Climate change affects agricultural productivity worldwide. Increased prices of food commodities are the initial indication of drastic edible yield loss, which is expected to increase further due to global warming. This situation has compelled plant scientists to develop climate change-resilient crops, which can withstand broad-spectrum stresses such as drought, heat, cold, salinity, flood, submergence and pests, thus helping to deliver increased productivity. Genomics appears to be a promising tool for deciphering the stress responsiveness of crop species with adaptation traits or in wild relatives toward identifying underlying genes, alleles or quantitative trait loci. Molecular breeding approaches have proven helpful in enhancing the stress adaptation of crop plants, and recent advances in high-throughput sequencing and phenotyping platforms have transformed molecular breeding to genomics-assisted breeding (GAB). In view of this, the present review elaborates the progress and prospects of GAB for improving climate change resilience in crops, which is likely to play an ever increasing role in the effort to ensure global food security.

SummaryAgriculture is now facing the ‘perfect storm’ of climate change, increasing costs of fertilizer and rising food demands from a larger and wealthier human population. These factors point to a global food deficit unless the efficiency and resilience of crop production is increased. The intensification of agriculture has focused on improving production under optimized conditions, with significant agronomic inputs. Furthermore, the intensive cultivation of a limited number of crops has drastically narrowed the number of plant species humans rely on. A new agricultural paradigm is required, reducing dependence on high inputs and increasing crop diversity, yield stability and environmental resilience. Genomics offers unprecedented opportunities to increase crop yield, quality and stability of production through advanced breeding strategies, enhancing the resilience of major crops to climate variability, and increasing the productivity and range of minor crops to diversify the food supply. Here we review the state of the art of genomic‐assisted breeding for the most important staples that feed the world, and how to use and adapt such genomic tools to accelerate development of both major and minor crops with desired traits that enhance adaptation to, or mitigate the effects of climate change.

We report on the evaluation of a novel grass hybrid that provides efficient forage production and could help mitigate flooding. Perennial ryegrass (Lolium perenne) is the grass species of choice for most farmers, but lacks resilience against extremes of climate. We hybridised L. perenne onto a closely related and more stress-resistant grass species, meadow fescue Festuca pratensis. We demonstrate that the L. perenne × F. pratensis cultivar can reduce runoff during the events by 51% compared to a leading UK nationally recommended L. perenne cultivar and by 43% compared to F. pratensis over a two year field experiment. We present evidence that the reduced runoff from this Festulolium cultivar was due to intense initial root growth followed by rapid senescence, especially at depth. Hybrid grasses of this type show potential for reducing the likelihood of flooding, whilst providing food production under conditions of changing climate.

The phylogeny of Festuca arundinacea Schreb. (2n = 6x = 42) was determined using GISH. Total genomic DNA of putative ancestral species was labelled with rhodamine and hybridized to chromosome preparations of hybrids involving these species and F. arundinacea. The degree of hybridization to chromosomes known to be homologous to the probe DNA was compared with that found simultaneously on chromosomes of the genome of F. arundinacea. It was concluded that the tetraploid species Festuca arundinacea var. glaucescens contributed two genomes and the diploid species Festuca pratensis one, to create the allohexaploid species F. arundinacea.Peer reviewe

Water-soluble carbohydrate (WSC) contents of the early heading perennial ryegrass cultivar Aurora and five late heading cultivars were assessed in samples from 1 m x 2 m plots cut eight times in 1983 and five times in 1984. Despite fluctuations due to effects of the environment and plant development, the ranking of the cultivars in terms of WSC generally remained constant. Aurora had the highest overall WSC content. Majestic and Aberystwyth S23 had the lowest while Perma, Melle and Ba 9795 were intermediate. In the same trial, the ranking of the F2 hybrids between the late heading cultivars and Aurora was also consistent with that obtained previously in Fl and F2 spaced plants. Melle F2 families had the highest WSC followed by Perma F2, Ba 9795 F2, S23 F2 and finally Majestic F2 families. This ranking also remained constant over a generation of intense selection for uniformity of heading date. It was concluded that WSC is a consistent and heritable trait in breeding perennial ryegrass. Aurora was a good resource for improving WSC but the turf-type perennial ryegrass. Majestic, had a strong negative effect on WSC content in hybrid material.

