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Genetic divergence in Brazilian cotton, Gossypium hirsutum var. latifolium Hutch.^*

Luiz Paulo de Carvalho^I; Cosme Damião Cruz^II; Carlos Floriano de Moraes^II

^IEMBRAPA, Centro Nacional de Pesquisa de Algodão, 58107-720 Campina Grande, PB, Brasil. Send correspondence to L.P.C.
^IIUniversidade Federal de Viçosa, UFV, 36570-000 Viçosa, MG, Brasil

ABSTRACT

Analysis of genetic divergence has been used by breeders to group genotypes and to select parents for hybridization. In this work, the D² statistic of Mahalanobis and canonic variables coupled with the grouping methods of Tocher and nearest neighbor were used to study divergence in seven cotton cultivars Gossipium hirsutum L. var. latifolium Hutch. The seven cultivars were, in general, divided into four groups. There was an apparent association between genetic divergence and geographic origin. Selection for disease resistance, especially against "ratlose" was an important factor in the divergence among the materials. The most divergent traits were plant height, fiber percentage and earliness.

Keywords: genetic divergence; Brazilian cotton; Gossypium hirsutum; latifolium Hutch.

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* Part of a thesis presented by L.P.C. to Universidade Federal de Viçosa, in partial fulfillment of the requirements for the Doctoral degree.