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Philipp.
Agric. Scientist 87: 249-265 (2004)
PHILIPPINE
ENTOMOPATHOGENIC FUNGI i. oCCURRENCE AND DIVERSITY
Lina
T. Villacarlos* and Belen S. Mejia
Department of Pest
Management, College of Agriculture, Leyte State University, Visca,
Baybay, Leyte 6521-A, Philippines (*Author for correspondence;
e-mail: villa23carlos@yahoo.com)
Entomopathogenic
fungi were collected from selected areas in the Philippines from
1998 to 2001. The collection consisted of 53 species under 22 genera
as follows: Batkoa,
Conidiobolus, Entomophaga, Entomophthora, Erynia, Neozygites,
Orthomyces, Pandora and Zoophthora of the
Entomophthorales, and Akanthomyces, Beauveria, Fusarium,
Gibellula, Hirsutella, Lecanicillium (=Verticillium),
Metarhizium, Nomuraea, Sporothrix and Paecilomyces of
the Hyphomycetes. Coelomycetes
are represented by Aschersonia while Cordyceps and Torrubiella
represented the Pyrenomycetes-Hypocreales. These genera were
discussed in relation to reportedly existing species and their
general biodiversity in the country.
Philipp.
Agric. Scientist 87: 266-275 (2004)
PHILIPPINE
ENTOMOPATHOGENIC FUNGI II. PATHOGENICITY
OF COMMON
SPECIES
TO SELECTED INSECT PESTS
Lina
T. Villacarlos 1*,
Belen S. Mejia 1
and Remberto A. Patindol 2
1
Department of Pest Management, College of Agriculture
and 2 Department
of Mathematics, Physics and Statistics, College of Arts and
Sciences, Leyte State University, Visca, Baybay, Leyte 6521-A,
Philippines
*Author for
correspondence: villa23carlos@yahoo.com
Five
isolates of Beauveria bassiana (Bals.) Vuill., three of
Metarhizium anisopliae (Metch.) Sor. and one each of
Paecilomyces fumosoroseus (Wize) Brown & Smith, Lecanicillium
lecanii (Zimm.) Gams & Zare (=Verticillium lecanii)
and Neozygites fresenii (Now.) Remaudiere & Keller, from
the collection of entomopathogenic fungi were evaluated for their
pathogenicity on one or more insect species under the following
orders: Coleoptera, Hemiptera, and Lepidoptera. Results from the
bioassay showed variability in the susceptibility of the test
insects used. Dysdercus
cingulatus Fabr., Nezara viridula (L.), Aspidomorpha
miliaris Fabr., Aulacophora indica (Gmelin) and Ostrinia
furnacalis (Guenee) were not susceptible to B. bassiana.
Nymphs of Riptortus linearis L. were more susceptible to B.
bassiana than the adults, especially if the conidial suspension
was applied as spray than applied on the food.
Bb149 isolate of B. bassiana caused 67%
and 70% mortality on
larvae and adult Tribolium castaneum (Herbst), respectively.
This was the most susceptible among the coleopterans tested.
On the other hand, M. anisopliae caused 100% mortality on
nymphs of Physomerus grossipes Fabr. and 40-60% mortality on R.
linearis and D. cingulatus.
M. anisopliae (Ma-Tiaong) caused the highest
mortality of 73% with LT50
of 3.9 d on O. furnacalis (Guen.).
Both M. anisopliae and B. bassiana
were highly pathogenic
to Cylas formicarius (Fabr.) but not to P. fumosoroseus.
L. lecanii concentration of 107
conidia mL-1 caused
75.6% mortality on Pentalonia nigronervosa Coq. with an LT50
of 5.6 d while N. fresenii was not effective against P.
nigronervosa. The findings indicated the importance of using
different groups of insects in screening entomopathogenic fungi for
potential microbial
control. Method of
application and stage of insect are important considerations in any
bioassay.
Philipp.
Agric. Scientist 87: 276-284 (2004)
PURIFICATION
AND ANTISERUM PRODUCTION OF BANANA BRACT MOSAIC POTYVIRUS IN THE
PHILIPPINES
D.E.V.
