Search

Summary Pratylenchus thornei and P. neglectus attack common bean and cause economic yield losses throughout cultivated areas in Turkey. The most effective management strategy for the P. thornei and P. neglectus infections is crop rotation with non-host crops and breeding resistant/tolerant varieties. However, parent bean genotypes immune to P. thornei and P. neglectus are not available for breeding programmes; thus, resistant varieties are commonly incorporated as parents. In the present research, a total of 36 common bean varieties were tested in a growth room for their host response to these two nematode pests. The reproduction factor and the population density of both nematode species were calculated. All tested bean varieties showed varying levels of resistance and susceptibility to P. thornei and P. neglectus. Among the dry bean varieties, nine were found to be resistant to P. thornei and three to P. neglectus, with three varieties (‘Kantar-05’, ‘Önceler-98’ and ‘Karacasehir-90’) resistant to both species. Among fresh bean varieties, ten were found to be resistant to P. thornei and four to P. neglectus, with four varieties (‘Helda’, ‘Gina’, ‘Gelincik’ and ‘Bourgondia’) resistant to both species. The resistant common bean varieties identified in this study are a valuable untapped genetic pool that will offer improved resistance levels to P. thornei and P. neglectus, especially ‘Gina’ and ‘Önceler-98’, which seem to possess a great source of resistance to P. thornei and P. neglectus, respectively, and can be used in breeding programmes in the near future.

Summary The root-lesion nematode, Pratylenchus thornei, attacks a wide range of crops and causes significant reductions in global grain production. Breeding programmes are currently restricted to using parents with moderate resistance to P. thornei as cereal cultivars with complete resistance are yet to be identified. This study evaluated 484 of CIMMYT’s spring wheat accessions for resistance to P. thornei of which 56 lines were pre-identified as resistant under controlled growth room conditions. These lines were further evaluated for their resistance and tolerance reactions under field conditions, where 14 accessions maintained their resistance and 16 were moderately resistant against P. thornei. Four lines gave excellent resistant and tolerance reactions to P. thornei. The relationship between the nematode reproduction factor (Pf/Pi) and wheat grain yield in field experiments fits a linear regression model. These findings could be useful for improving P. thornei resistance in wheat.

Grassed waterways are used to mitigate the offsite transport of sediment generated by soil erosion. This study used a novel trait‐based ranking approach as a method to screen potential candidate grass monocultures and mixes based on their theoretical performance in reducing (1) detachment via rainsplash, (2) detachment via scouring due to concentrated flow and (3) sediment transport and deposition processes. Selected grass species were grown under simulated UK summer and autumn establishment conditions under three different replicated rainfall scenarios: drought, normal rainfall and excess rainfall. The grass species used were the novel hybrid species Festulolium cv Prior (Fest_1), Festulolium Bx511 (Fest_2) and a conventional mixture of Lolium perenne and Festuca rubra (Conv). Monocultures and mixtures of these species were studied. Plant traits pertinent to control of soil erosion by water were measured. Above ground traits included plant height, percentage ground cover, above ground biomass, stem diameter, stem area density and number of tillers. Below ground traits included total root length, root total surface area, below ground biomass, root diameter and % fine roots ≤0.25 mm. For summer conditions, the species treatments which had the highest overall soil erosion mitigation potential were Conv, Fest_1 + 2 + Conv and Fest_2. For autumn conditions, the best treatments were Fest_1 + 2, Fest_1 + 2 + Conv and Conv. The Fest 1 + 2 + conv had more desirable traits for erosion control than mono Festulolium treatments for the autumn conditions. The conventional mixture had more desirable traits for erosion control than mono Festulolium treatments in both climate scenarios. The results indicate that the trait‐based ranking approach utilised in this study can be used to inform rapid screening of candidate grass species for soil erosion control.

Soilborne diseases result in major economic losses for potato producers. Compost application can reduce soilborne diseases, however the effects of compost products on potato disease severity and incidence are still unclear. Diverse compost products were compared for their effects on soilborne diseases of potato in New Brunswick, Canada using field and growth room experiments. In the field, five products were applied at 45 Mg ha−1 dry weight to field plots in October of 2014 and 2015. In the growth room experiment, seven products were mixed to a 5% w/w ratio with naturally infested soil. Tubers were assessed for disease severity and incidence and compared with a no compost addition control. Severity of symptoms of silver scurf, black scurf (BS), common scab (CS), and powdery scab varied among treatments, experiments, and years. In the field experiment, BS severity was significantly greater in the control than in the poultry manure compost treatment (3.26% versus 0.90%) in 2016. Common scab severity...

The effect of two control contours on the shape of crystal‒melt interface has been examined. It is shown that the shape of crystal‒melt interface can be flexibly and efficiently governed using these contours with large and small time constants. The dependences of the shape of crystal‒melt interface on the fluctuations of cooling water temperature, growth room temperature, and input voltage have been established. The investigations made it possible to improve significantly the growth process parameters and obtain high-quality crystals.

Micropropagation, which employs various plant growth regulators (PGRs) in the culture medium for the induction of multiple shoots as well as adventitious roots, is a widely-used technique for the propagation of the genus Morus. The main objective of the present study was to evaluate the effect of PGR-free culture medium on the quantitative and qualitative characteristics of the micropropagation of Morus nigra under the growth room and greenhouse environmental conditions. Although a higher rate of multiplication (4.7-5.2 shoots/explant) was obtained from the treatments using Benzyladenine (BA) as the PGR, the PGR-free culture medium also exhibited comparable multiplication rate (4.1 shoots/explant) with a higher quality of shoots and without any symptoms of hyperhydricity. Furthermore, the use of PGR-free culture of M. nigra for in vitro propagation combined the steps of shoot multiplication and rooting phase using the same culture medium, further simplifying the process. In this study, the micro-shoots were also assessed for their in-vitro rooting and acclimatization potential. The incubation of an in-vitro culture of nodal explants in a controlled growth room for 28 days exhibited optimum response with about 90% rooting and 100% plantlet survival during the acclimatization phase. These results were better than those incubated under greenhouse conditions., Advances in Horticultural Science, Vol 33 No 3 (2019)

A survey for the presence of Rhizoctonia species on barley, bean, canola, corn, pea, soybean and wheat in 170 fields in Canada was completed during 2009–2011. Rhizoctonia solani was recovered from 52 (31%) of the 170 fields surveyed. A total of 191 isolates of R. solani belonging to anastomosis groups (AG) AG 2-1, AG 2-2, AG 4, AG 5, AG 9 and AG 11 were recovered. Fifty-two binucleate isolates of Rhizoctonia spp. were also recovered from 35 (21%) of the crops surveyed. In growth room pathogenicity studies, isolates belonging to AG 2-1 were pathogenic primarily on canola while isolates of other anastomosis groups tended to have wider host ranges. Symptoms included pre- and post-emergence damping off, crown rot and, to a lesser extent, root rot. The majority of binucleate isolates were not pathogenic or only had low aggressiveness on the hosts tested. There was considerable variation in host range among isolates of R. solani within individual AGs, and isolates recovered from asymptomatic seedlings o...