Differences in the water-soluble carbohydrate concentrations of herbage of northern European perennial ryegrass cultivars (Aurora, Melle, Cariad) grown under southern Australian conditions, and a New Zealand perennial ryegrass cultivar (Ellett) which yields well in southern Australia, were investigated in relation to their nutritive value. The water-soluble carbohydrates (WSC), total nitrogen, in vitro dry matter digestibility (IVDMD), neutral detergent fibre (NDF), and digestibility of NDF (NDFD) were measured in all cultivars. Aurora and Cariad exhibited higher WSC concentrations than the other cultivars, particularly during summer. This buffered the decline in IVDMD that was due to declining NDFD at that time of the year and resulted in an improvement in IVDMD of between 2 and 6%. Although WSC and nitrogen concentrations of the herbage were negatively correlated, this was due mainly to divergent seasonal variation in these components of the herbage.

Nitrogen (N) allocated to leaf growth in forage grasses and legumes following severe defoliation is predominately mobilized from the remaining root and leaf sheath tissues, since both N uptake from the soil and N # fixation are severely down-regulated for several days. The hypothesis that a low N reserve status at the time of defoliation limits N remobilization and leaf regrowth was tested with contrasting cultivars of Lolium perenne (cvs Aberelan and Cariad) in flowing solution culture. Plants were grown under ' high ' or ' low ' (uptake of N decreased by 50 %) regimes of N supply for 10 d before a single severe defoliation. Labelling with "&N was used to assess the importance of N reserves, including putative vegetative storage proteins, relative to N translocated from concurrent uptake, as a source of leaf N during regrowth. Leaf regrowth, N uptake and N mobilization were all affected by previous N supply. Low plant N status at the time of defoliation increased regrowth dry weight of ' Aberelan ' by 10 % and translocation of N absorbed from the medium by 23 %, while mobilization of N reserves was decreased by 56 %. On the contrary, regrowth dry weight of ' Cariad ' was decreased by 23 %, and translocation of N absorbed by 21 % in low plant N status, compared with high plant N status. Concentrations of soluble protein in roots and remaining leaf sheaths decreased after defoliation in plants only under optimal N supply. Analysis of soluble proteins in sheath material by SDS-PAGE suggested that three polypeptides (55, 36.6 and 24 kDa) might function as vegetative storage proteins, although they were of low abundance in plants, subjected to monthly harvests, grown in controlled conditions and in the field. The apparent antagonism between uptake of NH % + or NO $ − by roots and mobilization of N reserves is discussed together with evidence for functional vegetative storage proteins in L. perenne.

Grasslands cover a significant proportion of the agricultural land within the UK and across the EU, providing a relatively cheap source of feed for ruminants and supporting the production of meat, wool and milk from grazing animals. Delivering efficient animal production from grassland systems has traditionally been the primary focus of grassland‐based research. But there is increasing recognition of the ecological and environmental benefits of these grassland systems and the importance of the interaction between their component plants and a host of other biological organisms in the soil and in adjoining habitats. Many of the ecological and environmental benefits provided by grasslands emanate from the interactions between the roots of plant species and the soil in which they grow. We review current knowledge on the role of grassland ecosystems in delivering ecological and environmental benefits. We will consider how improved grassland can deliver these benefits, and the potential opportunities for plant breeding to improve specific traits that will enhance these benefits whilst maintaining forage production for livestock consumption. Opportunities for exploiting new plant breeding approaches, including high throughput phenotyping, and for introducing traits from closely related species are discussed.