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Since 2011, the Florida Keys Mosquito Control District (FKMCD) has used the WALS® application strategy with VectoBac® WDG containing Bacillus thuringiensis israelensis via helicopter in Key West for the control of Aedes aegypti larval populations. In 2018, FKMCD conducted a study to determine the effectiveness of using a trailer-mounted A1 Super Duty Mist Sprayer® (A1 Mist Sprayers) with a Micronair® AU5000 (Micron Group) atomizer to apply VectoBac WDG by ground at the rate of 0.5 lb/acre (0.56 kg/ha). Bioassay cups were placed in a residential area encompassing open, moderate, and heavy cover scenarios between 0 and 300 ft (0–91.44 m) perpendicular to the spray line. An application rate of 0.5 lbs/acre (0.56 kg/ha) was used. Bioassay cups were collected after application and returned to the laboratory where 100 ml of distilled water and 10 F1 generation Ae. aegypti larvae were added. Laval mortality was monitored at 2, 4, and 24 h. Three separate runs were completed during the summer of 2018. Average larval mortality at 24 h was >90%. The field trial demonstrated sufficient efficacy to introduce this method of larviciding into operational use.

Context Recently, Chee Fah and Fah Luang chickens have been registered as a black-bone native chicken in Thailand. Only a few studies revealed genetic information about them. No publication has reported any data related to their cross-mating, particularly, genetic parameters. Aims This study aimed to estimate genetic parameters for production traits of F1 generation of reciprocal crossbred Chee Fah and Fah Luang chickens. Methods A dataset of production traits of two crossbred groups was used in the present study. Effects of breed, month-day of incubation and sex were tested at P

Using Irradiation technique is a well-established tool alternative to chemicals for pest control and food preservation. This work was designed to compare between gamma and microwave irradiation in controlling the drugstore beetle (Stegobium paniceum L.). Four choice tests were designed for the study: choice packets, choice non-packets, non-choice packets and non-choice non-packets. Newly emerged adults of S. paniceum were introduced to the packets (tea bags) or to the peppermint from packets which were irradiated with gamma and microwave rays (6, 8 and 10kGy) (for 1, 2 and 3 mins.), respectively. The results displayed a significant reduction in the number of F1 and F2 generations and a significant increase in the development time of F1 generation, which were more pronounced in peppermint irradiated with gamma radiation. The biochemical analysis of the irradiated peppermint exhibited a significant increase in total phenol and flavonoid contents in the samples irradiated with gamma radiation, while, in peppermint irradiated with microwave the total phenols only was significantly raised. Therefore, we concluded that the storage of peppermint after irradiation with 10kGy without packets is suitable and insect could not develop in it.

Four candidate gallinacin polymorphic genes were sequenced in one direction from Fayoumi (F), Rhode Island Red (R) and their crosses (½R½F and ½F½R). Pairwise bioinformatics sequencing of GAL genes of the parents relative to F1 generation was identified. Bioinformatics analyses of GAL genes showed many sequence variations. The pairwise sequence alignment between F and ½F½R were identified, being 17 SNPs with identity ratio of 97% for GAL 2 gene, many SNPs and gaps with low identity ratio of 50% for GAL 3 gene, ten SNPs with identity ratio of 98% for GAL 4 gene and 18 SNPs with identity ratio of 97% for GAL 5 gene. Between F and ½R½F there were 11 SNPs with identity ratio of 98% for GAL 2 gene, 15 SNPs with identity ratio of 98% for GAL 3 gene, 20 SNPs with identity ratio of 96% for GAL 4 gene and many SNPs with low identity ratio of 50% for GAL 5 gene. Between R and ½F½R, the sequence in GAL 2 gene were 12 SNPs with identity ratio of 98%, 38 SNPs with identity ratio of 94% in GAL 3 gene, many SNPs and gaps with low identity ratio of 50% in GAL 4 gene and 37 SNP with identity ratio of 90% in GAL 5 gene. The sequence between R and ½R½F being 21 SNPs with identity ratio of 96% for GAL 2 gene and many SNPs and gaps with low identity ratio of 50% for GAL 3 gene. The gene SNP-trait associations are not identical among all genes in the gallinacins cluster.Bioinformatics analyses of GAL genes showed many sequence variations and mutations in intronic regions. The SNPs identified in gallinacin genes could be used in marker assisted selection in breeding program to enhance immune responses to Salmonella disease in chickens.

