Number Of Egg Masses Research Articles

Nematicidal Activity of some Nanoemulsions of Monoterpenes on Tomato Root-Knot Nematodes (Meloidogyne javanica)

The present study was initiated to explore at the nematicidal activity of some nanoemulsions of monoterpenes, i.e. (R)-carvone, cinnamaldehyde, citral, geraniol and pulegone against tomato knot-root nematode M. javanica, in both laboratory and under greenhouse conditions The results show that the pure and NE-monoterpenes tested considerably and severely decreased egg hatching at doses ranging from 25 to 1000 μg/ml. NE-Cinnamaldehyde, significantly, showed higher J2 mortality (90.67 %) and egg-hatching inhibition (8.67) than pure cinnamaldehyde. The most successful therapy for reducing root galls and the number of egg masses was NE- Cinnamaldehyde, which showed 90.3% and 92.8% reduction, followed by NE- Pulegone 84.2% reduction, respectively. The population of J2 in soil was considerably decreased after using the tested nanoemulsion monoterpenes. NE- Cinnamaldehyde was the most effective treatment, suppressing the final population of M. javanica by 81.8%. Beyond oxamyl, NE-Cinnamaldehyde was the most efficient treatment for increasing the weights and lengths of both fresh shoots and roots in infected tomato plants, consecutively. Meanwhile, pulegone measured the intermediate values of fresh root and shoot weights as well as for lengths. Normal and nanoemulsion cinnamaldehyde ranked the first as it increased polyphenoloxidase (PPO) activity, compared to the other treatments followed by nanoemulsion and normal pulegone. The highest enzyme activity was noticed 7 and 15 days after treatment. Peroxidase activity (POD) also increased by nanoterpene treatments in a trend similar to that of the PPO. Consequently, these effective monoterpene nanoemulsions could be effective potentially and environmentally safe to control tomato knot-root nematode.

First report of Meloidogyne hapla infecting Yunmuxiang (Aucklandia lappa) in China.

Yunmuxiang (Aucklandia lappa) is a tall, perennial herbaceous plant in the compositae family, occurring mainly in Asia and Europe. Yunmuxiang originated in India and was introduced into China in approximately 1940. Since then it has been widely cultivated in the southwest region of China for medicinal uses; it is included in the Chinese Pharmacopoeia. Yunmuxiang is used primarily as a sedative, including for anesthesia (Ting et al. 2012). Severely stunted and withered Yunmuxiang plants with rotted and galled roots were observed in a field in near the city of Lijiang (N 99°46'; E 27°18') in October 2019. These symptoms were typical of infection by root-knot nematodes.The second-stage juveniles (J2) were collected from the soil in the root zone, and adult females were dissected from roots. Population densities of J2 ranged from 325 to 645 per 100 cm3. Morphological analysis and species-specific PCR were performed on the second stage (J2) and females. Morphological characteristics are as follows: for J2 (n=20) , body length = 360.5 ± 23.4 µm, tail length = 47.2 ± 6.1 µm, and stylet length = 10.4 ± 1.9 µm, distance from dorsal esophageal gland opening to the stylet knot (DGO) = 3.96 ± 0.42 μm; females (n = 20) were pear-shaped, body length = 565.23 ± 86.68 μm, maximum body width = 407.24 ± 60.21 μm, stylet length = 9.93 ± 0.88 μm, DGO = 4.76 ± 0.32 μm, stylet median bulb width (MBW) = 29.67 ± 3.61 μm, perineum morphology is low and low dorsal arch round, with a typical inferior protrusion near the anus. These morphological characteristics are consistent with Meloidogyne hapla as described by Hunt and Handoo (2009). To confirm species identification, DNA was extracted from females (Blok, et al. 1997) and ITS region was amplified using the primers 18S/26S (Vrain et al. 1992). Furthermore, species-specific SCAR primers JMV1/JMV hapla were used as described by Adam et al. (2007). PCR produced 768 bp and 419 bp sequences. Fragments were sequenced (MW512922and MW228371, respectively) and compared with available sequences on NCBI. Sequences were 99.48% identical to the MT249016, KJ572385, and 100% identical to the GQ395574, GQ395569 M. hapla sequences, respectively. Morphological and molecular characterization supports the identification of the isolate found on Aucklandia lappa as M. hapla. Yunmuxiang seed were planted in 20 cm diameter, 10 cm deep plastic pots containing 1000 cm3 sterilized soil. Seedlings were thinned to one per pot. At the 2-3 leaf stage 10 pots were infested with 1500 M. hapla J2 per seedling, using a sterilized micropipette. Plants were maintained at 20-25°C in a greenhouse. Control plants received sterile water, and the pathogenicity test was repeated three times. After 30 days, plants were removed from pots and soil gently removed from the roots. A large number of galls (95.6 ± 2.5) and egg masses (33.5 ± 0.5) were found on each root system. Yunmuxiang was considered a good host for M. hapla in Lijiang. M. hapla is a major plant parasitic nematode with a wide geographic distribution and range of host plants and causes severe yield losses (Azevedo de Oliveira et al. 2018). Through investigation, this is the first report worldwide of M. hapla infecting Aucklandia lappa.

