Pollen Mixture Research Articles

Breeding System Evolution in Oxalis alpina: Asymmetrical Expression of Tristylous Incompatibility

Premise of research. Tristylous populations of Oxalis alpina have three floral morphs (short-, mid-, and long-styled), and populations appear to be at different stages in the evolution of distyly via loss of the mid-styled morph. In tristylous populations transitioning to distyly, asymmetrical incompatibility reactions could affect style-morph frequencies and slow the evolution of distyly. We hypothesized that greater success of pollen from long-styled relative to short-styled morphs leads to an excess of mid-styled progeny from mid-styled morphs and favors retention of tristyly despite other forms of selection acting against the mid-styled morph. Methodology. We quantified morph ratios of progeny from naturally pollinated plants. We also compared pollen tube and seed production of mid-styled plants following single-source pollinations using pollen from long- versus short-styled pollen parents, and we investigated the proportion of short-styled progeny following pollinations of mid-styled plants with mixtures of pollen from short- and long-styled plants. Pivotal results. Three lines of evidence generally support the hypothesis that reduced performance of short-styled pollen donors may favor retention of mid-styled plants. (1) Naturally pollinated mid-styled plants exhibited reduced numbers of short-styled progeny for two years in one of two tristylous populations with modified tristylous incompatibility. (2) In populations transitioning toward distyly, mid-styled plants pollinated by short-styled plants had fewer pollen tubes and lower seed production than crosses using long-styled plants as pollen parents. (3) Hand-pollinations of mid-styled plants using mixtures of pollen from short- and long-styled plants resulted in reductions in the proportion of short-styled progeny, consistent with the differences in pollen tube numbers produced by the paternal morphs. Conclusions. Asymmetry in paternity among different pollen donors via pollen tube performance influences the evolution of the breeding system of O. alpina, by affecting the relative proportions of different floral morphs and potentially counteracting selection through inbreeding depression and differential fitness of alleles controlling floral morphs.

Role of food quality in bee susceptibility to fipronil and clothianidin

Pollen is the honey bee’s main protein supply. Newly emerged bees need pollen alimentation to guarantee correct development of physiological conditions and breeding potential. To ensure functional and efficient adult bees not only the quantity but also the quality of pollen is important: pollen of different plant species vary in nutritional quality for honey bees. Previous studies showed that a protein alimentation with pollen mixture is more adequate for bees than monofloral pollen. The kind of pollen collected by bees is in close relationship with the vegetation spectrum of the hive surrounding area. Thus, if the bee colony is surrounded by areas characterised by intensive agriculture e.g. the Po Valley in Italy it may mainly collect monofloral pollen. In these areas, use of pesticides is generally widespread. The present study is based on the hypothesis that the quality of pollen available for the honey bee colony may influence the bee susceptibility to the intoxication by pesticides. For this reason, the same pesticide treatment could cause negligible or significant damages in relation to the availability of high-quality pollen (high amino acid diversity and high protein content). In the experimental apiary, in order to obtain newly emerged bees of the same age, the queen bee was isolated on a comb in a queen-excluding cage for about 30 hours. Subsequently the queen bee was removed from the cage and the comb was left isolated for another three days, to avoid further egg laying. The comb was incubated inside the beehive for 20 days in order to guarantee the most natural conditions, then it was moved to an emerging cage and kept at 34,5°C. The bees were incubated at this temperature until the end of the test. At the beginning of the emergence the bees were fed ad libitum with water, organic Robinia honey and a kind of pollen in relation to the thesis: Zea mays, Papaver, Cruciferae, Trifolium, Taraxacum or a mixture of pollen. Thus groups of bees provided with different pollen diets were obtained. On the 9 day, the bees were divided into groups of 20 individuals in small test cages in which clothianidin or fipronil pesticides considered as one of the possible causes of the recent colony losses in sucrose syrup (50%) were administered. Once the bees consumed completely the test solution, sucrose syrup (50%) was supplied ad libitum. Bee mortality was recorded and the LD50 of the active ingredients was calculated in relationship to the alimentation quality. In conclusion, the influence of the quality of protein nourishment provided during the first days of adult life on the response to intoxication by clothianidin and fipronil was shown as evidence. Bees fed with low-quality pollen (low amino acid diversity and low protein content) seem to be more susceptible to pesticide intoxication and other stress factors than bees fed with high-quality pollen.