Aim: To study the long-term effects of exposure of pregnant Wistar rats to low dose of bisphenol A (BPA) by measuring to the level of steroid hormones and sexual behavior of adult male offspring of the first generation. Material and research methods: BPA as part of the Dorfman gel was gavaged during the last week of pregnancy, when androgen-dependent sexual brain differentiation occurs, in a daily dose of 25 mcg/kg b.w. (threshold teratogenic dose). Male sexual behavior was evaluated by proceptive reactions, the duration of latent and refractory periods, the number of mounts, intromissions and ejaculations in the presence of a receptive female. Female sexual behavior was assessed by lordosis reactions of orchidectomized and activated by the introduction of estradiol and progesterone males in the presence of a normal male. A neuromorphological analysis of the sex-dimorphic area of the brain, the medial preoptic nucleus of the hypothalamus, was performed by histological examination and karyometry of neurons. Results: Prenatally administered BPA caused a very slight increase in the anogenital distance in newborn animals and did not affect the terms of puberty. The levels of testosterone and corticosterone in the blood plasma of males of 6 months of age did not differ from the control indices. At 10 months of age, all experimental males showed sharply weakened sexual motivation for mating with females, and in 4 from 5 animals, copulative components of sexual behavior were absent. There was no ejaculations in the 5th male as well, while numbers of the mounts without intromissions and ones with intromissions significantly reduced. In the BPA group, all descendants showed active female behavior in the presence of a normal male, which manifested in lordosis reactions and a high lordosis index. According to the histological study of medial preoptic nucleus, the activity of neurocytes in the male offspring of BPA-exposed females was significantly reduced, and their nuclei volume distribution was some different from the control. Conclusions: The data obtained indicate epigenetic disorders of the sexual brain differentiation program due to the prenatal exposure to BPA in dose that does not cause significant teratogenic effects. This should be taken into account when evaluating the potential hazard of BPA for reproductive health. Key words: bisphenol A, prenatal effect, male rats, sexual behavior, corticosterone, testosterone.

This study was carried out in Andro Research Farm, CAU, Imphal to study diallel analysis of yield and its important components in 10 genotype of wheat during two consecutive rabi season 2017-2019. All the 10 genotype and their 45 F1’s cross combination exhibited significant difference in characters under study Combining ability analysis showed that both gca and sca variances value were highly significant for most of traits studied in F1 progenies which suggest importance of both additive as well as non-additive genetic components for the expression of characters under study. VL 3017 was found good general combiner for the characters like fifty percent flowering, days to eighty percent maturity, plant height, total number of tillers per hill, total number of spikelets per spike, spike length, total number of filled grains per spike and grain yield per plant. Among all 45 crosses, cross combination VL 3018 x HS 490 and VL 892 x UP 3017 were good specific combiners for the grain yield per plant character in F1 generation.

In this paper, the theory of heterosis controlled by core traits (genes) was put forward. Growth period traits and stem type traits were two core traits of heterosis in crops. However, due to the low yield of early-maturing parents, although the relative advantage was high, the absolute yield level of heterosis in the F1 generation was not necessarily high. Because seed production requires that the difference between two parents’ growth periods should not be very big, it also limited the potential of using gene interaction of growth periods to improve heterosis. In addition, the genes that control the growth period also included the genes that control each growth stage, so that the genes that control the growth period were not many, but not very few, because there were more genes that disperse and weaken the action intensity of major genes and increasing heterosis of the F1 generation was difficult. The genes controlling different stem types were all single. When the maturity of two parents is the same or similar, the combinations with different stem types got the maximum heterosis of grain yield, and the F1 absolute yield level is also the highest. Therefore, in heterosis utilization breeding, the differences of stem types should be mainly used and differences of growth periods should be properly used. Mechanism and root producing heterosis of crops were that strong interaction of major genes among different types of the most important quality traits (ecological traits) lead to great improvement in the vitality of all quantitative traits. Growing period and Stem type were two nucleus traits producing heterosis of crops. Therefore this theory was called as core trait theory producing heterosis of crops.

