Description

In a not too distant future to come, it will be necessary to increase the production per hectare of cultivated plants to cope with the increasing world population and the gradual deterioration of environmental conditions. In this context, the study of the mechanisms that regulate the reproductive system is crucial as in many cases the stability and yield of crop plants depend on genetic factors and networks controlling fundamental aspects of seed and fruit development.

Reproduction in Angiosperms has a well-defined evolutionary meaning and if, on the one hand, it markedly determines the preservation of genetic diversity between species limiting or avoiding an exchange of genes between different genomes. On the other hand, it equally affects the genetic structure of populations contributing significantly to the composition of genotypes within species and the organization of their genomes. As a consequence, the opportunities and modalities for the genetic improvement of crop populations and the development of new varieties depend on plant reproductive systems (prevalent autogamy or allogamy) and barriers, including male-sterility, self-incompatibility, parthenocarpy and parthenogenesis or apomixis. The genetic analysis and molecular basis of the reproductive systems of crop plants, with particular reference to reproductive barriers and mutants, and their effects on the genetic structure of populations, are key elements of great importance for both basic research and applied research in plant genetics and breeding.

This Research Topic aims to collect both Original Research Articles and Reviews focused on the recent advances of our knowledge on the genetics of crop plant reproductive systems as a consequence of the application and exploitation of modern genomics. In particular, its main goal is the comprehension and identification of the genetic mechanisms and factors that control the expression of sexual barriers, such as male-sterility, self-incompatibility and parthenocarpy in some important species, including horticultural crops and fruit trees. Moreover, it also provides functional analysis of candidate genes for these and other barriers, including apomixis and its components (apospory or diplospory and parthenogenesis), in model species.

It is well known that the possibility to control fertilization, in order to achieve full hybridization between genetically divergent parental lines, is highly desirable for breeding F1 hybrid seeds and heterotic varieties, as farmers demand. Natural parthenocarpy is also desirable as a strategy for the production of seedless fruits, increasingly appreciated by consumers. With the strengthening of genomics, mapping and cloning of the genes that control meiosis, gametogenesis, pollen-pistil interaction and fertilization-independent hybrid seed and seedless fruit production is at our fingertips. Articles should be focused on these themes investigated in the most agronomically important crop plants.

This Research Topic will not only cover the state-of-the-art of plant reproduction-related topics but also pave the way to understand the genetic basis and develop the molecular tools necessary for marker-assisted selection of genotypes suitable for the production of hybrid seeds and seedless fruits. Moreover, it fosters the establishment of an international research network focused on the genomics of plant reproduction and crop improvement.

By bringing together international research groups our editorial project will also facilitate the goals of the European Technology Program “Plants for the Future”, including key aspects of the Strategic Research Agenda. We believe that seeds are the highest blend of technology that can be made available to farmers: knowledge and expertise on hybrid seed and seedless fruit production would be crucial for breeding superior cultivars amenable to sustainable agriculture systems and responding to quality food needs. In this sense, the control of plant reproduction systems and barriers could potentially change the distribution and scale of investment in new varieties, disrupt existing commercial supply chains and lead to greater uptake and use of agronomic sources and nutritional traits. Developing tools to implement F1 seed production would enable farmers to self produce and multiply their own seed stock. It is therefore desirable to move forward with research into hybrid seed production mainly in the public domain although synergistic connections with the seed companies’ market strategies should not be ruled out.