In vitro pollination in poplar of section Populus

Two methods of in vitro pollination of aspen were tested and compared, first with moist pollen by transferring swollen pollen grains from a wet agar surface to the stigma and, second, using dry pollen grains. In vitro pollination with dry pollen grains appeared to be more efficient and this method was applied in three subsequent years. Additionally, pollination was performed with selected pollen grains in order to obtain triploid plants. Diploid pollen was induced by heat-treatment of pollen mother cells, but the enrichment of unreduced pollen from natural pollen mixtures was also successful. The selection of diploid pollen, which is larger in diameter than haploid pollen, was performed by sieving using micro sieves. Five triploid plants from different poplar combinations were obtained from 1,227 zygotic embryos cultured after in vitro pollination of 2,676 ovaries with dry pollen over 3 years. Embryo rescue was used to facilitate the development of immature zygotic embryos. The results of this study demonstrate the possibility to effect pollination using selected single pollen grains with the help of in vitro techniques.

With a little help from my friends: hybrid fertility of exotic Populus x canadensis enhanced by related native Populus nigra

Hybridization and genetic swamping by planted exotic Populus taxa are putative threats for native Populus resources. We investigated the potential for hybridization between the exotic hybrid Populus x canadensis Moench and its wild relative, the European black poplar (Populus nigra L.), by a series of pollination experiments in the greenhouse. We also tested the effect of mixtures of pollen from the taxon’s own pollen and pollen of the foreign taxon on mating success in reciprocal crosses. We observed reduced pollen and seed viability of the hybrid clones of P. x canadensis compared to the clones of the parental species P. nigra. Surprisingly, when in combination with pollen of its wild relative P. nigra, pollen of exotic P. x canadensis sired significantly better on its own flowers. In poplar breeding, the pollen mentor technique which uses pollen mixes of artificially inactivated conspecific pollen and untreated incompatible foreign pollen, has been successfully used to overcome incompatibility barriers. The results of this study suggest that in the wild, where mixed pollen loads are common, similar effects as the pollen mentor effects may enhance the invasiveness of exotic P. x canadensis. This study helps to explain former field observations and contributes to the understanding of potential environmental impacts of commercial exotic and transgene poplar plantations.

Comparative Study of the Nutritional Value of Four Types of Egyptian Palm Pollens

Pollen grains are good sources of vitamins, minerals and amino acids with a high nutritional value that can be used as human food supplement. Date palm pollens are used in the Middle East especially Egypt in herbal mixtures as a folk medicine remedy for curing male infertility and promoting fertility in women .The raw materials purchased from the market are found to be a mixture of several palm pollens. The main objective of this study was to determine the nutritional value of four local Egyptian date pollen grains {Amhat(A), Hiani(H), Sewy(S)& Zaghlol(Z)} by microscopical and chemical means. These differences could determine the quality of separate pollen grains and show to what extent they affect the quality of the natural products manufactured from them? Each of the pollen samples were treated identically: collected from locations of similar clay loamy soils, in March 2011 at an early time of the day, subjected to electron microscope examination and chemical analysis of trace elements, amino acids & vitamins. The results showed that there are clear differences in the quality of the four Egyptian palm pollens which could be distinguished microscopically and chemically by the percentage of the trace elements, amino acids & vitamins.