EFFECT OF SPORE ATTACHMENT METHODS AND LEVELS ON INVASION AND PARASITISM OF ROOT-KNOT NEMATODE MELOIDOGYNE JAVANICA

Spore attachment is the first stage in the life cycle of Pasteuria penetrans. Therefore, the present studies were planned to find out whether an attachment level which can provide better reduction in root-knot disease. There was a significant difference (P0.01) regarding numbers of eggmasses produced by females of Meloidogyne javanica in the treatments. Higher numbers of eggmasses (237) were recorded in the treatment where unencumbered J2s were inoculated after spinning followed by the treatment where J2s were inoculated without spores (225) but this difference was not significant. Both spore attachment techniques revealed their influence on eggmass production as fewer eggmasses were recorded in the treatment where encumbered J2s were inoculated compared to controls. Significantly lesser numbers of eggmasses (123) were recorded where J2s were encumbered by exposing them to a spore suspension in plastic trays than by the centrifuge treatment (173). Root galling differed significantly (P0.01) among treatments showing higher root galling in control treatment (5.2). Lesser root galling was observed where J2s were encumbered in the normal manner by exposing nematodes to spore suspension (3.6) while greater root galling (4.0) was observed in the treatment where J2s were encumbered after centrifugation. Similarly, there was a significant difference (P0.01) among females parasitized by P. penetrans showing a higher level of infectivity (13.8) in the treatment where J2s were encumbered by the normal attachment method as compared to the centrifugation method (11.6). There was no significant difference (P0.05) in fresh root weight of plants among treatments. There was no significant difference (P0.05) in number of eggs/eggmass produced by females of M. javanica between the treatments.

Growth and root-knot nematode infection of tomato are influenced by mycorrhizal fungi and earthworms in an intercropping cultivation system with leeks

In a greenhouse experiment, we investigated the influence of leek (Allium porrum) intercropping, mycorrhizal fungi and earthworms on the root-knot nematode infection by Meloidogyne incognita (RKN) and the growth and development of tomato plants (Solanum lycopersicum). Tomato plants were grown in pots, intercropped with leeks or in monoculture, and earthworms and/or arbuscular mycorrhizal fungi (AMF) were introduced. The effects of these two treatments on root-knot nematode infection and tomato plant growth and development were assessed i) by counting the galls induced by the nematodes and the number of egg masses on their roots, and ii) by measuring their height increase, shoot and root dry biomasses and flowering time. Tomato growth was increased with leek compared to the monoculture (e.g., +82% shoot biomass), probably due to a lower plant-plant competition, although a facilitation effect cannot be excluded. The presence of leeks did not reduce the number of galls (per g of root). The presence of AMF (Rhizophagus irregularis) increased the overall infection of M. incognita (e.g., +36% egg masses) and induced more galls with multiple egg masses in the leek-tomato association (+71%) but did not increase plant biomass. On the other hand, it increased plant height in presence of the compost earthworms (Eisenia andrei) compared to earthworms alone with RKN (+2%). It also delayed the flowering compared to RKN alone (+7.6 days in average). Competition between the two tomato plants in monoculture probably strongly impacted plant growth, flowering time and thereby the RKN infection, but leek-tomato interactions should be further examined. The overall increased number of multiple egg masses per gall in presence of AMF is contrary to its protective effect reported in the litterature.

Performance and host association of spotted lanternfly (Lycorma delicatula) among common woody ornamentals

