R. Iñigo, Audrey Mae V. Orillaza, and Baby Richard R. Navarro 

Received: 11 August 2020/ Revised: 05 February 2021/ Accepted: 28 February 2021

Basi, a traditional sugarcane wine of the Philippines, was studied. Here, we used molecular- and cultural-based methods to isolate, identify and characterize acid-producing bacteria, specifically acetic and lactic acid bacteria, from basi. Acid producers were focused on owing to the rapid spoilage of basi via acidification with air exposure. Two strains each of acetic and lactic acid bacteria were isolated. DNA was extracted from these isolates. PCR-amplified DNA products were subjected to 16S rRNA gene sequencing. The sequences of the isolates were then aligned with BLAST database sequences and found to have high similarities to Acetobacter malorum (99%), Gluconobacter oxydans (97%), Lactobacillus paracasei (97%), and Enterococcus faecium (98%), which were supported by the relationships shown by phylogenetic trees constructed using the neighbor-joining method with MEGA 7 as well as by morphological, biochemical, and physiological characteristics. It is therefore unequivocal that basi harbors both acetic and lactic acid bacteria, surmised to play crucial roles in its fermentation and perhaps rapid spoilage. Thus, good manufacturing practices and food processing interventions such as ultrafiltration and pasteurization are recommended for basi shelf-life extension.

Evaluation of the Inactivation Kinetics of Cronobacter Sakazakii in Infant Formula Treated by Radio Frequency Dielectric Heating and UVC Light
Yuwei Wu, Yuanrong Zhen, Danfeng Wang, Zhenmin Liu, and Yun Deng

Received: 26 April 2019/ Revised: 21 November 2020/ Accepted: 04 December 2020

We studied the inactivation kinetics of Cronobacter sakazakii (CS) in infant formula subjected to radio frequency dielectric heating (RF) alone or sequential RF-UVC irradiation for 30 min. We used one linear model and two nonlinear models to fit the data and compared the results. Our findings revealed that CS was more susceptible to the combined treatment than to RF alone at the same temperature and that inactivation rate increased with increasing temperature. The sequential RF (90°C, 5 min) – UVC (25 min) treatment was the most effective at inactivating CS. The survival curves of CS were non-linear. The modified log-logistic model (R2 = 0.9783–0.9904, RMSE = 0.02–0.05, Af =1.04–1.07, Bf = 0.99–1.03) generated a better fit than the Weibull (R2 = 0.9111–0.9863, RMSE = 0.02–0.10, Af = 1.04–1.16, Bf =1.00–1.09) or first-order kinetics models (R2 = 0.6514–0.7937, RMSE = 0.07–0.30, A>sub>f = 1.12–1.77, Bf = 0.93–1.38). Overall, the survival curves of CS in infant formula subjected to RF alone or sequential RF – UV light were nonlinear. The modified log-logistic model may be a useful tool to describe the inactivation patterns for CS in infant formula, and our results also demonstrated the high color stability of samples after sequential RF – UVC treatments.

Effect of Hydrogen Peroxide on Physiological Quality and Germination of Aged Pumpkin Seeds under Drought Stress Condition
Hossein Reza Rouhi, Mohammad Hasan Vafaei, Maryam Saman, and Ali Abbasi Surki

Received: 26 April 2019/ Revised: 21 November 2020/ Accepted: 04 December 2020

The physiological quality of seeds decreases during their storage under unfavourable conditions. These deteriorated seeds exhibit a poorer performance, especially under stress conditions. A factorial experiment was conducted to investigate the effects of H2O2 on the germination of aged pumpkin seeds under drought stress. Hydroprimed seeds and also the seeds pre-treated with 100, 200 and 400 µM H2O2 were exposed to drought (0, -0.2, -0.4, and -0.6 MPa applied using PEG). Under drought conditions, seeds primed with H2O2 showed improved germination percentages and rates, higher vigour index, greater plumule and radicle lengths, enhanced soluble sugars and protein contents, and more antioxidant enzymes activities e.g. catalase, ascorbate peroxidase and superoxide dismutase in comparison to untreated controls. However, mean germination time and malondialdehyde (MDA) content total soluble proteins decreased in primed seeds. Those primed with 100 µM H2O2 showed the highest germination rate, vigour index, soluble sugars, and total soluble protein by 93, 46, 76, and 51% respectively at a drought level of -0.6 MPa. H2O2 at 100 Μm applied to deteriorated total soluble proteins pumpkin seeds reduced of the negative effects of deterioration, especially under drought stress.

Existing Users Log In