Abstract：
Drought stress is one of the most critical abiotic factors which negatively impacts on growth, productivity, and survival of plants. Grass species have an important role in the sustainable intensification of cropping systems. This review focus on the specific drought tolerance characteristics in grass species and application of prevalent classical and molecular methods for genetic improvement of them to drought stress. Generally, grass species adapt to drought stress by utilizing more than one strategy including of changes in the root growth, photosynthetic pigments, activation of antioxidant enzymes, and accumulation of compatible osmolytes. They also have other specific characteristics consisted of summer dormancy, drought recovery, and persistence, which lead to drought adaptation after prolonged drought. Studies on different grasses, indicated that most of above mentioned traits usually have positive correlation with drought tolerance. Also, high heritability has been reported for most of them in different grasses. Therefore, an effective index might be considering in identification of drought tolerance genotypes. Recently, high-throughput imaging phenotyping and advanced molecular techniques such as genotyping-by-sequencing (GBS), RNA sequencing, genome-wide association study, and genome editing help conventional breeding methods to increase the accuracy, selection efficiency, genetic gains, and speed of breeding programs for developing drought tolerant cultivars.
摘要：
干旱胁迫是影响植物生长的最关键的非生物因素之一。生产力,植物的生存。草种在种植系统的可持续集约化中起着重要作用。本文重点介绍了草种的特定耐旱性特征以及流行的经典和分子方法在干旱胁迫下对其进行遗传改良的应用。一般来说,草种通过利用包括根系生长变化在内的多种策略来适应干旱胁迫，光合色素,抗氧化酶的激活，和相容渗透物质的积累。它们还具有夏季休眠的其他特定特征，干旱恢复,和坚持，导致长期干旱后的干旱适应。对不同草的研究，表明上述大多数性状通常与耐旱性呈正相关。此外，据报道，它们中的大多数在不同的牧草中具有较高的遗传力。因此,在鉴定耐旱性基因型时，可能会考虑一个有效的指标。最近,高通量成像表型和先进的分子技术，如基因分型测序（GBS），RNA测序，全基因组关联研究，和基因组编辑帮助常规育种方法提高准确性，选择效率，遗传增益，以及开发耐旱品种的育种计划的速度。
