scholarly journals Estimation of genetic parameters in rubber progenies

2012 ◽  
Vol 12 (3) ◽  
pp. 185-190 ◽  
Author(s):  
Cecília Khusala Verardi ◽  
Marcos Deon Vilela de Resende ◽  
Reginaldo Brito da Costa ◽  
Paulo de Souza Gonçalves

This study was designed to evaluate the genetic variability, the potential for rubber yield and secondary traits of rubber tree progenies at three locations in the state of Sao Paulo. The experiments were conducted in a randomized block design with 22 progenies and 6 replications. At the age of three years, the progenies were evaluated for rubber yield, girth growth and total number of latex vessel rings. The results showed the existence of genetic variability among progenies for each location separately as well as between locations, with differences in the progeny performance for the traits. The individual heritabilities calculated for rubber yield, girth growth and total number of latex vessel rings (0.30, 0.63 and 0.29, respectively), associated with high genetic gains with selection for the traits studied at each site, showed that the populations can be considered suitable for the rubber breeding program, provided that an appropriate selection procedure is used.

2013 ◽  
Vol 48 (4) ◽  
pp. 411-416 ◽  
Author(s):  
Cecília Khusala Verardi ◽  
Erivaldo José Scaloppi Junior ◽  
Guilherme Augusto Peres Silva ◽  
Lígia Regina Lima Gouvêa ◽  
Paulo de Souza Gonçalves

The objective of this work was to assess the genetic parameters and to estimate genetic gains in young rubber tree progenies. The experiments were carried out during three years, in a randomized block design, with six replicates and ten plants per plot, in three representative Hevea crop regions of the state of São Paulo, Brazil. Twenty-two progenies were evaluated, from three to five years old, for rubber yield and annual girth growth. Genetic gain was estimated with the multi-effect index (MEI). Selection by progenies means provided greater estimated genetic gain than selection based on individuals, since heritability values of progeny means were greater than the ones of individual heritability, for both evaluated variables, in all the assessment years. The selection of the three best progenies for rubber yield provided a selection gain of 1.28 g per plant. The genetic gains estimated with MEI using data from early assessments (from 3 to 5-year-old) were generally high for annual girth growth and rubber yield. The high genetic gains for annual girth growth in the first year of assessment indicate that progenies can be selected at the beginning of the breeding program. Population effective size was consistent with the three progenies selected, showing that they were not related and that the population genetic variability is ensured. Early selection with the genetic gains estimated by MEI can be made on rubber tree progenies.


2020 ◽  
Vol 36 ◽  
Author(s):  
Michelle Souza Vilela ◽  
José Ricardo Peixoto ◽  
Jairo Vidal Vieira ◽  
Giovani Olegário Da Silva ◽  
Daiane da Silva Nóbrega ◽  
...  

Carrots are among the most planted vegetables in Brazil, which represents importance in the national market. This crop can be grown in conventional and agroecological systems, and studies to improve productivity, disease resistance and root quality in agroecological cropping systems are important. The aim of the present work was to estimate genetic parameters that provide a breeding strategy in the search for the development of new varieties of carrot adapted to the conditions of Distrito Federal’s agroecology cultivation. Considering data from tests performed in areas of agroecology cultivation (Natural Agriculture-NA and Organic Agriculture-OA), the following characteristics were evaluated: incidence of leaf blight-LB, incidence of root cracking-CRACK, root length-COMP, format of root tip-TP, format of root shoulder-TO, measure of the color of the a* xylem parameter-a*X, measure of the color of the a* phloem parameter-a*F. Traits were evaluated in 100 half-sib progenies derived from Brasília cultivar, using a completely randomized block design. For the characters COMP, a*X, a*F, TP and TO, the treatment X environment interaction was significant according to the results from test F. The values of the individual variance analyses presented significant effect for the following characteristics: COMP, a*X, TP, TO, LB for NA system, and COMP, a*X, a*F, TP for OA system. In NA system, the values of heritability estimates-ha² for the plant characters fluctuated from 65.66 to 25.52% and, in the OA system, the ha² of the characters a*X, was 81.13%. Estimates of genetic gain per cycle for the characters a*X and a*F were lower in NA system than the estimates observed in OA system.  


2013 ◽  
Vol 48 (12) ◽  
pp. 1562-1568 ◽  
Author(s):  
João Tomé de Farias Neto ◽  
Elisa Ferreira Moura ◽  
Marcos Deon Vilela de Resende ◽  
Pedro Celestino Filho ◽  
Sebastião Geraldo Augusto

The objective of this work was to estimate genetic parameters and to evaluate simultaneous selection for root yield and for adaptability and stability of cassava genotypes. The effects of genotypes were assumed as fixed and random, and the mixed model methodology (REML/Blup) was used to estimate genetic parameters and the harmonic mean of the relative performance of genotypic values (HMRPGV), for simultaneous selection purposes. Ten genotypes were analyzed in a complete randomized block design, with four replicates. The experiment was carried out in the municipalities of Altamira, Santarém, and Santa Luzia do Pará in the state of Pará, Brazil, in the growing seasons of 2009/2010, 2010/2011, and 2011/2012. Roots were harvested 12 months after planting, in all tested locations. Root yield had low coefficients of genotypic variation (4.25%) and broad-sense heritability of individual plots (0.0424), which resulted in low genetic gain. Due to the low genotypic correlation (0.15), genotype classification as to root yield varied according to the environment. Genotypes CPATU 060, CPATU 229, and CPATU 404 stood out as to their yield, adaptability, and stability.


