Evaluation of root-knot nematode disease control and plant growth promotion potential of biofertilizer Ning shield on Trichosanthes kirilowii in the field

Abstract Biofertilizer Ning shield was composed of different strains of plant growth promotion bacteria. In this study, the plant growth promotion and root-knot nematode disease control potential on Trichosanthes kirilowii in the field were evaluated. The application of Ning shield significantly reduced the diseases severity caused by Meloidogyne incognita, the biocontrol efficacy could reached up to 51.08%. Ning shield could also promote the growth of T. kirilowii in the field by increasing seedling emergence, height and the root weight. The results showed that the Ning shield could enhance the production yield up to 36.26%. Ning shield could also promote the plant growth by increasing the contents of available nitrogen, phosphorus, potassium and organic matter, and increasing the contents of leaf chlorophyll and carotenoid pigment. Moreover, Ning shield could efficiently enhance the medicinal compositions of Trichosanthes, referring to the polysaccharides and trichosanthin. Therefore, Ning shield is a promising biofertilizer, which can offer beneficial effects to T. kirilowii growers, including the plant growth promotion, the biological control of root-knot disease and enhancement of the yield and the medicinal quality.

Avaliação da eficácia de taboa (Typha domingensis Pers.) e batata-de-purga [Operculina hamiltonii (G. Don) D.F. Austin & Staples] in natura sobre nematóides gastrintestinais de caprinos, naturalmente infectados, em clima semi-árido / Evaluation of the effectiveness of "taboa" (Typha domingensis Pers.) and "batata-de-purga" [Operculina hamiltonii (G. Don) D.F. Austin & Staples] in natura on gastrointestinal nematodes of goats, naturally infected, in the semi-arid region

Avaliou-se a eficácia da Typha domingensis (taboa) e da Operculina hamiltonii (batata-de-purga) in natura sobre nematóides gastrintestinais de caprinos, naturalmente infectados, em clima semi-árido. Foram utilizados 30 caprinos da raça Moxotó, e o rizoma da taboa e a raiz da batata-de-purga, avaliados através da fitoquímica. As fezes foram coletadas nos dias zero, sete e 25, após, o tratamento da contagem de OPG. Os animais foram distribuídos inteiramente ao acaso, com cinco tratamentos e seis repetições. Grupo I tratado com Moxidectina 0,2 por cento em dose única de 0,5 mg Kg-1; o Grupo II tratado com Taboa na dose (10 g 20 Kg-1 peso vivo); Grupo III com batata-de-purga na dose de 9 g 20 Kg-1 p.v.; Grupo IV tratado com taboa 10 g 20 Kg-1 p.v. associada a batata 9 g 20 Kg-1 p.v. durante três dias consecutivos, todos administrados oralmente e o Grupo V como grupo controle. Os grupos tratados apresentaram redução no número médio de OPG aos 7 e 25 dias pós-tratamento, quando comparado com o grupo controle no respectivo período, sendo a batata-de-purga com maior redução aos 7 e a taboa aos 25 dias. A maior eficácia foi da batata-de-purga de 84 por cento e 70 por cento, nos dias 7 e 25 pós-tratamento. Verificou-se que a batata-de-purga foi eficaz no controle de nematóides gastrintestinais de caprinos no clima semi-árido e que a taboa associada com a batata tem potencial para serem utilizadas em programas alternativos de controle parasitário.

The effectiveness of Typha domingensis ("taboa") and Operculina hamiltonii ("batata-de-purga") in natura was evaluated on gastrointestinal nematodes of goats, naturally infected, in the semi-arid region. Thirty Moxotó goats were used, and the rhizome of "taboa" and the root of "batata-de-purga" were analyzed through phytochemistry. Feces were collected on days zero, seven and 25 after the treatment for FECs. The distribution of animals was completely at random, with five treatments and six replicates. Group I was treated with Moxidectin 0.2 percent in a single dose of 0.5 mg kg-1; Group II was treated with "taboa" at the dose of 10 g 20 Kg-1 body weight; Group III was treated with "batata-de-purga" at the dose of 9 g 20 Kg-1 b.w.; Group IV was treated with "taboa" at 10 g 20 Kg-1 b.w. associated with "batata-de-purga" at 9 g 20 Kg-1 b.w. during three consecutive days. All treatments were orally administered and Group V was used as control. Treated groups showed a reduction in the average number of FECs at seven and 25 days post-treatment when compared to the control group in the respective period; "batata de purga" had a greater reduction at seven days, while "taboa" showed a more pronounced reduction at 25 days. The highest effectiveness was observed for "batata de purga": 84 percent and 70 percent at seven and 25 days post treatment. "Batata-de-purga" was effective in controlling gastrointestinal nematodes of goats in the semi-arid climate and "taboa" associated with "batata de purga" have the potential to be used in alternative programs for parasite control.