U ovome istraživanju prikazana je varijabilnost visine biljaka i broja klasova po klasu u dvije kombinacije križanja. Korištena jednostavna metoda hibridizacije u kojoj se kao majčinska biljka odabrao kultivar koji je izdvojen prema svojstvima od interesa. Kultivar Beaver odabran je kao majčinska komponenta, a kultivari Achat i Mv Kucsma kao očinske komponente. Provedena je hibridizacija majčinske biljke s očinskim komponentama, te su razvijene F₁ i F₂ generacije. Biljni materijal je uzgojen na pokušalištu „Tenja“ Fakulteta agrobiotehničkih znanosti. Svojstvo visine biljke i svojstvo broj klasova po biljci su kvantitativna svojstva koja određuje velik broj minor gena koji su osjetljivi na utjecaj činitelja vanjske sredine. Cilj ovog istraživanja je jednostavnom hibridizacijom pšenice u dvije kombinacije križanja dobiti podatke o navedenim svojstvima u F₁ i F₂ generaciji, te analizom podataka usporediti distribucije varijanata u obje kombinacije križanja. Analizom podataka kombinacije križanja Beaver i Achat utvrđena je mogućnost intermedijarnim načinom nasljeđivanja svojstvo visine biljke, a analiza podataka za svojstvo broj klasova po biljci ukazuje na pojavu transgresivnog cijepanja. Analizom podataka druge kombinacije križanja Beaver i Mv Kucsma za svojstvo visine biljke ukazuje na mogućnost pokazuje punom dominacijom kao načina nasljeđivanja i visine biljke i broja klasova po klasu., Variability of plant height and number of spikes per plat was examined in two cross combinations. A simple hybridization method was used in which maternal component was selected according to the characteristics of interest. The Beaver cultivars was maternal, while cultivars Achat and Mv Kucsma were selected as paternal components. A cross between maternal plant and two paternal plants was carried out, and F ₁ and F ₂ generations were produced. All plant material was grown at filed trial “Tenja” of the Faculty of agrobiotechnical sciences. Plant height and spike number per plant are quantitative traits controlled by many minor genes which are under great influence of external factors. The aim of this research is to obtain data on variability and distribution of plant height and number of spikes per plant between parental and F ₁ and F ₂ generations in two cross combinations. After data analysis possibility of intermediate gene effect of plant height in cross combination Beaver and Achat was presumed possibility of transgressive segregation. Data analysisi of second cross combination between Beaver and Mv Kucsma revealed the possibility of full dominance for plant height as well number of spikes per plant.

The experiment was conducted in a well-known private livestock research and development farm in Bangladesh to find out the variation of semen quality parameter among three generations (F1, F2 and F3) of Holstein Friesian upgraded breeding bulls. A total of 312 ejaculates were collected from 6 upgraded breeding bullsthrought the experimental year. The recorded data were summarized using Microsoft Excel 2010 and analyzed using GraphPad Prism 5 softwere. Out of the 312 ejaculates, 273 (87.50%) were found to be creamy in color followed by 26 (8.33%) and 13 (4.17%) as yellowish and watery, respectively. Generation had significant (P0.05) but initial motility and post freezing motility had the significant differences among the three generations. Initial motility ranges from 75.87±0.32 to 78.40±0.38 percent and the post freezing motility ranges from 50.38±0.41 to 52.16±0.43 percent. It could be concluded that most of the semen quality parameters were influenced by generation and freezing. Semen characteristics were better in F2 followed by F3 and F1 generation in upgraded Holstein Friesian bulls. Res. Agric., Livest. Fish.7(3): 457-463, December 2020

The reproductive stage in many crops including Maize (Zea mays L.) is most sensitive to heat stress. Due to limitations in sporophytic selection, an alternative pollen selection approach opens a way for breeders to develop heat stress resilient lines. In present study, the efficiency of different methods of pollen selection for heat stress tolerance was evaluated. The effect of selection in F1 generation in terms of the frequency of heat-tolerant plants in F2 generation was assessed. The heat susceptible line BTM4 was crossed to heat-tolerant BTM6, and the true F1 plants were identified using two SSR markers. Three different methods of pollen selection for heat tolerance, viz. incubating the freshly dehisced pollen grains of F1 plants at 36 °C for 3 h in growth chamber (GRC), dry bath (DB) before selfing and growing F1 plants in summer at ARS, Bheemarayanagudi (BGD). Thus, selected F2 from different treatments was produced. The control F2 was also produced without heat treatment of pollen grains. The control and selected F2 population were compared for heat tolerance by selfing the F2 plants with heat-stressed pollen grains. The selected F2 (GRC) showed superiority over other methods for seed yield traits and its component traits and also positive effect of pollen selection for heat tolerance.

