PEAR VARIETIES AND SELECTIONS, WITH EXTRA-EARLY AND EARLY RIPENING, OBTAINED AT THE FRUIT RESEARCH STATION CLUJ (FRS CLUJ)

Pear-breeding in the Fruit Research Station Cluj started in 1953 when the Fruit Research Station was founded, carrying the following objectives: productivity, quality and different ripening periods in order to assure fresh fruits for a longer period of time. Due to this activity, the following pear varieties have been certificated: Napoca, Doina, Haydeea, Ina Estival, Virgiliu Hibernal, Jubileu 50 and Milenium. To obtain the first generation of hybrids were used the 400 existent varieties at FRS Cluj. The method used concerning the issue of variety was conducted hybridisation. Taken by the improvement objectives which were proposed, there were chosen as genitors the varieties and selections that were suitable for the aim to follow. At the time being, in the trial fields of FRS Cluj, there are over 140 selections of pear hybrids, obtained by selections. From the large number of tested selections can be noticed a few selections with extra-early and early ripening, with great perspectives for being certificated: 72-17-11, 72-2-16, 72-15-45, 99-7-51, 72-21-13. We recommend studying them in production conditions and promoting the best selections for propagation and for being included in the local and national range of varieties

Types of tree growth and fruit setting in F1 apple hybrids

1656 F1 hybrid apple seedlings, belonging to 127 combinations, have been screened according to their growing and fruit setting types, as it was phenotypically expressed. LESPINASSE (1977; 1992) amalgamated these two traits into a single one which was named ";ideotype";. The screened F1 individuals have been considered as resembling one of the following four architectural ideotypes of the trees indicated by Lespinasse: columnar, spur, standard and weeping. Different ratios of spur, standard and columnar F1 individuals were obtained depending on genitors and on the fact that a certain genitor had been used as a maternal or paternal partner in direct/reciprocal crosses. The monogenic inheritance of the columnar ideotype, proposed by Kelsey and Brown (1992); Lane (1992), does not seem to be the only genetic mechanism involved in the inheritance of this trait. Our experimental results suggest the polygenic determination of this ideotype as more probable than the monogenic one

GCA AND SCA EFFECTS FOR RAMIFICATION CAPACITY OF TREES IN F1 APPLE SEEDLINGS

The number of branches per tree was analysed on F1 individuals originated in several crosses between apple cultivars with different architectural ideotypes: spur (Starkrimson, Golden spur), semispur (Liberty), weeping (Florina). The number of branches per tree in F1 hybrid apple, in their third year of vegetation, was different in six combinations, depending on the genotype of genitors, respectively on their architectural ideotype. There have been noticed significant differences among the tested cultivars used as genitors, the average of trait on hybrid combination being comprised between 4.28 in Goldenspur x Liberty and 7.14 in Starkrimson x Florina. A small number of branches per seedling were registered in Starkrimson x Goldenspur combination (4.32), where the both genitors are spur ideotypes. The variability of analysed characters was high, with s% between 33.9 at Liberty x Florina and 56.8 at Starkrimson x Liberty. These values suggest that seedlings with very different number of branches are likely to be identified in each combination. The analysis of variance for GCA and SCA has emphasised the fact that, in the studied apple combinations, both effects of general and specific combining ability contributed to the phenotypic expression of number of branches per tree. Goldenspur showed negative value for GCA, thus this could produce descendents with low vigour and number of branches, if they are used as genitors in apple breeding. Based on the values of general combining ability (GCA) and specific combining ability (SCA) selection of genitors can be very efficient for desirable characters of growth in apple breeding

VARIABILITY OF TRAITS OF GROWTH - IN VIVO AND IN VITRO - ON GREENHOUSE CARNATION

Several traits of growth on greenhouse carnation were analysed at seven varieties, growing both in vivo and in vitro. In vitro culture, proliferation and root formation were more intense in Pink Sol, Caribe and Tanga than in Pink Sim, Obor and Domingo cultivars. The highest intervarietal variability, under in vivo conditions, was recorded for the number of flowers per plant and number of petals per flower, while in vitro all analysed characters showed an extremely large span of variability values (s% = 26.5 - 109.1). The heritability in broad sense showed high values for the analysed characters, both in vivo (H2 = 0.548 - 0.992) and in vitro (H2 = 0.688 -0.953) conditions. There has been noted a tight positive and negative correlation among a lot of the traits of plants, both in vivo and in vitro. Correlations among the desirable traits can be used as selection indices, in carnation breeding

Architectural ideotype of pear seedling in five hybrid combinations

The architectural ideotype - type of growing - was studied in a topcross experiment with five hybrid combinations in which Cluj 72-2-100 selection, typical spur, was used as a maternal tester. The analyzed seedlings were at the end of their sixth year of vegetation. There were no significant differences among the five hybrid combinations concerning the distributions of F1 seedling in the four accepted ideotypes (columnar, spur, standard, and weeping). A high variability was found for ideotype (between 18.8% in Cluj 72-2-100 x Napoca and 34.4% in Cluj 72-2-100 x Red Bartlett). The participation rate of genotype in the phenotypic manifestation of this character is relatively low. The coefficient of heritability in broad sense was 0.29 and the coefficient of heritability in narrow sense was very low, 0.001