Phototropic (PT) and gravitropic (GT) bending are the two major tropic movements that determine the spatial position of potato shoots. We studied PT bending of potato plantlets grown under long-day photoperiods in several prearranged position setups providing different interactions with the GT response. Starting with the standard PT stimulation setup composed of unilateral irradiation of vertically positioned shoots, experiments were also done in antagonistic and synergistic setups and in treatments with horizontal displacement of the light source. In the standard setup, PT bending suppressed the GT bending, which could occur only if the PT stimulation was cancelled. The antagonistic position, with phototropism and gravitropism attempting to bend shoots in opposite directions, showed phototropism and gravitropism as independent bending events with the outcome varying throughout the day reflecting diurnal changes in the competence of individual tropic components. Whilst gravitropism was constant, phototropism had a marked daily fluctuation of its magnitude with a prominent morning maximum starting an hour after the dawn in the growth room and lasting for the next 6 h. When phototropism and gravitropism were aligned in a synergistic position, stimulating shoot bending in the same direction, there was little quantitative addition of their individual effects. The long period of morning PT bending maximum enabled multiple PT bending events to be conducted in succession, each one preceded by a separate lag phase. Studies of secondary PT events showed that potato plantlets can follow and adjust their shoot position in response to both vertical and horizontal movements of a light source. PT bending was reversible, since the 180° horizontal change of a blue light (BL) source position resulted in reversal of bending direction after a 20-min-long lag phase. Electronic supplementary material The online version of this article (doi:10.1007/s10265-016-0821-4) contains supplementary material, which is available to authorized users.

http://dx.doi.org/10.5902/1980509821113 Araucaria angustifolia apresenta redução da taxa de crescimento durante o ano, podendo ser resposta às condições ambientais desfavoráveis, como ocorre nas fruteiras de clima temperado, que apresentam dormência de gemas como forma de sobrevivência. O objetivo deste trabalho foi avaliar a dinâmica da atividade respiratória de meristemas apicais de ramos plagiotrópicos de Araucaria angustifolia. Foram coletadas amostras de 0,4 g de brotações terminais de ramos plagiotrópicos de plantas jovens e adultas, as quais foram mantidas em 5 mL de solução de cloreto de 2,3,5 trifeniltetrazólio (1,2%) em sala de crescimento a 25°C. Em seguida, foram mantidas em 4 mL de álcool etílico absoluto para leitura por espectrofotometria da absorbância a 560 nm. A atividade respiratória de meristemas apicais de ramos plagiotrópicos de Araucaria angustifolia é variável durante o ano. A maior atividade respiratória ocorre na metade da primavera e a menor atividade respiratória ocorre no inverno, em plantas jovens e adultas. Plantas adultas permanecem em alta atividade respiratória por um período maior, até o início do verão.

Five field trials were conducted over a two-year period (2013, 2014) to determine the control of glyphosate-resistant (GR) giant ragweed with isoxaflutole (IFT) and metribuzin (MTZ) applied alone and in combination. Treatments were designed to assess the dose response of an IFT plus MTZ tank-mix as well as each chemical applied alone to classify the response using Flint’s adaptation of Colby’s equation. Two factor factorial experiments were performed in the growth room to ascertain the response of IFT versus glyphosate, IFT versus MTZ, and IFT plus MTZ versus glyphosate on single plants. Field experiments evaluated the control of GR giant ragweed with IFT plus MTZ in tank-mix in a 1:4 ratio. The rate of IFT plus MTZ for 80% control of GR giant ragweed at 4 and 8 weeks after application (WAA) was 518 (104 g a.i. ha-1 IFT + 414 g a.i. ha-1 MTZ) and 631 g a.i. ha-1 (126 g a.i. ha-1 IFT + 505 g a.i. ha-1 MTZ), respectively. A rate of 668 and 467 g a.i. ha-1 was required to reduce GR giant ragweed density and biomass by 80%, respectively. Field experiments evaluating the control of GR giant ragweed with tank-mixes of IFT plus MTZ, where glyphosate was a constant tank-mix partner, were mostly synergistic. However, the low tank-mix rate (52.5 + 210 g a.i. ha-1) had an additive response for GR giant ragweed biomass reduction. When tested in the greenhouse and growth room, glyphosate susceptible (GS) giant ragweed showed some antagonism with glyphosate and isoxaflutole tank-mixes at rates less than commercial field rates. GR giant ragweed showed an additive response across all treatments in the growth room. Greenhouse experiments evaluating IFT versus MTZ and IFT plus MTZ versus glyphosate revealed all tank-mix treatments to be synergistic at 2 WAA.

Kepok Banana (Musa balbisiana) is beneficial in fulfilling nutrition for it has a high B vitamin complex. Additionally, it is of high economic value as a food processing material. Bananas as processed ingredients for industrial scale are constrained by unsustainable production. Thus, efforts are needed to supply quality, uniform seeds and meet cropping patterns. In vitro culture technique is an innovation in meeting the availability of standardized banana seed sources. This study aimed to examine the effectiveness of fruit extracts and temperature differences for in vitro culture in Kepok banana. Murashige and Skoog (MS) base media were used in the multiplication stage with the addition of melon, banana, and papaya extracts (150 g.L−1). The explants were stored at various growth room temperatures (±25, ±28, and ±31°C). The results showed that the Kepok banana explants morphogenesis using MS media enriched with papaya extract gave no difference effectivity result with vitamin synthesis in the parameters of number of shoots (4), number of leaves (7), number of roots (7.3), and length roots (6.3 cm) and showed the highest results with parameter height of plantlets (9 cm). The best condition for the proliferation of Kepok banana explants was room temperature (±28°C).

