Grazing criteria for perennial peanut (Arachis pintoi cv. Amarillo) consumed by sheep in rotational stocking / Critérios de pastejo para amendoim forrageiro (Arachis pintoi cv. Amarillo) consumido por ovelhas em sistema rotacionado

The objective of work was to study the productive profile of perennial peanut in a rotational stocking environment under different criteria. The treatments corresponded to pre-grazing height of 14 and 18cm or 95% of light interception (LI) distributed in a completely randomized design. The studied variables were forage mass, percentage of structural components, forage mass and the structural components in the lower and upper canopy strata. The entrance criterion of 18cm in height, despite having higher forage mass, presented lower percentage of leaves and higher percentage of stems and forage losses. The criteria of 14cm and 95% light interception presented similar production between them and the highest rate of forage accumulation. In all criteria, in the upper strata of pasture a higher percentage of leaves were found. The criteria of 95% LI and 14cm in height presented the best productive performances. The entry criterion of 18cm presented a higher mass of pre-grazing forage with lower percentage of dead material, but with higher forage losses, resulting from senescent leaves. Due to changes in the structural components, as grazing cycles increase, the interception of 95% of the incident light by the perennial peanut occurs at lower heights.(AU)

O objetivo do presente trabalho foi estudar o perfil produtivo do amendoim forrageiro em um ambiente rotacionado, sob diferentes critérios. Os tratamentos corresponderam à altura de pré-pastejo de 14 e 18cm ou 95% de intercepção de luz (LI), distribuídos em delineamento inteiramente ao acaso. As variáveis estudadas foram massa forrageira, porcentagem de componentes estruturais, densidade da massa forrageira e densidade dos componentes estruturais nos estratos do dossel inferior e superior. O critério de entrada de 18cm de altura, apesar de ter maior massa forrageira, apresentou menor porcentagem de folhas e maior porcentagem de hastes e perdas de forragem. Os critérios de interceptação de luz de 14cm e 95% apresentaram produção similar entre eles e a maior taxa de acumulação de forragem. Em todos os critérios, no estrato superior de pastagem, foi encontrada maior porcentagem de folhas. Os critérios de 95% LI e 14cm de altura apresentaram os melhores desempenhos produtivos. O critério de entrada de 18cm apresentou maior massa de forragem pré-pastagem com menor porcentagem de material morto, mas com maiores perdas de forragem, resultantes de folhas senescentes. Devido às mudanças nos componentes estruturais, à medida que os ciclos de pastagem aumentam, a intercepção de 95% da luz incidente pelo amendoim forrageiro ocorre em alturas mais baixas.(AU)

Promotion of iron nutrition and growth on peanut by Paenibacillus illinoisensis and Bacillus sp. strains in calcareous soil

ABSTRACT This study aimed to explore the effects of two siderophore-producing bacterial strains on iron absorption and plant growth of peanut in calcareous soil. Two siderophore-producing bacterial strains, namely, YZ29 and DZ13, isolated from the rhizosphere soil of peanut, were identified as Paenibacillus illinoisensis and Bacillus sp., respectively. In potted experiments, YZ29 and DZ13 enhanced root activity, chlorophyll and active iron content in leaves, total nitrogen, phosphorus and potassium accumulation of plants and increased the quality of peanut kernels and plant biomass over control. In the field trial, the inoculated treatments performed better than the controls, and the pod yields of the three treatments inoculated with YZ29, DZ13, and YZ29 + DZ13 (1:1) increased by 37.05%, 13.80% and 13.57%, respectively, compared with the control. Based on terminal restriction fragment length polymorphism analysis, YZ29 and DZ13 improved the bacterial community richness and species diversity of soil surrounding the peanut roots. Therefore, YZ29 and DZ13 can be used as candidate bacterial strains to relieve chlorosis of peanut and promote peanut growth. The present study is the first to explore the effect of siderophores produced by P. illinoisensis on iron absorption.