Villamor 1, L.E.
Herradura 2
and N.B. Bajet 3*
1 Research
Department, Lapanday Agricultural Development Corporation, Mandug,
Davao City, Philippines
2 Supervising
Agriculturist, Davao National Crops Research Development Center (DNCRDC),
Bureau of Plant Industry (BPI), Bago-Oshiro, Davao City, Philippines
3 Deparment
of Plant Pathology, College of Agriculture, University of the
Philippines Los Baños (UPLB), College, Laguna 4031, Philippines
*Author
for correspondence; e-mail: nbbajet@yahoo.com
Banana
bract mosaic potyvirus (BBrMV) was extracted and purified from field
collected, BBrMV-ELISA positive banana leaves using virus antiserum
from Australia by following the procedure of Thomas et al. (1997).
Rate zonal cesium chloride gradient centrifugation of the partially
purified preparation showed one distinct light scattering band and
this band was collected. Assays of its aliquots showed that it has a
typical nucleoprotein profile at UV 220-320 nm, reacted with the
same antiserum in ELISA and showed major proteins of about 31 and 39
kDa in SDS-PAGE. These proteins showed strong signals with the same
antiserum in western blot. Low virus yield was obtained but the
concentration was enough to produce virus antiserum in rabbits.
After immunizing two rabbits with the purified virus preparations,
only one produced antiserum (R2BBrMV-As) with relatively sufficient
titer and of comparable reaction with the antiserum from Australia
in both ELISA and western blot. The successful purification
demonstrates local capability of obtaining relatively pure samples
for more fundamental studies on the virus particle. The availability
of this R2BBrMV-As complements and expands existing antibody-based
assays for the detection of this virus in banana and other host
plants, thus, enhancing diagnosis of virus diseases of Musa
spp. in the country.
Philipp.
Agric. Scientist 87: 285-297 (2004)
GIBBERELLIC
ACID (GA3) EFFECTS ON
HEADING CHARACTERISTICS OF TEN CYTOPLASMIC
MALE STERILE (CMS) LINES AND ON HYBRID RICE SEED PRODUCTION
USING IR58025A CMS LINE
R.
R. Suralta 1*
and R. P. Robles 2
1 Seed
Production and Health Division, PhilRice, Science City of Muñoz,
Nueva Ecija, Philippines (*Author
for correspondence; e-mail: rrsuralta@philrice.gov.ph)
2 Department
of Agronomy, College of Agriculture, University of the Philippines
Los Baños College, Laguna 4031, Philippines
The
effects of gibberellic acid (GA3)
as a pre-flowering treatment for cytoplasmic male sterile (CMS)
lines in hybrid rice seed production (HRSP) were assessed in a
greenhouse study and a field experiment during the 2002 dry season
(DS). The greenhouse study determined the differences in panicle
exsertion and other heading characteristics among 10 CMS lines using
five levels of GA3
at 5-10% heading while the field experiment determined the
outcrossing characteristics and seed yield of CMS line IR58025A
under various levels and the number of splits of pre-flowering
application of GA3.
In
the greenhouse, foliar application of GA3
significantly increased the panicle exsertion from the flagleaf
sheath by a maximum of 80% at 150 g ha-1
concentration. Also, other morphological traits associated with
outcrossing such as DPF (distance between panicle tip and flagleaf
tip), flagleaf angle, degree of spikelet openings and percentage of
spikelets with exserted stigma were also improved by GA3
application, along with significant genotypic differences. The most
responsive CMS lines to GA3
application
were IR73328A, IR70959A, IR64829A and IR58025A while the least
responsive were IR68888A, IR69627A and IR68897A.
In
the field, foliar application of GA3
significantly increased panicle exsertion, seed set and seed yield
of CMS line IR58025A by a maximum of 80%, 20% and 77%, respectively
at 150 g ha-1
concentration. Increase in seed yield was highly influenced by the
increase in percentage of seed set presumably as a result of higher
panicle exsertion, higher DPF, wider flagleaf angle, higher degree
of spikelet openings, and stigma exsertions. During the dry season,
the optimum rate of GA3
application in hybrid rice seed production of PSB Rc72H (Mestizo)
is 150 g ha-1
applied in at least two splits beginning at 5-10% panicle heading of
the CMS population.