Irradiation is a quarantine treatment option for stored product pests. In the present studies, we try to investigate the effect of low gamma irradiation doses in the range of 20–300 Gy on the different developmental stages of Rhyzopertha dominica in wheat grains. It was found that no adults emerged after irradiation of eggs, larvae, and pupae at 140, 240, and 260 Gy, respectively. Treatment of adult weevils at the radiation dose of 180 Gy resulted in 71.33% mortality after 14 days post-treatment and there was no adult emergence in the F1 generation. When the adult emergence of the F1 generation was used for the measuring effective irradiation dose and phytosanitary efficacy, 280 Gy was required for quarantine security of wheat weevils. The comet assay serves to verify the DNA damage induced by the phytosanitary irradiation dose, 280 Gy on the R. dominica, and wheat grains. DNA damage was measured as the percentage of comet tail DNA. A significant linear increase in DNA damage was observed in the irradiated adult stage of R. dominica but there is no DNA damage in the wheat grains. Also, the wheat grains viability (in terms of wheat germination) was not affected by the dose level, 280 Gy. Thus, an irradiation dose of 280 Gy is recommended as an effective phytosanitary irradiation dose for quarantine security to control lesser grain borer.

Wheat (Triticum aestivum L.) is number one cereal of the world and is grown on the largest area. Field experiment conducted at Crop Research Farm, Nawabganj of CSAUA&T in Kanpur. In this study the high heritability and high genetics advance for the twelve characters were observed in normal conditions. In different genotypes, high heritability (narrow sense) were recorded for days to maturity, one thousand grains weight, grain weight per spike, number of grains per spike, number of tillers per plant and while moderate heritability were found for plant height, harvest index, grain yield per plant, biological yield, spike length (cm) and days to 50% heading whereas number of spikelets per spike showed low heritability. The estimate of genetic advance in percentage over mean ranged from 5.56 (days to maturity) to 43.04 (number of productive tillers per plant) in Fl generation. The high value of genetic advance was recorded for number of tillers per plant. Moderate genetic advance were recorded for days to 50% heading, plant height (cm), spike length (cm), 1000 grain weight (g), grain weight per spike (g), biological yield per plant (g), grain yield per plant and harvest index. Low values of genetic advance were recorded for days to maturity, number of spikelets per spike and number of grain per spike in F1 generation.

The aim of this study was to investigate the biological efficacy of diatomaceous soil against Khapra beetle ( Trogoderma granarium Everts) larvae which has gained importance in agriculturalpest management in Turkey in recent years.The experiments were carried out with three different diatomaceous earth (two native diatomaceous earth, Ankara, Aydin provinces and SilicoSec® imported brand) two different temperatures (25 and 30 °C) and 50-65% humidity cultivar with four different doses, i.e., 0, 1000, 1500, 2000 ppm and four replications for each treatment under controlled conditions. Dead-live counts of the larvae counts were made 7, 14 and 21 days after diatomaceous earth applications and 60 days after the end of the experiments, fertility of F1 generation was determined separately for each treatment. The biological activity of native diatomaceous earths on Khapra larvae increased with increasing application dose, exposure time and temperature. The highest biological activity was determined for Aydin diatom earth with 2000 ppm on day 21 (65.4 %), followed by Ankara diatom (53.8 %) at 30 °C, whereas the effect of SilicoSec®was determined to be the lowest (11.9%). Besides, biological activity of three diatomaceous earth at 25 °C was recorded very low (the highest rate was 30.7% for Ankara 21 days with 2000 ppm). No differences were found in terms of F1 offspring (15.2-18.7%) in all diatomaceous earth replications at 25 °C after days, whereas the lowest (9%) F1 offspring was recorded at 30 °C with 2000 ppm dose. As a result, it was determined that native diatomaceous earths were more effective and promising on khapra larvae than SilicoSec® branded diatomaceous earth.

Irradiation is a physical, environmentally friendly treatment which does not leave any residues in the product. It is increasingly used as an alternative to methyl bromide and other chemical fumigants for disinfestation of insect pest in stored grains. In this research, we try to evaluate the effect of low gamma irradiation doses in the range of 50–1200 Gy on the different stages of Callosobruchus maculatus. It was found that no adults emerged after irradiation of eggs at 450 Gy. No emerging adults (F1 generation) have been shown when larvae or pupae were exposed to 650 Gy. Also, no emerging adult has been shown from the parental C. maculatus adults irradiated with 650 Gy. When suppression of F1 generation was used for the measuring effective irradiation dose and phytosanitary efficacy, 650 Gy was required for disinfestation of cowpea seed weevils. The irradiation dose level of 650 Gy was used for the large-scale confirmatory tests applied to 27,754 adults of C. maculatus in cowpea seeds resulting in non F1 adults' production with a confidence level of 93.77%. All the physical and chemical characteristics of cowpea seeds were non-significantly (P ≤ 0.05) affected by the irradiation dose of 650 Gy. Meanwhile, this irradiation dose very slightly reduced the microbial load of cowpea seeds. We recommend the generic dose 650 Gy as the phytosanitary irradiation dose for the cowpea seed weevil.