Compatibility of Azospirillum brasilense and Pseudomonas fluorescens in growth promotion of groundnut ( Arachis hypogea L)

ABSTRACT We attempted to study the compatibility among plant beneficial bacteria in the culture level by growing them near in the nutrient agar plates. Among all the bacteria tested, Rhizobium was found to inhibit the growth of other bacteria. From the compatible group of PGPR, we have selected one biofertilizer (Azospirillum brasilense strain TNAU) and one biocontrol agent (Pseudomonas fluorescens strain PF1) for further studies in the pot culture. We have also developed a bioformulation which is talc powder based, for individual bacteria and mixed culture. This formulation was used as seed treatment, soil application, seedling root dip and foliar spray in groundnut crop in vitro germination conditions. A. brasilense was found to enhance the tap root growth and P. fluorescens, the lateral root growth. The other growth parameters like shoot growth, number of leaves were enhanced by the combination of both of the bacteria than their individual formulations. Among the method of application tested in our study, soil application was found to be the best in yielding better results of plant growth promotion.

Plant Growth Promotion and Root Colonization by EPS Producing Enterobacter sp. RZS5 under Heavy Metal Contaminated Soil.

The heavy metal resistant bacterium isolated from field soil and identified as Enterobacter sp. RZS5 tolerates a high concentration (100-2000 mM) of various heavy metal ions such as Mn2+, Ni2+, Zn2+, Cu2+, CO2+ and Fe2+ when grown in such environment and produces exopolysaccharides (EPS). Here, we have demonstrated EPS production by Enterobacter sp. RZS5 during 60 h of growth in yeast extract mannitol broth (YEMB). The yield increased by two fold after the addition of 60 M of Ca2+; 50 M of Fe2+ and 60 M of Mg2+ ions in YEMB, and the optimization of physico-chemical parameters. EPS was extracted with 30% (v/v) of isopropanol as against the commonly used 50% (v/v) isopropanol method. EPS-rich broth promoted seed germination, shoot height, root length, number of leaves and chlorophyll content of wheat (Triticum aestivum) and peanut (Arachis hypogaea) seeds. The higher colony-forming unit of Enterobacter sp. in soil inoculated with EPS rich broth of Enterobacter sp. indicated the root colonizing potential and rhizosphere competence of the isolate. The FTIR spectra of the EPS extract confirmed the presence of the functional group characteristics of EPS known to exhibit a high binding affinity towards certain metal ions. This overall growth and vigour in plants along with the effective root colonization, reflected the potential of the isolate as an efficient bio-inoculant in bioremediation.

Fenologia e produtividade do amendoim em diferentes épocas de semeadura no recôncavo sul baiano / Phenology and yield of peanut in different sowing seasons in southern bahia recôncavo

O trabalho foi feito com o objetivo de avaliar a fenologia e a produtividade de duas cultivares de amendoim (Arachis hypogaea L.) em diferentes épocas de semeadura na região do Recôncavo sul Baiano. A primeira época de semeadura foi julho-outubro e a segunda abril-julho. Para cada época, foi instalado um experimento no delineamento em blocos casualizados no esquema fatorial 2 x 2 (cultivares x época) com quatro repetições, em parcelas de 5,0 m de comprimento e largura de 4,0 m, constituídas de oito linhas cada, nas quais foram observados, a cada três dias, os estádios de desenvolvimento das plantas das cultivares Vargem Lisa e BRS Havana. Avaliou-se a fenologia (germinação, aparecimento das primeiras folhas tetrafoliadas, aparecimento dos primeiros ramos, início da floração, aparecimento do ginóforo, início da formação da vagem, final da floração e maturação completa da vagem) e a produtividade de vagens e grãos (kg ha-1). A época de semeadura e a cultivar influenciam diretamente na fenologia das plantas de amendoim. A cultivar Vagem Lisa teve um maior rendimento de vagens e grãos na segunda época de semeadura.