2012 ◽  
Vol 12 (4) ◽  
pp. 237-244 ◽  
Author(s):  
Ulisses José de Figueiredo ◽  
José Airton Rodrigues Nunes ◽  
Cacilda Borges do Valle

The objectives of this study were to estimate genetic parameters for agronomic and nutritive value traits for leaves and stems of Brachiaria humidicola progenies and to compare the selection using an additive index considering the agronomic traits alone or combined with the main nutritive value traits. Fifty progenies of the cross cv. BRS Tupi x H31 were evaluated. The experiment was arranged in a randomized block design with eight replications. The forage was cut seven times, at intervals of 30 - 35 days in the rainy season and two intervals of 60 days in the dry season. Trait variability among the progenies was confirmed. The mean progeny heritability ranged from 49.14% to 75.56% for the agronomic and from 19.59% to 71.11% for nutritive value traits. Nine of the ten best lines coincided in the selection for agronomic traits alone and in the selection including the main traits of nutritive value.


Revista CERES ◽  
2017 ◽  
Vol 64 (2) ◽  
pp. 159-166 ◽  
Author(s):  
Helton Santos Pereira ◽  
Renata Cristina Alvares ◽  
Leonardo Cunha Melo ◽  
Antônio Félix da Costa ◽  
Hélio Wilson Lemos de Carvalho

ABSTRACT The objectives of this work were to study the genetic variability and the interaction between genotypes and environments for cooking time and protein content of bean grains as well as to identify elite lines of Carioca grain type with short cooking time, high protein content and high adaptability and stability for these two traits. Sixteen experiments were conducted in a complete randomized block design with three replications during the rainy, dry and winter seasons, in Goiás, Distrito Federal, Pernambuco, Sergipe, Bahia and Paraná States, in 2009 and 2010. Each trial was composed by 16 elite lines of Carioca grain type and the data of cooking time and protein content were obtained. Data were submitted to analysis of variance and to stability and adaptability analysis, according to the methodology proposed by Annichiarico. Genetic variability was found for cooking time and for protein content among Carioca common bean elite lines; however, for protein content this variability is lower. The environmental effect is important for the expression of these traits and is larger than the genetic effect. The interaction between genotypes and environments is important for cooking time and for protein content of common beans. The lines CNFC 11951 and CNFC 11962 presents short cooking time, high protein content and high stability and adaptability for both traits.


1999 ◽  
Vol 34 (7) ◽  
pp. 1223-1232 ◽  
Author(s):  
Paulo de Souza Gonçalves ◽  
Alberto Kazutoshi Fujihara ◽  
Altino Aldo Ortolani ◽  
Ondino Cleante Bataglia ◽  
Nelson Bortoletto ◽  
...  

Rubber tree [Hevea brasiliensis (Willd. ex Adr. de Juss.) Müell. Arg.] budgrafts of seven clones were evaluated on five contrasting sites in the plateau region of the São Paulo State, Brazil. The objective of this work was to study the phenotypic stability for girth growth. The experimental design was a randomized block design with three replications and seven treatments. Analysis of variance of girth at six-year plant growth indicated a highly significant clone x site interaction. Only linear sites and clone x site components of clone x year interaction were significant, indicating that the performance of clones over sites for this trait could be predicted. The clones GT 1 and PB 235 showed the greatest stability in relation to girth growth, with foreseen responses to change, introduced in the sites. The clones PB 235 and IAN 873 showed significative difference in relation to regression coefficient, representing clones with specific adaptability on favorable and unfavorable sites respectively. The clone GT 1 became the most promissory one in the study of stability and adaptability even showing low girth growth. Expected genetic gains from planting sites, along with estimates of clonal variance and repeatability of clonal means are generally greatest or close to the greatest when selection is done at the same site.


2018 ◽  
Vol 31 (3) ◽  
pp. 572-583
Author(s):  
LEANDRO DE SOUZA ROCHA ◽  
ROBERT FELIX DE SANTANA ◽  
ANA CRISTINA FERMINO SOARES ◽  
FERNANDO HADDAD