Aspectos biológicos do período embrionário dos curculionídeos-das-raízes dos citros / Biological characteristics of the egg phase of citrus root weevils

O objetivo deste trabalho foi estudar algumas características da fase de ovo de três espécies de curculionídeos-das-raízes dos citros. Os insetos foram coletados em citros em Itapetininga, SP, levados ao Laboratório de Biologia de Insetos da ESALQ/USP, em Piracicaba, SP, onde foram mantidas as espécies numericamente mais importantes: Naupactus cervinus (Boheman), Naupactus versatilis (Hustache) e Parapantomorus fluctuosus (Boheman). Dessas espécies foi avaliada duração e a viabilidade da fase de ovo e calculados o limite térmico inferior de desenvolvimento (Tb) e a constante térmica (K). As espécies de curculionídeos-das-raízes dos citros apresentaram diferenças quanto à fase de ovo. O período embrionário, variou de 40,4 a 18,6 dias para N. cervinus, 38,7 a 20,0 dias para N. versatilis e 35,0 a 13,8 dias P. fluctuosus, dependendo da temperatura. Os limiares térmicos inferiores de desenvolvimento foram de 8,1; 8,3 e 9,9°C com constante térmica 385,7; 397,7 e 294,1 graus dia (GD), respectivamente para N. cervinus, N. versatilis e P. fluctuosus. A duração da fase de ovo foi muito semelhante para N. cervinus e N. versatilis, nas mesmas temperaturas e P. fluctuosus, apresentou desenvolvimento mais rápido do que Naupactus spp., em todas as temperaturas testadas.

The goal of this work was to study some characteristics of the egg phase of three species of citrus root weevils. The insects were collected from citrus plants in Itapetininga, SP, and brought to the Laboratório de Biologia de Insetos of ESALQ/USP, in Piracicaba, SP, where the species Naupactus cervinus (Boheman), Naupactus versatilis (Hustache) and Parapantomorus fluctuosus (Boheman) were kept. Duration and viability of the egg phase were evaluated, and the lower temperature threshold and thermal constant (K) were calculated for these species. The species of citrus root weevils showed different duration of egg phases. The egg phase ranged from 40.4 to 13.8 N. cervinus, from 38.7 to 20.0 days for N. versatilis, and from 35.0 to 13.8 days for P. fluctuosus, depending upon temperature. The temperature thresholds of this stage were 8.1, 8.3, and 9.9°C at thermal constant was 385.7, 397.7 and 294.1 degree-days, for N. cervinus, N. versatilis and P. fluctuosus respectively. The duration of the egg phases of N. cervinus and N. versatilis were similar at the same temperatures and P. fluctuosus had a faster development than Naupactus spp. in all temperatures tested.

Inheritance of resistance to Meloidogyne incognita race 2 in the hot pepper cultivar Carolina Cayenne ( Capsicum annuum L. )