Philipp.
Agric. Scientist 87: 298-305 (2004)
PERFORMANCE
OF THREE COMMERCIAL MAIZE HYBRIDS UNDER SIMULATED SEED RECYCLING
CONDITION
Gregorio
M. Villegas, Joveno S. Lales*
and Sherwin Alain L. Tagle
Department of Agronomy,
College of Agriculture, University of the Philippines Los Baños,
College, Laguna 4031, Philippines
*Author
for correspondence; e-mail: jslales@yahoo.com
Three segregating populations (F2,
F3
and F4)
of three commercial hybrid maize varieties (C-818, P-3014 and
IPB-911) were generated through simulated hybrid seed recycling for
simultaneous evaluation against their F1
generations under favorable environmental conditions to quantify
yield depression, to identify traits associated with yield
depression and to determine forgone economic benefit.
Of
the three hybrids, only C-818 showed significant yield depression.
Loss of uniformity in ear length and ear diameter, and significant
reduction of shelling recovery accounted for significant yield
depression. Leaf area index, number of functional leaves above the
ear, stalk diameter and ear height were relatively stable. The
magnitude of forgone economic benefit differed from one hybrid to
another. Forgone economic benefit (PhP5,383 to PhP8, 156/ha) was
highest in C-818. Recycling the F2
and F4
generations of P-3014 and IPB-911 likewise led to forgone economic
benefit ranging from PhP106 to PhP1,003/ha and from Php1,521 to
PhP2,832/ha, respectively. Despite yield fluctuations, profit
remained positive in each crop cycle.
Based
on yield depression and forgone economic benefit, the segregating
generations of C-818 should not have been recycled. In contrast,
P-3014 was fit for the three-season hybrid seed recycling while
IPB-911 was suited to only two crop cycles. Using profit as basis
for decision making, recycling the segregating generations of the
three hybrids for three crop cycles was economically viable.
Philipp. Agric. Scientist 87: 306-311 (2004)
Research
Note: INDUCTION OF IN VITRO SHOOT PROLIFERATION AND ROOTING OF
AXILLARY BUDS OF PINEAPPLE CV. QUEEN (Ananas comosus (L.) Merr.)
Russell
John C. de Juras, Evalour T. Aspuria*
and Rene Rafael C. Espino
Department of
Horticulture, College of Agriculture, University of the Philippines
Los Baños, College, Laguna 4031, Philippines
*Author for
correspondence; e-mail: aspog@laguna.net
The responses of axillary buds of pineapple cv. Queen to plant
growth hormones and coconut water supplementation in Murashige and
Skoog’s basal medium (MS) were evaluated. Maximum number of
multiple shoots were obtained from the explant grown in MS + 2.0 ppm
kinetin (Ki) + 2.0 ppm naphthalene acetic acid (NAA) + 2.0 ppm
indole-3-butyric acid (IBA) with an average of 6 shoots per culture.
All in vitro proliferated shoots produced roots in rooting
media supplemented with different concentrations (0, 0.1, 0.5, 1.0
and 2.0 ppm) of NAA and indole-3-acetic acid (IAA) added singly or
in combination.
The
number of days to root formation and the number of roots formed were
directly proportional to the concentration of the NAA when added in
the culture medium. On the other hand, root elongation was inversely
proportional to the concentration of NAA.
The
regenerated plantlets were successfully established in plastic pots
containing sterilized soil with 95% success.
Philipp.
Agric. Scientist 87: 312-321 (2004)
Mercury
Uptake and Phytochelatin Production in Ipomoea
aquatica Forsk.