Lycorma delicatula (spotted lanternfly) has a broad host range with a strong preference for the invasive host plant from its native range, tree of heaven (Ailanthus altissima); it had long been speculated that L. delicatula could not develop or reproduce without access to tree of heaven. In 2019, we found that this assumption was incorrect, but fitness was reduced in the absence of A. altissima in that the number of egg masses laid was dramatically fewer for insects reared on suitable non-A. altissima host plants that had recently been established. We hypothesized that longer established, larger trees (of the same species) would improve the fitness of L. delicatula in the absence of tree of heaven. In spring 2020, we examined insect performance with and without access to A. altissima by tracking development, survival, host tree association and oviposition in large enclosures with trees planted two years prior to the study. Each enclosure included one each of Juglans nigra, Salix babylonica and Acer saccharinum along with either one A. altissima or one Betula nigra; these trees had twice the diameter of the same trees the previous year. We reared nymphs with and without access to A. altissima, released them into the corresponding large enclosures as third instars, and monitored them from early July 2020 through November 2020. We also determined whether lack of access to A. altissima by parents of L. delicatula have any fitness effects on offspring performance. To ensure adequate adult populations for comparing fecundity between treatments, third instars were released into the multi-tree enclosures due to high mortality in earlier instars that occurred in a similar study in 2019. Insect survival was higher and development faster with access to A. altissima. Third and fourth instar nymphs were most frequently observed on A. altissima when it was present, while adults were equally associated with A. saccharinum and A. altissima. In the absence of A. altissima, nymphs were most frequently found on S. babylonica, while adults were most often on A. saccharinum. Females with access to A. altissima deposited nearly 7-fold more egg masses than those without access to A. altissima, which is consistent with the difference in egg mass numbers between the two treatments the previous year; thus, our hypothesis was rejected. The offspring of parents that had been reared without access to A. altissima showed similar survival and development time from egg to adult as offspring from parents that never had access to A. altissima. These findings suggest that managers need to be aware that even in the absence of A. altissima in the landscape, several hardwood host trees can be utilized by L. delicatula to develop and reproduce, but fitness without A. altissima is likely to still be reduced.

Rice Straw and Peanut Residues Biochars as Eco-Friendly Approaches for Controlling Root-Knot Nematode, Meloidogyne incognita Infecting Eggplant

Biochar is a vital carbon complex and can improve plant growth and suppress of soil-borne pathogens. Root-knot nematode, Meloidogyne incognita is identified as one of the most demoralizing pests blighting roots of many crops and lead to notable decrease in their productivities. So, the present study was carried out with a hypothesis that the application of biochar from various feed-stocks may cause significant enhancements in the tolerance of eggplant for M. incognita infection. Two types of biochars were manufactured by the slow pyrolysis process of rice straw and peanut residues. A pot experiment was conducted to explore the effects of rice straw biochar (RSB) and peanut residues biochar (PRB) on M. incognita and the growth and yield performances of eggplant in loamy soil. Eight treatments were achieved in the current experiment, resulted from the combination between RSB and PRB at four applied rates [zero =no addition, 5.25, 10.5 and 21 g/pot, which were equated to 0, 5, 10 and 20 t/ha, respectively]. Treatments were arranged in a randomized complete block design (RCBD) and with five replicates. The individual incorporation of RSB and PRB at rates of 5.25, 10.5, and 21 g/pot exhibited significant enhancements in growth parameters (length, fresh and dry weight of shoots and roots), and productivity of eggplant. Application of RSB or PRS at 21 g/pot caused superior impacts in enhancing the fresh fruit yield of eggplant (946 and 1012 g/pot). Soil pH increased after applications of RSB and PRB from 5.85 in the control treatment to 6.12-6.39 and 6.28-6.75, respectively. Both RSB and PRB revealed variable degrees in lessening numbers of egg masses and galls/root system and J2/250 g soil of M. incognita and this caused marked improvements in eggplant growth parameters in comparison to the control. The use of high doses of RSB and PRB was responsible for larger efficiency in declining the above-mentioned M. incognita parameters than their low rates. The largest declines in galls/ root system (80 and 93%), egg-masses/ root system (90 and 96%), egg/egg-mass (76 and 90%) and J2/250g soil (83 and 92%) at 50 and 90 days after transplanting (DAT) were shown after application of PRB at a rate of 21 g/pot. This study indicated that RSB and PRB can be used as effective materials in dropping the harmful effects of M. incognita and also can be recommended as eco-friendly alternatives to synthetic pesticides with marked nematicidal activity to control M. incognita infection.

In vivo and in vitro management of Meloidogyne incognita (Tylenchida: Heteroderidae) using rhizosphere bacteria, Pseudomonas spp. and Serratia spp. compared with oxamyl.

