Search
Search Results
-
Genetic relatedness among Asian Cotoneaster species investigated with DNA marker analysis
43-46.Views:187The widespread genus Cotoneaster has its centre of diversity in the Himalayas and surrounding areas. Most taxa appear to be polyploid and apomictic, and many of them have become popular ornamentals due to their attractive foliage and berries. One of the taxonomically most critical groups is Section Alpigeni which contains several important ornamental plants. The number of species belonging to this section varies widely between different taxonomic treatises, depending on whether 'splitting' or 'lumping' of species is preferred. Using a rather narrow species definition, we have investigated 13 different species using RAPD analysis. A simple matching (SM) coefficient-based principle coordinate analysis (PCO) was calculated from the RAPD data. Some species were clearly more similar to each other than to other species in the analysis. The levels of similarity did, however, not correspond very well to the lumping together of several taxa under the same species name as performed e.g. in the recent Flora of China. Obviously, the complex hybridogenous origination and, in some cases, still ongoing recombination with sexual species or among the apomictic taxa themselves, produces a genetic variability structure that cannot be properly reflected in a hierarchical taxonomy.
-
Relative ecological and biological indicator values of plum and prune cultivars
37-53.Views:220The study was conducted to compare historical plums, gene collections, and is currently cultivated and recent perspective varieties from the author. The object of the study was the relative ecological Borhidi’s figures and classification of varieties under the new definition, as the relative biological values. There were 11 figures no one in particular affect the data of the plums grown in importance as TB, WB, RB, LB, and the values are relative biological value (OP, FR, SS, and DR). The specificity of each indicator was different, but in general the importance and specific breeds was associated with. The SB (salt figures) is not proved informative, partly because small data in the literature, on the other hand, had little to their own observations as well. The gene bank of Cegléd is now third-generation (1951–1972, 1973–1991, since 1992) kind of collection, during which many aspects have changed climatic conditions: cold winter eased the strictness, but has increased the threat
of spring frost advection. The relative biological scores markedly influenced around flowering extreme weather (dry, windy weather and so flowering in within 2-3 days), optimal conditions of the plum pox virus vectors and of course the presence of fruit and foliage harmful fungi. It see to be, in the case of semi-wild and wild fruit species – are possible with similar comparative analyzes, and hopefully will in feral forms, culture – as we have seen previously (Surányi 2000 and 2006). In the continuation analysis of the natural vegetation and cultural context of the complex multifactorial factors will be carried out more easily, according to the relative value figures, as well as rootstock effects and plantation’s habitat studies, and even the most phytotechnical evaluation of interventions. -
Sugar composition of floral nectar in sour cherry cultivars
109-113.Views:208The composition of floral nectar in sour cherry cultivars studied in 1997 at Újfehértó was in agreement with our previous data, the three most frequent sugar components being glucose, fructose and sucrose. Nectar secreted at night is generally more diluted than nectar produced during the day. None of the nectar samples produced at night reached the threshold value (100 mg/ml) of bee visitation. In the majority of cultivars the difference in concentration between night and day nectar is not too high, but in two cultivars, 'Korai pipacs' and ‘Újfehértói fürtös’ the difference is quite significant. Most sucrose was found in the nectar of cvs. 'Érdi jubileum' and ‘Újfehértói fürtös’, but a high amount of sucrose was measured also in the flowers of 'Korai pipacs' and 'Meteor USA'. Nectar concentration varies from opening of the flower to petal fall to a smaller or greater degree, depending on the given cultivar. From the 9 sour cherry cultivars studied ‘Újfehértói fürtös’ and Tandy 48' had the most attractive nectar for bees. There was no correlation between nectar composition and free fertilisation. On the basis of nectar composition the majority of the sour cherry cultivars studied can be classified into the sucrose-rich category; only one cultivar, 'Érdi jubileum' had a sucrose-dominant secretory product. The composition of nectar in the studied sour cherry cultivars is preferred by bees.
-
The importance of clonal selection of grapevine and the role of selected clones in production of healthy propagating stocks
15-24.Views:356Genetical alterations and phytosanitary status promote the variability and modify the appearance of vine. Old vine varieties in old vineyards are highly variable and well adapted to selection. Clonal selektion is based on a visual performance: valuable individuals (clones) are picked out according to visible symptoms or characters. The genetical stability of clones is proved by testing the vegetatively propagated progenies on the basis of morphological and molekular (SSR, AFLP, SMPL, RAPD) markes. Authors take great care of the visual phytosanitary selection as part of the clonal selection being the oreliminary step to develop pathogen-free propagation stocks. In Serbia (Vojvodina) the selection breeding has been carried on for several decades resulted in comparative clone trials with home and imported clones of Welsch Riesling, Chardonnay, Pinot gris, White Riesling. Among the clones of home selection SK.54 Welsch Riesling clone is the most valuable. Its clearing from pathogene is being carried on in an interregional IPA programme (HUSRB/0901/214/123) in Kecskemét. In Kecskemét, the centre of the Hungarian Danube vine region 5 vine clones have been registered (Cegléd szépe K.73, Irsai Olivér K.11, Kövidinka K.8, Hárslevelû K.9, Pannónia kincse K.56). Besides them 18 virus-tested clones have also been qualified.Works aiming at their complete exemption are going on in order to obtain clones free of propagation wood-borne diseases.
-
Studies on the Tobamovirus resistance of the pepper (Capsicum annuum L.) cultivar Greygo
71-75.Views:172Resistance of the Hungarian pepper (Capsicum annuum L.) cultivar "Gre.ygo" to Tohamoviruses has been investigated. All plants of the population of Greygo proved to be resistant to tobacco mosaic and tomato mosaic viruses (TMV, ToMV), both represent the pepper pathotypes Po of Tohamoviruses. Individuals of Greygo, however, were found to be susceptible to pathotypes P12 and P123 of pepper mild mottle virus (PMMV). When inoculated with the XM isolate of dulcamara yellow fleck virus (DYFV, pathotype P1) the population of Greygo segregated in resistant and susceptible plants. These results as well as inoculations of the progenies of three TMV resistant plants clearly showed, that besides the resistance allele Li the cultivar Greygo possesses also an another allele. This allele, provisionally marked by L2g behaves like to the allele L2 characteristic to Capsicum frutescens cv. . Tabasco. Determination of the identity of the allele L2g to the allele L2 needs further genetic and pathological informations. Relations between the Tohamoviruses pathogenic to pepper and the alleles of the resistance gene L are outlined for the discussion.