Rosemarie
D.R. Josue 1,
James A. Villanueva 2
and Gilda C. Rivero 3*
1 Department
of Natural Resources, College of Arts and Sciences, Mindanao State
University – Maguindanao, Dalican, Datu Odin Sinsuat, Maguindanao
9601, Philippines
2 Institute
of Biology, College of Science, University of the Philippines,
Diliman, Quezon City 1101, Philippines
3 Institute
of Chemistry, College of Science, University of the Philippines,
Diliman, Quezon City 1101, Philippines (*Author for correspondence;
e-mail: gilda.rivero@up.edu.ph)
The
Hg content of the vegetative organs and their subcellular fractions
were determined in Ipomoea aquatica Forsk. plants grown in
nutrient solutions supplemented with three levels of Hg (0, 0.5, and
1.0 mg L-1).
The
increase in plant height and recovery in dry weight of Ipomoea aquatica plants
grown in nutrient solutions with as high as 1.0 mg L-1
Hg for 7 d indicated a high degree of tolerance to Hg.
Significant levels of Hg2+
were
translocated in the young leaves, which were 6- to 7-fold the levels
found in the control plants or 65- to 75-fold the soil Hg.
Total protoplasmic fractions had higher levels of Hg2+
compared
to the cell wall fractions. The
presence of Hg2+
was detected in all subcellular fractions especially in the vacuole
fractions with the vacuolar sap having the higher levels.
The
mercury-binding phytochelatin-like peptides involved in the uptake
and accumulation of Hg were purified and quantified using reversed
phase-high performance chromatography. These sulfhydryl and
glutathione-containing peptides were detected mostly in the
fractions from the young leaf extracts. The
level of phytochelatin-like peptides, which was directly influenced
by Hg2+
concentrations, was highest in the young leaves.
The phytochelatin-like peptides were also detected at high
levels in the stems and least in the mature leaves, although Hg2+
concentrations were higher in the mature leaves than in the stems.
Philipp.
Agric. Scientist 87: 322-334 (2004)
STRUCTURE,
COMPOSITION AND WATER VAPOR ADSORPTION BEHAVIOR
OF
SILICA GELS FROM RICE HULL
Leni
L. Quirit 1*
and Elma C. Llaguno 2
Institute of Chemistry,
College of Science, University of the Philippines Diliman, Quezon
City 1101, Philippines
*Author for
correspondence; e-mail: lquirit@chem.upd.edu.ph, fax: 9205427
Silica
gels prepared from rice hull were found to have properties
comparable to two commercial silica gels and a silica gel prepared
by the Industrial Technology Development Institute (ITDI) in terms
of chemical and amorphous structure, surface area, desiccant
characteristics and heats of adsorption. These properties were
determined from infrared and x-ray diffraction spectra and from
water vapor adsorption measurements. Microstructure comparison by
electron microscopy showed greater uniformity in particle size and
distribution for the rice hull silica gels. The acid-treated rice
hull gels may have potential as chromatographic material, based on
fewer number of elemental impurities detected by x-ray fluorescence,
compared to the commercial and ITDI gels. The economic advantage of
preparing silica gels (and other silica products) from rice hull
could be considerable if the rice hull ash is obtained from properly
designed burners using rice hull as a renewable energy source. Aside
from production of cheap energy and silica products, the process
will contribute to agricultural waste utilization and pollution
abatement through reduction of emissions from the current practice
of open field burning of rice hull.
Philipp.
Agric. Scientist 87: 335-348 (2004)
TAXONOMIC
SURVEY AND BIOLOGICAL OBSERVATIONS OF INSECTS ASSOCIATED WITH BAMBOO
SHOOTS IN THE PHILIPPINES
Ireneo
L. Lit, Jr. 1
and Merdelyn T. Caasi-Lit 2
1 Curator
and University Extension Specialist III, Entomology Section, UPLB
Museum of Natural History, University of the Philippines Los Baños
(UPLB), College, Laguna 4031, Philippines (e-mail: junlit@hotmail.com); 2
University Researcher III, Entomology Laboratory,
Institute of Plant Breeding, College of Agriculture, UPLB, College,
Laguna. 4031, Philippines (e-mail: binglit@hotmail.com)
This
is the first comprehensive report on insect pests associated with
bamboo shoots in the Philippines. Twenty-two insects were observed
to be associated with the basal shoots (labong) of several
bamboo species in plantations and natural stands. They were
collected from the field, further observed in the laboratory and
identified. Of the 22, nine species are herbivorous. The primary
insect pests include at least three species of bamboo aphids [Pseudoregma
alexanderi (Takahashi), Ps. bambusicola (Takahashi) and Ps.
