Comparative estimation of phlox sorts (Phlox L.) in culture in the south of Tomsk region

This research was carried out in open ground of a subgreen-house and experimental plots of Siberian botanical garden of Tomsk State University in 2007-2009. Comparing phlox sorts by flower diameter revealed a low level of variability within every variety. Average flower diameter indices of different varieties range significantly: from 2.8 to 4.6 cm. The variability within the variety of this feature is unessential, but intervarietal variability prevails. It was determined that high indices of pollen fertility (80-100%) were noticed at the majority of garden phloxes varieties, except for ‘Nikolay Schors’ (14%), ‘Yunost’ (26%), etc. Maximal germination of pollen was, mainly, noticed on agar solution (1%) with the highest sugar content (30%). The pollen of ‘Tuman’, ‘Stanislav Parkovyi’ and ‘Olenka’ garden phlox varieties is the most viable. The pollen of ‘Sneszhok’, ‘Panama’ and ‘Arctica’ is practically unviable. It was revealed that in the conditions of introduction in the south of Tomsk oblast such phlox varieties as ‘Festivalnyi’ and ‘Schneepyramide’almost do not bear fruit.. Seed productivity of other varieties fluctuated within the limits from 1.8 to 25.2 seeds per sprout. Most varieties under study were stricken by powdery mildew, white spotting, lower leaves damage (fusarios (Fusarium species) and verticillesus (Verticillium albo-atrum R. et B.)). Grey mould (cause of disease - Botrytis cinerea Pers.), such as powdery mildew and white spotting was found on inflorescence. Spore-fruits of B. cinerea are found on post-blooming flowers and buds, rarely on flower-stalk and the upper leaves. In our investigations the cause of white spotting was determined as Septoria phlogis Sañc. et Speg. The signs of white spotting were observed on phloxes from the beginning of vegetation, progressively increasing by a blooming period, mass occurence of powdery mildew was noted in September. Field observations of powdery mildew development on phloxes pointed out that the character of variety affection by this disease was slightly different. In Tomsk conditions phlox affection by powdery mildew and white spotting depends on a variety. Each variety sensibility to infectious diseases is to be taken into account during plant selection for the purpose of landscape gardening. Furthermore, the same variety may be subjected to fungi diseases in a different degree in different growing conditions: disease development is lower in conditions of thin clump planting, than in dense phlox growing in monoculture beds.

Keywords

Authors

References