In tissue culture it is necessary to use seeds of good quality and free of pathogens in order to avoid damages in the work to be carried out in the laboratory. Therefore, strict cleaning of the seeds intended for in vitro cultivation is essential. Thus, the objective of this study was to evaluate fruit biometry, germination and morphogenesis of 'Cravo' (Citrus limonia Osbeck) and Persia Lima (Citrus aurantium) seeds in vitro submitted to different concentrations of NaClO for asepsis. Fruits of 'Cravo' lemon and Lima of Persia. Subsequently, they were transported to the Biotechnology Laboratory of the Goiano Federal Institute Campus Urutaí-GO, where they performed the biometric characterization of the fruits. The seeds of these fruits were submitted to treatment with sodium hypochlorite solution in different concentrations: 0,0; 1.0; 1.5; 2.0 and 2.5% for 10 minutes, constituting then five treatments for each variety and placed in an acclimatized growth room to analyze the results. The variables evaluated were: biometry of fruits and seedlings; oxidation indexes; germination; contamination; and types of contamination. NaClO doses were compared from 95% confidence intervals. The analyzes were performed using the glm () function of software R version 3.4.1. It was verified that the aseptic treatment with NaClO for lime and lemon was promising for the morphological processes of germination and development of seedlings, as well as for the control of contaminating agents in vitro.

RESUMO A técnica de microestaquia e enraizamento ex vitro pode resultar em mudas com o sistema radicular de melhor qualidade e com maior número de raízes secundárias, quando comparada com a estaquia convencional. O objetivo deste trabalho foi avaliar o enraizamento ex vitro e a aclimatização de microestacas de erva-mate em diferentes doses do fitorregulador ácido 3-indolibutírico (AIB) e substratos. Em sala de cultivo foi avaliada diferentes doses de ácido 3-indolibutírico (0, 250, 500, 1000 e 2000 mg.L-1) e diferentes substratos utilizados puros (areia grossa, casca de arroz carbonizada, vermiculita, fibra de coco e substrato comercial). Em câmara úmida foram avaliados os mesmos substratos utilizados puros e as seguintes composições de mesmas proporções de volume: casca de arroz carbonizada + areia grossa; casca de arroz carbonizada + areia grossa + substrato comercial; casca de arroz carbonizada + substrato comercial. O enraizamento e a aclimatização ex vitro de microestacas de erva-mate podem ser realizados em câmara úmida, sendo necessário o uso de ácido 3-indolibutírico na dose de até 1250 mg.L-1. O substrato composto em iguais proporções volumétricas de casca de arroz carbonizada + areia grossa + substrato comercial proporcionou uma maior porcentagem de microestacas enraizadas. ABSTRACT The technique of microcutting and ex vitro rooting can result in plantlets with better quality of radicular system and larger number of secondary roots, when compared with conventional cutting. The objective of this work was to evaluate the ex vitro rooting and acclimatization of holly microcuttings in different doses of phytoregulator indole-3-butyric acid (IBA) and substrate. In the growth room were evaluated different doses of indole-3-butyric acid (0, 250, 500, 1000 and 2000 mg.L-1) and different substrates used pure (coarse sand, carbonized rice husk, vermiculite, coconut fiber and commercial substrate). In humid chamber were evaluated the same pure substrates and the following combinations of the same volume ratios: carbonized rice husk + coarse sand; carbonized rice husk + coarse sand + commercial substrate; carbonized rice husk + commercial substrate. The ex vitro rooting and acclimation of holly microcuttings can be done in the humid chamber, necessitating the use of indole-3-butyric acid at a dose of 1250 mg.L-1. The substrate composed in equal proportions of carbonized rice husk + coarse sand + commercial substrate provided a higher percentage of rooted microcuttings.

The aim of this study was to investigate which hydroponic system is the optimum for growth and photosynthetic characteristics of Angelica gigas during experiment. Angelica gigas ‘Manchu’ were sowed and managed under a growth room chamber. The environmental conditions (temperature 22℃/18℃ (day/night), relative humidity 50-70%, photosynthetic photon flux density (PPFD) 120±6 μmol m -2 s -1 ) were maintained for 3 weeks. Forty eight seedlings with 4-5 leaves were transplanted in deep flow technique (DFT), substrate, and spray culture systems [culture bed: 800 (L) x 800 (W) x 400 mm(H)] under 150±5 μmol m -2 s -1 PPFD provided with fluorescence lamps and cultivated for 11 weeks. At the end of the experiment, fresh and dry weights, leaf lenghth and width, SPAD, root fresh, and dry weights, and root volume of Anglica gigas were measured. Photosynthetic rate of Anglica gigas were measured with portable photosynthesis systems to investigate optimum PPFD, CO₂ concentration, and air temperature conditions. Fresh and dry weights of Anglica gigas grown in substrate were significantly greater than DFT-treated, but there were not significant with spray treatment. Leaf photosynthesis of Anglica gigas showed the tendency to sharply increase as PPFD was increased from 50 to 200 μmol m -2 s -1 . Though CO₂ saturation point was around 1000-1200 μmol mol-1, increase in air temperature from 16 to 26℃ did not quite affect photosynthesis of Anglica gigas. In conclusion, Anglica gigas may be optimally cultivated with a spray culture system as air temperature, PPFD, and CO₂ concentration for environment are controlled at 20±3℃, 150 μmol m -2 s -1 , and around 1000 μmol mol -1 for mass production.

Bertholletia excelsa H.B.K.,known as Brazil nuttree, belongs to the Lecythidaceae botanic family and is endemic to the AmazonianRegion. Its nuts have high economic and nutritional value. The objective of this work was to establish efficient protocols for callus induction from immature seeds of B.excelsa, as a preliminary step to its further micropropagation. After disinfestation, fragments of immature seeds were cultivated in WPM (Wood Plant Medium) supplemented with 2,4-D (0, 1, 2, 4 and 8 mg.L-1) and TDZ (0, 1.6 and 3.2 mg.L-1) in factorial combination. Twenty-one days later the callus induction was evaluated. Cultures were kept in a growth room in the dark at 24±2ºC. The highest percentage of callus induction was found with the combination of 2 mg.L-12,4-D with 3.2 mg.L-1TDZ.

