Physiological basis of drought tolerance in potato grown under long-term water deficiency

Document Type: Research Paper

Authors

1 College of Agronomy, Inner Mongolia Agricultural University, Hohhot, 010019, China.

2 Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan.

3 College of Ecology & Environmental Science, Inner Mongolia Agricultural University, Hohhot, 010019 China.

4 College of Life Sciences, Inner Mongolia Agricultural University, Hohhot, 010019, China.

Abstract

Coping with water shortages without compromising tuber yield is a major
challenge for potato (Solanum tuberosum L.) production in northern China. In this
study, we used three potato cultivars with different sensitivities to drought to
evaluate the effect of long-term drought stress on morphological and physiological
characteristics under field conditions during three growing seasons (2009-2011).
Our aim was to identify the specific drought tolerance traits of the potato cultivars
to enable their cultivation in arid and semi-arid regions. Our results show that the
drought-tolerant cultivars had higher tuber yields under conditions of drought due
an increased number of tubers per hill and increased individual tuber weight.
Compared with the drought-sensitive cultivar Neishu no. 7, the drought-tolerant
cultivars Kexin no. 1 and Konyu no. 3 had stronger root systems and a higher
capacity for water absorption at later developmental stages and a higher leaf
relative water content, which conferred enhanced water retention under drought
conditions. Moreover, the levels of superoxide radical and hydrogen peroxide were
lower and the activities of antioxidative enzymes, including superoxide dismutase,
peroxidase and catalase, were higher in the drought-tolerant cultivars under
drought stress conditions. These combined characteristics allowed the cultivars to
exhibit different levels of water deficiency. The above agro-morphological and
physiological parameters could be used as a basis for breeding potato varieties with
enhanced drought tolerance.


Keywords