Adriana Cibele de Mesquita Dantas

Number of anthers per flower, pollen grains per anther and pollen germination capacity of different cultivars of apple trees

The objective of this study was to evaluate the number of anthers per flower, the number of pollen grains per anther and the pollen germination capacity of different cultivars of apple trees. The study was performed at the Physiology and Plant Genetics Laboratory of Federal University of Santa Catarina. The field collecting were performed at Epagri / Cacador Experimental Station, in Santa Catarina State during October, 2005. It was used the following apple cultivars developed in Brazil: Primicia, Princesa, Fred Hough, Catarina, Baronesa, Lisgala, Suprema, Condessa, Daiane, Duquesa, Imperatriz and Joaquina. It was concluded that the apple cultivars Condessa, Princesa, Eva, Duquesa, Imperatriz, Gala, Fred Hough, Daiane, Baronesa and Suprema produce pollen grains of satisfactory quantity and of good germination capacity. The cv. Condessa, although having high pollen germination capacity, produces less anthers and less pollen grains per anther than the others. Princesa is the cultivar of best pattern as pollinizer, once it combines number of anthers/flower, number of pollen grains/anther and pollen germination capacity in a better satisfactory level.

The self-incompatible RNase S-alleles of Brazilian apple cultivars

Apple plants are self-incompatible because a genetic mechanism allows the female reproductive organ to recognize and reject self-pollen or pollen from genetic related individuals and allows non-self pollen to effect fertilization. Thus, there are implications to both breeding strategies and orchard management for fruit production. The purpose of this study was to identify and to characterize the S-RNase alleles of the gametophytic incompatibility among apple cultivars developed in Brazil, seeking to give support for choosing right combinations of parent in the apple breeding programs. It also sought to identify correct combinations of scion/pollinator cultivars of commercial apple orchards. A total of 16 specific S-RNase alleles primers were tested against DNA extracted from 12 Brazilian cultivars and their parents. The molecular analysis confronted to the reference cultivars, showed that the cultivars Daiane, Imperatriz and Princesa have the same incompatibility S3 and S5 alleles, while ‘Lisgala’ showed the alleles S2 and S5; ‘Suprema’, S1 and S9; ‘Catarina’, S1 and S19; ‘Joaquina’ and ‘Fred Hough’, S5 and S19; ‘Baronesa’, S3 and S9; ‘Duquesa’, S2 and S3. For ‘Primícia’ and ‘Condessa’ it was only possible to identify one of the S-alleles, namely S24 and S2, respectively, with the second allele remaining to be identified. Progeny test indicated the Mendelian inheritance for RNase alleles. Results of this study will be helpful to judiciously choose parents in apple breeding programs to improve compatibility.

Studies of the genetic resistance of the accesses of the bank of germoplasma of apple tree of epagri to the stain to foliate of glomerella (Colletotrichum gloeosporioides)

RESUMO-Uma das prioridades do Programa de Melhoramento Genetico de Macieira da Epagri e a obtencao de cultivares resistentes a mancha foliar de glomerella - MFG, doenca essa causada principalmente pela especie Colletotrichum gloeosporioides, que tem causado elevadas perdas na producao. Os resultados obtidos neste estudo tem, dentre outras, a finalidade de subsidiar os programas de melhoramento genetico da macieira na selecao de parentais, objetivando a incorporacao de resistencia genetica a MFG nas futuras novas cultivares. Para tanto, o primeiro passo e a identificacao de germoplasma portador dos genes de resistencia. No presente trabalho, foram utilizados 3 isolados de C. gloeosporioides provenientes de diferentes regioes produtoras de maca. Estes isolados foram inoculados em 245 acessos pertencentes ao Banco de Germoplasma de Macieira – BGM, da Epagri / Estacao Experimental de Cacador - EECd, SC. Para a inoculacao em tecido foliar, a concentracao de conidios foi ajustada para 10 3 esporos/mL. Apos 72h de incubacao, sob temperatura de 25 o C, foi realizada a avaliacao da incidencia para presenca ou ausencia de sintomas e para a severidade da doenca. O delineamento experimental foi o inteiramente casualizado, com tres repeticoes. As diferencas de severidade entre os acessos foram testadas atraves da Anova nao parametrica Kruskal Wallis. Entre os acessos testados, 187 (76,3%) manifestaram resistencia e 58 (23,7%) suscetibilidade a MFG. Entre as cultivares suscetiveis, nao houve diferenca no grau de severidade de ataque da MFG. Termos para indexacao: Malus domestica Borkh, inoculacao, acessos, resistencia, suscetibilidade, melhoramento.