Greenhouse production of potato (Solanum tuberosum L. cv. Désirée) seed tubers using in vitro plantlets and rooted cuttings in large propagation beds     

Regan D. Roy  V. Souza Machado  S. M. M. Alam  A. Ali 《Potato Research》1995,38(1):61-68

Summary Seed tuber production fromin vitro potato plantlets and cuttings was conducted in large propagation beds in a greenhouse. Propagules of wholein vitro plantlets (WIP), plantlets with apical (ACR) and lateral (LCR) cuttings removed, the rooted apical cuttings (RAC) and rooted lateral cuttings (RLC) were planted at three densities of 25, 49 and 100 plants per m². The plantlets from which cuttings were removed (ACR and LCR) produced more tubers than the rooted cuttings (RAC and RLC); however, the most tubers were produced by WIP. RAC produced highest tuber yields followed by WIP and RLC. Intact WIP and plantlets with cuttings removed (ACR and LCR) produced twice as many tubers <40 g as those from rooted cuttings (RAC and RLC). The yield (kg/m²) as well as the number of tubers per m² increased with the increasing planting density within the densities tested.  相似文献   

Diurnal and seasonal patterns of leaf gas exchange in bahiagrass (Paspalum notatum Flügge) growing in a subtropical climate     

R. V. Ribeiro†  G. B. Lyra†  A. V. Santiago†  A. R. Pereira†  E. C. Machado  R. F. Oliveira‡ 《Grass and Forage Science》2006,61(3):293-303

The objective of this study was to evaluate the seasonal and diurnal changes in leaf gas exchange in bahiagrass (Paspalum notatum) plants grown in an irrigated lawn. Carbon dioxide assimilation, transpiration, stomatal conductance, leaf temperature and leaf‐to‐air vapour pressure difference were measured during the daylight period from April 2003 to March 2004. The monitored environmental variables were photosynthetic photon flux density, air temperature, air relative humidity, photoperiod and sunshine rate. Factor and cluster analyses were used to select variables and to group months with similar physiological and meteorological characteristics, and three distinct periods were identified: (i) May to July: with low energetic availability, low leaf temperatures and low photosynthetic activity; (ii) September to January: with high energetic availability, high leaf temperatures and high photosynthetic activity; and (iii) April–March–August: a transient period with environmental and physiological characteristics showing intermediate values. The reduced plant development and growth during the winter season was in accordance to the lower photosynthetic activity recorded from June to August, this variable being a potential indicator of reduced phytomass production. The relationships between leaf gas exchange and seasonal growth are discussed.  相似文献   

Progress in breeding interspecific hybrid ryegrasses     

M. LL. JONES  M. O. HUMPHREYS 《Grass and Forage Science》1993,48(1):18-25

Stable hybrids were produced between tetraploid perennial and Italian ryegrasses derived from commercial varieties and germplasm introduced from European collections. Spaced plant characteristics were used to select Fl plants for the production of F2 families which were assessed in small plots for growth and quality traits. Ten of the 19 selected hybrid families were based on perennial ryegrass collected from the Zurich Uplands. The influence of this parental material in improving vegetative growth during early spring, late summer and autumn was demonstrated. Its use in improving feeding value by increasing the water-soluble carbohydrate content of hybrids was also shown. Consequently, selected hybrid varieties based on this new genetic resource showed considerable improvements in seasonal growth and quality over the older hybrid variety Augusta and Italian ryegrass variety RvP.  相似文献   

Trichoderma as a biological agent of Fusarium oxysporum species complex and Vigna unguiculata growth promoter     

do Amaral  Ana Cl&#;udia Ten&#;rio  de Holanda Cavalcanti Maciel  Mar&#;lia  Machado  Alexandre Reis  de Oliveira  Luciana Gon&#;alves  Lima  Cristiano Souza  da Costa  Antonio F&#;lix  de Oliveira  Neiva Tinti 《European journal of plant pathology / European Foundation for Plant Pathology》2022,163(4):875-890