Increasing long-term safety of seasonal grass pollen sublingual immunotherapy: the ECRIT study

Objective: The usual build-up phase of days or weeks in allergen-specific immunotherapy entails inconveniences for individuals with symptoms only during the pollen season. Additionally, affected individuals often appear for treatment shortly before the expected start of the season without enough time for titration. This double-blind, placebo-controlled study evaluated the safety of ultra-rush grass pollen immunotherapy with sublingual drops (Staloral)® in co-seasonal treatment over three consecutive seasons.Methods: 209 patients with grass pollen allergic rhinitis received ultra-rush titration (30, 90, 150 and 300 index of reactivity (IR)) of a five grass pollen mixture or placebo every 20 min at the start of the season, followed by 300 IR daily or placebo until the end of the respective season for three consecutive years. Adverse events were documented.Results: Mean treatment duration varied between seasons (81.8 − 92.7 days). No systemic or anaphylactic reactions were reported and no unexpected adverse events were observed. Adverse events included application site irritation, oedema, abdominal pain and diarrhoea. Fourteen patients discontinued treatment due to adverse events (placebo: four (6%) patients, verum: ten (7%) patients). Adverse events decreased in frequency over each consecutive year of treatment.Conclusion: Seasonal sublingual immunotherapy with ultra-rush titration is well tolerated even when administered as co-seasonal treatment. It may be a valuable option for patients who present late.

Hybridization between diploidCentaurea pseudophrygiaand tetraploidC. jacea(Asteraceae): the role of mixed pollination, unreduced gametes, and mentor effects

We studied hybridization between the diploid Centaurea pseudophrygia and the tetraploid C. jacea by performing crossing experiments and screening natural populations using flow cytometry. The experiments confirm that the studied species exhibit strong reproductive isolation. Interspecific hybrids were formed at a low frequency, including triploids (originating from reduced gametes) and tetraploids (involving unreduced gametes of the diploids). In contrast, hybrids were almost absent among seeds and adult plants of natural mixed populations and among the offspring from experimental pollinations with a mixture of pollen of both ploidy levels. We found that mixed pollination is an important mechanism for preventing hybridization between plants of different ploidy levels and sustaining the reproduction of the tetraploids. A mentor effect (induced selfing in the presence of pollen of different ploidy levels) was observed in both diploids and tetraploids, reinforcing the reproductive isolation between cytotypes. Higher ploidy levels (pentaploid, hexaploid) involving unreduced gametes of the tetraploid species were identified. Notably, pentaploids were discovered for the first time in Centaurea sect. Jacea. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 104, 93–106.

Pollen Siring Success in the California Wildflower Clarkia unguiculata (Onagraceae)

Abstract Cryptic self-incompatibility (CSI) is a type of non-random mating observed in self-compatible plants in which outcross pollen sires proportionally more seeds than self pollen when both pollen types are available on the stigma. Levels of CSI are known to vary among individuals and populations. We conducted competitive pollinations consisting of mixtures of self and outcross pollen to investigate reports of CSI in certain populations of Clarkia unguiculata Lindl. We also investigated how the order of self and outcross pollen deposition on the stigma influences the degree of nonrandom mating. Finally, we looked at whether the source population of outcross pollen affected the ability of outcross pollen to outcompete self pollen. We utilized recessive (white-petaled) maternal (and self pollen donor) plants from a locality near Morro Bay, California, and dominant (pink-petaled) outcross pollen donor plants from 17 localities widespread through the species range in California. Progenies from pollination...

Honeybee-collected pollen from five Portuguese Natural Parks: Palynological origin, phenolic content, antioxidant properties and antimicrobial activity

The aim of this study was to determine the palynological origin, phenolic content, antioxidant and antimicrobial properties of pollen from five Portuguese Natural-Parks [Parque Nacional Peneda Gerês (PNPG); Parque Natural do Montesinho (PNM); Parque Natural do Alvão (PNA); Parque Natural da Serra da Estrela (PNSE) and Parque Natural do Douro Internacional (PNDI)]. Eight families were found in the mixture of bee pollen: Rosaceae, Cistaceae, Boraginaceae, Asteraceae, Fagaceae, Ericaeae, Myrtaceae and Fabaceae. The phenolic compounds content, determined by the Folin–Ciocalteu method, varied between 10.5 and 16.8mg of gallic acid equivalents/g of extract (mg GAE/g) found in bee pollen from PNM and PNDI, respectively. The free radical scavenging measured showed the highest effective extract – PNM with EC50 2.16, followed by PND with 2.24mg/mL. In the β-carotene bleaching assay the same behaviour as in the DPPH method was verified. We also verified that the presence of pollen differentially affected the growth of bacteria Gram-positive, Gram-negative and yeasts under study, depending this on the microorganism and the pollen used. This is an important study since, as far we know, it is the first time that Portuguese bee pollen from Natural Parks was studied, and their characterization can increase their economic value.