Guizotia abyssinica(L.F.) Cass. is one of the important oilseed crops cultivated in India. The seed of the plant is used by the tribal and rural people of our country as a source of edible oil. The present investigation of the Niger plant deals with the study of the back cross-program and improvement in the variety. Unknown local variety (A) of niger was selected as a non-recurrent parent because of having some desirable characters like less vegetative growth (dwarf), resistance to waterlogged condition, and large seed grains while IGP-76 variety (B) was selected as a recurrent parent and used as a female having characters like small black grains, resistant to leaf-eating cater Piller and powdery mildew result shows successfully transfer of the characters in the F1 generation. The average number of capitulum/plant shows very good and positive results in F1 as well as BC1 generation. As compared to the recurrent parent (B) an average number of capitulum per plant was increased in F1 generation by 14.28% and in BC1 generation by 28.5%. The table indicates that there is incensement in the average number of seeds per capitulum. The average number of seeds per capitulum was increased by 8.3% in the F1 generation and by 11.11 % in the BC1 generation as compared to the recurrent parent. Average weights of 1000 seeds were also increased in F1 generation by 31.78% and in BC1 generation by 47.28% along with the total yield per plant.

1.AbstractThe aim of this study was to investigate the effect of ocean acidification (OA) and warming (OW) as well as the transgenerational effect of OA on larval and juvenile growth and metabolism of a large economically important fish species with a long generation time. Therefore we incubated European sea bass from Brittany (France) for two generations (>5 years in total) under current and predicted OA conditions (PCO2: 650 and 1700 µatm). In the F1 generation both OA condition were crossed with OW (temperature: 15-18°C and 20-23°C). We found that OA alone did not affect larval or juvenile growth and OW increased developmental time and growth rates, but OAW decreased larval size at metamorphosis. Larval routine metabolic rate (RMR) and juvenile standard metabolic rate (SMR) were significantly lower in cold compared to warm conditioned fish and also lower in F0 compared to F1 fish. We did not find any effect of OA on RMR or SMR. JuvenilePO2critwas not affected by OA, OW or OAW in both generations.We discuss the potential underlying mechanisms resulting in beneficial effects of OW on F1 larval growth and RMR and in resilience of F0 and F1 larvae and juveniles to OA, but on the other hand resulting in vulnerability of F1, but not F0 larvae to OAW.. With regard to the ecological perspective, we conclude that recruitment of larvae and early juveniles to nursery areas might decrease under OAW conditions but individuals reaching juvenile phase might benefit from increased performance at higher temperatures.Summary statementWe found that OA did not affect developmental time, growth, RMR and SMR, while OW increased these traits. OAW decreased larval size at metamorphosis. We discuss underlying mechanisms and the ecological perspective resulting from these results and conclude that recruitment to nursery areas might decrease under OAW conditions but individuals reaching juvenile phase might benefit from increased performance at higher temperatures in Atlantic waters.

The pea aphid Acyrthosiphon pisum has a worldwide distribution and causes serious losses for agricultural production. Drunken horse grass Achnatherum inebrians is a widely distributed perennial poisonous grass on the grasslands of Northern and Northwestern China. The present study focused on contact toxicity activity of aqueous extracts of endophyte-infected (E+) and endophyte-free (E−) A. inebrians in different growth periods of pea aphids, and the growth and development of two color morphs of F1 generation nymphs. Both of the color morphs had development durations in E+ treatments that tended to be longer at 1st, 2nd, 3rd, and 4th instars than E− and control (CK). The E+ treated aphids also showed decreased weights at maturity with over all lower mean relative growth rates (MRGR). Aphid survival of E+ treated aphids was lower than that of E− and CK at all growth periods. Seeding stage E+ extracts showed a greater propensity for negatively affecting aphids than did E+ extract at maturity and the yellowing stage. These results show that extracts from endophyte-containing plants may contain compounds that may be used to control insects.

