Establishment of Tissue Culture System for Cold-Resistant Line ‘HY15’ of ‘Korlaxiangli’ Pear and Transcriptome Analysis of Shoot Proliferation

‘Korlaxiangli’ pear occupies a pivotal position in the pear industry of Xinjiang, with both its cultivation area and total output ranking first in the region. However, ‘Korlaxiangli’ is vulnerable to freezing injury and has suffered frequent frost damage in recent years. A cold-tolerant superior individual plant was identified via preliminary field surveys and designated as cold-tolerant superior line 15-25-15 (abbreviated as ‘HY15’). To facilitate the large-scale application of this germplasm, tissue culture technology was adopted for its rapid propagation. Using spring-collected young shoots and autumn-collected dormant buds as explants, the optimal proliferation medium was determined to be DKW supplemented with 1.0 mg/L of 6-BA and 0.5 mg/L of NAA, while the optimal rooting medium was identified as 1/2 MS containing 2.5 mg/L of NAA and 15 g/L of sucrose. Transcriptome analysis revealed eight candidate genes potentially associated with shoot proliferation, among which ARF3 and ARR12 might be associated with high proliferation efficiency. This study provides a theoretical foundation and practical technical support for the conservation, genetic improvement, and establishment of efficient propagation systems of elite pear germplasm resources.