sp. nr. pseudomontana (Takahashi)], the bamboo shoot
mealybug [Palmicultor lumpurensis (Takahashi)], the
bamboo shoot soft scale (Coccus sp.), the bamboo pit scale [Bambusaspis
bambusae (Boisduval)], the buho shoot borer (Cyrtotrachelus
sp.), an undetermined species of thrips (?Stenchaetothrips
sp.) and the bamboo planthopper (Purohita cervina
Distant). Based on
frequency of occurrence and qualitative damage to bamboo shoots, the
planthoppers, mealybugs and aphids can be considered the major pests
of Philippine bamboo shoots. Ants that attend to honeydew-producing
pests and which cover the emerging shoots with earthen nests or
bivouacs are here considered secondary pests and include Dolichoderus
sp., Solenopsis geminata Fabricius, Anoplolepis gracilipes
Jerdon and Oecophylla smaragdina Fabricius. Five species
of insects were observed to prey on Pseudoregma spp.,
namely: the large ladybird beetle Synonycha grandis (Thunberg),
the syrphid Ischiodon scutellaris (Fabricius), the green
lacewing Anisochrysa basalis (Walker), the giant green
lacewing Nobilinus sp., the brown lacewing (Micromus
igorotus Banks) and the pyralid Cryptoblabes aphidivora
Yoshiyasu and Ohara. The predatory lycaenid (Spalgis epius
Westwood) attacks bamboo shoot mealybugs. Two species of Pseudoscymnus
are also believed to prey on young aphids, scale insects,
mealybugs and possibly also mites.
An undetermined fungal pathogen infests the bamboo
planthopper. The
continuous presence or build-up of natural enemies should be
encouraged to help maintain the relatively low herbivore or pest
pressure.
Philipp.
Agric. Scientist 87: 349-355 (2004)
Research
Note: SOIL LOSS THROUGH SHEET EROSION UNDER VARIOUS SYSTEMS OF
BIOMASS INCORPORATION AND CROP COMBINATION IN AN ALLEY CROPPING
SYSTEM
S.
M. Asaduzzaman
Senior Scientific
Officer, On-Farm Research Division, Bangladesh Agricultural Research
Institute (BARI), Gazipur – 1701, Bangladesh (e-mail: sharifmilu@yahoo.com)
To
assess soil loss through sheet erosion, pattern of biomass
incorporation and crop combination were tested in an alley cropping
system. Three
treatments of biomass incorporation were used in the main plot and
the same number of crop combination treatments were also tested in
the subplots. A split-plot in randomized complete block design was
laid out with three replications. Biomass incorporation consisted of
three treatments: BI1
(application in the upper one-third portion of the alleyways), BI2
(biomass application in the upper two-thirds portion of the
alleyways) and BI3
(biomass application throughout the alleyways which served as the
control). On the other hand, the three crop combination treatments
consisted of: CC1
(corn
as pure stand or sole crop as control), CC2
(corn
+ sweet potato) and CC3
(corn
+ peanut) which were placed in the three subplots of each main plot.
The study was done during the wet season of 1999 and the dry season
of 1999-2000.
Sheet
erosion was not statistically significant among the treatments
during the wet season but erosion in the downslope varied
significantly during the dry season. In the dry season, the maximum
sheet erosion due to biomass incorporation was observed in BI2
(1.40 kg m-2) and the
minimum sheet erosion in BI3
(1.24 kg m-2). In the
same season, the maximum sheet erosion due to crop combination was
observed in CC1 (1.39
kg m-2) and the minimum
erosion in CC2 (1.29 kg
m-2). Soil loss (erosion)
due to interaction effect of biomass incorporation and crop
combination was significant only in the upslope during the wet
season and in the midslope and downslope only during the dry season.
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