Although the number of vaping-related deaths in the US is rising, the specific cause remains unidentified. Therefore, determining what long-term effects vegetable glycerin (VG) and propylene glycol (PG), the main non-nicotine components in e-cigarettes, may have is crucial. Discovering that these components are harmful when tested on fruit flies (Drosophila melanogaster), a model organism, may suggest similar effects in humans. In this study, the number of offspring, changes in behavior, and phenotypic mutations in fruit flies were observed for the parent, F1, and F2 generations after the parent generation was exposed to one of four treatments of aerosolized solution. These included a 50% PG/50% VG, a 30% PG/70% VG, a 70% PG/30% VG, or no solution (control) using a nebulizer for 18 seconds each day, for two days. It was found that each experimental group had fewer offspring than the control. A two-sample T-test (α = 0.05) was used to find that the size of the flies in the F1 generation was statistically significantly smaller in ⅔ of the experimental groups when compared to the control. Furthermore, it was observed using a two-proportion Z-test (α = 0.05) that ⅔ of experimental groups in the parent generation, and all F1 experimental groups were statistically significantly more likely to develop at least one phenotypic mutation than the control. Additionally statistically significant changes were seen in activity patterns and reflex immediately after exposure. Overall, it is probable that exposure to aerosolized VG and PG is a major problem. Although the number of vaping-related deaths in the US is rising, the specific cause remains unidentified. Therefore, determining what long-term effects vegetable glycerin (VG) and propylene glycol (PG), the main non-nicotine components in e-cigarettes, may have is crucial. Discovering that these components are harmful when tested on fruit flies (Drosophila melanogaster), a model organism, may suggest similar effects in humans. In this study, the number of offspring, changes in behavior, and phenotypic mutations in fruit flies were observed for the parent, F1, and F2 generations after the parent generation were exposed to one of four treatments of aerosolized solution. These included a 50% PG/50% VG, a 30% PG/70% VG, a 70% PG/30% VG, or no solution (control) using a nebulizer for 18 seconds each day, for two days. It was found that each experimental group had fewer offspring than the control. A two-sample T-test (α = 0.05) was used to find that the size of the flies in the F1 generation was statistically significantly smaller in ⅔ of the experimental groups when compared to the control. Furthermore, it was observed using a two-proportion Z-test (α = 0.05) that ⅔ of experimental groups in the parent generation, and all F1 experimental groups were statistically significantly more likely to develop at least one phenotypic mutation than the control. Additionally statistically significant changes were seen in activity patterns and reflex immediately after exposure. Overall, it is probable that exposure to aerosolized VG and PG is a major problem.

Herbivorous insects can escape the strong pressure of parasitoids by switching to feeding on new host plants. Parasitoids can adapt to this change but at the cost of changing their preferences and performance. For gregarious parasitoids, fitness changes are not always observable in the F1 generation but only in the F2 generation. Here, with the model species and gregarious parasitoid Anaphes flavipes, we examined fitness changes in the F1 generation under pressure from the simulation of host switching, and by a new two-generation approach, we determined the impact of these changes on fitness in the F2 generation. We showed that the parasitoid preference for host plants depends on hatched or oviposited learning in relation to the possibility of parasitoid decisions between different host plants. Interestingly, we showed that after simulation of parasitoids following host switching, in the new environment of a fictitious host plant, parasitoids reduced the fictitious host. At the same time, parasitoids also reduced fertility because in fictitious hosts, they are not able to complete larval development. However, from a two-generation approach, the distribution of parasitoid offspring into both native and fictitious hosts caused lower parasitoid clutch size in native hosts and higher individual offspring fertility in the F2 generation.

Phthalates are used in many consumer products, leading to daily human exposure. Although many studies focus on single phthalates, humans are exposed to mixtures of phthalates. Our laboratory created a phthalate mixture consisting of six different phthalates and found that it negatively affected female reproduction and accelerated some biomarkers of reproductive aging. However, it was unknown if prenatal exposure to the mixture accelerates the natural decline in reproductive capacity and ovarian aging in mice. Therefore, we tested the hypothesis that prenatal exposure to a phthalate mixture accelerates the age-related decline in reproductive capacity and biomarkers of ovarian aging in the F1 generation of mice. Pregnant CD-1 dams were orally dosed with control or phthalate mixture (20 µg/kg/day–200 mg/kg/day) daily from gestational day 10—birth. The F1 female pups were aged to 11–13 months, and then estrous cyclicity and breeding trials were conducted at 11 and 13 months. Ovaries were collected from the F1 females at 13 months to examine biomarkers of ovarian aging. Prenatal exposure to the phthalate mixture decreased the time the F1 females spent in proestrus and the ability of the F1 females to give birth at 11 and 13 months of age compared to control. In contrast, prenatal exposure to the mixture did not affect biomarkers of direct aging of the ovary in the F1 generation. Collectively, our data show that prenatal phthalate mixture exposure accelerates the natural age-related decline in reproductive capacity but may not affect some biomarkers of ovarian aging in the F1 generation.