Biological control using rhizosphere bacteria, Pseudomonas spp. and Serratia spp. is a prospective alternative technique to overcome plant parasitic nematodes infection. So, the current study was conducted in vitro on five egg-masses, 100 free eggs and 100 infective juveniles (IJs) of Meloidogyne incognita as well as greenhouse treatments on Luffa aegyptiaca L. to evaluate the nematicidal potential of six strains belong to Pseudomonas spp. and Serratia spp. as compared to oxamyl.Results showed that the inhibitory effect and juvenile mortality varied according to bacteria species, strains and exposure time. All the tested bacteria significantly (P ≤ 0.05) inhibited egg hatching and increased juvenile mortality in vitro. After 3 days of treatment, Pseudomonas spp. were more effective against eggs (48.31to 55.15%) and IJs (20.98 to 25.30%) than Serratia spp. (44.55 to 49.75% with eggs) and (19.06 to 21.61% with IJs), respectively. In the pot experiment, Luffa aegyptiaca L. treated with Serratia spp. and Pseudomonas spp. displayed significantly higher (P ≤ 0.05) levels of growth (as indicated by root length, fresh roots weight and fresh shoots weight) compared to control plants and significantly (P ≤ 0.05) suppressed galling (number of galls) and reproduction (as indicated by number of egg-masses on roots and number of eggs and juveniles in pot soil). Meanwhile, among the treated plants, Serratia spp. and Pseudomonas spp. gave the best results in shoot weight of pots infected by eggs of M. incognita than those infected with IJs as compared with positive control. While, oxamyl treatment gave the best results in pots infected by eggs and IJs.The lowest galling (gall index), number of eggs and juveniles in soil was observed in the treatment with mixture of Serratia spp. and Pseudomonas spp. as well as, enhanced growth of sponge gourd more than application each of them alone. Pots treated with oxamyl overwhelmed those treated with mixture of Serratia spp. and Pseudomonas spp.

Evaluation of Effective Microorganisms (EM®) against Root-Knot Nematode (Meloidogyne javanica) in Tomato

Introduction: Plant-parasitic nematodes cause significant yield losses in a wide range of crops (Nicol et al. 2011). Root-knot nematodes (Meloidogyne spp.) are the most important plant-parasitic nematodes, because they widely distributed all around the world and have wide host range (Chapuis-Lardy et al. 2015). Chemical nematicide is one of the primary means of control for plant-parasitic nematodes. Due to negative impact of synthetic nematicides, it will be necessary to develop other management strategies for plant-parasitic nematodes which are safe for the environment and humans (Huang et al., 2016). Latest interest in organic farming lead to substitution for conventional nematicides by low-risk compounds such as natural products derived from plants (Oka et al. 2006). Also, biological control is an interesting option to control these nematodes (Mosahaneh et al. 2020). Effective microorganisms (EM®) consist of a mixture of live cultures of microorganisms such as photosynthetic bacteria, which they are reported to reduce the incidence of pathogenic microorganisms (Condor et al., 2007). Materials and Methods: In the present study, the aerial parts of the marigold (Tagetes erecta) were collected from Shiraz, Iran. Marigold leaves dried in shade and finely grinded using an electric grinder and a stock solution (10% w/v) was prepared. Seeds of tomato (cv. Early-Urbana) were sown in plastic pots containing 1500 g of a sterilized mixture of farm soil (sandy loam soil) and cow manure. The pots were kept under greenhouse conditions with 16:8 h light to dark photoperiod and 27 ± 4 °C. Four-leaf stage seedlings were soil-drenched (50 ml per plant) with EM® or a mixture of equal amount of EM®+ marigold leaf extract at the rate of 5, 10, 15 and 20% and simultaneously inoculated with a suspension of M. javanica (6000 eggs per pot). The experiment was carried out in a completely randomized design with five replications. Sixty days after nematode inoculation, plants were harvested and the vegetative indices including shoots length, shoot fresh and dry weight and root fresh weight and the nematode population indices including the number of eggs as described by Hussey and Barker (1973), number of galls and egg masses per root system as described by Taylor and Sasser (1978) and the number of second stage juveniles (J2s) in the pot were recorded. Finally, the reproduction factor calculated as described by Sasser and Taylor (1978). Data were subjected to one-way analysis of variance (ANOVA) for plant growth parameters and two-way ANOVA for nematode population indices using SAS 9.1 program (Statistical Analysis System Institute Inc., USA). Treatment means were compared using least significance differences (LSD) at p<0.01.Results and Discussion: Results showed that soil drenching of EM® and EM®+ marigold leaf extract increased the plant growth parameters on inoculated and non-inoculated plants as compared to control. The treatment with EM®+ marigold leaf extract at the rate of 20% was the most effective treatment and increased shoot length, shoot fresh weight and shoot dry weight of non-inoculated plants by 33, 39 and 11% respectively, as compared to non-inoculted control plants. In the case of inoculated plants, shoot length, shoot fresh weight, shoot dry weight and root fresh weight of treated plats with EM®+ marigold leaf extract at the rate of 20% were 34, 31, 15 and 11% higher than inoculated control plants. The number of eggs and egg masses per root system and the reproduction factor were significantly reduced in treated plants with EM®+ marigold leaf extract at the rate of 15 and 20%. EM®+ marigold leaf extract at the rate of 20% reduced the number of eggs, galls, egg masses per root system and the reproduction factor by 28, 40, 37 and 27% respectively, as compared to control. The lowest numbers of eggmasses were observed in the root system of tomato plants treated with EM®+ marigold leaf extract at the rate of 20%. It had significant difference than other treatments, except EM® at the rate of 20%. These data for the first time in Iran, suggest that EM® might have utility in controlling root-knot nematodes. A mixture of EM® and marigold leaf extract was more effective than alone application of EM® for control of M. javanica. Findings from this study, suggest that a mixture of equal amount of EM® and marigold leaf extract at the rate of 20% reduced M. javanica reproduction rates in tomato plants grown in greenhouse.

