Research program

Effect of rootstock, tree architecture and environment on organoleptic properties, health and nutritional aspects of stone fruit production.

University Co-ordinator

Università Politecnica delle MARCHE - SCIENZE AMBIENTALI E DELLE PRODUZIONI VEGETALI - ANCONA(AN)

Research Unit Leader


Description

RESEARCH


The aim of this research is to study the rootstock influence in stone fruit (apricot - cv. San Castrese, peach – cv. Suncrest and European plum – cv. Stanley) production, fruit quality and nutrition by using plants growing in the Faculty's Experimental Farm, but also by using fruits deriving from the experimental trials of the other research Units, so to better identify also the influence of the environment and plant architecture on fruit quality and nutritional value.

By working on the experimental trials already available in the Faculty's Experimental Farm, the research program of the Unit will be focused on the following rootstocks, for each of the three Prunus species:

-Apricot rootstocks
This study will be developed on the experimental trial started in
2001 having San Castrese grafted with the following rootstocks: Adesoto 101 (P. insitia), Barrier 1 (P. davidiana x P. persica), Franco (P. armeniaca), Mirabolano 29C (P. cerasifera), Plumina (P. bessey x P. cerasifera), Penta and Tetra (both P. domestica).

-Peach rootstocks
By working on the peach rootstocks experimental trial having Suncrest as standard cultivar, in this study the effects on fruit quality and nutritional value of Ishtara (P. cerasifera x P. salicina) x (P. cerasifera x P. persica); Julior (Fedor) (P. insititia x P. domestica); GF677 (P. persica x P. amygdalus), Barrier 1 (P. davidiana x P. persica) will be compared with other quite recently released rootstocks Penta and Tetra, both P. domestica. For each rootstock fruits will be analysed at different harvesting periods and after different conservation intervals.

-European Plum rootstocks
This study will be developed on the experimental trial started in 2001 having Stanley grafted on the following rootstocks: GF677 (P. persica x P. amygdalus), Mirabolano 29C (P. cerasifera), Mr. S 2/5 (P. cerasifera), Penta, Tetra (both P. domestica), Ishtara (P. cerasifera x P. salicina) x (P. cerasifera x P. persica), Julior (Fedor) (P. insititia x P. domestica). For the more interesting rootstocks (GF 8-1, Ishtara, Julior e Mirabolano 29C) fruits will be analysed as fresh and dried (prunes), at different harvesting periods and after different conservation periods.

STUDIES
By working in the apricot, peach and European plum experimental trials, the research work of this Unit will include as a priority the evaluation of the rootstock effect on plant development and fruit quality and nutritional value.
For the experimental trials carried out at the University experimental farm the following studies, for two production cycles, will be considered:

1. Plant - rootstock relation

With the aim to study the rootstock influences of fruit quality and nutritional attributes, the following parameters will be considered:

#Vegetative parameters:
• trunk circumferences;
• canopy size;
• total dormant pruned weight;

#Physiologic parameters:
• blooming period;
ripening period;

#Yield parameters:
• total plant production;
• fruit mean weight;
• stone weight;

#Qualitative parameters by physical descriptors:
• fruit description by descriptors (including shape, size, symptoms);
• colour evaluation by Minolta colorimeter;
• fruit firmness;

#Qualitative parameters by chemical descriptors:
• soluble solid content;
• titratable acidity of fruit;

#Nutraceutical parameters:
• total antioxidant capacity of fruit (CAT);
• quantitative and qualitative determination of phenols;
• quantitative and qualitative determination of flavonoids;
• quantitative and qualitative determination of anthocyanins.

The total antioxidant capacity of fruit (CAT) will be determined by using the TEAC (Pellegrini et al., 1999) and FRAP (Deighton et al., 2000) methods. The phenol and anthocyanins content will analyzed by using the Folin-Cicolteau assay (Slinkard and Singleton, 1997) and pH-differential method (Giusti and Wrolstad, 2001), respectively. In add on samples showing the most peculiar differences well be also developed a qualitative study by performing HPLC profiles of the major antioxidant components. This HPLC study will be carried out thanks to collaboration with the Biochemistry Institute of the Faculty of Medicine of our University. For all these studies on the antioxidant compounds, fruit samples will be extracted by using a common protocol already developed by Scalzo et al. (2005). The extraction procedure will include the full fruit (fresh and stored) with and without peeling.

2. Effect of the rootstocks on fruit quality and nutritional value in post-harvest

By considering fruits from trials of the University Experimental Station, different parameters affecting fruit quality and nutraceutical attributes will be studied such as: different harvesting and post-harvest periods, and also changes in fruits when dried (prunes). The study on dried prunes will be carried out thanks to collaboration with a local fruit processing industry that will take care of processing the sampled fruits with an industrial standardized procedure.

-Fruit harvesting. Qualitative parameters by physical and chemical descriptors and nutraceutical will be studied in fruits at each harvesting time (at least 3 harvests at 5 days of interval), for different rootstocks, so to better understand changes of quality and nutritional compounds during fruit ripening. For each rootstock well be randomly sampled 20 fruit at commercial ripening stage (well coloured fruits), each harvest at 5 days of interval, and analysed for quality and nutraceutical parameters as described in step 1. To test the stability of the qualitative and nutritional parameter at post-harvest conditions, for each rootstock a sample of 30 fruits will be stored in fridge and then analysed after 3 intervals of 10 days (10 fruits each interval).

-Post-harvest. To better understand the role of the rootstock in stone fruit post-harvest conservation, apricot, peach and plum samples will be analysed after 10, 20 and 30 days of cold storage at 2-7°C.

-Drying. With the aim to study the rootstock effect in prunes quality and nutritional attributes also after their drying with the processing technology commonly used for European plum, samples of 60 fruits each rootstocks will be analysed for each rootstock and harvesting. The main aim of this study will be to identify the differences in antioxidant capacity between the fresh and dried fruits. Furthermore, by following the results by Fang et al., (2002), it will be established the reduction of the anthocyanins components due to the industrial drying treatment.

3. Environment, plant architecture and fruit position affecting stone fruit quality and nutraceutical attributes.

By using fruits deriving from the experimental trials carried out by the other research Units, the role of this research unit will be to analyse the effect of the environment and plant architecture on fruit quality and nutritional value.

-Environment. To better understand the environment effect on quality and nutritional attributes, fruit from four different sites (research Units), deriving from the research trials with the same rootstocks, will be analysed for the same quality and nutritional parameters described in step 1. This study will allow to better identifying the qualitative and nutritional effect induced by the rootstocks in four different cultivation areas of major importance for the stone fruit production in Italy.

-With the aim to study also the effect of plant architecture on fruit quality and nutrition, fruit from plants trailed with different systems (delayed vase, free spindle and Y), provided also by other research Unit will be analysed for all the quality and nutritional parameters described in step 1. In particular, different fruit samples for different branch site (shadow, mid-shadow, full sun) are considered and analysed with the aim to define the role of fruit position in quality and nutrition. These results will allow identifying the effect of the trailing system on the homogeneity of fruit quality and nutritional value.

4. Dissemination
Results from the different research activities will be presented to scientific National and international meetings, published on scientific and dissemination journals and also included in a web page that will be prepared specially for this project.