Variable spring temperatures may expose developing insects to sublethal conditions, resulting in long-term consequences. The alfalfa leafcutting bee, Megachile rotundata, overwinters as a prepupa inside a brood cell, resuming development in spring. During these immobile stages of development, bees must tolerate unfavorable temperatures. In this study, we tested how exposure to low temperature stress during development affects subsequent reproduction and characteristics of the F1 generation. Developing male and female M. rotundata were exposed to either constant (6°C) or fluctuating (1 h day−1 at 20°C) low temperature stress for 1 week, during the pupal stage, to mimic a spring cold snap. Treated adults were marked and released into field cages, and reproductive output was compared with that of untreated control bees. Exposure to low temperatures during the pupal stage had mixed effects on reproduction and offspring characteristics. Females treated with fluctuating low temperatures were more likely to nest compared with control bees or those exposed to constant low temperature stress. Sublethal effects may have contributed to low nesting rates of bees exposed to constant low temperatures. Females from that group that were able to nest had fewer, larger offspring with high viability, suggesting a trade-off. Interestingly, offspring of bees exposed to fluctuating low temperatures were more likely to enter diapause, indicating that thermal history of parents, even during development, is an important factor in diapause determination.

The epidemiology of Tomato chlorosis virus (ToCV) in China is closely associated with its vector whitefly, Bemisia tabaci (Gennadius) MED. However, the transmission characteristics of ToCV by B. tabaci MED remain poorly understood. In this study, we analyzed: 1) the horizontal and vertical transmission of ToCV by B. tabaci MED whiteflies; 2) the acquisition of ToCV by male and female B. tabaci MED whiteflies after different feeding durations; 3) the transmission efficacy of viruliferous male and female B. tabaci MED whiteflies after different inoculation access periods (IAPs); 4) the retention of ToCV by viruliferous male and female B. tabaci MED whiteflies after a 48 h acquisition access period (AAP); and 5) the effects of ToCV on host choice of healthy or ToCV-infected tomato plant of viruliferous and non-viruliferous B. tabaci MED at different time points. Our results showed that: 1) viruliferous males could not transfer ToCV to non-viruliferous females, and vice versa, viruliferous females could not pass on ToCV to non-viruliferous males. ToCV could not be detected in the F1 generation adults; 2) ToCV could be detected within 4.0% of females or males after a 20 min AAP; 3) ToCV could be detected in 33.3% of tomato plants inoculated by 10 viruliferous males or females with IAPs of 20 or 30 min; 4) the maximum retention time in females was 7 and 5 days in males; and 5) non-viruliferous B. tabaci MED did not show a preference for ToCV-infected tomato plants or healthy tomato plants. However, viruliferous B. tabaci MED whiteflies did prefer to settle on healthy tomato plants over ToCV-infected tomato plants. These findings will be helpful to better understand the epidemiology of the recently emerged plant virus, ToCV, in tomato fields in China.

The oriental armyworm, Mythimna separata is an important crop pest in eastern Asia. Nocturnal insects, including nocturnal moths, have phototactic behavior to an artificial light source. Phototactic behavior in insects is species-specific in response to different wavelengths of light sources. Our previous study showed that green (520 nm) light emitting diode (LED) light resulted in a significantly higher phototactic behavior in M. separata moths compared to the other wavelength LED lights. The goal of the present study is to investigate the influence of green light illumination on biological characteristics of different developmental stages in M. separata. Our results revealed that when different developmental stages of M. separata were exposed to the green light illumination in a dark period, several biological characteristics in all developmental stages except for egg stage were positively changed, but those of F1 generation M. separata which are next generation of the adults exposed to the green light did not significantly change compared with the control level. These findings suggest that green light illumination at night (or dark period) has a positive effect on the development and longevity of M. separata.

Background Previous studies have shown that cypermethrin has a teratogenic effect on rat feti born to exposed dam or buck with no information on its effect on their reproductive parameters at maturity. The present study was aimed at evaluating the reproductive effect of perinatal beta cypermethrin (β-cyp) exposure on female F1 generation rat. Methods Fifteen pregnant animals (day 0 = day of mating, average body-weight = 190 g) were randomly divided into 3 groups. Group A (control) received 0.5 ml olive oil, group B (15 mg/kg β-cyp), and group C (30 mg/kg β-cyp) by oral gavage from gestational day (GD) 1—post natal day (PND) 20. On PND 21, the pups were weaned and bred to 12 weeks of age (maturity). At maturity, 5 females were randomly taken from each group. The estrous cycle was determined for 14 days. Thereafter, the animals were anesthetized and blood was collected for hormonal assay (LH, FSH, estrogen, progesterone) using enzyme immunoassay. Results β-cyp had no significant effect (p > 0.05) on the estrous cycle. There was no significant (p > 0.05) change in the serum concentration of the sex hormones except the LH concentration where there was a dose-dependent significant (p < 0.05) decrease in treated groups relative to the control. Conclusion It is therefore concluded that perinatal beta cypermethrin exposure could have a deleterious effect on the reproductive development of female F1 generation rats, even at maturity.