Photoperiod controls egg laying and caudodorsal cell hormone expression but not gonadal development in the pond snail Lymnaea stagnalis.

Photoperiod is a reliable cue to regulate growth and reproduction for seasonal adaptation. Although photoperiodism has been well studied in Chordata and Arthropoda, less is known about Mollusca. We examined photoperiodic effects on egg laying, body size, gonad-somatic index, oocyte size and relative amounts of caudodorsal cell hormone mRNA in individual rearing conditions in the pond snail Lymnaea stagnalis. Twenty-five weeks after hatching, the percentages of egg-laying snails under a photoperiod of 12h light and 12h darkness (12L:12D) were significantly smaller than those under longer days. The total numbers of eggs and egg masses under 12L:12D were significantly smaller than those under longer days. Significant differences between 16L:8D and 12L:12D were not observed in the soft body and ovotestis weight, and the gonad-somatic index. Photoperiodic effects were also not observed in oocyte diameters twenty-two weeks after hatching. Twenty-seven weeks after hatching amounts of caudodorsal cell hormone mRNA were significantly lower in the cerebral ganglia with commissure under 12L:12D than 16L:8D. L. stagnalis exhibited a clear photoperiodic response in egg laying and the amount of caudodorsal cell hormone mRNA, but not in gonadal development. Under 12L:12D suppression of caudodorsal cell hormone expression might suppress egg laying.

Ecofriendly management of root-knot nematodes on Eggplant using compost

Root-knot nematodes (RKN) became a true limited factor for eggplant production worldwide. Experiments were designed to evaluate the effectiveness of different compost types on RKN management in Eggplant under greenhouse conditions. Different compost types i.e. plant, animal, rice straw and maize wood compost at different doses 10, 20, 30, 50 and 100g/ pot were used. Results indicated that all evaluated treatments showed a great potential in decrease all related nematode parameters i.e. number of galls, egg masses, females/root system and second stage juveniles(J2s)/250g soil compared with control. The most effective treatment in reducing all nematode parameters was animal compost. Results illustrated that all compost types markedly increased eggplant growth parameters. The highest plant growth parameters enhancement obtained when plants treated with animal compost at 10g/ pot, followed by maize wood compost at the same rate of 10g/ pot. The lowest plant enhancement recorded with rice straw compost at 100g/ pot.

Effects of multiple stressors on amphibian oviposition: Landscape and local determinants in central Japan

Amphibian declines are caused by multiple stressors at the landscape and local levels, resulting in habitat loss, fragmentation, splits, and degradation. However, the combined effects of different landscape scales on the amphibian declines are poorly understood. We examined the breeding distribution of three frog species, Rana japonica, Rana ornativentris, and Bufo japonicus formosus, along an ecological gradient from urban to mountain areas. The number of egg masses and data on landscape and local variables were collected at 124 sites in Toyota, Okazaki, and Shitara, central Japan. The best model with the lowest value of the Akaike Information Criteria (AIC) was obtained using landscape variables at a 500-m-radius buffer for all three species. The number of egg masses increased with forest area for all frog species. Yet, other variables differently affected the number of egg masses of three species at each site. The egg-mass number of R. japonica was positively affected by the residential region with much vegetation area & elevation difference, and negatively affected by elevation. That of R. ornativentris was positively influenced by the abandoned paddy-field, and negatively influenced by the total road density. Regarding B. japonicus formosus, its egg-mass number was positively affected by the residential region with much vegetation area, and negatively affected by elevation difference. At the local scale, the water area positively affected the number of egg masses of all three species, while the percentage of concrete revetment has negative effects. This study not only assesses how the assemblage of frogs respond to different habitats at multiple spatial scales along the land use gradient (urban-mountain), but also emphasizes the importance of strategic management actions in agricultural landscapes, allowing the maintenance of habitat diversity for amphibians.

Compatibility of Predatory Nematode, Fictor composticola and Bacterial Parasite, Pasteuria penetrans for the Management of Root-Knot Nematode.