ABSTRACT The interaction Fusarium oxysporum f. sp. cubense (Foc) x nematode and the genetic variability of Foc are the main problems with potential to affect the use of resistant varieties in the management of the Panama disease. The objective of this work was to evaluate the interaction between Foc and Meloidogyne javanica on the banana of the Prata Anã, Grande Naine and BRS Princesa cultivars. The experiment was conducted in a randomized block design, with six treatments and ten replications, which differed in the inoculation time of each pathogen. Simultaneous inoculation with Foc and M. javanica, inoculation with Foc one week before inoculation with M. javanica, and inoculation with M. javanica one week before inoculation with Foc. In addition to the controls, Foc isolated, M. javanica isolated, and cultivars without the pathogens. The seedlings were transplanted in 3-liter pots with sterile soil infested with 40 grams of Foc inoculum at the concentration of 1x106CFU/gram and 1000 eggs and J2 of M. javanica. At the end of 56 days, the treatments with 'Grande Naine' presented the highest reproduction factors of M. javanica. In the 'Prata Anã' no interaction was observed between Foc x M. javanica. The treatments with simultaneous inoculation of the two pathogens, and with Foc a week before, in the 'BRS Princesa', presented the highest external disease indices (DI), which promoted the highest AUDPC. The highest internal DI were observed in the treatments Foc+Mj+Grande Naine, Foc+Mj+BRS Princesa, Mj+Grande Naine+Foc and Foc+BRS Princesa+Mj. The simultaneous presence of M. javanica and Foc increases the severity of the Panama disease in Grande Naine and BRS Princesa cultivars.


Author(s):  
Rama T. Rashad ◽  
Rashad A. Hussien

The solubility and availability of Si from the feldspar, silica, and zeolite as Si-bearing minerals were studied in a sandy soil. Silicon uptake by the soybean (<em>Glycine max L.</em>)<em> </em>plant was discussed. The minerals used were applied before planting in two separate rates; rate 1 ≈ 595.2 and rate 2 ≈ 1190.5 kg ha<strong><sup>-1</sup></strong> accompanied by a ≈ 4.8 kg ha<strong><sup>-1</sup></strong> constant rate of the K-humate sprayed as a solution on soil after planting in a complete randomized block design. The dissolved Si from the different minerals at rate 2 followed an opposite direction to their SiO<sub>2</sub> percentage that may be due to the structural differences: silica (1.46 mg kg<strong><sup>-1</sup></strong> - SiO<sub>2 </sub>=98.4%) &lt; zeolite (1.71 mg kg<strong><sup>-1</sup></strong> - SiO<sub>2 </sub>=75.9%) &lt; feldspar (2.09 mg kg<strong><sup>-1</sup></strong> - SiO<sub>2 </sub>= 71.9%). The individual mineral treatments at rate 2 have almost decreased the available NPK estimated after soybean harvesting. The K-humate has enhanced the effect of silica at rate 2 for the available N and P. The soybean seed yield (kg ha<strong><sup>-1</sup></strong>) increased significantly by 117.9% for the S1 + H, 109.2% for K-humate and 57.5% for the Z2 + H. The seeds’ Si (mg kg<strong><sup>-1</sup></strong>) increased significantly from 3.6% to 102.9% affected by the silica treatments.


Bragantia ◽  
2009 ◽  
Vol 68 (3) ◽  
pp. 629-637 ◽  
Author(s):  
Ananda Virginia de Aguiar ◽  
Roland Vencovsky ◽  
Lázaro José Chaves ◽  
Mara Fernandes Moura ◽  
Lizz Kezzy de Morais

The objective of this study was to estimate genetic parameters of quantitative traits in a living germplasm collection of Eugenia dysenterica. The genetic material consisted of 110 progenies derived from 10 natural Eugenia dysenterica subpopulations sampled in the southeastern region of the state of Goiás. The experiment was established in a complete randomized block design, with 110 treatments, four replications and one tree per plot. The study variables were total height, stem diameter and respective growth rates. After the analysis of variance some genetic parameters were estimated. The levels of genetic variation in the collection were high and the highest proportion was found within subpopulations. Highest coefficients of heritability and genetic variation were observed in subpopulations from the counties Catalão, Três Ranchos, Cristalina and Senador Canedo. Considering the promising expected progress for growth traits, this collection can be converted into an unrogued seedling seed orchard, aiming the production of improved seed.


2000 ◽  
Vol 23 (2) ◽  
pp. 457-462 ◽  
Author(s):  
Reginaldo Brito da Costa ◽  
Marcos Deon Vilela de Resende ◽  
Antônio José de Araújo ◽  
Paulo de Souza Gonçalves ◽  
Marcelo de Almeida Silva

The heritability coefficients and the genetic gains associated with individual, combined and among and within progeny selection, and with multi-effect index selection in long-term rubber tree [Hevea brasiliensis (Willd. ex Adr. de Juss.) Muell.-Arg.] breeding were determined using effective population size (Ne) restriction. Twenty-two half sib progenies were planted at the Jaú Experimental Station, São Paulo State, Brazil, in a complete randomized block design, with five replications and 10 plants per plot. The following traits were assessed when the plants were three years old: number of laticiferous vessel rings (NR), dry rubber production (RP), bark thickness (BT) and stem girth (SG). Significant variability was found among progeny with good chances of obtaining genetic gain for RP, BT and SG. Effective population size restriction caused a greater reduction in genetic gain for RP with combined selection and with the multi-effect index than for individual or among and within progeny selection. The simultaneous use of accuracy values and genetic gain from the lower limits of the confidence intervals for gain indicated that individual selection is to be preferred in Hevea breeding programs.


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