A series of field experiments were undertaken at three locations in Khyber PukhtunKhwa (KPK) Province, Pakistan to assess the effects of low temperatures and phytohormone applications on chickpea ( Cicer arietinum L.) growth and yield. These trials showed that ABA application (10 −4 M) to 40-day-old plants (before the first seasonal frost) offset low temperature-induced growth and yield depression at harvest (200-day-old plants) by up to 17%. These yield improvements were mainly due to an increase in the number of seeds pod −1 . Growth room experiments were carried out under controlled environmental conditions to establish how foliar application of 10 −4 M ABA to 40-day-old plants might improve seed production at harvest. The foliar application of 10 −4 M ABA had no detectable effect on endogenous shoot or root ABA levels four-days after spraying or on biomass when plants were maintained in warm conditions. When exposed to night temperatures of −2 °C, however, the endogenous ABA levels increased dramatically in both control and ABA-treated plants, but this rise was more rapid after ABA application ( p p

The pot cultivar of Chrysanthemum × grandiflorum 'Leticia Time Yellow' was cultivated and stored in a growth room under fluorescent light of white, blue, green, yellow and red colour. Quantum irradiance was 30 μmol · m-2 × s-1. The colour of light exerted a significant influence on the opening of closed inflorescence buds and on post-harvest longevity of pot chrysanthemums grown earlier in an unheated plastic tunnel. Under florescent lamps emitting blue light at a wavelength of 400-580 nm, inflorescence buds opened and coloured the earliest. The number of developed flower heads was the greatest under blue and white light. Flower heads developing in blue light were bigger than flower heads developing in white and green light. In red light at a wavelength of 600-700 nm, plants flowered latest and they produced the smallest flower heads. Post-harvest longevity was preserved longest in chrysanthemums kept under blue, white and green light. In red and yellow light, the flowers were overblown earliest.

The substrate must promote the growth of the plants, being an important component during the acclimatization of micropropagated plants. The aim of this research was to evaluate the effects of different substrates during the acclimatization of fox grape cv. Bordô. The experiment was carried out at the greenhouse during February and March of 2009. Five substrates were tested: Plantmax® HT, Plantmax® HT: Coconut fiber (7,5:2,5 v/v), Plantmax® HT: Coconut fiber (1:1 v/v), Plantmax® HT: Coconut fiber (2,5:7,5 v/v) and Coconut fiber. The process of acclimatization consisted of three phases. After 20 days of in vitro culture, it was removed the PVC film (Polyvinyl chloride) that covered the flasks and after two days, flasks had lids partial opening for two hours at the growth room conditions. The plants were transferred for the different substrates and placed in a greenhouse with intermittent nebulization during 16 days proceeded by 20 days of daily manual irrigation. The best substrate for acclimatization of fox grape cv. Bordô was Plantmax® HT, benefitting the formation of roots and aerial part of the plants. The coconut fiber must not be used alone as substrate or in larger proportions than 25% in the mixture with Plantmax® HT., O substrato deve promover o crescimento das plantas, sendo um componente importante durante a aclimatação das plantas micropropagadas. O objetivo desta pesquisa foi avaliar os efeitos de diferentes substratos durante a aclimatação da uva de raposa cv. Bordô. O experimento foi realizado em casa de vegetação nos meses de fevereiro e março de 2009. Cinco substratos foram testados: Plantmax® HT, Plantmax® HT: fibra de coco (7,5: 2,5 v / v), Plantmax® HT: fibra de coco ( 1: 1 v / v), Plantmax® HT: fibra de coco (2,5: 7,5 v / v) e fibra de coco. O processo de aclimatação consistiu em três fases. Após 20 dias de cultura in vitro, foi removido o filme de PVC (cloreto de polivinil) que cobria os frascos e após dois dias, os frascos tinham tampas abrindo parcialmente por duas horas nas condições da sala de crescimento. As plantas foram transferidas para os diferentes substratos e colocadas em casa de vegetação com nebulização intermitente durante 16 dias seguidos por 20 dias de irrigação manual diária. O melhor substrato para aclimatação da uva de raposa cv. O Bordô foi o Plantmax® HT, beneficiando a formação de raízes e parte aérea das plantas. A fibra de coco não deve ser usada sozinha como substrato ou em proporções maiores que 25% na mistura com Plantmax® HT.

Robust calibration of phenological models requires long term field observations, which are not always available or sufficiently widespread. This has motivated the evaluation of short-term experiments using cuttings under semi-controlled conditions as an alternative data source. Single-node cuttings from two grapevine cultivars were exposed to variable chilling durations and allowed to sprout in a growth room. The observed budburst dates and temperature series were used to calibrate two budburst models, which were validated against a 39-year field observation dataset by means of a fuzzy-logic based integrated index (FI). Satisfying validation scores were obtained, ranging from 0.262 to 0.411 on a 0-1 scale (best-worst response). The experiment was then inverted, using field data for calibration and cuttings for validation, and FI scores ranging between 0.352 and 0.495 were obtained. On this occasion however, the models were not able to estimate budburst occurring after short chilling exposures, where they returned either high overestimations or failed completely. This was due to the narrow winter length variability in the field dataset, which made the optimization algorithm converge towards unrealistically high chilling requirements and artifactual descriptions of the temperature effects on dormancy. Cutting-based calibration on the other hand produced parameterizations that were more consistent with available experimental knowledge. Despite this difference between them, the two approaches proved to be equivalent under the climatic conditions present, but not when tested on projected scenarios of climate change over the period 1990–2090, where cutting-calibrated models, which are more sensitive to decreasing winter length, predicted higher variations of the budburst dates.

