Genética de Coffea: XI - A influência do gen recessivo na sôbre a produtividade do cafeeiro (Coffea arabica L.)

Krug, C. A.; Carvalho, A.

doi:10.1590/S0006-87051946001100001

Resumo

In the present paper the difference in yielding ability of two genotypes which differ by only one single gene is compared : Na Na (bourbon) and Na na (murta). 20 plants of each of 14 murta (Na na) progenies were used for comparison after discarding all na na plants which are dwarfed and practically unfruitful; each progeny was made of 10 Na Na and 10 Na na individuals. The individual yields were recorded during 8 years (1939 to 1946) and it was shown that the na allele, besides its well known effect on the morphology of the leaves, has a remarkable influence on the yielding capacity of the Na na plants, reducing it, in average, to only 55,9% as compared with the Na Na genotype. The Bartlett's test of homogeneity of variance when applied to study the variability between the plants of the bourbon and murta groups has shown that both groups are homogeneous, but a significant difference between their variances was found, the bourbon one being larger. The same test when applied to study the variation between the annual yields of the same groups of plants has led to the same conclusion. The Na na plants however were more suceptible to the die-back of the lateral branches after harvest, which even caused the death of several plants. Considering that fruit size and weight of both varieties (bourbon and murta) are practically identical, it is concluded that the lower fruit number of the murta genotype is responsable for its lower yields. As its flowers are normally fertile, pollen being produced in abundance, it is supposed that a lower number of internodes, or a lower number of flowers in the inflorescences or even a lower total number of flowers in each leaf axil is responsable for the decrease in yield of the murta variety. The results of this study are also of practical importance suggesting the elimination of all murta plants in a coffee plantation and their replacement by bourbon.

Genética de Coffea. XI A influência do gen recessivo na sôbre a produtividade do cafeeiro (Coffea arabica L.)^* (* ) Trabalho apresentado à 1.ª Reunião das Sociedades de Biologia do Brasil, realizada em São Paulo, em Setembro de 1946.

C. A. Krug; A. Carvalho

SUMMARY

In the present paper the difference in yielding ability of two genotypes which differ by only one single gene is compared : Na Na (bourbon) and Na na (murta). 20 plants of each of 14 murta (Na na) progenies were used for comparison after discarding all na na plants which are dwarfed and practically unfruitful; each progeny was made of 10 Na Na and 10 Na na individuals. The individual yields were recorded during 8 years (1939 to 1946) and it was shown that the na allele, besides its well known effect on the morphology of the leaves, has a remarkable influence on the yielding capacity of the Na na plants, reducing it, in average, to only 55,9% as compared with the Na Na genotype. The Bartlett's test of homogeneity of variance when applied to study the variability between the plants of the bourbon and murta groups has shown that both groups are homogeneous, but a significant difference between their variances was found, the bourbon one being larger. The same test when applied to study the variation between the annual yields of the same groups of plants has led to the same conclusion. The Na na plants however were more suceptible to the die-back of the lateral branches after harvest, which even caused the death of several plants. Considering that fruit size and weight of both varieties (bourbon and murta) are practically identical, it is concluded that the lower fruit number of the murta genotype is responsable for its lower yields. As its flowers are normally fertile, pollen being produced in abundance, it is supposed that a lower number of internodes, or a lower number of flowers in the inflorescences or even a lower total number of flowers in each leaf axil is responsable for the decrease in yield of the murta variety.

The results of this study are also of practical importance suggesting the elimination of all murta plants in a coffee plantation and their replacement by bourbon.

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AGRADECIMENTOS

Os autores desejam expressar os seus agradecimentos ao Sr. Constantino Fraga Júnior, Chefe da Secção de Técnica Experimental e Cálculo, pela orientação dada na escolha dos métodos estatísticos utilizados.