Compatibility of Fictor composticola and Pasteuria penetrans was evaluated through two experiments against Meloidogyne incognita. In vitro assay conducted in 5 cm diameter Petri plates containing 1% water agar. Two males and two females of F. composticola were released alongwith 200 P. penetrans encumbered or healthy J2 of M. incognita. Observations on prey consumed were taken after 24 and 48 h of release. P. penetrans-encumbered J2 were consumed more by the predator than healthy J2. In a pot assay, cucumber plants grown in one kg pots were inoculated with 2000 P. penetrans encumbered or healthy J2 of M. incognita and 400 individuals of F. composticola. After 45 days; numbers of galls, egg masses and final J2 population in soil were significantly less in the treatment with F. composticola + P. penetrans-encumbered J2 than F. composticola with healthy J2. The root galls and the number of Pasteuria-infected females were more in the absence of predatory nematode.

Combining ability and heterosis to root-knot nematode resistance on seven genotypes of kenaf using full diallel cross analysis

A full diallel cross is confirmed to be able to advocate kenaf breeders to select breeding materials, such as inbred lines that produce the best combination with heterosis properties. The results of this study provided information about general combining abilities (GCA) of parents, specific combining ability (SCA), as well as heterosis values. This study aims to estimate the combining abilities and heterosis values of root-knot nematodes in kenaf originated from the full diallel cross. Semi-field research was conducted in an experimental garden located at Karangploso Balittas, from November 2018 to January 2019. The variance of GCA values was higher than SCA values for the number of root knot, reproductive factors, and number of egg mass. In contrast, the variance of GCA values was lower than SCA values for the number of second-stage juvenile (J2) and the number of egg per egg mass characters. KR4, K45, and KR15 genotypes indicated negative GCA values on all characters tested. Meanwhile, KR1, Kin2 and DS028 genotypes signified susceptibility with a positive GCA value. The crossbreeding combinations showed negative SCA values on the number of second-stage juvenile, the number of egg mass and the number of egg per egg mass characters of resistance to root-knot nematodes (M. incognita), i.e. KR6 x DS028. KR4, KR5 and KR15 genotipe was quite consistent with negative GCA and SCA values, as well as heterosis values for characters of resistance to root-knot nematodes on kenaf roots on the number of second-stage juvenile (J2), the number of egg mass and the number of egg per egg mass characters tested. Genotype of KR4 x KR5 and its reciprocal have negative heterobeltiosis values on number of second-stage juvenile, egg mass, and the number of eggs per egg mass evaluated characters

Effect of the diallel cross line and generation on some productive traits in two lines of quail bird (brown and gold)

The aim of this study was to determine the effect of the diallel cross between the two lines on some productive traits, depending on plumage color, to get a genetic combination that is distinguished in productive performance and superior in its performance on pure lines, to demonstrate 79 chicks of quail with brown plumage and 72 chicks of golden plumage color one-day old, mating resulting from two lines of quail, were used in the study. 10 males from the golden plumage colour line and 10 females from the brown plumage colour line to perform crosses as for reciprocal crosses 10 males from the brown plumage colour line and 10 females from the golden plumage colour line. These birds selected and raised in rooms with dimensions of 40 x 40 x 40 cm were numbered and distributed Randomly placed to rooms in the form of families and each one by (1: 1), the productive traits of the parents and the first generation were measured. The experiment was designed according to the design of the Factorial Experiment Design to study the effect of the diallel cross, generation and the overlap between them.The results of the study showed the superiority of crosses over reciprocal crosses regardless of the effect of the generation on the average body weight trait at sexual maturity, and the first generation also outperformed the parents regardless of the effect of the mutilation of the same trait, while no significant differences were found between crosses and reciprocal crosses as well between parents. and the first generation in the trait of the average age at sexual maturity, the average weight of the first egg, the average number of eggs, the weight of the eggs, and the mass of eggs during 56 days of production. Sexual maturity, the average weight of the first egg, the average number of eggs, egg weight, and egg mass during 56 days of production. The results also indicated that the first generation of reciprocal crosses achieved the highest heterosis in the trait of average body weight at sexual maturity and the average weight of the first egg while crosses and reciprocal crosses parents achieved the highest heterosis in the trait of average egg number, average egg weight and average egg mass, as for the trait of average age at sexual maturity the crosses and reciprocal crosses parents of and achieved the highest negative heterosis for early life at sexual maturity.

