Genetic Diversity and Genomic Insights into Physiological Adaptations of Grasses to Diverse Ecological Niches

With approximately 12,000 species and 771 genera, Poaceae is one of the largest plant families. In addition to many cereal crops, a large number of grass genera also belong to this family. After the probable origin in Late Cretaceous period, the grasses now occupy a wide range of habitats and are integral to the vast grasslands and rangelands spread over 26% of earth’s surface supporting livelihood of more than 800 million people. These anthropogenic grasslands harbor rich biodiversity in a varied climate ranging from tropical, temperate to alpine, and play a significant role in food for livestock, habitat for wildlife, checking soil erosion, support pollinators and conserve about 20% of the world’s soil carbon stocks. These grasses can be seen growing at high temperatures (up to 45°C) to sub zero; high salinity and alkalinity levels; high moistures and light stress and poor soil nutrients. Over the period of domestication and adaptation, these grasses developed physiological properties so as to survive. Inter and intra species diversity for various physiological activities shows that genetic diversity played significant role in their adaptation. Hence, these grasses are likely to harbor genes for adaptation to diverse ecological niches. Additionally, many tropical grasses also harbor genes for apomixis. Thus, we see that in time to come, these genes may play crucial role in crop breeding.

Here we wish to bring the articles addressing the status, mechanism and prospects of the genetic diversity and physiological adaptation of grasses to diverse ecological niches. Please note: studies focussed on physiological adaptations and their influences on alpine grassland ecosystems are to be submitted to the following collection: "Patterns, Functions, and Processes of Alpine Grassland Ecosystems under Global Change". Broadly the topic may cover, but is not limited to, the following points:

• Diverse grass genotypes adapted to various stress conditions – Evaluation, characterization (phenotypic and molecular) and documentation of interspecies and intraspecies genetic diversity.
• Intraspecies diversity vis-à-vis physiological adaptation of grasses.
• Physiological mechanism of tolerance to salinity, shade and drought.
• Improving abiotic stress tolerance in grasses – A genomic approach.
• Water use efficiency of grasses.
• Progress in identifying genes for stress tolerance in grasses and way forward for their utilization.
• Is apomixis a physiological adaptation to complete life cycle without fertilization undress stressed environment?
• Development of genetic markers for stress tolerance traits
• Evolution of photosynthetic pathways among grasses to survive under high light intensity and warm temperatures.
• Phenotypic plasticity among grasses for adaptation to new niches.
• Coexistence of cytotypes/polyploid of grasses in rangelands – a model for dominance in grasslands.
• Grassland sequestration and adaptive capacity under future climates-physiological perspective.