European Journal of Plant Pathology - This study aimed to evaluate the potential antagonistic role of Trichoderma in the control of Fusarium isolates belonging to the Fusarium oxysporum species...  相似文献   

Multifractal and joint multifractal analysis of soil micronutrients extracted by two methods along a transect in a coarse textured soil     

Ênio Farias de França e Silva  Aitor García-Tomillo  Diego Henrique Silva de Souza  Eva Vidal-Vázquez  Glécio Machado Siqueira  Daniel da Costa Dantas  Antonio Paz-González 《European Journal of Soil Science》2021,72(2):608-622

  相似文献   

Formulation and Physicochemical and Sensorial Evaluation of Biscuit-Type Cookies Supplemented with Fruit Powders     

Ana Maria Athayde Uchoa  José Maria Correia da Costa  Geraldo Arraes Maia  Tatyane Ribeiro Meira  Paulo Henrrique Machado Sousa  Isabella Montenegro Brasil 《Plant foods for human nutrition (Dordrecht, Netherlands)》2009,64(2):153-159

Cashew apple and guava residues from fruit juice industry were prepared as dehydrated fruit powders and used at different levels of wheat flour substitution for cookies formulations. The effects of guava and cashew apple fruit powders supplementation on physicochemical and sensorial characteristics of the cookies were evaluated. The pH, fibre and protein content were significantly affected. Biscuits with 15 g and 20 g/100g cashew apple and guava fruit powders showed the highest scores for sensorial attributes, respectively. The supplementation seems to be suited for wheat flour substitution and it is possible to obtain cookies with value-added food ingredient within the standards.  相似文献   

Inheritance and heritability of resistance to citrus leprosis     

Bastianel M  de Oliveira AC  Cristofani M  Filho OG  Freitas-Astúa J  Rodrigues V  Astúa-Monge G  Machado MA 《Phytopathology》2006,96(10):1092-1096

ABSTRACT The genetic inheritance of resistance to leprosis, the most important viral disease of citrus in Brazil, was characterized through the phenotypic assessment of 143 hybrids resulting from crosses between tangor 'Murcott' (Citrus sinensis x C. reticulata) and sweet orange 'Pêra' (C. sinensis), considered to be resistant and susceptible to the disease, respectively. All plants were grafted onto Rangpur lime (C. limonia) and inoculated with Citrus leprosis virus, cytoplasmic type through the infestation with viruliferous mites, Brevipalpus phoenicis. The experiments were arranged in a completely randomized block design with 10 replicates. Incidence and severity of the disease in leaves and stems as well as plant growth parameters (plant height and stem diameter) were recorded for 3 years after the infestation with the viruliferous mites. The average values of all variables were analyzed using principal component analysis, discriminant factorial analysis, estimation of the clonal repeatability coefficients, and frequency of the distributions of the average values for each measured variable. The principal component analysis resulted in the identification of at least two groups with resistance and susceptibility to leprosis, respectively. About 99% of all hybrids were correctly classified according to the discriminant factorial analysis. The broad-sense heritability coefficients for characteristics associated with incidence and severity of leprosis ranged from 0.88 to 0.96. The data suggest that the inheritance of resistance to leprosis may be controlled by only a few genes.  相似文献   

An enzyme-linked immunosorbent assay (ELISA) for detection of antibodies against Toxocara vitulorum in water buffaloes     

Starke-Buzetti WA  Machado RZ  Zocoller-Seno MC 《Veterinary parasitology》2001,97(1):55-64