Root-knot nematodes of the genus Meloidogyne are important pathogens affecting vegetable crop production in Brazil and worldwide. The pepper species Capsicum annuum includes both hot and sweet peppers; very little emphasis has been placed on breeding sweet peppers for nematode resistance. We report on the inheritance of resistance to Meloidogyne incognita (Kofoid & White) Chitwood race 2 in the hot pepper cultivar Carolina Cayenne. The hot pepper cv. Carolina Cayenne was used as seed parent and the sweet pepper cv. Agronômico-8 was used as pollen parent to obtain the F1 and F2 generations and the backcross generations BC11 and BC12. The plants were inoculated with M. incognita race 2 at a rate of 60 eggs/ml of substrate and, after a suitable incubation period, the numbers of root galls and egg masses per root system were evaluated on each plant. Broad- (0.77 and 0.72) and narrow-sense (0.77 and 0.63) heritability estimates were high for both root galls and egg masses, respectively. The mean degree of dominance was estimated as 0.29 and 0.25 for numbers of galls and egg masses, respectively; these estimates were not significantly different from 0, indicating a predominantly additive gene action. The results were consistent with a hypothesis of monogenic resistance in Carolina Cayenne.

Inheritance of resistance to the root-knot nematode Meloidogyne javanica in lettuce

Resistance to the root-knot nematodes Meloidogyne spp. would be a valuable attribute of lettuce Lactuca sativa L. cultivars grown in tropical regions. The looseleaf lettuce 'Grand Rapids' is resistant to both M. incognita and M. javanica. Resistance to M. incognita has a high heritability, under the control of a single gene locus, in which the 'Grand Rapids' allele, responsible for resistance (Me), has predominantly additive gene action, and has incomplete penetrance and variable expressivity. We studied the inheritance of the resistance of 'Grand Rapids' (P(2)) to M. javanica in a cross with a standard nematode-susceptible cultivar Regina-71 (P(1)). F(1)(Regina-71 x Grand Rapids) and F(2) seed were obtained, and the F(2) inoculated, along with the parental cultivars, with a known isolate of M. javanica to evaluate nematode resistance. A high broad sense heritability estimate (0.798) was obtained for gall indices. Class distributions of gall indices for generations P(1), P(2), and F(2) were in agreement with theoretical distributions based on a monogenic inheritance model for the range of assumed degrees of dominance between approximately -0.20 and 0.20. M. javanica resistance appears to be under control of a single gene locus, with predominantly additive gene action. Whether or not the Grand Rapids allele imparting resistance to M. javanica is the same Me allele imparting resistance to M. incognita remains to be determined

The laticifer system of Chamaesyce thymifolia: a closed host environment for plant trypanosomatids

Specimens of Chamaesyce thymifolia (Euphorbiaceae) infected and uninfected by Phytomonas sp., a parasite of the Trypanosomatidae family, were anatomically and ultrastructurally analyzed with special emphasis on the laticifer system. C. thymifolia presents branched non-articulated laticifers and was heavily infected by Phytomonas sp. in all collection sites. Infection was often observed in the initial stages inside the vacuole, when the latex particles could be seen. In intermediary stages of laticifer differentiation, Phytomonas sp. were found free in the cytoplasm, inside small vacuoles or in the central vacuole. In differentiated laticifers that had only the plasma membrane, Phytomonas sp. were free in the latex and close to the cell membrane. Infected and uninfected plants showed identical anatomy and ultrastructure and the starch grain numbers in the latex were not reduced in the presence of this flagellate. Biochemical analysis of the latex of infected and uninfected plants presented similar levels of protein, carbohydrate and beta-1,3-glucanase, suggesting that this species is not pathogenic for the host. Besides, all infected plants complete its life cycle. Plants infected with Phytomonas presented occasionally virus like particles and bacteria inside the laticifer tubes.

Prospección micológica en rizosfera y rizoplano en un vivero forestal de eucalyptus globulus labill en la V región, Chile / Mycological prospection in rhizosphere and rhizoplane at a forest nursery of eucalyptus globulus labill at the V region, Chile