English

In the present study, fifteen cucumber genotypes were screened against Zucchini yellow mosaic virus (ZYMV) and root-knot nematode (Meloidogyne incognita) individually and in combinations. All the cucumber genotypes behaved differently regarding root and shoot lengths and weights, number of galls, eggmasses and ZYMV infection when inoculated with M. incognita and ZYMV alone and in combinations. None of the fifteen cucumber genotypes was found immune, highly or moderately resistant to M. incognita. Two genotypes viz., Alpha Prime and Patio were found resistant to the nematode. Contrarily, Max Pack and Beti-alpha were highly susceptible as evident by maximum galls on their roots and reductions in growth variables. Similarly, the genotypes Best PIC, Songrooh, Northern Pack, C-7 and C-5 appeared as moderately susceptible whereas Shaheen, Jakson, C-1, C-2, C-3 and C-9 genotypes showed susceptible reactions to the nematode alone. Similar trend was noticed when the genotypes were inoculated with both the nematode and the virus. Similarly, on the basis of disease rating scale, two genotypes viz., Alpha Prime and Patio were grouped as moderately resistant to ZYMV. On the other hand, eleven genotypes viz., Max Pack, Shaheen, Songrooh, Northern Pack, Jakson, Beti-alpha, C-1, C-2, C-3, C-5 and C-9 were catalogued as highly resistant while two genotypes Best PIC and C-7 were categorized as susceptible against ZYMV alone. Similarly, all the genotypes behaved in the same way when inoculated with M. incognita. Two genotypes Alpha Prime and Patio were found resistant against both the pathogens inoculated simultaneously and hence are recommended for cultivation. © 2021 Friends Science Publishers

Green Synthesized Silver Nanoparticles Mitigate Biotic Stress Induced by Meloidogyne incognita in Trachyspermum ammi (L.) by Improving Growth, Biochemical, and Antioxidant Enzyme Activities.

Meloidogyne incognita is an important plant-parasitic nematode that causes significant crop losses all over the world. The primary control strategy for this pathogen is still based on nematicides, which are hazardous to human health and the environment. Considering these problems, this study aimed to determine the efficacy of different concentrations (25, 50, and 100 ppm) of silver nanoparticles against M. incognita on Trachyspermum ammi. Silver nanoparticles synthesized from Senna siamea were thoroughly characterized using various physicochemical techniques, viz., UV–visible spectrophotometer, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy-dispersive X-ray analyzer (EDX). Results revealed that plants treated with 50 ppm silver nanoparticles one week before M. incognita inoculation (T2) exhibited maximum and significant (p ≤ 0.05) increases in plant growth, biochemical characteristics, and activities of defense enzymes such as peroxidase, catalase, superoxide dismutase, and ascorbate peroxidase over the inoculated control (IC) plants. Furthermore, the maximum reduction in the number of galls, egg masses, and root-knot indices was recorded in plants treated with 100 ppm silver nanoparticles (T3) followed by plants treated with 50 ppm silver nanoparticles before nematode inoculation (T2), over inoculated plants (IC). Anatomical studies showed accumulation of lignin in the transverse section (TS) of roots treated with 50 ppm silver nanoparticles. As a result, the present finding strongly suggests that silver nanoparticles synthesized from S. siamea had nematicidal activity, and it could be an efficient, safe, cost-effective, and affordable alternative to chemical nematicide.

Micro RNA-induced gene silencing strategy for the delivery of siRNAs targeting Meloidogyne incognita in a model plant Nicotiana benthamiana.

Occurrence of multiple biotic stresses on crop plants result in drastic yield losses which may have severe impact on the food security. It is a challenge to design strategies for simultaneous management of these multiple stresses. Hence, establishment of innovative approaches that aid in their management is critical. Here, we have introgressed a micro RNA-induced gene silencing (MIGS) based combinatorial gene construct containing seven target gene sequences of cotton leaf curl disease (CLCuD), cotton leaf hopper (Amrasca biguttula biguttula), cotton whitefly (Bemisia tabaci) and root-knot nematode (Meloidogyne incognita). Stable transgenic lines of Nicotiana benthamiana were generated with the T-DNA harboring Arabidopsis miR173 target site fused to fragments of Sec23 and ecdysone receptor (EcR) genes of cotton leaf hopper and cotton whitefly. It also contained C2/replication associated protein (C2/Rep) and C4 (movement protein) along with βC1 gene of betasatellite to target CLCuD, and two FMRFamide-like peptide (FLP) genes, Mi-flp14 and Mi-flp18 of M. incognita. These transgenic plants were assessed for the amenability of MIGS approach for pest control by efficacy evaluation against M. incognita. Results showed successful production of small interfering RNA (siRNA) through the tasiRNA (trans-acting siRNA) pathway in the transgenic plants corresponding to Mi-flp18 gene. Furthermore, we observed reduced Mi-flp14 and Mi-flp18 transcripts (up to 2.37 ± 0.12-fold) in females extracted from transgenic plants. The average number of galls, total endoparasites, egg masses and number of eggs per egg mass reduced were in the range 27-62%, 39-70%, 38-65% and 34-49%, respectively. More importantly, MIGS transgenic plants showed 80% reduction in the nematode multiplication factor (MF). This study demonstrates successful validation of the MIGS approach in the model plant, N. benthamiana for efficacy against M. incognita, as a prelude to translation to cotton. © 2021 Society of Chemical Industry.

