Frost Resistance Of Species Research Articles

Frost Resistance of Species and Forms of Ulmus L. Genus under the Conditions of Uman City

The frost resistance of tissues of stems and generative buds of the genus Ulmus L. in the conditions of compelled rest was investigated. The results of direct freezing of shoots laboratory method using a system of coefficients with an improved assessment of the degree of tissue damage that takes into account their physiological disparity in the life and regeneration ability of plants were presented. The minimum critical temperatures that affect the growth and development of members of the genus that grow in cultural dendroflora city of Uman were set. Discovered that damage to the escape have a similar trend for all investigated species, which may indicate similarity of their biological properties. The most resistant to low temperatures was the middle part of the escape in the internode, the less stable is the upper part of the escape and the tissues around the kidney and the kidney.

Comparative winter frost resistance of plant species from southern Africa, Australia, New Zealand, and South America grown in a common environment (Dunedin, New Zealand)

The foliar frost resistance of plant species from the Southern Hemisphere is generally less than that of their northern equivalents, but are there differences between species from different southern land masses? Frost damage was determined visually and from measures of chlorophyll fluorescence: the two methods gave similar estimates of frost resistance. Amajority of species had frost resistances that were in accord with frost hardiness ratings derived from USDA climate zones, but species assigned to warmer climate zones were often more frost resistant than expected. USDA climate zones, which are based on continental climates in the Northern Hemisphere, may need re‐evaluation for the oceanic climates in the Southern Hemisphere. The frost resistance of various plant species from New Zealand, Australia, South America, and South Africa was determined in a common environment in the Dunedin Botanic Garden and its environs during the Dunedin winter (June‐July 2005). South American species were the most frost resistant, followed by New Zealand, Australian, and South African species, which were generally the least resistant. Broadleaved trees and shrubs, and conifers, showed a similar pattern of resistance with respect to countries. These patterns were less consistent for families and genera and it was concluded that the climate of origin rather than taxonomic affinity determined the winter frost resistance of species sampled in the Botanic Gardens.

Frost resistance of Eucalyptus species in northern Greece

Summary Ten frost hardy Eucalyptus species were planted on two sites in the oak zone of northern Greece, with absolute minimum temperatures about −12.6°C. The analysis of the 4th year measurements shows significant (p<0.01) differences in frost resistance between the species. Two groups were clearly distinguished: the first with survival over 60% consisting of E. stellulata, E. pauciflora ssp niphophila, E. camphora and E. parvifolia, and the second with survival below 30% consisting of E. glaucescens, E. coccifera, E. delegatensis and E. badjensis. E. dalrympleana falls between the two groups, while E. fraxinoides was completely eliminated. Significant (p<0.025) species-site interactions in survival may indicate the influence of soil and other factors on the frost resistance of some species. All the species suffered heavy damage restricting their growth and proving the oak zone unsuitable for commercial cultivation of eucalypts.