Single-Species Grass Pollen Extracts and Mixtures of Extracts From Multiple Phylogenetically Related Grass Species Activate Allergic Patients' Basophils to the Same Degree

RATIONALE: The necessity of complete identity between the sensitizing allergens and allergens used for immunotherapy has been debated. We have previously demonstrated that the effect of individual Derp2 isoforms on basophil activation is minimal, given a polyclonal IgE response (Christensen et al Journal of Immunology (2010) 184, 4966). Similarly, we here demonstrate that extracts of single-pollen and mixes of multiple grass species, respectively, activate basophils from grass-pollen allergic individuals to the same extent. METHODS: Blood basophils from grass allergic donors or basophils sensitized with IgE from grass allergic donors were incubated with either Phleum pratense, a 5-grass (Dac glo, Fes pra, Lol per, Phl pra, Sec cer) or 7-grass mix (Dac glo, Fes pra, Lol per, Phl pra, Poa pra, Arr ela, Sec cer). Activation was measured by flow cytometry. Also, alum-formulated vaccines in the form of Phleum pratense alone or grass mixes were compared in basophil activation assays. RESULTS: No differences in the ability of the single-species Phleum pratense extract and the 5- or 7-grass mixes to activate basophils from individual allergic donors were seen. Comparable responses were maintained after formulation of Phleum pratense and 5- and 7- species grass mixes with ALOH. CONCLUSIONS: Identical responses to single-species and multiple-species extract mixes in basophil activation assays indicate that in allergic individuals antibody responses to epitopes that are shared between different related grass species dominate over species-specific epitopes and -isoforms. This is in agreement with the confirmed clinically efficacy of single-species (Phleum pratense) grass pollen vaccines, both in subcutaneous and Allergy Immunotherapy Tablet regimens.

Local allergic rhinitis: Allergen tolerance and immunologic changes after preseasonal immunotherapy with grass pollen

Local allergic rhinitis: Allergen tolerance and immunologic changes after preseasonal immunotherapy with grass pollen

Microbial quality of honey mixture with pollen

The aim of this study was evaluation of microbial quality in raw materials (honey, pollen) and evaluation of microbial quality in honey mixture with pollen (2.91 % and 3.85 %) and also dynamics of microbial groups in honey mixtures with pollen after 14 days storage at the room temperature (approximately 25 °C) and in cold store (8 °C). We used dilution plating method for testing of samples. Detections of total plate microbial count (aerobic and anaerobic microorganisms), sporulating bacteria, coliform bacteria, Bifidobacterium sp., Lactobacillus sp. and microscopic fungi were performed. In general, counts of microorganisms decreased in honey mixture with pollen compared to raw pollen and these counts increased compared to natural honey. Total plate count was 5.37 log KTJ.g-1 in pollen; 1.36 log KTJ.g-1 in honey; 2.97 log KTJ.g-1 in honey mixture with 2.91 % pollen and 2.04 log KTJ.g-1 in honey mixture with 3.85 % pollen. Coliform bacteria were detected in pollen (1.77 log KTJ.g-1). Then, we found coliform bacteria in one sample of honey mixtures with pollen (2.91 %) - 1.00 log KTJ.g-1.Bifidobacterium species were detected only in raw pollen. We did not findLactobacillus sp. in any of the samples. Microscopic fungi were detected on two cultivating media. Yeasts were present in pollen sample (average 5.39 log KTJ.g-1), honey mixture with 2.91 % pollen (average 2.51 log KTJ.g-1) and honey mixture with 3.85 % pollen (average 1.58 log KTJ.g-1). Filamentous microscopic fungi were detectable in pollen (average 3.38 log KTJ.g-1), in honey (only on one medium: 1.00 log KTJ.g-1), in honey mixture with 2.91 % pollen (average 1.15 log KTJ.g-1) and in honey mixture with 3.85 % pollen (1.71 %). Raw pollen contained microscopic fungi as Absidiasp., Mucor sp., Alternaria sp. andEmericella nidulans. Honey mixture with 2.91 % pollen after storage (14 days) contained lower microbial counts when compared with the sample analyzed at the beginning, beside sporulating bacteria and filamentous microscopic fungi in sample stored at 8 °C. We recorded growth of anaerobic microorganisms in honey mixture with 3.85 % pollen after storage (8 °C, 25 °C / 14 days).

