APPRECIATION OF THE FROST-RESISTANCE AND WINTER-HARDINESS OF THE COMMON SEA BUCKTHORN (HIPPOPHAE RHAMNOIDES L.) CULTIVARS AND HYBRID FORMS IN THE NORTHERN PART OF THE UKRAINE’S LISOSTEPPE

DOI: 10.35205/0558-1125-2022-77-41-48
UDC 632.111:631.526.32:582.866

The authors present the results of researching the potential level of the common sea buckthorn 11 cultivars and 17 hybrid forms frost-resistance and winter hardiness with applying the laboratory freezing method on the basis of the Laboratory of the Plant Physiology and Microbiology of the Institute of Horticulture (NAAS of Ukraine). The microscopial analysis has determined the damage level of shoots and buds tissues under the temperatures -15°С and minus 17°С (in the natural conditions) as well as -25°С and 35°С. Cv Necra and the hybrid 1-15-11 have the highest summary point of the slight freezing under the temperature – 25°С – 10.8 and 10.7 respectively while the hybrid form 1-15-17 and control variety Chuiska the lowest degree – 4.6 and 5.2. Under the mentioned temperature the shoot tissues have suffered from greater freezing on the cut off through the bud and in the upper part of a one year increment.

When temperature decreasing to -35°С the given tendency somewhat changes. Most of the studied samples have stronger shoot apical part damage. Under the temperature -35°С all the strains have a rather low summary point of the shoots tissues damage – from 6.3 to 13.9. This does not exceed even a half of the thresh-hold level (30 points). On the level of the tissues it is hardwood and heart-bark that have appeared the most susceptible to the above mentioned temperature regimes (within 0.7-1.5 points). Among all the investigated cultivars and temperature regimes the greatest damage has been fixed in the heart-back, however slight this tissue freezing almost does not influence the total plants state. It is a bark that is the most resistant tissue irrespective of a shoot part and under -35°С the hybrids 1-15-17, 5-17-144, 1-15-8C and cv Chuiska. Somewhat less fros-resistant ones are the forms 1-10-11 (Surpryz Baltyky), 1-15-9 (Karotynna) and 1-15-15. The hybrids 2-15-173, 2-14-4, 1-15-11 and the variety Necra have suffered from the greatest damages, although lower than the threshold level.

The sea buckthorn plants buds are also characterized with the high temperatures resistance level. Under the experiment conditions the bud of all the strains and hybrid forms have endured the effect of the temperatures both -25°С and -35°С without critical damage. The buds of the plants of the hybrids 1-15-17, 1-15-9 (Karotynna), 1-15-8C and the cultivar Chuiska have suffered from the slightest freezing. The high resistance has been displayed by the hybrid forms 5-17-144, 1-10-11 (Surpryz Baltyky), 1-15-11 and cvs Yeva and Nivelena, lower by 2-14-4, 2-15-173 and varieties Mikki (male and female forms) and Leikara. Even under the maximum freezing temperature (-35°С) the degree of the slight freezing of the explored samples buds does not exceed 36 %

The extraordinarily high potential frost-resistance of all the studied strains has been established as well as of the forms. The most frost-resistant hybrids 1-15-17, 1-15-9 (Karotynna), 1-15-8C, 1-10-11 (Surpryz Baltyky), 1-15-11, 5-17-144 and cultivars Chuiska, Yeva and Nivelena have been selected on their background.

As a result of the field researches the most winter-hardy cvs Nivelena and Moskvichka and forms 1-15-50 (Adaptyvna), 1-15-9 (Karotynna) and 1-10-11 (Surpryz Baltyky) have been selected which endure, better reflexive low temperatures after thaw (the average damage point is not higher than 0.5).

On the whole according to the comprehensive estimation of the common sea buckthorn varieties and promise hybrids it is 1-15-9 (Karotynna), 1-10-11 (Surpryz Baltyky) and strain Nivelena distinguish themselves for the nigh winter-hardiness and frost-resistance in the natural and laboratory conditions.

Key words: sea buckthorn, cultivar, hybrid form, laboratory freezing, frost-resistance.

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