Avocado rootstock influences fruit quality and postharvest performance

The choice of rootstock has a significant impact, not only on fruit growth and development, but also on avocado fruit quality and postharvest performance. The objective of this study was to evaluate and compare attributes related to the postharvest quality of Hass avocados from ?Mexicola? and ?Duke 7? rootstocks grown under similar conditions. This study included two harvests: early (23?26% dry matter) and middle (>26?30% dry matter) per season for the 2016/2017 and 2017/2018 seasons and two storage conditions (regular air (RA) at 5 ?C and controlled atmosphere (CA) at 4 kPa O2 and 6 kPa CO2 at 5 ?C) for 55 days. The results showed significant differences in firmness, color and vascular and flesh browning between storage conditions; in addition to these last three attributes, the rootstock played an important role. The fatty acid profile did not reveal significant differences between fruit from both rootstocks. Finally, the polar metabolite profiles revealed differences only for the storage condition, not associated to the rootstock, which could affect the postharvest performance of Hass avocado fruit. This study is one of the few available showing the interaction of rootstock/Hass cultivar on fruit quality and postharvest performance. The text before corresponds to the Abstract IntroductionAvocado production, demand and commercialization have significantly increased worldwide, in part due to it being considered as a superfood with health attributes. Avocado demand in international markets has expanded, and as a consequence for exporting countries (e.g., Chile, Peru, etc.), the challenges have increased regarding their ability to reach markets demanding up to 55 d travel, as in the case of Asia. The cultivar Hass dominates the international market, representing 95% of the fruit commercialized worldwide [1], and most of the fruit is commercialized in the formats ?ready to eat? and ?triggered? in the main consuming countries (e.g., Europe and the USA) [2,3] As shipping days increase, avocado condition can be affected. The main quality problems reported for Hass avocado are related to fruit ripening heterogeneity in terms of color and firmness [4,5,6,7], increased incidence of rots and physiological disorders such as pulp and vascular browning [8], and during the last seasons, disorders such as black spots on the exocarp not associated with rots have also been reported [9,10].Grafting is a well-known and well-used commercial practice in fruit production. Previous studies have shown that an appropriate combination of rootstock/scion is key in respect to nutrient uptake, water potential, plant vigor, fruit yield and even fruit quality [11,12].There are numerous investigations evaluating the effect of a large number of rootstocks of different origins and characteristics on avocado crop yield (e.g., A8, A10, Barr Duke, Dusa? (Merensky 2), Latas? (Merensky 1), Duke 7, Reed, Rigato, SHSR-02, SHSR-04, SHSR-05 Thomas, Toro Canyon, Velvick (Whiley), Velvick (Anderson), Velvick (Lynwood), V1, A10?xVelvick, Velvick?xA10, VC26, VC27, VC28, VC55, VC66, VC68, VC96, VC140, VC152, VC159, VC162, VC207, VC320, VC801, VC802, VC804, VC840, Degania 62, Nachlat 3, among many others) in which they have observed differences among rootstocks in their susceptibility to Phytophtora cinnamomi [13,14,15] and to Verticillium [16], in their mineral nutrient uptake [17,18] and in their response to salinity [19,20], among other characteristics.Currently, the Chilean avocado industry relies on seedling rootstocks (mainly Mexicola and Zutano) and, to a much less extent, on vegetative propagated or clonal rootstocks (mainly Dusa? and Duke 7), which are being used in part due to their claimed greater potential in terms of productivity, uniformity and benefits such as their ability to adapt to stress factors, both pathological and edaphic [21]. Previous studies have reported the effects of rootstocks on avocado fruit quality, but they are limited to fruit and seed weight and shape, fruit oil concentration [22,23,24], anthracnose susceptibility [25] and internal quality such as flesh discoloration and pulp browning, potentially driven by their different capacities to absorb and transport nutrients to the fruits [26,27].There is a need for the assessment of the effect of rootstocks on avocado cv. Hass on global fruit quality parameters (e.g., firmness, color, physiological and pathological disorders, etc.) and postharvest performance considering the extremely distant export markets and complete characterization at the metabolite level with a focus on key components (fatty acid profiles and polar metabolite analysis). Recently, Tietel et al. [12], by applying a complete metabolomics analysis, reported the impact of scion/rootstock reciprocal effects on fruit yield and biochemical fruit quality of Citrus reticulata. Thus, this research aimed (i) to evaluate the effect of two commercially used rootstocks for avocado cv. Hass in Chile on global fruit quality parameters and postharvest performance, simulating internal and distant markets, and (ii) to evaluate the effect of these two rootstocks on the key metabolite profiles (fatty acid and polar metabolite profiles) of avocado cv. Hass. SourcesDo Rootstocks Influence Global Fruit Quality, Postharvest Performance and Metabolite Profiles of Persea americana cv. Hass?Ignacia Hern?ndez, Vitalia Molina, Claudia Fuentealba,Juan E. Alvaro, Bruno G. Defilippi & Romina PedreschiHorticulturae 2023, 9(2), 184https://doi.org/10.3390/horticulturae9020184 Picturehttps://biotrendies.com/frutas/aguacate