Investigation of pollen competition between wild and cultivated sorghums (Sorghum bicolor (L.) Moench) using simple sequence repeats markers

In self-compatible plant species stigmata receive a mixture of self and outcrossed pollen and competition between them is expected to play a major role in determining the pollen-mediated gene flow. The use of male sterile bait plants in field trials to demonstrate the rate of gene flow is questionable due to lack of pollination competition. However, little direct evidence has been published. A field experiment of male sterile and male fertile sorghum pollen recipient bait plants was conducted to evaluate pollen competition between wild and cultivated sorghums and the effects of pollen competition on gene flow assessment. Pollen competition between wild and cultivated sorghums was estimated from two-component pollen mixtures of wild and cultivated sorghum (1:1 ratio) applied to wild, cultivated and male-sterile maternal bait plants. Paternity was determined in the progeny using two diagnostic Simple Sequence Repeat markers. The study found that self pollen has higher seed-siring success. Maternal genotype influences the siring ability of the pollen donor components which significantly deviated from the 1:1 pollen loads. The study showed that published estimates of gene flow derived from studies using male-sterile bait plants seriously overestimate gene flow and that pollen competition may be a significant factor influencing outcrossing rates. The results suggest that the predominant direction of gene flow is from cultivated to wild sorghum, potentially leading to introgression of crop genes into wild sorghum. Pollen competition should be taken into account in gene flow estimation, since presence of self-pollen can account for over half of seed produced irrespective of maternal genotype.

Consumption rate of some proteinic diets affecting hypopharyngeal glands development in honeybee workers

The experiment was carried out under laboratory condition to study the consumption of some proteinic diets and their effect on hypopharyngeal glands (HPG) development during nursing period. The results showed that the bee bread and the pollen loads mixture with sugar (1:1) were more consumed by honeybee workers followed by Nectapol® and Yeast-Gluten mixture. The lowest consumption amount was recorded with traditional substitute. Clear differences were found in HPG development under feeding with different diets. The maximum development degree was observed when fed with bee bread followed by pollen loads and mixture from Yeast, Gluten and sugar (1:1:2). The acinal surface of HPG showed clear difference under feeding with difference diets. The largest area was recorded when honeybee workers fed on bee bread followed by Yeast-Gluten-sugar mixture (diet,4) and pollen loads(diet,2).

Variability of flowering of CMS corn tassels

The characteristics of flowering of CMS corn tassels are given. After a microscopic analysis of pollen grains and count of the kernel number on ears pollinated by a pollen mixture (of the tested yellow kernel and fertile white kernel lines), it is established that the pollen of semifertile plants is weakly viable and non-competitive. This allows referring plants of maternal forms with a flowering score of 1–2 to sterile.

