Key Laboratory for Forest Resources Conservation and Utilization in the Southwest Mountains of China, Ministry of Education, Southwest Forestry University, Kunming, 650224, China.
State Key Laboratory of Efficient Production of Forest Resource, Beijing Forestry University, Beijing, 100083, China.
BMC Plant Biol. 2023 Nov 13;23(1):557. doi: 10.1186/s12870-023-04578-0.
Artificial induction of polyploidy is the most common and effective way to improve the biological properties of Populus and develop new varieties of this tree. In this study, in order to confirm and expand earlier findings, we established a protocol using colchicine and based on an efficient shoot regeneration system of leaf blades to induce tetraploidy in vitro in three genotypes from diploid Populus hopeiensis. The stomatal characteristics, leaf blade size, and growth were evaluated for diploids and tetraploids of three genotypes.
We found that genotype, preculture duration, colchicine concentration, and colchicine exposure time had highly significant effects on the tetraploid induction rate. The optimal protocol for inducing tetraploidy in P. hopeiensis was to preculture leaf blades for 7 days and then treat them for 4 days with 40 mg/L colchicine. The tetraploid induction rates of genotypes BT1, BT3, and BT8 were 21.2, 11.4 and 16.7%, respectively. A total of 136 tetraploids were identified by flow cytometry analysis and somatic chromosome counting. The stomatal length, width, and density of leaf blades significantly differed between diploid and tetraploid plants. Compared with their diploid counterparts, the tetraploids produced larger leaf blades and had a slower growth rate. Our findings further document the modified morphological characteristics of P. hopeiensis following whole-genome duplication (e.g., induced tetraploidy).
We established a protocol for in vitro induction of tetraploidy from diploid leaf blades treated with colchicine, which can be applied to different genotypes of P. hopeiensis.
人工诱导多倍体是改良杨树生物学特性和培育该树种新品种最常用和最有效的方法。本研究旨在验证和扩展早期的研究结果，我们建立了一种利用秋水仙素并基于叶片高效再生体系的方法，在 3 个来自二倍体银腺杨的基因型中体外诱导四倍体。评估了 3 个基因型的二倍体和四倍体的气孔特征、叶片大小和生长情况。
我们发现，基因型、预培养时间、秋水仙素浓度和秋水仙素暴露时间对四倍体诱导率有高度显著影响。诱导银腺杨四倍体的最佳方案是将叶片预培养 7 天，然后用 40mg/L 秋水仙素处理 4 天。基因型 BT1、BT3 和 BT8 的四倍体诱导率分别为 21.2%、11.4%和 16.7%。通过流式细胞术分析和体细胞染色体计数共鉴定出 136 个四倍体。叶片的气孔长度、宽度和密度在二倍体和四倍体植株之间存在显著差异。与二倍体相比，四倍体产生的叶片较大，生长速度较慢。本研究进一步证明了银腺杨在全基因组加倍后（如诱导四倍体）的形态特征发生了改变。
我们建立了一种利用秋水仙素诱导二倍体叶片产生四倍体的体外诱导方法，可应用于不同基因型的银腺杨。