Nonylphenols (NPs) are widely used industrial materials, and are considered as potent endocrine disrupting chemical. Present study was undertaken to clarify the effect of subchronic low-dose NP exposure to F1 generation male mice. Mice were divided into 2 groups; (1) CON, control animals and (2) NP-50 (50 μg/L), animals were treated with NP via drinking water. NP exposures were continuously conducted from parental pre-mating period until the postnatal day (PND) 55 of F1 offsprings. Mice were sacrificed on PND 55 and the tissue weights were measured. The initial body weights (at PND 21) and terminal body weights (PND 55) of the NP-50 animals were significantly lower than those of control animals (p

Here, we perform cross-generational GS analysis on coastal Douglas-fir (Pseudotsuga menziesii), reflecting trans-generational selective breeding application. A total of 1321 trees, representing 37 full-sib F1 families from 3 environments in British Columbia, Canada, were used as the training population for (1) EBVs (estimated breeding values) of juvenile height (HTJ) in the F1 generation predicting genomic EBVs of HTJ of 136 individuals in the F2 generation, (2) deregressed EBVs of F1 HTJ predicting deregressed genomic EBVs of F2 HTJ, (3) F1 mature height (HT35) predicting HTJ EBVs in F2, and (4) deregressed F1 HT35 predicting genomic deregressed HTJ EBVs in F2. Ridge regression best linear unbiased predictor (RR-BLUP), generalized ridge regression (GRR), and Bayes-B GS methods were used and compared to pedigree-based (ABLUP) predictions. GS accuracies for scenarios 1 (0.92, 0.91, and 0.91) and 3 (0.57, 0.56, and 0.58) were similar to their ABLUP counterparts (0.92 and 0.60, respectively) (using RR-BLUP, GRR, and Bayes-B). Results using deregressed values fell dramatically for both scenarios 2 and 4 which approached zero in many cases. Cross-generational GS validation of juvenile height in Douglas-fir produced predictive accuracies almost as high as that of ABLUP. Without capturing LD, GS cannot surpass the prediction of ABLUP. Here we tracked pedigree relatedness between training and validation sets. More markers or improved distribution of markers are required to capture LD in Douglas-fir. This is essential for accurate forward selection among siblings as markers that track pedigree are of little use for forward selection of individuals within controlled pollinated families.

The effect of reduced balanced protein (RP) diet in the F0 and F1 generation of broiler breeders on the learning ability and memory retention of the F2 generation was investigated by means of a reward v. no reward discrimination T-maze test. There were two treatments for the F0 generation: control (C) group, reared on standard commercial diets, and reduced balanced protein (RP) group, fed with RP diets (25% reduction in CP and amino acids). The female F0-progeny of each treatment was again separated into the two dietary treatments, resulting in four treatments for the F1 generation: C/C, C/RP, RP/C and RP/RP (breeder feed in F0/F1 generation). The RP diets fed breeders received on average 10% more feed than C diets fed breeders to achieve a similar target BW. The F2 generation was composed of four treatments coming from the female F1-progeny of the four treatments and were all fed with C diet (namely C/C/C, C/RP/C, RP/C/C and RP/RP/C). All four F2 generation groups were able to complete the T-maze learning test with a slight difference in success rate but a significant difference within groups was observed regarding the time needed to complete the test. In general, the RP/RP/C group needed more time for completing the test compared with the other three groups and the shortest time was recorded for the RP/C/C group. At similar ages, breeders with early learning experience spent significantly less time in completing the test compared with unexperienced breeders. Long-term memory retention was observed in all four groups whereas the learning ability in solving the test decreased with age. It took longer for the breeders to complete the test at older ages. In conclusion, under our experimental conditions, the RP dietary treatment in previous generations had no influence on the T-maze learning ability and memory retention of broiler breeders of the third generation, although it might have effects on the working performance in the T-maze learning test of F2 generation breeders. ispartof: Animal vol:13 issue:6 pages:1-9 ispartof: location:England status: Published online