Development and reproduction of Adalia bipunctata on factitious and artificial foods

The native coccinellid Adalia bipunctata (L.) (Coleoptera: Coccinellidae) may be an alternative to exotic species like Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae) for the biological control of aphid pests in Europe. The availability of adequate factitious or artificial foods may help optimize its mass production. This study examines the nutritional value of Ephestia kuehniella Zeller (Lepidoptera: Phycitidae) eggs plus bee pollen, pea aphids Acyrthosiphum pisum (Harris) (Hemiptera: Aphididae) and mixtures of bee pollen and cysts of Artemia franciscana Kellogg (Branchiopoda: Artemiidae) and/or a lyophilized artificial diet based on bovine meat and liver. Reproducing adults of A. bipunctata were obtained on all diets tested, but immature survival, adult weights, development times and reproductive rates differed among diets. Over 84% of first instars fed on E. kuehniella eggs plus pollen or aphids survived to adulthood. Feeding predator larvae on pollen combined only with A. franciscana cysts or artificial diet yielded 40–55% immature survival, but survival increased to 74% when all of these components were mixed. Adult weights of A. bipunctata on the mixtures of pollen, A. franciscana cysts and/or artificial diet were 55–75% of those on aphids or on E. kuehniella eggs plus pollen. Lifetime fecundity was superior on E. kuehniella eggs plus pollen (1,864 eggs) to that on the other diets (264–889 eggs). The use of mixtures of plant and animal foods for A. bipunctata and other predators may contribute to increasing the cost-effectiveness of commercial mass production by reducing inputs of natural prey like aphids, or of nutritious but expensive factitious foods like lepidopteran eggs.

التغيرات البيئيه للمسطحات المائيه في جنوب العراق إعتمادا على الدراسات البالينولوجيه

Palynological techniques are useful in reconstructing past environments, especially when other sources of information are lacking. We have embarked on a palynological study of the wetlands in Southern Iraq in an attempt to determine the nature and extent of past plant communities and other conditions prior to the drying of the wetland in the 1990s. Ten 1-m depth cores were collected from selected locations in marshes and shallow open water wetlands in Mesopotamian wetlands of Southern Iraq. Pollen diagrams from three short cores from the Hawizeh wetlands serve as a reference because this site has not been drained. The palynomorphs in these cores were Gramineae, Chenopodiaceae, Typha, Isonandra lanceolata, Bursarea, Artocarpus, Ireantea, Arenga, Crinum, Palmae, Navia, Tofieldia, Ipomorea, Xyris, and Morus. Fungal spores including Polyporisporites, Pluricellaesporites palyadosporites, Fusiformisporites, Spegazzinites indicus, Diporisporites, Plochmopellinites, Lycoperdon, Miliolinites, Dryadosporites constrictus, and Trichothyrites padapakarensis were noteworthy. Charcoal was scattered through the cores and indicate activities associated with human settlements. Many other forms of cuticles, filaments, insects, algae, and foraminifera test linings were also recorded. A second set of pollen samples were analyzed from 160 soil samples from eight cores collected from the wetland area which was dried during the 1990s. These data show a mixture of pollen and spores that could be used to evaluate past vegetation, climatic, and ecological changes. Preliminary results indicated that chenopodiaceous have increased while germinate types have declined which probably reflected desertification and a trend towards a more aeolian landscape during the 1990s. It is hoped that these studies will be useful in establishing conditions of the wetlands prior to destruction and will assist in setting restoration goals in the future. Case studies of one deep borehole (153 m) near Amara city for evaluating late Quaternary history and dig of 3 m depth to evaluate ancient desertification by wetland dryness were taken for correlation and connection with this recent sediment.

