Genetic Variability for Yield and Other Agronomic Traits in Sweet Potato

2006 ◽  
Vol 6 (1) ◽  
pp. 94-99 ◽  
Author(s):  
Engida Tsegaye . ◽  
Nigussie Dechassa . ◽  
E.V. Devakara Sastry .
Author(s):  
Thien Minh Nguyen ◽  
Tien Thi My Pham

The agronomic values of this population have been evaluated in the field experiments based on their phenotypic performance of agronomic traits, but the genetic variability of this population needs to be evaluated via techniques based on genetic material - DNA. In this study, the genetic variability in the investigated population of 71 hybrids and their parents was evaluated by RAPD technique, using eight selected arbitrarily primers; Genetic parameters and dendrogram expressing the genetic relationships among the investigated population were analyzed by GenALEx 6.1, Popgene 1.31 and NTSYSpc 2.1 softwares. Eight primers were used to generate the amplify products on each individual in the investigated population. From 74 genotypes, a total of 109 fragments were generated, among which, there were 89 polymorphic bands representing 81.65% with an average of 11 polymorphic bands/primer. Genetic similarity coefficient among the investigated population, based on DICE coefficient, ranged from 0.560 (LH05/0822 and PB260) to 0.991 (LH05/0781 and LH05/0841) with an average of 0,796, meaning that the genetic distance among ranged from 0.009 to 0.440 with an average of 0.231. The Shannon index and mean heterozygosity values were 0.328 and 0,176, respectively. This indicated that the progenies of the two investigated crosses possessed a relatively high range of genetic variability. The analysis of molecular variance (AMOVA) showed that genetic variation within population represented 62%, while genetic variation among two different crosses contributes 38% to the total genetic variability. Dendrogram based on DICE’s genetic similarity using UPGMA method showed that the hybrids divide into two major genetic groups (0.75), but the crosses were scattered independently of the hybrid.


2016 ◽  
Vol 7 (1) ◽  
pp. 58
Author(s):  
Enrique Navarro ◽  
Cristina Vega ◽  
Fernando Narváez ◽  
Hugo Córdova

This study was carried out in 1993 to evaluate S2 lines from four maize tropical populations improved by reciprocal recurrent selection. These lines were evaluated under field and laboratory conditions, the latter one to determine physiology quality. The main goal was to measure genetic variability within and among populations for traits such as grain yield, vigor and germination and to select the best lines under field and laboratory conditions. The combined analysis of variance showed great genetic variability among the S2 lines within and among populations for grain yield, days to flower, plant and ear height, among others. The maximum genetic variability was observed on the lines from population 43 and pool 23 for most of the traits, although the latter showed a greater genetic variability for grain yield. Besides, it is important to mention that the above populations included the best genotypes for grain yield, germination and vigor. Taking into account the above mentionel agronomic traits, fifteen lines were selected; 2 belong to population 43* pool 20, 2 from pool 19* pool 23, 8 from population 43, and 3 from pool 23. These results confirm the genetic superiority of the lines from populations 43 and pool 23, so that these populations should be recommended for future genetic improvement by reciprocal recurrent procedures.


2019 ◽  
Vol 35 (6) ◽  
Author(s):  
Rosa maria de Deus De Sousa ◽  
José Ricardo Peixoto ◽  
Geovani Bernardo Amaro ◽  
Michelle Sousa Vilela ◽  
Paula Andrea Osorio Carmona

Studies on the determination of genetic divergence among genotypes are important tools in breeding programs, contributing to the identification of parents with considerable productive potential. However, little is known about the combinatorial capacity of sweet potato (Ipomoea batatas) accessions and its adaptation to the different regions of Brazil. The objective of this study was to evaluate the morpho-agronomic traits from 102 sweet potato accessions from the Germplasm Bank of Embrapa Hortaliças. The experiment was laid out as an augmented block design comprised of 102 treatments. Nineteen above ground traits were measured using descriptors for the respective parts. Estimated values of broad sense heritability were high for the traits mean branch length (95.75%), immature leaf color (85.06%), and predominant branch  color (90.57%). Coefficients of environmental variation were below 30.00% for all variables, except for branch weight (51.62%). The 102 clones analyzed presented broad genetic variability for the different traits evaluated, especially for branch weight, and branch length, and mature leaf color.