Vink, J. P., Soltani, N., Robinson, D. E., Tardif, F. J., Lawton, M. B. and Sikkema, P. H. 2012. Occurrence and distribution of glyphosate-resistant giant ragweed ( Ambrosia trifida L.) in southwestern Ontario. Can. J. Plant Sci. 92: 533–539. Giant ragweed is the first confirmed glyphosate-resistant (GR) weed in Canada. A survey was conducted to document the distribution of GR giant ragweed in southwestern Ontario. Giant ragweed seed was collected from 102 sites in Essex (70), Chatham-Kent (21), Lambton (10) and Waterloo counties (1) during the autumn of 2009 and 2010 prior to soybean harvest. Plants were grown in a growth room, sprayed with glyphosate at 1800 g a.e. ha−1 and classified as resistant or susceptible. GR giant ragweed has been confirmed at 47 new locations in three counties (Essex, Chatham-Kent and Lambton). The results from this survey indicate that GR giant ragweed biotypes occur across a greater area in southwestern Ontario than originally thought. This survey provides an important baseline for future surveys in the province.

Visible light is the basic energetic driver of plant biomass production through photosynthesis. The constantly fluctuating availability of light and other environmental factors means that the photosynthetic apparatus must be able to operate in a dynamic fashion appropriate to the prevailing conditions. Dynamic regulation is achieved through an array of homeostatic control mechanisms that both respond to and influence cellular energy and reductant status. In addition, light availability and quality are continuously monitored by plants through photoreceptors. Outside the laboratory growth room, it is within the context of complex changes in energy and signalling status that plants must regulate pathways to deal with biotic challenges, and this can be influenced by changes in the highly energetic photosynthetic pathways and in the turnover of the photosynthetic machinery. Because of this, defence responses are neither simple nor easily predictable, but rather conditioned by the nutritional and signalling status of the plant cell. This review discusses recent data and emerging concepts of how recognized defence pathways interact with and are influenced by light-dependent processes. Particular emphasis is placed on the potential roles of the chloroplast, photorespiration, and photoreceptor-associated pathways in regulating the outcome of interactions between plants and pathogenic organisms.

In this study, a number of biologic characteristics of Tetrastichus gallerucae, the most important natural enemy of Xanthogaleruca luteola (Col.: Chrysomellidae), were studied. Experiments were carried out in growth room with a temperature of 25°C±1°C, relative humidity of 60%±5% and light period of 16L:8D. The results demonstrated the following outcomes: without food and host egg, the longevity of male and female bees was respectively, 1.23 and 1.35 days. On the host egg, their longevities were 3.85 and 6.02 days, respectively. On rarefied honey their longevities were 14.04 and 24.74 days, respectively and on the host eggs together with rarefied honey, their longevities were 13.4 and 34.72 days, respectively. The average growth period times in the egg of elm leaf beetle of male and female bees were 12.97 and 12.63 days, respectively. The percentage of female bees decreases as the longevity of the insects increases. These bees lay eggs in the 1–9-day-old eggs of elm leaf beetle but 1-day-old eggs of the h...

Submitted by Guilherme Lemeszenski (guilherme@nead.unesp.br) on 2013-08-22T19:00:18Z No. of bitstreams: 1 S0103-84782011000300004.pdf: 159836 bytes, checksum: a94b91c253cb14da0776d02ce8bd75b4 (MD5) Made available in DSpace on 2013-08-22T19:00:18Z (GMT). No. of bitstreams: 1 S0103-84782011000300004.pdf: 159836 bytes, checksum: a94b91c253cb14da0776d02ce8bd75b4 (MD5) Previous issue date: 2011-03-01 Made available in DSpace on 2013-09-30T19:58:36Z (GMT). No. of bitstreams: 2 S0103-84782011000300004.pdf: 159836 bytes, checksum: a94b91c253cb14da0776d02ce8bd75b4 (MD5) S0103-84782011000300004.pdf.txt: 24514 bytes, checksum: 18e0fa51a6f1106784ec3e489f174e43 (MD5) Previous issue date: 2011-03-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T13:12:48Z No. of bitstreams: 2 S0103-84782011000300004.pdf: 159836 bytes, checksum: a94b91c253cb14da0776d02ce8bd75b4 (MD5) S0103-84782011000300004.pdf.txt: 24514 bytes, checksum: 18e0fa51a6f1106784ec3e489f174e43 (MD5) Made available in DSpace on 2014-05-20T13:12:48Z (GMT). No. of bitstreams: 2 S0103-84782011000300004.pdf: 159836 bytes, checksum: a94b91c253cb14da0776d02ce8bd75b4 (MD5) S0103-84782011000300004.pdf.txt: 24514 bytes, checksum: 18e0fa51a6f1106784ec3e489f174e43 (MD5) Previous issue date: 2011-03-01 Visando a alcançar alta eficiência na indução de calos a partir de explantes foliares de plantas matrizes de C. arabica com alta heterozigose, por meio da embriogênese somática indireta, foram instalados três experimentos. O primeiro experimento foi conduzido em esquema fatorial 2x5, constituído de dois meios de cultura (BOXTEL & BERTHOULY, 1996 e TEIXEIRA et al., 2004) e cinco genótipos de C. arabica. No segundo experimento, foi avaliado o potencial de produção de calos embriogênicos em 10 genótipos, sendo cada genótipo considerado como um tratamento e, no terceiro experimento, foram avaliadas as variações nas concentrações de 2.4-D (2,5 e 20µM) e 2-iP (2,5 e 20µM) nos meios primário e secundário de TEIXEIRA et al. (2004). As culturas foram mantidas a 25oC, sob obscuridade. Para os genótipos 2.2 e 7.2, verificou-se a superioridade do meio de cultura Teixeira et al. (2004) em relação ao meio BOXTEL & BERTHOULY (1996). No genótipo 4.2, observou-se o comportamento inverso, ou seja, a superioridade do meio BOXTEL & BERTHOULY (1996). Os genótipos 3.0 e 5.0 apresentaram o mesmo comportamento em ambos os meios de cultura estudados, evidenciando que a produção de embriões somáticos é fortemente dependente do genótipo. A indução de calos depende da relação de 2-iP e 2.4-D. A combinação de 20.0µM of 2.4-D e 20.0µM of 2-iP promoveu a maior porcentagem de indução de calos embriogênicos. Three experiments were carried out with the objective of achieving high effectiveness in calli induction from high heterozygosis leaf explants of Coffea arabica through indirect somatic embryogenesis. A randomized-block design in a 2x5 factorial arrangement made up of two media [BOXTEL & BERTHOULY (1996) and TEIXEIRA et al. (2004)] and five C. arabica genotypes were used in the first experiment. In the second experiment the embryogenic calli production potential was evaluated in ten genotypes. Each of them was considered as a treatment. In the third experiment the variations in both 2.4-D (2.5 e 20µM) and 2-iP (2.5 e 20µM) concentrations in TEIXEIRA et al. (2004) medium and secondary media were evaluated. Crops were kept in a growth room under darkness, at 25±2oC. The medium described by TEIXEIRA et al (2004) was found to be superior when compared to that described by BOXTEL & BERTHOULY (1996) in the 2.2 and 7.2 genotypes. An opposite behavior was noticed in 4.2 genotype, that is, BOXTEL & BERTHOULY (1996) had medium superiority. Both 3.0 and 5.0 genotypes had the same behavior in both media studied, which shows that the somatic embryo production depends on the genotype. Calli induction depends on the 2-iP and 2.4 D ratio. The 20.0µM of 2.4-D and 20.0µM of 2-iP combination caused the highest embryogenic calli induction rate. Empresa de Pesquisa Agropecuária de Minas Gerais Unidade Regional do Sul de Minas Empresa Brasileira de Pesquisa Agropecuária Café Fundação Procafé Universidade Federal de Lavras (UFLA) Departamento de Agricultura Universidade Estadual Paulista Centro de Estudo de Insetos Sociais Universidade Estadual Paulista Centro de Estudo de Insetos Sociais

