Genetic diversity and selection gain in the physic nut (Jatropha curcas)

Abstract

ABSTRACT. The use of efficient breeding methods depends on knowledge of genetic control of traits to be improved. We estimated genetic parameters, selection gain, and genetic diversity in physic nut half-sib families, in order to provide information for breeding programs of this important biofuel species. The progeny test included 20 halfsib families in 4 blocks and 10 plants per plot. The mean progeny heritability values were: 50% for number of bunches, 47% for number of fruits, 35% for number of seeds, 6% for stem diameter, 26% for number of primary branches, 14% for number of secondary branches, 66% for plant height, and 25% for survival of the plants, demonstrating good potential for early selection in plant height, number of branches, and number of fruits per plant. In the analysis of genetic diversity, genotypes were divided into 4 groups. Genotypes 18, 19, 20, and 8 clustered together and presented the highest means for the vegetative characters and production. Lower means were observed in the 17, 12, 13, and 9 genotypes from the same group. We detected genetic variability in this population, with high heritability estimates and accuracy, demonstrating the possibility of obtaining genetic gains for vegetative characters and production at 24 months after planting.

Mixed models for selection of Jatropha progenies with high adaptability and yield stability in Brazilian regions

“…The coefficient of variation was 23.39% (Table 1), which is was similar to other studies conducted with Jatropha Wani et al, 2012;Brasileiro et al, 2013;Everson et al, 2013;Laviola et al, 2014;Teodoro et al, 2016a,b). Since this is a quantitative trait with continuous distribution and complex inheritance influenced by the soil and climatic features of each environment, this value can be considered low, indicating good experimental precision.…”

Número mínimo de medições para a avaliação acurada de características agronômicas de pinhão-manso

“…Portanto, o dimensionamento adequado do número de medições a serem realizadas é fundamental para a caracterização dos genótipos, pois, vários anos podem ser necessários para quantificar a expressão de uma característica que se manifesta ao longo do tempo. Recentemente, as pesquisas de campo com pinhão-manso têm-se intensificado, principalmente quanto a: desempenho agronômico (Everson et al, 2013;Laviola et al, 2014); estimativas de parâmetros genéticos (Laviola et al, 2012;Wani et al, 2012;Brasileiro et al, 2013); divergência genética Alves et al, 2013;Shabanimofrad et al, 2013;Sharma et al, 2013); e análise de trilha (Das et al, 2010;Spinelli et al, 2010). Para identificar indivíduos com desempenho superior, normalmente, têm-se realizado entre uma e quatro medições, ao longo do ciclo da cultura.…”

Variación fenotípica y rendimiento de Jatropha curcas L. introducida a Túnez

“…With respect to molecular markers, the level of variation is different in localities. In America, where J. curcas is autochthonous, molecular analysis revealed high genetic variation (Ovando-Medina et al, 2011b;He, 2011;Brasileiro et al, 2013;Salvador-Figueroa et al, 2014). In contrast, assessment of J. curcas germplasm, using molecular markers in Asia and Africa, indicated low genotypic diversity and close clustering of accessions from both regions indicating a common ancestor (Basha and Sujatha, 2007;Singh et al, 2010;Zhang et al, 2011;Xu et al, 2012).…”