Rootstock breeding in Prunus species: Ongoing efforts and new challenges

Abstract

The current global agricultural challenges imply the need to generate new technologies and farming systems. In this context, rootstocks are an essential component in modern agriculture. Most currently used are those clonally propagated and there are several ongoing efforts to develop this type of plant material. Despite this tendency, lesser number of rootstock breeding programs exists in comparison to the large number of breeding programs for scion cultivars. In the case of rootstocks, traits evaluated in new selection lines are quite different: From the agronomic standpoint vigor is a key issue in order to establish high-density orchards. Other important agronomic traits include compatibility with a wide spectrum of cultivars from different species, good tolerance to root hypoxia, water use efficiency, aptitude to extract or exclude certain soil nutrients, and tolerance to soil or water salinity. Biotic stresses are also important: Resistance/tolerance to pests and diseases, such as nematodes, soil-borne fungi, crown gall, bacterial canker, and several virus, viroids, and phytoplasms. In this sense, the creation of new rootstocks at Centro de Estudios Avanzados en Fruticultura (CEAF) offers an alternative to stone fruit crop, particularly in Chile, where just a few alternatives are commercially available, and there are site-specific problems. The implementation of molecular markers in order to give support to the phenotypic evaluation of plant breeding has great potential assisting the selection of new genotypes of rootstocks. Marker-Assisted Selection (MAS) can shorten the time required to obtain new cultivars and can make the process more cost-effective than selection based exclusively on phenotype, but more basic research is needed to well understood the molecular and physiological mechanisms behind the studied trait.

Screening of Different Physalis Genotypes as Potential Rootstocks or Parents Against Vascular Wilt Using Physiological Markers

“…Rootstocks are an important component in modern fruit production because of their ability to acclimate a particular crop to diverse environmental conditions and their capability to provide traits that are absent in the scion, such as disease resistance (Gainza et al, 2015). In this sense, the knowledge of mechanisms of resistance to vascular wilt in Physalis species and their use as rootstocks are not well known.…”

Desempenho de pessegueiro ‘BRS Libra’ autoenraizado e enxertado sobre porta-enxertos clonais em Minas Gerais

“…Assim, a escolha da cultivar copa e o uso ou não de porta-enxertos são fatores importantes para garantir melhores rendimentos. Apesar da fruticultura moderna estar embasada na utilização de porta-enxertos (Picolotto et al, 2009;Gainza et al, 2015), o uso de mudas autoenraizadas é uma boa opção para reduzir os custos de produção e manter todas as características genéticas da cultivar original. No entanto, essa técnica não é utilizada comercialmente, principalmente pela falta de domínio por parte dos viveiristas e de estudos em campo que comprovem a produção, produtividade, qualidade dos frutos, respostas às condições abióticas e bióticas, bem como a longevidade das plantas em relação às enxertadas (Pereira & Mayer, 2005).…”

Current achievements and future directions in genetic engineering of European plum (Prunus domestica L.)

“…Plum rootstocks are selected based on traits such as rootstock-scion compatibility, scion vigor control, tolerance to different soil conditions (salinity, pH, drought, etc. ), lack of root suckers and resistance to soil diseases and insects (Gainza et al 2015 ). Iron chlorosis that often occurs in calcareous soils is one of the most limiting factors in the production of Prunus.…”

“…), bacterial canker ( P. syringae pv. syringae ), oak root rot fungus, Armillaria mellea and Armillaria tabescens (Gainza et al 2015 ).…”