The research for new techniques of in vitro cultivation is being object of many studies around the world, in order to optimize and decrease production costs of seedlings with agronomical interest. The main goal of this work was to compare different systems of in vitro cultivations using Ananas comosus L. Merril. So, the in vitro growth of the plantlets was promoted in two different bioreactors: Bioreactor of Immersion by Bubbles (B.I.B.®) and the Reactor of Temporary Immersion (R.I.T.A.®) with immersion cycle every 2 hours for 15 minutes and the traditional system in flasks with 200 mL. All cultivation systems used the MS liquid nutritive solution, supplemented with BAP (1 mgL-1), ANA (0.25 mgL-1), sucrose (30 gL-1) and Tween 20® (0.5 µL). The pH was adjusted to 5.8 and sterilized at 120°C for 15 minutes. The cultures were kept into a growth room during 30 days, with controlled temperature of 25±2°C, under white cold light (46.8 µmol.m-2.s-1), with photoperiod of 16 hours. The experimental design used was randomized, with three treatments, three repetitions and ten plants each stage. Among the evaluated systems, the BIB® presented the best results for the tested variables, mainly the total number of shoots, being 2.3 e 3.1 times superior when compared with the system R.I.T.A.® and the traditional consecutively. So the system of immersion by bubbles turns into an effective equipment to produce seedlings of pineapple in large scale.A busca por novas técnicas de cultivo in vitro vem sendo amplamente estudadas, visando otimizar e baixar o custo de produção das mudas que tenham interesse agronômico. O objetivo deste trabalho foi comparar diferentes sistemas de cultivo in vitro de Ananas comosus L. Merril. Para tanto, o crescimento in vitro de plântulas foi promovido em sistemas de biorreatores (B.I.B.® e R.I.T.A.®) com ciclo de imersão a cada 2 horas por 15 minutos e o sistema tradicional em frascos de 200 mL. Em todos os sistemas de cultivo, foram utilizadas solução nutritiva líquida MS, suplementado com 1 mg L-1 de BAP, 0,25 mg L-1 de ANA, 30 g L-1 de sacarose e 0,5 µL de Tween® 20, pH ajustado para 5,8 e autoclavagem a 120°C por 15 minutos. As culturas foram mantidas em sala de crescimento durante 30 dias, temperatura controlada de 25±2°C, sob luz branca fria (46,8 µmol.m-2.s-1), com 16 horas de fotoperíodo. O delineamento foi inteiramente casualizado, com três tratamentos, três repetições e dez plantas por estágios. Para os sistemas avaliados, o biorreator de imersão por bolhas apresentou os melhores resultados dentre as variáveis analisadas, com destaque ao número total de brotações, sendo 2,3 e 3,1 vezes superiores quando comparado com o sistema R.I.T.A.® e sistema tradicional respectivamente. Portanto, o sistema de imersão por bolhas torna-se um equipamento eficaz na produção de mudas de abacaxizeiro em larga escala.

With the increased interest of plants in space, gravity cannot be ignored in studies of plant–water relations. Although photosynthesis has been measured on the International Space Station, apparently no published information exists concerning the stomatal resistance of plants in space. Growth is directly related to stomatal opening, which is controlled by hormones produced in the roots. The objective of this study was to determine the effect of gravity on plant water take and stomatal resistance. To simulate gravity-free conditions, wheat plants ( Triticum aestivum L. ‘Jagger’) were grown in columns oriented horizontally. Two experiments, each with a different depth of planting (3 cm or 3 mm), were performed in a growth room. Four columns (7 cm diam., 40 cm long), filled with a commercial potting mix were used in each experiment: two were placed horizontally and two were placed vertically. Stomatal resistance was measured with a steady-state porometer. In the first experiment (3-cm planting depth), plants in horizontal columns emerged poorly. In the second experiment (3-mm planting depth), plants in horizontal columns emerged, but leaves often were plastered on the soil surface, making it difficult to determine stomatal resistance. In both experiments, roots in columns placed on their sides did not grow into the columns. Because the plants grown horizontally could not take up water, they wilted and died, and stomatal resistance readings were high (>50 s cm −1 ).

Patterns of carbon allocation in northern red oak (Quercus rubra L.), characterized by episodic growth through recurrent single-season flushing, vary by growth stage. To examine post-transplant timing and carbohydrate sources for new root growth, dormant, bare-root, half-sibling northern red oak seedlings were transplanted to pots and placed in a favorable growth chamber environment. Unlabeled seedlings were harvested at transplant and at the bud swell stage. After leaf emergence, seedlings were exposed to (14)CO(2) at the linear shoot, linear leaf or lag growth stages. Seedlings were then placed in a growth room for 48 h to allow for translocation of (14)C-labeled current photosynthate and its stabilization in sink component plant parts. Seedlings were subsequently harvested and tissue (14)C:(12)C ratio analyzed. New root growth began during the linear shoot growth stage. However, no increase in (14)C:(12)C ratio was found in new roots until the linear leaf and lag growth stages, indicating a downward shift in translocation of current photosynthate to fuel new root growth. In old roots, (14)C:(12)C ratio increased at the lag stage. Our results indicate that both stored carbohydrates and current photosynthate contribute to new root growth of transplanted northern red oak seedlings; stored carbohydrates promote initial new root proliferation, whereas current photosynthate assumes a greater role as new leaves mature and the flush terminates. Optimizing nursery practices to increase carbohydrate reserves may reduce the time required to establish root-soil contact and facilitate early post-planting survival.

