Aneuploid somaclonal variants are frequently observed during tissue culture of caladium (Caladium × hortulanum Birdsey), a popular ornamental plant. Certain variants exhibit improved ornamental characteristics, rendering them valuable for future breeding, provided that they maintain genetic uniformity in subsequent vegetative cycles.
This study investigated the genetic uniformity, tuber yield potential, and chilling-stress responses of two types of aneuploid caladium somaclonal variants (VT7 and VT9) produced previously in the second vegetative cycle. Morphological characterization revealed that all established plants displayed no observable alterations in leaf coloration, except for two out of 30 (6.67%) VT7 and one out of 14 (7.14%) VT9. Furthermore, VT7 and VT9 displayed relatively consistent distributions of the measured morphological parameters, suggesting a high degree of morphological uniformity of these variants.
Further analysis revealed that all assessed plants from VT7 and VT9 exhibited no alteration in relative nuclear DNA content, chromosome number, and simple sequence repeat (SSR) banding patterns except the three newly observed variants. These results indicated relatively high genetic uniformity of the two aneuploid variants in the second vegetative cycle. Compared with the wild caladium, the two aneuploids yielded more tubers with a reduction in average fresh weight.
Additionally, both VT7 and VT9 showed improved chilling tolerance relative to wild caladium, as evidenced by enhanced superoxide dismutase (SOD) activity, peroxidase (POD) activity, proline (Pro) content, and maximum photochemical efficiency (Fv/Fm), along with reduced relative electrical conductivity (REC) and malondialdehyde (MDA) content during chilling stress. Consequently, aneuploid somaclonal variants represent valuable resources for genetic studies and cultivar improvement in caladium.
Xiang, Yuanyuan & Zeng, Zhen & Wang, Yida & Zhao, Xiaoqing & Cai, Xiaodong. (2024). Evaluation of the genetic uniformity, yield potential, and chilling-stress responses of tuber progeny of aneuploid caladium somaclonal variants in the second vegetative cycle. Plant Cell, Tissue and Organ Culture (PCTOC). 159. DOI:10.1007/s11240-024-02882-7.
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