scholarly journals Divergência genética entre progênies de polinização aberta de Pinus caribaea var. hondurensis a partir de caracteres quantitativos

2016 ◽  
Vol 36 (86) ◽  
pp. 127
Author(s):  
Wanderley Dos Santos ◽  
Elton Gean Araújo ◽  
Danilla Cristina Lemos Souza ◽  
Janaína Rodrigues da Silva ◽  
Camila Regina Silva Baleroni Recco ◽  
...  

Este trabalho foi realizado com o objetivo de estimar a divergência genética entre progênies de Pinus caribaea var. hondurensis, por meio de caracteres quantitativos. O experimento foi instalado em delineamento látice 10 x 10, triplo, com 100 tratamentos (96 progênies oriundas de polinização aberta de um pomar clonal da espécie e quatro testemunhas). Foram avaliados os caracteres: diâmetro a 1,30 m do solo, altura total de planta, volume cilíndrico, produção de resina total e resina por área de painel. Utilizou-se a distância generalizada de Mahalanobis (D2) e o método de otimização de Tocher. A maior distância genética observada entre as progênies foi de 100% (D2 = 65,51) e a menor foi de 0,09% (D2 = 0,15). O caractere volume foi o que mais contribuiu para a divergência genética entre os grupos avaliados. O agrupamento a partir do método de otimização de Tocher possibilitou a separação das progênies em quatro grupos, com concentração de 96,9% das progênies em um único grupo. Para que estas progênies possam ser incluídas em programas de melhoramento genético para produção de resina e madeira, cruzamentos controlados deverão ser priorizados entre indivíduos mais produtivos, que apresentaram maior divergência genética.Genetic divergence genetic between Pinus caribaea var. hondurensis progenies based on quantitative traitsThe proposal of this study was to estimate the genetic divergence among Pinus caribaea var. hondurensis progenies through quantitative traits. Trail was established in lattice design 10 x 10, triple, with 100 treatments (96 progenies from clonal seed orchard of P. caribaea var. hondurensis and four controls). The genetic divergence was estimated using the generalized Mahalanobis distance (D2) and Torcher’s optimization method. Diameter at 1.30 above the ground, total plant height, cylindrical volume, total resin production and resin per panel area were evaluated. The largest genetic distance observed between the progenies was 100% (D2 = 65.51) and the lowest was 0,09% (D2 = 0.15). Clustering by Torcher’s optimization method separated the progeny in four groups, with a concentration of 96.9% of the progenies in a single group. Volume was the largest contributor to the genetic divergence among groups. To include these progeny in breeding programs for resin and wood production controlled crossings should be prioritized among the most productive individuals that presented greater genetic divergence.Index terms: Genetic breeding; Generalized Mahalanobis distance; Tocher optimization

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0254413
Author(s):  
João de Andrade Dutra Filho ◽  
Tercilio Calsa Júnior ◽  
Djalma Euzébio Simões Neto ◽  
Lauter Silva Souto ◽  
Anielson dos Santos Souza ◽  
...  

The best agro-industrial performance presented by a crop genotype in one environment may not be reproduced in another owing to complex edaphoclimatic variations. Therefore, breeding programs are constantly attempting to obtain, through artificial hybridization, novel genotypes with high adaptability and stability potential. The objective of this study was to analyze genetic divergence in sugarcane based on the genotypic values of adaptability and stability. A total of 11 sugarcane genotypes were analyzed for eight agro-industrial traits. The genotypic values of the traits were determined using mixed model methodology, and the genetic divergence based on phenotypic and genotypic values was measured using the Mahalanobis distance. The distance matrices were correlated using the Mantel test, and the genotypes were grouped using the Tocher method. Genetic divergence is more accurate when based on genotypic values free of genotype–environment interactions and will differ from genetic divergence based on phenotypic data, changing the genotype allocations in the groups. The above methodology can be applied to assess genetic divergence to obtain novel sugarcane genotypes with higher productivity that are adapted to intensive agricultural systems using diverse technologies. This methodology can also be tested in other crops to increase accuracy in selecting the parents to be crossed.


