Um enrolamento das fôlhas do fumo de causa genética

Bragantia, Feb 2019

A type of leaf-roll has been noticed for many years in commercial tobacco plantings in the State of S. Paulo. Leaf-roll plants were supposed to be affected by a virus disease, but repeated attempts to transmit it by grafting, juice inoculation and by insect vectors failed consistently. Later studies showed that the leaf-roll condition is due to genetic factors and that probably more than a pair of recessive genes are involved in its transmission. Even after the genetic nature of the leaf-roll condition was definitely established, attempts were made to induce the leaf-roll condition in plants genetically normal by several methods : 1. Spraying their leaves with the juice from leaf-roll plants ; 2. Approach-grafting a leaf-roll scion onto a normal plant and vice-versa, following with defoliation, cutting back or shading of the normal graft component. This was done to stimulate translocation of the phloem contents from the leaf-roll scion or stock into the normal stock or scion respectively. It was thought that if leaf-roll were due to the genetically controlled production of a hormone-like substance, these treatments might induce the leaf-roll condition in plants genetically normal. The results, however, have been negative.

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Um enrolamento das fôlhas do fumo de causa genética

Um enrolamento das fôlhas do fumo de causa genética(1)     A. S. CostaI; R. ForsterII IEngenheiro agrônomo. Secção de Genética IIEngenheiro agrônomo, Subdivisão de Estações Experimentais. Instituto Agronômico de Campinas     SUMMARY A type of leaf-roll has been noticed for many years in commercial tobacco plantings in the State of S. Paulo. Leaf-roll plants were supposed to be affected by a virus disease, but repeated attempts to transmit it by grafting, juice inoculation and by insect vectors failed consistently. Later studies showed that the leaf-roll condition is due to genetic factors and that probably more than a pair of recessive genes are involved in its transmission. Even after the genetic nature of the leaf-roll condition was definitely established, attempts were made to induce the leaf-roll condition in plants genetically normal by several methods : 1. Spraying their leaves with the juice from leaf-roll plants ; 2. Approach-grafting a leaf-roll scion onto a normal plant and vice-versa, following with defoliation, cutting back or shading of the normal graft component. This was done to stimulate translocation of the phloem contents from the leaf-roll scion or stock into the normal stock or scion respectively. It was thought that if leaf-roll were due to the genetically controlled production of a hormone-like substance, these treatments might induce the leaf-roll condition in plants genetically normal. The results, however, have been negative.     Texto completo disponível apenas em PDF. Full text available only in PDF format.     LITERATURA CITADA 1.  Bennett, C. W. and A. S. Costa. A curly top disease of tomato and tobacco in Brazil closely resembling curly top of sugar beet in the United States and Argentina. Jour. Agr. Research. (No prelo).         [ Links ] 2.  Costa, A. S. e R. Forster, Uma suspeita moléstia do vírus do fumo (Nicotiana tabacum L.) semelhante a "leaf-curl", presente no Estado de São Paulo. Jornal de Agronomia 2 : 295-302. 1939.         [ Links ]     (1) Trabalho apresentado à "Segunda Semana de Genética", realizada em fevereiro de 1949 na Escola Superior de Agricultura "Luiz de Queiroz", de Piracicaba, São Paulo.


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A. S. Costa, R. Forster. Um enrolamento das fôlhas do fumo de causa genética, Bragantia, 43-45, DOI: 10.1590/S0006-87051949000100005