Propuesta de descriptores para Acca sellowiana (Berg.) Burret

AUTOR(ES)
FONTE

Rev. Bras. Frutic.

DATA DE PUBLICAÇÃO

2014-12

RESUMO

The feijoa plants [Acca sellowiana (Berg.) Burret] is one of the most valued genetic resource plants underutilized from Uruguay and Brazil. This tree is endemic of a narrow area of South America, comprising the northeast of Uruguay and the south of Brazil. Beyond the fact that it has edible fruits, cultivation is limited to domestic scale or small orchards. The use of genetic resource plants from this species is hindered by the lack of knowledge about the diversity both in natural and cultivated stands. The goal of this research is to generate a list of descriptors in order to facilitate the characterization and evaluation of plant material for conservation, sustainable uses and the incorporation into plant breeding programs. A preliminary list with 41 morpho-phenological descriptors for leaves, flowers and fruits was elaborated and applied in situ to 204 individuals belonging to four wild populations of the northeast Uruguay. Using the Restricted maximum likelihood, variance components between populations were estimated (s²P), between plants inside populations (s²I(P)), between samples from the same individual (s²M(IP)) and their confidence intervals using a Mixed Linear Model. In order to determinate the discriminative power of quantitative variables the adopted statistical criteria consisted in the IC comparison (lower limit ICs²I(P) >upper limit ICs²M)IP)) and then the coefficient between s²I(P)/s²M(IP) was calculated. In the case of qualitative variables, the F statistical index was estimated in order to identify significant differences between individuals with the aim to establish discriminant descriptors for individuals. Discriminant variables at population level were also determined. Seven qualitative descriptors (fruit shape, sepals position, pulp color, inner skin color, skin hardness, distance classes for stigma-stamen) and eight quantitative descriptors (height, fruit diameter and weight, pulp weight, skin thickness and resistance, stigma-stamen distance and number of stamens) were validated for individual differentiation. Among studied populations 16 quantitative and 10 qualitative variables were identified.

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