1 Plants sharing pots have been observed to show more allocation to roots than do solitary plants, even when resources per plant are constant, indicating plasticity to root neighbours. Lowered red to far-red ratio (R : FR), a cue of above-ground competition, is known to cause increased stem elongation and decreased allocation to roots. In nature, however, cues for above- and below-ground competition are likely to be experienced simultaneously, and may elicit contradictory responses. 2 We investigated whether the presence of the above-ground competition cue (low R : FR) affected the responses to the below-ground competition cue (presence of neighbouring roots) in soybean and whether these responses depended on the presence or absence of symbiotic bacteria or on the availability of nutrients. 3 In a fully factorial study in a growth room, light quality, root neighbours, nutrient availability and Bradyrhizobium inoculation were manipulated. Stem elongation and biomass allocation were measured. 4 As predicted, plants allocated more to roots in the presence of root neighbours, regardless of R : FR, Bradyrhizobium and nutrient treatment. Plants elongated under low R : FR, although the degree of elongation was affected by Bradyrhizobium and nutrients. R : FR did not affect allocation to roots. Surprisingly, we found no reduction in reproductive allocation and therefore no 'tragedy of the commons' cost; instead, growth was increased in the presence of root neighbours. 5 We conclude that soybean responds to both competition cues independently, but that below-ground resources such as Bradyrhizobium and nutrient availability moderate the morphological responses to above- and below-ground competition. 6 To our knowledge, this is the first study that tests responses to above- and below-ground competition cues simultaneously and that shows the independence of these responses. This study provides supporting evidence that plants can sense neighbouring roots as a cue of impending competition and demonstrates clearly that the root allocation response is not dependent on the presence of Bradyrhizobium or an artefact of inadvertent R : FR manipulation.

O presente trabalho teve como objetivo testar alguns substratos para elevar a taxa de germinação de uredosporos e promover um maior crescimento dos tubos germinativos do agente causal da ferrugem da folha do trigo (Puccinia triticina) e compará-los ao substrato água-ágar considerado padrão. Foram testados os substratos: água-ágar, batata sacarose ágar (BSA), 1/4 BSA, dextrose-ágar, frutose-ágar, manitol-ágar, sacarose-ágar, infusão de folhas de trigo-ágar e extrato de folhas de trigo-ágar. Após a deposição dos uredosporos nas placas de petri contendo os substratos, o material foi incubado em câmara de crescimento, no escuro a 20 ºC, por 6, 12 e 24 horas. Avaliou-se a germinação dos uredosporos e mediu-se o comprimento dos tubos germinativos. As médias de germinação e de comprimento dos tubos germinativos foram comparadas pelo teste de Duncan a 5%. Os valores mais elevados de germinação de uredosporos e do comprimento do tubo germinativo foram observados nos substratos infusão de folhas de trigo-ágar e extrato de folhas de trigo-ágar. The objective of this study was to test a methodology which provides a better germination rate of urediniospores and higher growth of germ tubes of the causal agent of wheat leaf rust (Puccinia triticina) in relation to the water-agar substratum. The following substrata were tested: water-agar, potato-sucrose-agar (PSA), 1/4 PSA, dextrose-agar, fructose-agar, manitol-agar, sucrose-agar, wheat-leaves infusion-agar and, wheat-leaves extract-agar. A urediniospore suspension was poured on the substrata in Petri dishes and incubated in growth room, in darkness at 20 ºC, for 6, 12 and, 24 hours. Germination of urediniospores and length of the germ tube were assessed. Means for germination and germ tube length were compared by Duncan test at 5%. The highest germination rate and germ tube growth were observed on the wheat-leaves infusion and wheat-leaves extract-agar substrata.

The present attempt aimed to optimize micropropagation protocols supplemented with different concentrations and combinations of benzylaminopurine (BAP) (0, 2, 4, 6 mg L-1) and indole acetic acid (IAA) (0.5 and 1.0 mg L-1). Exotic banana (Musa spp) genotypes GCTCV-215 (AAA), ‘Yangambi’ Yangambi Km-5 (AAA) and FHIA-23 (AAAA) were used in research work. Experiments were conducted at Plant Tissue Culture Laboratory of Nuclear Institute of Agriculture (NIA), Tando Jam. Data collected for in vitro shoot consists of the following parameters: days for bud initiation, rate of shoot proliferation (%), number of multiple shoots, shoot length (cm) and fresh mass of shoot (g). Significant (p≤ 0.05) variations were observed for varieties, treatments and varieties x treatment for all the parameters. Synergistic effects of BAP and IAA were observed in GCTCV-215 and Yangambi Km-5. Out of various treatments, best concentration for multiple shoot in short period of time for GCTCV-215 and Yangambi Km-5 was found in 4.0 mg /l BAP + 0.5 mg L-1 IAA. Maximum fresh mass of shoot observed at same concentration and combination of BAP and IAA and for shoot length combination of 4.0 mg L-1 BAP with 1.0 mg L-1 IAA was found to be most suitable for GCTCV-215 and Yangambi Km-5. FHIA-23, show better performance in MS medium supplemented with only BAP at concentration 4.0 mg/L-1. After development of root, in vitro plantlets were shifted from growth room to green house in polythene bags containing garden soil and humus mixture in ratio (1:1). Key words: Micropropagation efficiency, exotic musa genotype, growth regulators.