A pesar de que la fumigación-esterilización de los suelos es de utilidad en la producción de los viveros forestales, la microbiota residente puede sufrir alteraciones difíciles de evaluar. Con la finalidad de detectar específicamente las variaciones de la micota y corroborar el manejo sanitario, se efectúo un muestreo en rizósfera y raíces de plántulas de eucalyptus globulus labill (Diciembre 93 a Julio 94), para evidenciar la presencia de patógenos, oportunistas y saprófitos. La metodología, basada en la selección de muestras al azar desde las platabandas, consistió en procesar la rizósfera, en suelos fumigados y esterilizados, mediante diluciones en cultivos sólidos (DCPA) y las raices, en agar agua, previa esterilización superficial y en medios específicos para phytophthora y pythium. Se aislaron un total de 1643 colonias representadas por 40 géneros y 72 especies. En rizósfera, las principales taxa considerados como patógenos u oportunistas, fueron los géneros: aspergillus (12,1 porciento) con frecuencias similares en las tres etapas y fusarium (11,1 porciento) que decayó en la etapa final. En cambio los saprófitos de mayor presencia fueron cladosporium (8,7 porciento), penicillium (8,4 porciento y botryotrichum (6 porciento). En raíz, los principales patógenos integraron los géneros: pythium (sin porcentaje por metodología diferente), fusarium (14,6 porciento) y trichoderma (4 porciento) f.oxysporum (82,5 porciento del total del género), aumentó considerablemente en el segundo y tercer muestreo, mientras t. harzianum, fue siempre dominante (85,9 porciento del total). Los saprófitos fueron representados mayoritariamente por penicillium (16 porciento), ulocladium (9,7 porciento) y acremonium (2,2 porciento). La baja mortalidad observada en las plántulas del vivero durante los muestreos, puede atribuirce en cierta medida a: 1) la acción de los fungicidas empleados, 2) la competencia y antagonismo ejercido por los hongos saprófitos presentes en los suelos muestreados (resistentes a las fumigaciones) y 3) a los taxa "competentes de la rizósfera" como t. harzianum y f.oxysporum, que pueden ejercer un rol importante. Todos estos factores podrían contribuir al control de algunos fitopatógenos detectados principalmente en las raíces tales como: pythium altimun, alternaria alternata, phoma leveillei. Las variaciones de las poblaciones fúngicas en los suelos de viveros fumigados, deben evaluarse mediante controles periódicos en el tiempo

Hongos del maiz de interés en pre y post-cosecha en el norte de Italia: microcomunidades asociadas a raíces y hojas / Pre and post harvest fungi of interest in norther Italy: microcommunities associated to roots and leaves

Mediante técnicas de lavado y esterilización superficial, se analizó mensualmente en la zona norte de Italia, la variación estacional de la micota de raíces, hojas y semillas (éstas últimas, sólo previo a su siembra), durante el ciclo vegetativo de 3 cultivares de maíz (aida, hawaiano, hibisco). La mayor cantidad de aislamientos con ambas metodología y en todos los sustratos sembrados en PDA y agar agua, correspondió al cultivo aida. Los taxa más frecuente en raíz, fueron: fusarium, oxysporum, rhizopus stolonifer, trichoderma viride, alternaria alternata, pyrenochaeta terrestris, ramichloridium sp., penicillium spp. y epicoccum purpurascens. En hoja, en cambio, se observó un orden y presencia diferentes. Como modelos de variación estacional, se seleccionaron los integrantes de los 8 taxa o grupos de taxa más frecuentes en raíz y hoja: (alternaria, epicoccum, fusarium, pyrenochaeta-phoma spp., rhizopus, trichoderma, drechslera-bipolaris spp. y penicillium spp.), donde solo los tres últimos presentaron variaciones de magnitud. F. oxysporum, fue dominante en todos los sustratos (80 por ciento), mientras f. moniliforme (gibberella fujikuroi) fue escaso, salvo en las hojas (14 por ciento). En las semillas de los 3 cultivares, las especies frecuentes fueron: f. oxysporum, penicillium spp., c. cladosporioides y f. moniliforme, mientras el mayor número de aislamientos se detectó en aida. A pesar de las buenas condiciones de manejo y al uso de agrotóxicos, se detectó: ustilago zeae, diplodia zeae maydis, bipolaris maydis, botrytis cinerea, f. moniliforme (gibberella fujikuroi), macrophomina phaseolina y pyrenochaeta terrestris). Entre las especies toxicogénicas a. flavus, se aisló sólo en la rizósfera, mientras debe considerarse en post-cosecha la frecuencia constante de los géneros alternaria, fusarium y penicillium