The data support the conserved roles of CRC orthologues in carpel fusion, style/stigma development and nectary development. In addition, an intriguing new aspect of CRC function in legumes was the unexpected role in vascular development, which could be shared by other species from widely diverged clades within the angiosperms, suggesting that this role could be ancestral rather than derived, as so far generally accepted.

Citrus species are the most widely produced fruit crops in the world, and Spain is one of the leading citrus producers that supply the fresh market. Rootstocks greatly influence variety behaviour as it ensures tolerance to abiotic stress conditions, as well as the provision of minerals and water for the total plant, and consequently impact crop yield and fruit quality. So, rootstock choice is one of the most important decisions a grower makes when establishing commercial citrus orchards. In this chapter, we attempted to provide an overview of the response in terms of plant growth, fruit quality and yield parameters of several citrus cultivar trees grafted onto different commercial rootstocks, plus new hybrids and some dwarfing genotypes, to reduce costs in some cultural practices. In particular, we considered the rootstock influence on scion photosynthetic capacity linked to carbohydrate distribution for plant vegetative and reproductive development.

Persimmon (Diospyros kaki Thunb.) production is facing important problems related to climate change in the Mediterranean areas. One of them is soil salinization caused by the decrease and change of the rainfall distribution. In this context, there is a need to develop cultivars adapted to the increasingly challenging soil conditions. In this study, a backcross between (D. kaki x D. virginiana) x D. kaki was conducted, to unravel the mechanism involved in salinity tolerance of persimmon. The backcross involved the two species most used as rootstock for persimmon production. Both species are clearly distinct in their level of tolerance to salinity. Variables related to growth, leaf gas exchange, leaf water relations and content of nutrients were significantly affected by saline stress in the backcross population.Water flow regulation appears as a mechanism of salt tolerance in persimmon via differences in water potential and transpiration rate, which reduces ion entrance in the plant. Genetic expression of eight putative orthologous genes involved in different mechanisms leading to salt tolerance was analyzed. Differences in expression levels among populations under saline or control treatment were found. The 'High affinity potassium transporter' (HKT1-like) reduced its expression levels in the roots in all studied populations. Results obtained allowed selection of tolerant rootstocks genotypes and describe the hypothesis about the mechanisms involved in salt tolerance in persimmon that will be useful for breeding salinity tolerant rootstocks. OPEN ACCESS Citation: Gil-Muñoz F, Pérez-Pérez JG, Quiñones A, Primo-Capella A, Cebolla J, Forner-Giner MÁ, et al. (2020) A cross population between D. kaki and D. virginiana shows high variability for saline tolerance and improved salt stress tolerance. PLoS ONE 15(2): e0229023. https://doi.org/10.increased by four times and production by near five [1]. Despite the recent and fast increase in persimmon production in the Mediterranean, the persimmon industry is facing important problems related to climate change. One of them is the soil salinization caused by the decrease and change of the rainfall distribution, which is causing an increase of salts in the irrigation water [2]. In order to keep the production in these areas, availability of rootstocks tolerant to salinity is required [3].The most commonly used rootstocks for persimmon production in these areas are seedlings from Diospyros lotus species, because of its tolerance to lime-filled soils and its adaptability to the Mediterranean conditions. Furthermore, D. lotus has a root system that does not produce basal shoots [4], facilitating the management of the orchards. However, this species is highly sensitive to salinity [5,6]. Other species used as rootstocks in some countries is Diospyros virginiana. This species is tolerant to salinity and performs well on lime-filled soils, but confers too much vigor to the plant, and produces many basal shoots, thus hindering crop management [7,8]. The most used rootstock around th...