Seleção entre e dentro de famílias de irmãos completos de maracujazeiro (Passiflora edulis f. flavicarpa) / Among and inside selection of the full sibling families of passion fruit plants (Passiflora edulis f. flavicarpa)




A population of yellow passion fruit (Passiflora edulis f. flavicarpa), constituted of twenty-six full sibling families, was evaluated in outline of blocks at random, with three blocks and four plants per parcel (spacing 4 x 3 m), installed in the experimental area at Fitotecnia Department of the Universidade Federal de Viçosa. The objective of this work was to select promising genotypes, using among and inside selection, direct and indirect, and classic selection index, and also to compare the efficiency of the among and inside selection strategies, massal selection, stratified massal selection and combined selection. It was measured number of fruits by plant, mass fruit, length of the fruit, diameter of the fruit, thickness of the peel, pulp mass, pulp coloration, tenor of total soluble solids, peel mass, relationship between pulp mass /fruit mass, titrable total acidity, relationship between tenor of total soluble solids /titrable total acidity and evaluation of plant production. For the variance analysis, variability was verified among full sibling families in 10 of the 13 measured characteristics. The characteristics that didn t show variability (peel thickness pulp coloration and titrable total acidity) were not considered in the subsequent analyses. It was observed that the measured characteristics showed enough variability among families, and that the relationship between CVg and CVe overcame the character number of fruits per plant (1,39), fruit mass (1,31), fruit length (2,34), fruit diameter (1,39), tenor of total soluble solids (1,18), peel mass (1,91), relationship between pulp mass/fruit mass (1,10) and plant production (1,32), being indicators of viability to practice selection with genetic earnings in those characteristics. From each block, the six superior families were selected and a plant from those families was used per parcel, totaling 18 selected plants. The indirect selection, basing in the characteristic of fruit length (characteristic of easy mensuration), showed expectation of considerable earnings in the characteristics of fruit mass (11,60%), fruit diameter (3,06%) and pulp mass (14,00%). Satisfactory result was also obtained with the use of classic selection index in obtaining the productive potentials of the genotypes, with predicted earnings of 56,93%, when they were used as consideration weights to measure the coefficient of genetic variation among families, the estimation of the deviation-pattern of genetic or the herdability coefficient in family level. The strategies of combined selection, massal selection, stratified massal selection and among and inside selection showed larger efficiency in pointing the superior genotypes of the predicted earnings. The strategy of combined selection, besides presenting the largest predicted earnings for the most measured characters, indicated the recombination of a larger number of different families that can contribute to larger variability in the segregating population, which has great importance in genetic improvement programs of passion fruit plant.


seleção passion fruit passiflora edulis maracujá melhoramento de plantas plant breeding passiflora edulis selection melhoramento vegetal

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