2017 ◽  
Vol 35 (4) ◽  
pp. 534-541 ◽  
Author(s):  
Rodrigo P Alves ◽  
Arie F Blank ◽  
Alisson Marcel S Oliveira ◽  
Aléa Dayane D Santana ◽  
Vanderson S Pinto ◽  
...  

ABSTRACT Sweet potato (Ipomoea batatas) spreads mainly by vegetative propagation, and therefore this vegetable may have duplicate accessions in germplasm banks. The authors aimed to characterize morpho-agronomically the sweet potato germplasm from the Active Germplasm Bank (AGB) of Universidade Federal de Sergipe (UFS).The experiment was carried out at the Research Farm “Campus Rural da UFS”. The experimental design was a randomized block design, testing 73 sweet potato accessions with two replicates and four plants per plot. Morpho-agronomic traits of aboveground part and roots were evaluated. We observed that the leaf lobe type, the number of lobes per leaf, shape of central lobe, and general leaf shape were traits which provided the most variability among the accessions. For damage caused by soil insects, 52 accessions showed tolerance. The accessions presented a range from 0.33 to 2.71 t/ha for dry mass of aboveground part and from 1.20 to 10.89 t/ha for the total productivity of the roots. The high phenotypic variability of this crop shows good prospect for breeding programs.


OCL ◽  
2019 ◽  
Vol 26 ◽  
pp. 35 ◽  
Author(s):  
Souhail Channaoui ◽  
Mostapha Labhilili ◽  
Mohamed Mouhib ◽  
Hamid Mazouz ◽  
Mohamed El Fechtali ◽  
...  

Genetic variability is a prerequisite for any plant breeding program, and mutagenesis is a proven way of creating new variation within a crop germplasm. Novel genetic variability in rapeseed was induced by gamma rays, Ethyl Methane Sulphonate (EMS) and combined mutagen treatment, using various doses and concentrations. The objective was to evaluate and compare the obtained M2 mutants for important quantitative traits in two contrasted environments. Data on phenological, morphological and agronomic parameters were recorded. A large variability was observed and mutagenic treatments had a significant effect on all traits studied. Compared to control plants, mutant genotypes derived from seeds treated with low EMS concentrations during moderate time were earlier and characterized by a higher number of pods per plant. For high concentration of EMS during long time and for combinations of physical and chemical mutagens, a significant decrease in plant height and stature was noticed, as compared to control. Besides, plants derived from gamma rays-treated seeds exhibited the highest 1000-seed weight. The novel induced variability may be integrated in rapeseed breeding program as a new germplasm with improved agronomic traits. Particularly, EMS1-7-stable mutant may be exploited to develop efficiently and quickly a new rapeseed cultivar with some desirable traits. The present study highlights once more the possibility to bring novel genetic diversity for rapeseed desirable traits improvement through mutation breeding.


2009 ◽  
Vol 39 (1) ◽  
pp. 19-24 ◽  
Author(s):  
Ana Raquel Ribeiro e Souza ◽  
Glauco Vieira Miranda ◽  
Messias Gonzaga Pereira ◽  
Leandro Vagno de Souza

The objectives of this research were to evaluate the genetic variability and predict genetic gain in the white maize landrace rescued in Barbacena, Minas Gerais, Brazil. The Brazilian maize landraces have economic and social importance for certain areas in Brazil, and research on this germplasm is very important for local food security. Three experiments were carried out with 100 half-sib progenies, in Campos dos Goytacazes, RJ, Coimbra and Barbacena, Minas Gerais, Brazil. These sites were chosen for their soil and climatic differences. An analysis of variance was significant among the progeny for all characters, indicating the presence of genetic variability between the three populations. In Campos dos Goytacazes and Coimbra, the genetic variation of the white maize landrace was responsible for most of the phenotypic variance in grain yield and can be used in selection cycles. There was no significant genetic variance in grain yield in Barbacena. For the white maize landrace it was concluded that: the characters of the component of productivity such as plant density and number of plants with kernels can produce indirect genetic gain for grain yield and are suitable for breeding; prebreeding of the maize landrace is necessary before being used directly in the elite germplasm; the population contains high genetic variability and opportunities for genetic gain; the average agronomic traits are suitable only for traditional production systems with few inputs, and polyculture; the difference between environments produces specific responses in the progeny i.e. there is a progeny x environment interaction.


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