Plant tissue culture broadly refers to the in vitro cultivation of all plant parts under aseptic conditions. Any laboratory in which tissue culture techniques are performed must contain a number of basic facilities. These include areas for general washing and media preparation, sterilization, storage, aseptic transfer, observation/data collection, and environmentally controlled incubators or culture rooms. The most important work area is the culture transfer room where the core activity takes place. Plant tissue cultures should be incubated under well-controlled temperature, humidity, air circulation, light quality, and for specific duration. The plant culture technique requires various organic and inorganic chemicals for the preparation of culture media. Growth room is an equally important area where plant cultures are maintained under controlled environmental conditions to achieve optimal growth. Plants regenerated from in vitro tissue cultures are transplanted to vermiculite pots. The potted plants are ultimately transferred to greenhouses or growth cabinets and maintained for further observations under controlled conditions of light, temperature, and humidity.

Phenoxy herbicides are frequently used to control volunteer canola populations. However, there have been claims that poor control could be due to cold acclimation of canola plants in the spring. The objective of this study was to determine whether cold acclimation or growth stage affected the response of canola volunteers to herbicides. In a growth room experiment, canola plants were prehardened and cold acclimated or were grown at 20/12 C and treated with one of six 2,4-D doses. Cold acclimation as achieved by this experiment affected upper and lower asymptotes of the dose–response curve but not the herbicide dose required to reduce canola weight by 50% relative to the nontreated control (GR50), indicating limited cold-related effects on canola tolerance to 2,4-D. Field experiments, conducted in the provinces of Québec and Saskatchewan, examined the effects of canola growth stage on the efficacy of 2,4-D, MCPA, and carfentrazone. Comparisons of the estimates from the dose–response curves confirmed that herbicide efficacy was consistently greater when canola plants were treated at an early growth stage, regardless of cultivar or herbicide used. The GR50estimates for canola plants treated at a later growth stage exceeded the recommended rates. Some canola plants grown as volunteers in a wheat crop survived 2,4-D or MCPA treatments at 0.5× and 1× rates and produced up to 148 seeds/m2. Efficient control of canola volunteers will be obtained when plants are sprayed at an early growth stage, but near-total control will be highly desirable in order to restrict seedbank buildup, particularly when dealing with canola cultivars with different herbicide-resistant traits.

New formulations of phosphonates (AG3) were tested for their efficacy to control Pythium damping-off of cucumber seedlings in peat-based mix (P-mix), muck soil (Mu-soil), and sandy loam soil (SL-soil). Aqueous solutions of various phosphonate formulations (0.035%–0.280% active ingredient (a.i.), v/m) were added to pathogen-infested Pmix or SL- or Mu-soils as a preplanting amendment or postplanting drench treatments. In artificially infested P-mix, preplanting amendment with powder or liquid phosphonate formulation provided control of damping-off and disease suppression that increased with the concentration of phosphonate. Higher rates (0.140% or 0.280% a.i.) provided almost 100% disease control whereas lower rates (0.035% or 0.070% a.i.) had on average 34%–75% healthy plants compared with less than 5% in the control. AG3 liquid formulation as a preplanting treatment also provided effective control in naturally infested Mu-soil and artificially infested SL-soil. Postplanting drench with AG3 was equally eff...

The influence of leaf-wetness duration and temperature on infection of Amelanchier alnifolia (saskatoon) by Entomosporium mespili was quantified in controlled-environment studies. Plants were inoculated with a conidial suspension and then subjected to a period of leaf wetness (0, 6, 12, and 24 h), after which they were moved to a growth room set at a fixed temperature (10, 15, 20, 25, and 30°C) for a period of 14 d. Infection levels rose as the leaf-wetness duration increased for combined temperature treatments up to 24 h. Temperatures between 10 and 20°C promoted optimal leaf infection for leaf-wetness periods longer than 6 h. Above the optimal temperature range, mean disease levels decreased. ANOVA with orthogonal contrasts and stepwise regression were used to create a regression equation that describes the relationship of E. mespili infection on saskatoon to both temperature and leaf-wetness duration. Combinations of temperatures between 10 and 25°C and leaf-wetness periods between 6 and 24 h were opti...

Com objetivo de avaliar o efeito do ácido giberélico sobre a germinação de sementes de porta-enxertos cítricos, um experimento foi instalado no Laboratório de Cultura de Tecidos da UFLA. Utilizou-se o delineamento de blocos casualizados, com quatro repetições. Os tratamentos foram constituídos a partir do fatorial 5 x 4 (porta-enxertos: Limoeiro-'Cravo', Tangerineira-'Sunki', Tangerineira-'Cleópatra', 'UFLAD-4' e 'UFLAD-5'; ácido giberélico: 0; 60; 120 e 180 mg L-1 ). A parcela experimental foi constituída por 25 tubos de ensaio com uma semente/tubo, empregando-se a água + ágar a 7 mg L-1 como meio de cultura, sendo usadas sementes intactas. Após a inoculação, os tubos foram armazenados em sala sob temperatura de 25 ºC e 80 % de umidade relativa, com fotoperíodo de 16 horas. O experimento foi avaliado a partir da determinação da percentagem de germinação, índice de velocidade de germinação (IVG ) e número de plântulas por semente (NPS). O limoeiro-'Cravo' apresentou maior taxa de germinação e IVG, enquanto o híbrido 'UFLAD-5' apresentou maior NPS, não havendo efeito da aplicação do ácido giberélico sobre as características avaliadas. With the aim to evaluate the effect of the giberellic acid on germination of seeds of citrus rootstocks an experiment was carried out at the Tissue Culture Laboratory of Universidade Federal de Lavras. A randomized block design was used with factorial scheme 5 x 4, with four replications adopting: lemon tree 'Cravo', mandarin tree 'Sunki', mandarin tree 'Cleópatra', hybrids 'UFLAD- 4' and 'UFLAD-5' as rootstocks; 0, 60, 120 and 180 mg L-1 as the giberellic acid concentrations. The experimental plot was made up of 25 test tubes with one intact seed per tube inoculated at culture medium employing water + agar at 7 mg L-1. After inoculation, the tubes were stored in growth room at 25ºC and 80% of relative humidity, with a photoperiod of 16 hours. The following variables were evaluated: determination of the germination percentage, speed germination index (IVG) and seedling number per seed (NPS). The analyses showed that lemon tree 'Cravo' presented the better germination rate and speed germination index; the hybrid 'UFLAD-5' presented the highest seedling number per seed, there being no effect of giberellic acid on characteristics evaluated.