The purpose of this study was to evaluate the effect of diazotrophic bacteria inoculation and nitrogen fertilization on grain yield and nitrogen accumulation in rice plants. We used seeds of rice cultivars IR42 and IAC4440, which were inoculated with peat containing the strains ZAE94 (BR 11417 - Herbaspirillum seropedicae) and M130 (BR 11340 - Burkholderia sp.). We used the first 20 cm of an Albaqualf Ecological Series. The experiment was conducted in a completely randomized design with four replications and four plants per pot. We applied three levels of nitrogen (0, 50 and 100 kg N ha--1) and evaluated the parameters of shoot dry weight, nitrogen accumulation in shoots and grains, in addition to grain yield and the quantification of population of diazotrophic plants. Positive effects of inoculation were observed in both cultivars studied in all parameters evaluated, mainly in the accumulation of nitrogen in plants and grains.

Phylogeography has become a powerful approach for elucidating contemporary geographical patterns of evolutionary subdivision within species and species complexes. The aim of this paper was to evaluate the extracted quality of DNA and amplification of noncoding chloroplast DNA for phylogeography studies in Ficus bonijesulapens. The comparative analysis of protocol DNA extraction was based in the CTAB method and protocol from Mogg and Bond. DNA samples were assessed for successful PCR amplification of universal primers for the amplification of noncoding regions of cpDNA. Amplified DNA was separated by electrophoresis, stained with ethidium bromide and photographed under UV light. The protocol Moog e Bond produced the best DNA quality. This method will be used because it produces a high quality DNA in a short time and is less expensive. The primers HA, SG, BF, Q16, F32, FV, DT, CS and JA provided the strongest support for the inferred phylogeography, genetic diversity centers and for successful management in tree-conservation programmes.

In Brazil, the production of watermelon with seeds is highly representative. However, available information about fruit quality of different varieties grown in the same environment is still rare, which makes it necessary to carry out trials that can fill this gap. Thus, the present study aimed to evaluate the postharvest quality of different varieties of watermelon (Crimson Sweet, Charleston Gray, Sugar Baby, Fairfax and Tendersweet), grown under conventional conditions in Mossoró - RN. The experiment was carried out from September to November 2008 in the experimental field of the Federal Rural University of the Semiarid (UFERSA). The data for the fruit quality were recorded in the Laboratory of Postharvest of UFERSA. The experiment was set under a completely randomized design with six replications and each replication consisted of a fruit. The quality characteristics were analyzed: fruit fresh mass (kg), fruit dimensions (greater length and width), overall appearance, pulp yield in percentage, seed characteristics, pH, acidity, vitamin C, soluble solids and SS/TA ratio. The physical determinations showed variations for fruit fresh mass (4.2 to 9.7 kg), pulp yield (42.0 to 58.5%), rind thickness (1.1 to 2.5 cm), as well as to the number and mass of seeds. In the physical-chemical determinations it was observed phenotypic uniformity among the varieties for almost all variables and, although all of them favorable to consumption, this result indicates narrowing of the genetic basis of varieties, which makes it necessary the evaluation of other genotypes.

Macambira is a bromélia used in the alimentation of man and domestic animals on Northeast of Brazilian, especially in times of drought. The study was conducted to evaluate at identifying breaking dormancy methods and verifying how temperature and light can affect germination of its seeds. In the first experiment, the seeds were treated the following treatments: immersion in acetone, in alcohol, to eter, hot water, wash in running water, dry cold and dry heat, aiming at breaking dormancy and control. Were determinate the percentage of germination, first count of germination, index of velocity of germination and the mean time of germination. In the second experiment, after treatment of immersion in acetone during 60 minutes, the seeds were germinated under the following conditions: continued light and 25 ºC constant; continued light and 30 ºC constant; continued light and 35 ºC constant; continued light and temperatures (35 ºC/8 h and 20 ºC/16 h); continued dark and 25 ºC constant; continued dark and 30 ºC constant; continued dark and 35 ºC constant; continued dark and temperatures (35 ºC/8 h and 20 ºC/16 h); alternation of light (dark/16 h and light/8 h) and temperature of 25 ºC constant; alternation of light (dark/16 h and light/8 h) and temperature of 30 ºC onstant; alternation of light (dark/16 h and light/8 h) and temperature of 35 ºC constant; alternation of light and temperature (dark/20 ºC/16 h and light/35 ºC/8 h) and alternation of light and temperature (dark/25 ºC/16 h and light/35 ºC/8 h). It follows that the immersion in acetone during 60 minutes was the treatment more efficient to promote the of vigor and germination of seeds. The seeds do not germinate in the light absence, behaving as fotoblásticas positive.

This study was aimed to carried out a floristic survey in four communities that are localized in the São Miguel do Gostoso municipality - RN, focusing on the Leguminosae species and its potential use. Field research was carried out between May and October/2007, for acquire information about the use of plants and samples of them in the local communities. The study registered 102 species pertaining 73 genera and 30 families. Leguminosae/Fabaceae (25), Asteraceae (10) and Euphorbiaceae (8) were the most representative families in number of species and the genus Mimosa L. and Senna Mill., with five species each. Most species of Leguminosae (68%) have economic value and are recognized seven categories of use: medicinal (8), technology (7) fuel (8), construction (6), fodder (14), veterinary (2) and other (9). Although many species have different types of utilities, Poincianella pyramidalis (Tul.) L.P.Queiroz stood out from others by being quoted in all use categories considered.