Screening for Tolerance-Resistance to Root-knot nematode Meloidogyne incognita in Grafted and Ungrafted Cucurbit Rootstocks

THE CURRENT study aimed to screen eight ungrafted and grafted cucurbit rootstocks as well as melon Hybrid London genotype against root-knot nematode infection. Ungrafted and grafted rootstocks i.e. Nun 6001, Squash No3, Super Shintosa, Flixel Fort, Ferro RZ, Coplt, Bottle gourd were classified as tolerant to M. incognita infection whereas melon genotype Hybrid London and Pakistani Loof rootstock ranked as susceptible hosts. Grafted cucurbit rootstocks i.e. Nun 6001 and Ferro RZ, gave the higher plant survival rate and growth parameters compared to ungrafted ones and the rest of rootstocks and melon genotype. Number of galls, females, and egg masses of M. incongita were significantly suppressed in ungrafted and grafted rootstocks compared to melon plant Hybrid London. All the rootstocks differed in their ability to stimulate peroxidase (PO), polyphenol oxidase (PPO) activities, and phenol content. The study revealed that grafting melon plants onto all the previous tolerant rootstocks is an effective tool that may enable the susceptible melon scion to tolerate M. incognita which leads to an increase in plant survival rate and growth parameters.

Combined effect of β-aminobutyric acid and silver nanoparticles on eggplants, Solanum melongena, infected with Meloidogyne javanica

Summary The acquired resistance of plants to root-knot nematodes (Meloidogyne spp.) can be achieved by applying chemical inducers, such as β-aminobutyric acid (BABA). Recently, the use of metal nanoparticles with multifunctional use against plant-parasitic nematodes has been presented. In this study, silver nanoparticles (AgNPs) were synthesised using the aqueous leaf extract of Malva sylvestris. The effect of different AgNPs concentrations on hatching and mortality of the second-stage juveniles (J2) of Meloidogyne javanica was investigated in vitro. The effects of AgNPs on eggplants infected with 0, 1, 2, 4 and 8 eggs (cm3 soil)−1 were investigated under glasshouse conditions. The combined effects of AgNPs and BABA on eggplants infected with 4 and 8 eggs (cm3 soil)−1 were investigated in another study. The results showed that increasing the concentration of AgNPs the hatching of M. javanica decreased and the mortality of J2 increased. The number of eggs, galls, egg masses and reproduction factor in plants treated with AgNPs infected with 4 eggs (cm3 soil)−1 decreased by 43.4, 24.7, 23.5 and 43.2%, and in plants infected with 8 eggs (cm3 soil)−1, decreased by 64.5, 25.5, 63.1 and 64.5%, respectively, compared to control plants. The reproduction factor in infected plants with 4 and 8 eggs (cm3 soil)−1 that were treated with BABA (1 mM) and AgNPs decreased by 51.6 and 55.9%, respectively, compared to control plants. The results of this study demonstrated the effects of BABA, AgNPs and the combination of these two substances in reducing the damage of different inoculum densities of M. javanica in eggplant.

Nondestructive Sampling for Spotted Lanternfly (Hemiptera: Fulgoridae) Egg Masses in Woodlands Based on Fixed-Radius Plots.

A nondestructive sampling method was developed for Lycorma delicatula egg masses based on fixed-radius plot (100 m2) in 2020. All trees >1.0 cm DBH (diameter at breast height, 1.37 m in height) on each plot were visually inspected from the ground 4 m from the tree with binoculars. Egg masses found on trees were separated into six within-tree positions (lower trunk, middle trunk, upper trunk, first branch, second branch, above second branch) and recorded by cardinal directions, whereas those laid on shrubs/vines and stones were recorded without such separation. In total, 146 trees were inventoried at 28 plots over seven study sites (four plots per site). Egg masses were found on 19 tree species plus summer grape (Vitis aestivalis) and stone. Of the 421 total egg masses recorded, 31.1% were on Norway maple (Acer platanoides), followed by tree-of-heaven (Ailanthus altissima; 14.7%), black birch (Betula lenta; 12.6%), tuliptree (Liriodendron tulipifera; 11.9%), and American beech (Fagus grandifolia; 10.2%). Egg mass density per tree was positively correlated with tree diameter, and egg mass density per plot was positively correlated with plot basal area. Egg mass density after conversion ranged from 600 to 3,930 eggs masses/ha with no significant difference among study sites. Cardinal direction had no effect; however, significantly more egg masses were found on the first branches and upper trunks than other within-tree positions. Overall, branches were better than trunks in predicting egg mass number for the tree. The role of distance and late season adult aggregation on oviposition substrate selection are discussed.