Morphological Dissimilarity Among Assai Palm Trees Progenies from Anajás - PA

Abstract

The interest in assai fruits in different regions of the country necessitates genetic improvement of the species. With the aim of determining the dissimilarity of the assai palms trees grown in Tomé-Açu, Pará, the following characteristics were evaluated in 30 different progenies: average weight of the bunches (PMC), total fruit weight (PTF), average weight of empty bunches (PMCV), average length of the rachis/bunch (TMR), average weight of 100 fruits (PCF), total number of bunches (NTC), and total weight of the bunches (PTC). The experimental design utilized was randomized block, three replicates, and five plants per plot. The matrix of dispersion was obtained using multivariate methods, Unweighted Pair Group Method, with Arithmetic Mean (UPGMA). The average Euclidean distance was used as a dissimilarity measure. The results showed the presence of the G effect only in TMR and NTC and GxE interaction effect in all evaluated characteristics. PTC and PTF were responsible for 99.85% of the total diversity based on the mean Euclidean distance. With 50% of the dissimilarity limit, two large groups (A and B) were obtained, involving 70% of the progenies. With 70% of the dissimilarity limit, five groups ("a" to "e") were obtained with a majority group (a) containing 80% of the total progenies. The following conclusions were reached: there are pronounced effects of the different years on the characteristics PTF, NTC, and PTC and the progenies respond to environmental changes with significant G×E interaction; the most important characteristics for evaluation were PTC and PTF which are mainly responsible for the total divergence; the progenies are not classified sequentially in the for performing crosses.

Productive capacity and genetic variation behavior in progenies from irrigated açai according to plant age

“…O coeficiente de variação genética individual exibiu valores variando de 29,888 na primeira avaliação a 4,1719 na quarta avaliação. Em termos gerais, esses resultados indicam que existe ampla variabilidade genética entre progênies no primeiro ano agrícola, que permite a seleção genética de plantas superiores, semelhante ao citado por Galate et al (2014) This fact is consistent with the estimates of genetic variances and the heritability coefficient for these ages, suggesting a clear tendency for a decrease in genetic gain over the ages evaluated, since the development of the açai tree tends to reach a limit level over the years (YOKOMIZO et al, 2010), associated with increased pollination among related individuals of plants of the genus Euterpe established in the experimental areas (OlIvEIRA et al, 2015).…”

“…Tal fato é coerente com as estimativas de variâncias genéticas e de coeficiente de herdabilidade para essas idades, sugerindo nítida tendência para decréscimo do ganho genético com o passar das idades de avaliação, pois o desenvolvimento do açaizeiro tende a atingir um patamar limite com o passar dos anos (YOKOMIZO et al, 2010), associado ao aumento de polinização entre indivíduos aparentados de plantas do gênero Euterpe instalados em áreas experimentais (OlIvEIRA et al, 2015).…”

“…To meet consumption demands, the açai tree is a species that still needs a long process of domestication (TAvARES et al, 2020). Work on improving its genetic parameters is only in the initial stage of development, and the literature offers only preliminary or occasional results (FARIAS NETO et al, 2018;AZÊvEDO et al, 2019;YOKOMIZO et al, 2019), requiring a more detailed study of the species at different productive stages/ages. Studies on the evolution of genetic variation over the plant ages at the time of evaluation, the efficiency of early selection in segregating populations to determine the reliability of a character evaluated in the juvenile stage as an indicator of the individual's productive performance in adulthood, and the importance of the positive association from early emission of tillers and other agronomic traits with productivity in adulthood have not yet been established in the literature.…”

“…O açaizeiro para atender as demandas de consumo é uma espécie que ainda necessita de um longo processo de domesticação (TAvARES et al, 2020), os trabalhos de melhoramento estão em fase inicial de desenvolvimento, e a literatura oferece apenas resultados iniciais ou pontuais (FARIAS NETO et al, 2018;AZÊvEDO et al, 2019;YOKOMIZO et al, 2019), sendo necessário estudo mais detalhado da espécie nas diferentes fases/idades produtivas. Estudos sobre a evolução da variação genética ao longo das idades de avaliações, a eficiência da seleção precoce em populações segregantes procurando determinar a confiabilidade de um caráter avaliado na fase juvenil como indicador do desempenho produtivo do indivíduo na fase adulta e a importância da associação positiva da emissão precoce de perfilhos e de outros caracteres agronômicos com a produtividade na fase adulta ainda não foram estabelecidos na literatura.…”