Features of clonal micropropagation of plum PK SK 1 clonal rootstock

Methodological features of the main clonal micropropagation stages of plum PK SK 1 clonal rootstock (of NCFSCHVW selection) are described. The rootstock is characterized by a high adaptability to soil and climatic conditions of the region. In particular, it exhibits good winter hardiness, resistance to overwatered soils, tolerance to drought, and the capacity to grow on heavy soils. Plum seedlings on this rootstock develop a powerful root system. These advantages render the development and improvement of methods for clonal micropropagation of plum PK SK 1 clonal rootstock highly relevant. The research was carried out in 2019-2022. The period of active shoot growth, i.e., the first and second decade of may, was established to be the most optimal period for introduction of explants into in vitro culture. In this period, regeneration reaches 78.1–93.8 %. Eff ective shoot multiplication proceeds on MS medium with Fe-EDTA or MS medium with Fe-EDDHA and 6-BAP in the amount of 1 mg/L, with the highest number of shoots formed from one explant following the fourth passage (on average, 11.7 and 12.3 shoots per explant). A signifi cant eff ect of the 6-BAP concentration on the number of shoots formed was observed. The combined eff ect of the form of chelated iron and 6-BAP concentration on the number of shoots formed was established only after 3-5 passages on MS medium with Fe-EDDHA. The rooting stage of PK SK 1 rootstock can also be carried out on a hormone-free MS medium with Fe-EDDHA. The rooting effi ciency reaches 57.1–61.8 %. On average, 2.4 roots are formed per shoot with a length from 1.2 to 5.1 cm, with the root quality being high (not cartilaginous and not brittle). For the adaptation stage, rooted shoots with a height of at least 2 cm having two or more roots with a length of at least 2-3 cm are selected. A mixture of the Agrobalt plant nutrient soil, vermiculite, and perlite in a ratio of 3:1:1 can be used as a substrate. Following four weeks of adaptation, the number of adapted plants averaged 87.5 %. 

1. Zaremuk R. Sh., Kochubey A. A. Assessment of the quality of fruits of domestic plum hybrids [Electronic resource] Fruit growing and viticulture of the South of Russia. 2023;82(4):28-38. URL: https://journalkubansad.ru/pdf/23/04/03.pdf. DOI 10.30679/2219- 5335-2023-4-82-28-38.

2. Zaremuk R. Sh. Domestic plum varieties to optimize the southern assortment // Subtropical and ornamental gardening. 2018;66:34-40. DOI: 10.31360/2225-3068-2018-66-34-40. EDN: VJVZMK. Access mode: https://www.elibrary.ru/item.asp?id=36286857.

3. Sherstobitov V. V., Bandurko I. A., Ozersky P. V. Analysis of data from the variety study of domestic plum (Prunus domestica L.) selection of the Maikop experimental station - a branch of VIR. Works on applied botany, genetics and selection. 2022;183(2):113-121. DOI: 10.30901/2227-8834-2022-2-113-124.

4. Upadysheva G. Yu. On the infl uence of clonal rootstocks on the productivity and longevity of domestic plum trees. Selection and variety breeding of horticultural crops. 2017;4(1):145-148.

5. Fruit growing: textbook. allowance. Ed. Krivko N. P. [and others]. St. Petersburg: Lan, 2023, 440 p.

6. Chernikov E. A., Popova V. P., Kuznetsova A. P. et al. Assessment of plum productivity on rootstocks of domestic selection and soils with limiting parameters [Electronic resource]. Fruit growing and viticulture in the South of Russia. 2021;70(4):129-145. URL: http://journalkubansad.ru/pdf/21/04/12.pdf. DOI: 10.30679/2219- 5335-2021-4-70-129-145. (Date of access: 06/20/2023).

7. Safarov R. M., Ermin V. G. Selection of scion-rootstock combinations of Russian plum for intensive cultivation technologies // Fruit growing and berry growing of Russia. 2020;61:142-152. DOI 10.31676/2073-4948-2020-61-142-152.

8. Gorbacheva N. N. Evaluation of clonal plum rootstocks in the conditions of the Leningrad region // News of the St. Petersburg State Agrarian University. 2017;4(49):11-15.

9. Kalchenko E. Yu., Nozdracheva R. G., Gladysheva O. V. Features of compatibility of some variety-rootstock combinations of plum in the nursery // News of the St. Petersburg State Agrarian University. 2018;2(51):70-75.

10. Rootstock PC SK 1 / website: https://kubansad.ru/content/ pk-sk-1/.

11. Mine Pakyurek, Serra Hepaksoy. A Study on In Vitro Propagation Possibilities of Some Clone Rootstocks of Prunus Species // International Journal of Scientifi c and Technological Research. 2019;5(9):65-84. DOI: 10.7176/JSTR/5-9-10.

12. Mutu (Sima) Nicoleta, Mîndrilă Gheorghița. Evaluation of hormonal balance infl uence on the micropropagation of some rootstocks plum // JOURNAL of Horticulture, Forestry and Biotechnology. 2020;24(3):37 – 40.

13. Ugur R. Development of in vitro sterilization protocol for DO-1 (Prunus domestica) rootstock // Applied ecology and environmental research. 2020;18(2):2339-2349.

14. Palaz E. B., Ugur R. Diff erent approaches to in vitro rooting possibilities in Prunus rootstocks // International Journal of Agricultural and Natural Sciences. 2023;6(1):33-40.

15. Thakur M., Sharma V., Luharc R. Propagation of plum (Prunus salicina L.) cultivar Frontier in vitro through control of shoot tip necrosis (STN) and validation of genetic integrity using ISSR markers // Plant Physiol. Rep. 2021;26(2):238–246.

16. Pakyurek M., Hepaksoy S. A. Study on In Vitro Propagation Possibilities of Some Clone Rootstocks of Prunus Species // International Journal of Scientifi c and Technological Research. 2019;5(9):65-84.

17. Methodological recommendations for the use of biotechnological methods in working with fruit, berry and ornamental crops / Ed. E. N. Dzhigadlo. – Orel: GNU VNIISPK, 2005. 50 p.

18. https://apk-volga.ru/khelat-zheleza-fe.

19. ГОСТ Р 54051-2010. Плодовые и ягодные культуры. Стерильные культуры и адаптированные микрорастения. М.: Стандартинформ, 2011. 11 с.

20. Suprun I. I., Winter M. A., Fedorovich S. V., Lobodina E. V., Avakimyan A. O., Al-Nakib E. A. Effi ciency of in vitro propagation of the clonal rootstock of stone fruit crops PK SK 1 // Fruit growing and berry growing in Russia. 2023;72:16-23. URL: https://elibrary.ru/item.asp?id=50489034.

21. Center of competence in the fi eld of nursery farming. https://kubansad.ru/content/centr-kompetencij-v-oblasti-pitomnikovodstva/