Growth response and tolerance of potato (Solanum tuberosum L.) seedlings to root-zone hypoxia stress

In order to analyze the waterlogging resistance of different potato varieties and screen waterlogging resistant genotypes, this paper investigated the effects of root-zone hypoxia stress on seedling growth of 14 potato varieties under pot-cultured waterlogging condition. The waterlogging-tolerance of these potato varieties was comprehensively evaluated according to the adversity resistance coefficient (ARC), waterlogging index (WI) and cluster analysis. The results showed that compared with normal cultivation (control), waterlogging significantly decreased plant fresh weight, dry weight, new leaf number, height and maximum length of new root of “Wuyangyu”, “Zaodabai”, “Favorita” and “Vagor” with the average ARC of 0.61~0.68, which indicated that those four varieties were sensitive to root-zone hypoxia stress. The plant growth was not significantly inhibited for “Zhugen”, “Zangshu-1” and “Kexin-12” under hypoxic conditions with the average ARC of 0.90~0.93, those three species showed higher waterlogging tolerance. “Kexin-16”, “Kexin-18”, “713NS51-5”, “717NS78-7”, “Cersa”, “458 DTO-33” and “Chuanyu” had a certain degree of tolerance to hypoxia stress with the average ARC of 0.75~0.83. After 8 days for waterlogging treatment, “Vagor” and “Favorita” showed the lowest waterlogging tolerability, with the highest WI of 3.0 and mortality rate of 47% and 50%. “Kexin-18”, “Wuyangyu” and “Zaodabai” were poorly waterlogging resistant with the WI of 2.5~2.8; while “Zhugen”, “Zangshu-1”, “Kexin-12” and “Kexin-16” had higher waterlogging tolerance with the WI of 0.2~0.8. “713NS51-5”, “717NS78-7”, “Cersa”, “458 DTO-33” and “Chuanyu” were intermediately waterlogging tolerant with the WI of 1.4~1.9. The comprehensive evaluation on hypoxia stress tolerance with ARC, WI and cluster analysis divided 14 potato varieties into four groups, the high tolerant varieties of “Zhugen”, “Zangshu-1” and “Kexin-12”; medium tolerant varieties of “Kexin-16”, “713NS51-5”, “717NS78-7”, “458DTO-33”, “Chuanyu” and “Cersa”; no-tolerant varieties of “Kexin-18”, “Wuyangyu” and “Zaodabai”; sensitive varieties of “Favorita” and “Vagor”.