ISRN Forestry ◽  
2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Edward Missanjo ◽  
Gift Kamanga-Thole ◽  
Vidah Manda

Genetic and phenotypic parameters for height, diameter at breast height (dbh), and volume were estimated for Pinus kesiya Royle ex Gordon clonal seed orchard in Malawi using an ASReml program, fitting an individual tree model. The data were from 88 clones assessed at 18, 23, 30, 35, and 40 years of age. Heritability estimates for height, dbh, and volume were moderate to high ranging from 0.19 to 0.54, from 0.14 to 0.53, and from 0.20 to 0.59, respectively, suggesting a strong genetic control of the traits at the individual level, among families, and within families. The genetic and phenotypic correlations between the growth traits were significantly high and ranged from 0.69 to 0.97 and from 0.60 to 0.95, respectively. This suggests the possibility of indirect selection in trait with direct selection in another trait. The predicted genetic gains showed that the optimal rotational age of the Pinus kesiya clonal seed orchard is 30 years; therefore, it is recommended to establish a new Pinus kesiya clonal seed orchard. However, selective harvest of clones with high breeding values in the old seed orchard should be considered so that the best parents in the old orchard can continue to contribute until the new orchard is well established.


2006 ◽  
Vol 36 (4) ◽  
pp. 1054-1058 ◽  
Author(s):  
O K Hansen ◽  
E D Kjær

A paternity analysis using five microsatellite markers was conducted in a Danish clonal seed orchard with 13 Abies nordmanniana (Stev.) Spach clones. The purpose was to investigate potential seed-orchard dysfunctions, with special emphasis on nonequal pollen contributions and selfing. Male paternity was found for 232 seedlings germinated from seeds collected on three ramets, each of eight clones, and the relative contribution of each clone to the gene pool of male gametes was calculated. Furthermore, 49 ramets were genotyped to check for erroneous grafting. The effect of an unbalanced male contribution was quantified by means of two measures: (1) the status number (NS), which reflects buildup of coancestry in the seed-orchard crop as a result of a low number of clones and an unequal male contribution, and (2) the asymptotic variance effective population number (Ne(v)). The contributions by pollen donors from the 13 clones were highly skewed. Three clones were fathers to more than 75% of the progenies, while making up only 24% of the ramets in the seed orchard. Four clones sired no progenies at all. The unequal contribution on the male side corresponded to NS = 4.2 and Ne(v) = 5.8. Some selfing was observed, which may give rise to concern if clonal seed orchards with few clones are established. The estimated maximum pollen contamination from outside the seed orchard was 4.3%. No grafting–labelling errors were identified.


2016 ◽  
Vol 7 (3) ◽  
pp. S61-S63
Author(s):  
Zainal Muttaqin ◽  
Sri Wilarso Budi R ◽  
Basuki Wasis ◽  
Iskandar Z Siregar ◽  
Corryanti .

Mistletoe is hemiparasitic plants (macroparasite) on seasonal and annual plants include trees, however, mistletoes are also beneficial as key species that fill in the ecological niche, and a potential to non-wood forest product such as medicinal plants as one of them. The objectives of this research are to identify species of teak mistletoes at Padangan Clonal Seed Orchard (CSO) in Perum Perhutani and to aim its posibilities as medicinal plant. The inventory methods on species of teak mistletoes was carried out in compartements/blocks of teak clones that are designated as Observation Sample Plots (OSPs/PCP) of the attack intensity from low, medium, high, control; and four units Observation Measurement Plots (OMPs/PUP) on each OSPs/PCP. Continously, it was analized by comparing the same species of mistletoes on other host trees as reference which was efficacious to be used as medicinal plant. Three species of mistletoes parasitizing teak clone stands were identified as Dendrophthoe pentandra (L.) Miq. of family of Loranthaceae which is also attacking other host trees, Macrosolen tetragonus (Blume) Miq. of family of Loranthaceae too, Viscum articulatum Burm. F. of family of Santalacea/Viscaceae that is hyperparasite on two other mistletoes. The comparison with the same teak mistletoe but on different host trees shows that including D. pentandra and V. articulatum have the potential for hypertension treatment. D. pentandra is used too for medicine to cure ilness, wounds, fester and recovery from parturition. Known that chemical content this mistletoe comprise of flavonoid ingrident, fenolat acid (terulat acid, para hidroksi benzoate acid, kumarat acid, protokatekuat acid and vanilat acid. As for the utilization of M. tetragonus hasn’t been discovered up to this moment.Key words: mistletoe, identification, teak clone, non-wood forest product, medicinal plant