The goal of this research was to assess the phenology and productivity of two peanut cultivars (Arachis hypogaea L.) in different sowing seasons in the region of southern Bahia Recôncavo. The first sowing season was from July to October and the second season from April to July. For each season, an experiment was conducted carried out in randomized block design in a factorial scheme 2 x 2 (cultivars x sowing season) with four replicates. Each in plot was consisted of eight lines with 5.0 m in length and 4.0 m in width. The assessments were done every three days during the plant development stages of Vargem Lisa and BRS Havana cultivars. We evaluated the phenology (germination, emergence of first leaves tetrafoliadas, onset of the first branches, beginning of flowering, emergence of gynophore, beginning of pod formation, ending of flowering and full pod maturity) and yield of pods and grains (kg h-1). The sowing season and cultivar directly influence the peanut phenology. The cultivar Vagem Lisa had a highergreater pod lat and grain yield in the second sowing season planting.

EST sequencing and SSR marker development from cultivated peanut (Arachis hypogaea L)

Making use of the gene resources of wild type peanuts is a way to increase the genetic diversity of the cultivars. Marker assisted selection (MAS) could shorten the process of inter-specific hybridization and provide a possible way to remove the undesirable traits. However, the limited number of molecular markers available in peanut retarded its MAS process. We started a peanut ESTs (Expressed Sequence Tags) project aiming at cloning genes with agronomic importance and developing molecular markers. In this study we found 610 ESTs that contained one or more SSRs from 12,000 peanut ESTs. The most abundant SSRs in peanut are trinucleotides (66.3 percent) SSRs and followed by dinucleotide (28.8 percent) SSRs. AG/TC (10.7 percent) repeat was the most abundant and followed by CT/GA (9.0 percent), CTT/GAA (7.4 percent), and AAG/TTC (7.3 percent) repeats. Ninety-four SSR containing ESTs were randomly selected for primer design and synthesis, of which 33 pairs could generate good amplification and were used for polymorphism assessment. Results showed that polymorphism was very low in cultivars, while high level of polymorphism was revealed in wild type peanuts.

interactive effect of genotypes and plant density on peanut yield and yield components

This experiment was conducted during the 1998, 1999 and 2000 growing seasons, using three genotypes of peanut IPA2 [runner type], IPA 4 [bunsh type] and IPA 8 [semi erect type] in Raihana Experiment Station at Anna in Alanbbar Province, to study the effect of spacing between rows which were 60,75 and 90 cm and spacing between hills which were 20,35 and 50 cm on yield and yield components of peanut. Results showed that the genotype IPA 2 surpassed the other genotypes in terms of; pods number/plant [71.23] pods weight / plant [103.91 gm], seeds weight / plant [63.33 gm], pods yield [5859 kg / ha] and seed yield [3658 kg/ha], while it did not differ from other genotypes in shelling percentage. The density [90x50] was superior in terms of pods weight / plant [119.26 gm] and seed weight / plant [74.37 gm], meanwhile the density [60x35] surpassed the others densities in terms of pods yield [7041 kg / ha] and seed yield [4255 kg / ha], on the other hand it gave the lowest value of shelling percentage [60.43%], while the density [90x20] gave the highest shelling percentage [64.55%].The study recommends that farmers must grow this crop at the density [90x35] for runner types, [60x35 cm] for bunsh types and the [75x20 cm] for semi erect types

Vegetative tissue lectins of peanut (A. hypogaea).

Lectin activities in roots, nodules, stems and leaves of 1-6 week old peanut plant (A. hypogaea) were checked by erythrocyte (human and rabbit) agglutination and sugar inhibition assays. Human and rabbit erythrocyte agglutinating activities were specifically inhibited by lactose/cellobiose (SLII) and methyl alpha-mannoside (SLI) respectively. Seeds, embryos and cotyledons agglutinated neuraminidase treated human erythrocytes and that activity was inhibited by T-disaccharide. In the roots of field grown plants SLI was the major activity, while nodules showed both activities (SLI and SLII). Specific activities of SLI and SLII were maximal in stem tissue and hypocotyl exhibited minimal levels. Actively growing tissues like newly emerging young leaves and elongating stem contained more SLII activity in comparison to the mature tissues. Immunological test indicated that all the vegetative tissue lectins are serologically related.