LITERATURA CITADA

1. Brieger, F. C. Tábuas e Fórmulas para Estatística, pg. 1-46. Cia. Melhoramentos de São Paulo. São Paulo 1937.
2. Carvalho, A. Causas da baixa produtividade do C. arabica L. var. maragogipe Hort ex Froehner. Bol. Técn. n.° 59 do Instituto Agronômico 1-45, fig. 2, 1939.
3. Carvalho, A. Genética de Coffea IV : Instabilidade do par de alelos Na na de Coffea arabica L. Bragantia 1 : 453:466 1941.
4. Carvalho, A. e C. A. Krug. Genética de Coffea IX : Observações preliminares sôbre quimeras genéticas em Coffea arabica L. Bragantia 6 : 239-250 : 1946.
5. Krug, C. A. Luiz Pereira Barreto e o Café Bourbon. "O Estado de São Paulo" de 15/10/1937.
6. Krug, C. A. The Genetics of Coffea Part I. Inheritance of a dwarf type na na. Jour. Genetics 37 (1) : 41-50 : 4 figs. 1938. tradução : Genética de Coffea Parte I Hereditariedade de um tipo anão na na. Bol. Técn. do Inst. Agron. n.° 47 : 5-13 4 figs. 1939.
7. Krug, C. A. e A. Carvalho. Genética de Coffea X : Hereditariedade da ocorrência de sépalas desenvolvidas nas flores de Coffea arabica L. var. goiaba Taschdjian. Bragantia 6: 251-264 1946.
8. Krug, A. C, J. E. T. Mendes e A. Carvalho. Taxonomia de Coffea arabica L. Descrição das variedades e formas encontradas no Estado de São Paulo. Bol. Técn. do Inst. Agron. n.° 62, pg. 9-57, 122 figs. 1938.
9. Snedecor, George W. Em "Statistical Methods" Iowa State College Press : 251, 1946.

(*

) Trabalho apresentado à 1.ª Reunião das Sociedades de Biologia do Brasil, realizada em São Paulo, em Setembro de 1946.

Datas de Publicação

Publicação nesta coleção
16 Jun 2010
Data do Fascículo
Nov 1946

This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.

[1] 1. Brieger, F. C. Tábuas e Fórmulas para Estatística, pg. 1-46. Cia. Melhoramentos de São Paulo. São Paulo 1937.

[2] 2. Carvalho, A. Causas da baixa produtividade do C. arabica L. var. maragogipe Hort ex Froehner. Bol. Técn. n.° 59 do Instituto Agronômico 1-45, fig. 2, 1939.

[3] 3. Carvalho, A. Genética de Coffea IV : Instabilidade do par de alelos Na na de Coffea arabica L. Bragantia 1 : 453:466 1941.

[4] 4. Carvalho, A. e C. A. Krug. Genética de Coffea IX : Observações preliminares sôbre quimeras genéticas em Coffea arabica L. Bragantia 6 : 239-250 : 1946.

[5] 5. Krug, C. A. Luiz Pereira Barreto e o Café Bourbon. "O Estado de São Paulo" de 15/10/1937.

[6] 6. Krug, C. A. The Genetics of Coffea Part I. Inheritance of a dwarf type na na. Jour. Genetics 37 (1) : 41-50 : 4 figs. 1938. tradução : Genética de Coffea Parte I Hereditariedade de um tipo anão na na. Bol. Técn. do Inst. Agron. n.° 47 : 5-13 4 figs. 1939.

[7] 7. Krug, C. A. e A. Carvalho. Genética de Coffea X : Hereditariedade da ocorrência de sépalas desenvolvidas nas flores de Coffea arabica L. var. goiaba Taschdjian. Bragantia 6: 251-264 1946.

[8] 8. Krug, A. C, J. E. T. Mendes e A. Carvalho. Taxonomia de Coffea arabica L. Descrição das variedades e formas encontradas no Estado de São Paulo. Bol. Técn. do Inst. Agron. n.° 62, pg. 9-57, 122 figs. 1938.

[9] 9. Snedecor, George W. Em "Statistical Methods" Iowa State College Press : 251, 1946.