Toxocara vitulorum, a parasite of the small intestine of cattle and water buffaloes, is mainly acquired by calves via the colostrum/milk from infected cows. To understand the development of immune responses in calves, antibody levels to a soluble extract antigen (Ex) from T. vitulorum infective larvae were measured by an indirect ELISA with sera of 15 buffalo calves, which were sampled every 15 days for the first 180 days after birth and 9 buffalo cows during the perinatal period. From all serum samples examined during the first 180 days, antibody level was lowest and highest in calves at 1 day of age before and after suckling colostrum, respectively, suggesting that the origin of antibodies was the colostrum. Immediately after birth, antibody levels in suckled calves remained at high levels until day 15, began to decrease to lower levels between 15 and 30 days and remained relatively stable until 120 days. By comparing the immune responses of these animals with their parasitological status it was considered possible to determine if passively acquired or actively produced antibodies provided protection against the infection. High numbers of T. vitulorum eggs in the feces between 30 and 60 days indicated that passively acquired antibodies did not provide protection against the infection, at least during these first days, and the maximum fecal egg counts during 30-45 days were coincident with decreased antibody levels. Between 60 and 120 days, when serum antibodies were detected at reduced, but stable levels, adult nematodes were expelled from the intestines and no more T. vitulorum eggs were found, suggesting development of acquired resistance. However, the potential and functional protective role of the antibodies against T. vitulorum infection and the process of self-cure requires further investigation.  相似文献   

Morphological and morphometric characterization of domestic cat epididymal sperm     

Brenna de Sousa Barbosa  Herlon Victor Rodrigues Silva  Beatriz Evaristo de Almeida Tabosa  Thalles Gothardo Pereira Nunes  Francisco Felipe de Magalhes  Lúcia Daniel Machado da Silva 《Reproduction in domestic animals》2019,54(12):1630-1636

Sperm morphometry is the tool that confers objectivity to the morphological evaluation by accurately measuring the dimensions of the gamete and its structures. Thus, the aim of the study was to perform a morphometric characterization of the domestic cat sperm. Therefore, sperm samples were collected from twenty pairs of epididymis in a TRIS extender at 37ºC. An aliquot of the sample was used to make a smear with Rose Bengal solution, and afterwards, the morphology and morphometry were analysed. In the morphology, were quantified the percentage of normal sperm cells, morphological changes of head, midpiece and tail. In morphometry, each normal sperm cell was measured for length, width, area and perimeter of head and midpiece, tail length and total length. The parameters ellipticity, elongation, regularity and rugosity were also determined. The percentage of normal sperm was 67.21%. Of the abnormalities, the curled/folded tail, followed by the curved midpiece, abnormal shaped head and detached head were the most quantified. The sperm head presented 5.56 ± 0.01 μm and 3.10 ± 0.01 μm of length and width, respectively. The head area was 16.94 ± 0.05 μm², while the perimeter was 16.16 ± 0.03 μm. In the derived parameters, the values were as follows: ellipticity of 1.81 ± 0.00; elongation of 21.39 ± 0.12; regularity of 0.81 ± 0.00; and rugosity of 0.14 ± 0.00. The midpiece presented length and width of 7.96 ± 0.01 μm and 0.76 ± 0.01 μm, respectively. The mean length of the sperm tail was 45.12 ± 0.06 μm, and the total cell size was 58.67 ± 0.06 μm. Thus, it was concluded that the cat sperm is an elongated cell, with high rugosity and regularity. The spermatic tail represents more than ¾ of the total length of the cell and the midpiece exceeds the length of the head.  相似文献   

Intake,digestibility, microbial protein production,and nitrogen balance of lambs fed with sorghum silage partially replaced with dehydrated fruit by-products     

Almeida  Júlio César Silva  de Figueiredo  Darcilene Maria  de Azevedo  Katharine Kelly  Paixão  Mônica Lopes  Ribeiro  Enilson Geraldo  Dallago  Gabriel Machado 《Tropical animal health and production》2019,51(3):619-627

Tropical Animal Health and Production - The objective of this study was to evaluate intake, digestibility, microbial protein production, and nitrogen balance of lambs fed with different dehydrated...  相似文献