Utilization of the S-locus as a Genetic Marker in Cherry to Differentiate Among Different Pollen Donors

Fruit set in sweet (Prunus avium L.) and sour cherry (P. cerasus L.) is frequently less than adequate for profitable production despite the availability of compatible pollen and abundant flowers. When fruit set consistently falls below acceptable levels, growers may attempt to increase fruit set by increasing the availability of compatible pollen. We describe the use of the self-incompatibility locus (S-locus) as a genetic marker to quantify the relative contributions of competing pollen sources in achieving fruit set in ‘Balaton™’ sour cherry. Pollen race experiments were conducted to determine if nonself-pollen provided in a pollen mixture was more competitive than self-pollen in achieving fruit set in ‘Balaton™’. We further investigated what pollen set the ‘Balaton™’ crop in two commercial ‘Balaton™’ orchards where multiple potential pollinators were planted in adjacent orchards. S-allele genotyping using DNA extracted from the seed was done to discriminate among the competing pollen sources. The results suggest that in certain environmental conditions, nonself-pollen may be more competitive in achieving fruit set in ‘Balaton™’ than self-pollen. These examples illustrate how seed genotyping can be used to further our understanding of the competitive abilities of different pollen sources in both controlled experiments and production orchards.

Quercetin-metabolizing CYP6AS enzymes of the pollinator Apis mellifera (Hymenoptera: Apidae)

Although the honey bee (Apis mellifera) genome contains far fewer cytochrome P450 genes associated with xenobiotic metabolism than other insect genomes sequenced to date, the CYP6AS subfamily, apparently unique to hymenopterans, has undergone an expansion relative to the genome of the jewel wasp (Nasonia vitripennis). The relative dominance of this family in the honey bee genome is suggestive of a role in processing phytochemicals encountered by honey bees in their relatively unusual diet of honey (comprising concentrated processed nectar of many plant species) and bee bread (a mixture of honey and pollen from many plant species). In this study, quercetin was initially suggested as a shared substrate for CYP6AS1, CYP6AS3, and CYP6AS4, by its presence in honey, extracts of which induce transcription of these three genes, and by in silico substrate predictions based on a molecular model of CYP6AS3. Biochemical assays with heterologously expressed CYP6AS1, CYP6AS3, CYP6AS4 and CYP6AS10 enzymes subsequently confirmed their activity toward this substrate. CYP6AS1, CYP6AS3, CYP6AS4 and CYP6AS10 metabolize quercetin at rates of 0.5+/-0.1, 0.5+/-0.1, 0.2+/-0.1, and 0.2+/-0.1 pmol quercetin/ pmol P450/min, respectively. Substrate dockings and sequence alignments revealed that the positively charged amino acids His107 and Lys217 and the carbonyl group of the backbone between Leu302 and Ala303 are essential for quercetin orientation in the CYP6AS3 catalytic site and its efficient metabolism. Multiple replacements in the catalytic site of CYP6AS4 and CYP6AS10 and repositioning of the quercetin molecule likely account for the lower metabolic activities of CYP6AS4 and CYP6AS10 compared to CYP6AS1 and CYP6AS3.

Food consumption and immature growth of Adalia bipunctata (Coleoptera: Coccinellidae) on a natural prey and a factitious food

One factor limiting the adoption of aphidophagous coccinellids in augmentative biological control is cost-effective mass production. The use of factitious foods may lower production costs by reducing space and manpower requirements for mass rearing of the predator and its prey and by enhancing mechanization of rearing procedures. The objective of this study was to compare the efficiency of food conversion, consumption indices and growth rates of first to fourth instars of Adalia bipunctata when fed either a mixture of Ephestia kuehniella eggs and fresh bee pollen, or on the natural prey Myzus persicae. Larval survival did not differ among treatments, averaging 80 and 90% on the respective diets. Mean dry body weights of the coccinellid were significantly lower on M. persicae than on the factitious food only for second instars and the pre-pupal stage. Dry food consumption by the predator throughout larval development averaged 20.61 mg on factitious food and 14.82 mg (corresponding to an average of 284 third and fourth instars) on M. persicae. The efficiency of conversion of ingested food for total larval development averaged 25 and 30% on factitious food and aphids, respectively. The relative growth rate of the larval instars was higher on aphids, whereas the consumption index was higher on the mixture of E. kuehniella eggs and pollen. An additional experiment showed that rearing the previous instars on the factitious food had no substantial effect on aphid consumption in the fourth instar. The study suggests that this factitious diet may be an appropriate food source for mass rearing A. bipunctata.