Author(s):  
Melusi Rampart

Maternal effects were assessed by germinating seeds sourced over multiple years from the same cloned mother trees, comparing germination capacity and rate between crop years. The relationships between climatic variables, seed characteristics and germination capacity were determined, and thermal time parameters were used to predict seed dormancy release and germination under the climatic conditions in the year after seed collection. There were significant differences in seed weight (P < 0.05), seed length and embryo occupancy (both P < 0.001) among crop years. Temperature during the seed development period explained 70% of the variation in seed weight and 63% of the variation in embryo occupancy. Germination capacity was significantly (P <0.001) different among crop years, among temperatures and among chilling durations, and thermal time requirements for germination increased from older (2007) to younger (2012) seeds. The mean base temperature without chilling was 7.1°C, while after chilling it was 4.6°C and 3.6°C for four and eight weeks chilling respectively. The mean thermal time to 50% germination without chilling was 135.1°Cd, while after chilling it was 118.3°Cd and 154.0°Cd for four and eight weeks chilling respectively. This experiment demonstrates that year-to-year differences in the environment experienced by mother trees during seed maturation can affect seed germination characteristics.


2021 ◽  
Vol 7 (5) ◽  
pp. 82-90
Author(s):  
Gezahegn Tefera ◽  

Assessing and understanding the variations existing in crops due to genetic composition and environmental variability is very important in order to exploit the genetic constitution of crop plants. To this aim, variability measures such as phenotypic coefficient of variation (PCV) and genotypic coefficient of variation (GCV) are commonly used. Heritability and genetic advance are major concerns for common bean to identify important traits for common bean genetic improvement. The field experiment was conducted at Mandura and Dibatie research substations working with sixteen genotypes of the common bean during 2017/2018 in lattice design with three replications to evaluate the performance of common bean genotypes and estimate the genetic variability. Heritability and genetic advance were estimated in relation to yield and its component traits for future breeding programs. Combined analysis of variance across locations revealed highly significant variations among genotypes for all traits under study. The PCV ranged from 3.36% for days to flowering to 15.91% for a number of pods per plant while the GCV value ranged from 0.75% for days to flowering to 13.74% for the number of pods per plant. Broad sense heritability values ranged from 5.00% for days to flowering to 84.61% for a hundred seed weight. Generally, the result of the study showed that significant genetic variability among tested genotypes and a simple selection for effective improvement of these traits. Keywords: common bean, genetic variability, genetic advance, heritability


2018 ◽  
Vol 36 (1) ◽  
pp. 112-117 ◽  
Author(s):  
Gabriel M Maciel ◽  
Rafael R Finzi ◽  
Alexandre William C Marra ◽  
Fábio J Carvalho ◽  
Ana Paula O Nogueira

ABSTRACT Evaluation of pre-commercial hybrids in a germplasm bank is essential for determining its commercial potential or its utility as a potential genitor in a breeding program. The objective of this study was to determine genetic divergence and per se behavior of 47 pre-commercial hybrids from okra germplasm bank of the Universidade Federal de Uberlândia. Precocity index (%), number of fruits (fruits per plant), average fruit mass (g) and productivity (g per plant) were evaluated. Analysis of genetic divergence was performed by multivariate analysis using Mahalanobis distance with different clustering methods (UPGMA and canonical analysis). The performance of hybrids was compared by Scott-Knott (p= 0.05). A significant genetic variability among okra hybrids was observed. UPGMA and canonical analysis grouped the hybrids similarly, being satisfactory to represent genetic divergence. Ten hybrids presented higher performance than the commercial hybrids. Among them, UFU-QB16 stood out as the most promising hybrid for being used as a potential parent in breeding programs after auto pollination.


Author(s):  
Thuanny Lins Monteiro Rosa ◽  
Caroline Palacio de Araujo ◽  
Rodrigo Sobreira Alexandre ◽  
Edilson Romais Schmildt ◽  
José Carlos Lopes

Abstract: The objective of this work was to evaluate the biometry of fruit and seed, and the diversity of paradise nut (Lecythis pisonis) genotypes. Fruit of 12 paradise nut genotypes were collected from plants in the northern region of the state of Espírito Santo and in the eastern region of the state of Minas Gerais, Brazil. Data were subjected to the analysis of variance, and means of the different genotypes were compared by Scott-Knott’s mean clustering test. The phenotypic diversity was analyzed using Mahalanobis’ generalized distance, and clustering, by Tocher’s optimization method and the graphical dispersion of canonical variables. The relative contribution of the characters to diversity was assessed by Singh’s method. The paradise nut genotypes differed regarding the morphological characteristics of fruit and seed. Genotype 1 produced the largest number of seed per fruit, and genotypes 2 and 7 produced the largest seed. These genotypes were clustered into different groups, which is indicative of their potential combination for use in genetic breeding programs.


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