Dong Baodi, Zheng Xin, Liu Haipei, Able Jason A, Yang Hong, Zhao Huan, Zhang Mingming, Qiao Yunzhou, Wang Yakai, Liu Mengyu
Key Laboratory of Agricultural Water Resources of Chinese Academy of Sciences and Hebei Key Laboratory of Water-Saving Agriculture, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of SciencesShijiazhuang, China.
School of Agriculture, Food and Wine, Waite Research Institute, The University of Adelaide, AdelaideSA, Australia.
Front Plant Sci. 2017 Jun 20;8:1008. doi: 10.3389/fpls.2017.01008. eCollection 2017.
Drought stress induced pollen sterility is a detrimental factor reducing grain number in wheat. Exploring the mechanisms underlying pollen fertility under drought conditions could assist breeding high-yielding wheat cultivars with stress tolerance. Here, by using two Chinese wheat cultivars subjected to different levels of polyethylene glycol (PEG)-induced drought stress, possible links between pollen fertility and stress tolerance were analyzed under different levels of drought stress at the young microspore stage. In both cultivars, higher grain number reduction was observed under condition of lower water availability. Overall, the drought tolerant cultivar (Jinmai47) exhibited less grain number reduction than the drought sensitive cultivar (Shiluan02-1) under all stress conditions. Compared with Shiluan02-1, Jinmai47 exhibited superior physiological performance in terms of leaf photosynthetic rate, ear carbohydrate accumulation, pollen sink strength, pollen development and fertility under stress. Moreover, Jinmai47 showed a lower increase in endogenous abscisic acid in ears than Shiluan02-1. Furthermore, higher levels of superoxide dismutase (SOD) and peroxidase (POD) activities were also found in the drought tolerant cultivar Jinmai47 under PEG stress, compared with the drought sensitive cultivar Shiluan02-1. Changes in these physiological traits could contribute to better pollen development and male fertility, ultimately leading to the maintenance of grain number under drought stress.
干旱胁迫诱导的花粉不育是降低小麦粒数的一个有害因素。探索干旱条件下花粉育性的潜在机制有助于培育具有胁迫耐受性的高产小麦品种。在此，通过使用两个中国小麦品种，对其施加不同水平的聚乙二醇（PEG）诱导的干旱胁迫，在小孢子幼龄期的不同干旱胁迫水平下分析了花粉育性与胁迫耐受性之间的可能联系。在两个品种中，水分可利用性较低的条件下均观察到粒数减少幅度更大。总体而言，在所有胁迫条件下，耐旱品种（晋麦47）的粒数减少幅度均小于干旱敏感品种（石栾02-1）。与石栾02-1相比，晋麦47在胁迫下的叶片光合速率、穗部碳水化合物积累、花粉库强度、花粉发育和育性方面表现出更优的生理性能。此外，晋麦47穗部内源脱落酸的增加幅度低于石栾02-1。此外，与干旱敏感品种石栾02-1相比，在PEG胁迫下耐旱品种晋麦47还具有更高水平的超氧化物歧化酶（SOD）和过氧化物酶（POD）活性。这些生理性状的变化有助于更好的花粉发育和雄性育性，最终在干旱胁迫下维持粒数。
