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Screening and Comparative Analysis of Drought Tolerance of Rice Varieties at the Reproductive Stage
Author(s) -
Pan Xiaowu,
Li Yongchao,
Zhang Haiwen,
Liu Sanxiong,
Deng Huafeng,
Li Xiaoxiang
Publication year - 2017
Publication title -
crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.76
H-Index - 147
eISSN - 1435-0653
pISSN - 0011-183X
DOI - 10.2135/cropsci2016.04.0268
Subject(s) - biology , agronomy , drought tolerance , oryza sativa , pollen , sugar , stamen , drought stress , yield (engineering) , botany , gene , biochemistry , materials science , metallurgy
Seasonal drought is a major constraint for rice ( Oryza sativa L.) production in rainfed lowland rice ecosystems. Water deficiency that occurs during reproduction always results in severe yield loss in these areas. Therefore, drought‐tolerant rice varieties are needed to avoid food security problems. The objectives of this study were (i) to find the relationship between drought and yield‐related traits for field conditions, (ii) to screen rice varieties that have high yield under drought stress, and (iii) to identify the variety‐specific mechanism of drought tolerance by investigating the gene expression and physiological characteristics of rice anther. Using 23 rice varieties in China, we found that drought stress at the reproductive stage seriously affected yield and its related traits. The genetic variability in the field was identified using the drought yield index. We found two inbred varieties, Xiangwanxian No. 12 (X12) and Xiangwanxian No. 13 (X13), that exhibit similar yield potentials but contrasting drought tolerances. Under controlled drought conditions, the drought‐tolerant rice variety X12 showed a higher pollen fertility and spikelet fertility than the susceptible X13. The difference in drought tolerance between X12 and X13 was correlated with the differential expression of anther‐expressed genes, which are involved in starch synthesis and sugar transport. Compared with X13, X12 can accumulate a higher content of soluble sugar; therefore, it maintains normal starch synthesis in the anthers under drought stress. Thus, X12 may be a new source of reproductive‐stage drought tolerance via the control of sugar transport and catabolism in anthers under drought stress. This mechanism may help to breed drought‐tolerant rice varieties in combination with a high yield potential.