Reproduction strategies of Populus species in the area of introgressive hybridization in the basin of Tom river

• Main Authors: B. V. Proshkin, A. V. Klimov
• Format: Article
• Language: English
• Published: Russian Academy of Sciences, Siberian Branch Publishing House 2020-08-01
• Series: Сибирский лесной журнал
• Subjects: poplar; clones; vegetative propagation; hybridization; introgression; backcrosses; kemerovo oblast
• Online Access: https://xn--80abmehbaibgnewcmzjeef0c.xn--p1ai/upload/iblock/978/9789d3ebccef327d11b7c91c134c66bb.pdf
• ISSN: 2311-1410; 2312-2099

Riverbed poplars are often a complex formation consisting of individuals of seed and vegetative origin. In the northern part of the Altai-Sayan mountain country, a significant proportion of them is formed by species of different sections of black poplar Populus nigra L. (section Aigeiros Lunell) and laurel-leaf poplar P. laurifolia Ledeb. (section Tacamahaca Mill.), which differ in the strategy of clone formation. In areas of joint growth, a process of their natural introgressive hybridization occurs. The aim of this work was to study the strategy of clone formation in parental taxa and hybrids in the zone of introgressive hybridization. Studies were conducted at five test sites in the river basin Tom. It was found that clone formation begins in the early stages of planting development and is stimulated by mechanical damage. Black poplar is characterized by compact clones of 2–10 ramet arising from the accessory buds at the base of the stem of a young plant. In the absence of further damage, the clone gradually decays with age, that is, it exists during the life of one generation. Clones of laurel-leaf poplar develop in several stages. At the first stage, a linear clone is formed of several ramets located parallel to the river bed. Subsequently, it grows greatly due to root offspring. These clones are capable of retaining developed territory for a long time. Clones of Irtysh poplar P. jrtyschensis Ch. Y. Yang in the education strategy may deviate towards one of the parent species or differ in intermediate characters. Study of the strategy of clone formation in backcrosses in the river basin Tom confirmed the previously identified direction of asymmetry during introgressive hybridization from laurel-leaf poplar to Black poplar. Probably, in suboptimal conditions of the river basin Tom, namely hybridization and subsequent introgression, provides not only an increase in general variability, but also a unidirectional transfer of valuable adaptive characters from laurel-leaf poplar to Black poplar. The latter, to a large extent, provides opportunities for the development of Black poplar (back-crosses), which are not characteristic of mountain habitats.