To evaluate the effect of the temporary replacement of shrimp ration (RC) by chicken ration (RF) in the culture of Litopenaeus vannamei shrimp, juvenils (1.07 ± 0.26 g), were cultivated (52/m2) for 30 days in 50 L boxes, with constant aeration, 0% of water exchange and fed with 10% of its biomass/day at 08:00 and 16:00 h, according to the treatments: (1) RC; (2) 1 week RC + 1 week RF, alternate; (3) RF and (4) 1 day RF + 1 day RC, alternate; with 5 repetitions each. There was no difference (P <0.05) in the weight of shrimp on the basis of treatments applied at the beginning (Kruskal-Wallis, P = 0003), 15 days (Kruskal-Wallis, P = 0.98) and at 30 days (Kruskal-Wallis, P = 0.07) to experiment. The Specific Growth Rate (rm ANOVA, P = 0.28) and survival (Friedman, P = 0,34 the animals were significantly similar, indicating that these parameters were not affected by treatments, with the possible replacement of shrimp ration by chicken ration, as a measure of containment of expenditure, for short intervals of time. Studies are needed to validate these results in earth ponds.

The callus culture facilitates the study of factors involved in somatic embryogenesis, technique that allows the production of embryos in vitro from somatic tissue, making the propagation possible of elite plants and constituting an important tool in breeding programs. The objective was to analyze the influence of growth regulators on the formation of callus on cotton cultivars BRS Araripe and BRS Seridó. In the Laboratory of Tissue Culture of Embrapa Algodão, for the induction and proliferation of callus, hypocotyledonary segments were cultured on MS medium supplemented with phytoregulators NAA, KIN and 2,4-D. For the induction of embryogenic callus, it was used redifferentiation medium, with no phytoregulators. Data were analyzed according to the nonparametric chi-square test, being verified high number of potentially embryogenic callus, with a friable consistence and cream-greenish coloration. In the treatment with addition of NAA and KIN was observed the formation of embryogenic callus of BRS Seridó. The dependence of the genotype is a major problem for the low frequency of somatic embryogenesis in cotton that has been achieved in a few cultivars; it is necessary to study in other varieties for the definition of appropriate protocols in this process.

Mycorrhizal fungi has been shown to affect some species of parasitic nematodes, in many cases reducing oviposition and the number of galls on the root system of infected plants. In order to evaluate the biocontrol potential of arbuscular mycorrhizal fungi to reduce the infectivity of Meloidogyne incognita in tomato plants, an experiment was conducted with a randomized block design with eight replications in a factorial with thefollowing treatments: with and without M . incognita, with presence and absence of fungal species Glomus clarum Nicolson & Schenck, Gigaspora albida Schanck & amp; Smith and Acaulospora scrobiculata Trappe. The fungus G. clarum significantly reduced the gall index (46.4%) and the number of egg mass (78.8%) of the nematode on tomato seedlings. The percentage of root colonization is not in itself an indicator of efficiency in controlling fungal infectivity of M. incognita in tomato plants, since A. scrobiculata exhibited a high degree of colonization (77.6%) and was not effective in controlling nematode reproduction. The species of mycorrhizal fungi differ in efficiency in reducing the infectivity of M. incognita in tomato seedlings.

This work evaluated the effect of two methods of determination of soil water (laboratory method and field method) and four levels of soil water availability (20; 40; 60 and 80%) on biomass of the aerial part, crop evapotranspiration, leaf area, plant height and yield in pit of herbaceous cotton plant, cultivar CNPA-7H. The randomized blocks experimental design was used in factorial scheme 2 x 4, with three replications. The determination of available soil water by the field method overcame the results of the studied variables in relation to the laboratory method and it represents more real conditions of the readiness of water for the cotton plant. The leaf area and the evapotranspiration, determined by field method, increased significantly with the levels of available soil water. The management with the available water of 61.61% by laboratory method promoted the maximum leaf area of 1755.4 cm2 and, with 74.4% of levels of available water, the maximum evapotranspiration was of 238 mm. There were earnings of 0.2 g of biomass per unit of levels of available soil water by field method; already by laboratory method the maximum biomass of 17.6 g was reached with the management of levels of available water of 62.9%. The best response for the cotton incomes in pit was given by field method with earnings in the income of 0.26 g for the field method and of 0.11 g for the laboratory method per unit of available soil water.

Excessive salt can to promote water soil retention, reducing your availability to plants. Besides, they can interfere in protoplasm metabolism. The plants ability to survive in salinity conditions is an important factor to geographic distribution and agriculture in salinized regions. The objective of this work was to verify the effects of the NaCl in the growth, dry matter distribution and N, K, Ca, Mg, Na, and Cl content in young plants. The experiment was conducted in 'Leonard' pots, with nutrient solutions, with NaCl (0, 25, 50 and 100 mmol L-1). Increasing of NaCl concentration reduces growth and total dry matter. There was an increase of N and K content, in shoots, and N and Mg content in roots. There was an reduction in Mg content in shoots, and reduction of Ca content in roots with increasing of NaCl. Leucaena plants were inefficient to exclude Na and Cl, in shoots principally.