Yield and nutritional quality of highbush blueberry genotypes trialled in a Mediterranean hot summer climate.

BACKGROUND: Cultivation of highbush blueberry (Vaccinium corymbosum L.) has been increasing in Europe in recent years, in particular due to the availability of new genotypes suitable for cultivation in many different environmental conditions. The aim of this study was to evaluate the resilience and nutritional quality of 11 highbush blueberry cultivars and two new selections (from the New Zealand Institute for Plant and Food Research Ltd breeding program) in Mediterranean hot summer climate conditions by measuring plant yield, seasonality, fruit sensorial traits, and phytochemical content in the fruits. RESULTS: The new blueberry genotype PFR005 showed a high level of adaptability to these environmental conditions, with the highest total plant yield, whereas PFR075 was the best genotype for nutritional characteristics. Among the cultivars, 'Cosmopolitan' showed the maximum average fruit weight, 'Blueray' and 'Hortblue Poppins' demonstrated a good sensorial profile, while the best cultivars from the nutritional point of view were 'Hortblue Poppins', 'Hortblue Petite', and 'Early Blue'. CONCLUSION: New cultivars and new genotypes able to satisfy the needs of different users, have been identified. The integration of germplasm evaluation with a tailored breeding program will help to create new cultivars that will be useful for the expansion of blueberry cultivation in hot Mediterranean summer climate conditions, which up to now have limited this crop. © 2020 Society of Chemical Industry.

Blueberry estimated harvest from seven new cultivars: fruit and anthocyanins.

This study compares the yields, weights and anthocyanin contents of fruit from a group of seven new cultivars released from the New Zealand blueberry breeding programme and selected for the longest possible combined harvest season. The measured factors were primarily influenced by cultivar, and seasonal variations had relatively minor effects. The late-ripening cultivars 'Velluto Blue' and 'Centra Blue' had the highest fruit yields, anthocyanin contents and estimated total anthocyanin harvestable from a given area. 'Blue Moon' and 'Sky Blue' had the largest fruit sizes. The early-ripening cultivars 'Blue Bayou', 'Blue Moon' and 'Sunset Blue' had the lowest anthocyanin contents. The yield, fruit size and total anthocyanin content results obtained from any single year were highly correlated with the average of the three years, which makes pursuing the evaluation for these traits from a single year and at an early stage of plant development a practical proposition.

The anthocyanin composition of different Vaccinium, Ribes and Rubus genotypes.

Anthocyanins, which give berryfruit their characteristic colour, have attracted the interest of researchers because of their putative health benefits. Over the past eight years, HortResearch has been analysing the anthocyanin content of numerous samples of different species of Vaccinium, Rubus and also Ribes nigrum. These samples were taken from different genotypes held in germplasm collections, cultivar and advanced selection trials, genetic studies and seedling populations. Averaged over all samples, Ribes had higher total anthocyanin contents (total ACY) than Vaccinium which was, in turn, higher than Rubus. However, all genera provided rich sources of anthocyanins and individual crop types within genera varied considerably. Five percent (i.e., 223) of our samples had total ACY of more than 5000 microg/g: most of these were blackcurrants, but some were black raspberries and three were ornamental blueberries. Vaccinium species generally contained the most diverse range of individual anthocyanins. In contrast, Ribes nigrum samples were dominated by cyanidin and delphinidin rutinosides which, on average, comprised almost 80% of the total ACY. For Rubus species almost all anthocyanins were cyanidins, although which ones were more prevalent varied with the species. The high degree of variation in total ACY and individual anthocyanin contents reported herein, coupled with the moderate to high heritabilities reported in the literature, indicate that good progress could be made in breeding cultivars with still higher total ACY levels.

Open field trial of genetically modified parthenocarpic tomato: seedlessness and fruit quality.

BACKGROUND: Parthenocarpic tomato lines transgenic for the DefH9-RI-iaaM gene have been cultivated under open field conditions to address some aspects of the equivalence of genetically modified (GM) fruit in comparison to controls (non-GM). RESULTS: Under open field cultivation conditions, two tomato lines (UC 82) transgenic for the DefH9-RI-iaaM gene produced parthenocarpic fruits. DefH9-RI-iaaM fruits were either seedless or contained very few seeds. GM fruit quality, with the exception of a higher beta-carotene level, did not show any difference, neither technological (colour, firmness, dry matter, degrees Brix, pH) nor chemical (titratable acidity, organic acids, lycopene, tomatine, total polyphenols and antioxidant capacity - TEAC), when compared to that of fruits from control line. Highly significant differences in quality traits exist between the tomato F1 commercial hybrid Allflesh and the three UC 82 genotypes tested, regardless of whether or not they are GM. Total yield per plant did not differ between GM and parental line UC 82. Fruit number was increased in GM lines, and GM fruit weight was decreased. CONCLUSION: The use in the diet of fruits from a new line or variety introduces much greater changes than the consumption of GM fruits in comparison to its genetic background. Parthenocarpic fruits, produced under open field conditions, contained 10-fold less seeds than control fruits. Thus parthenocarpy caused by DefH9-RI-iaaM gene represents also a tool for mitigating GM seeds dispersal in the environment.

Plant genotype affects total antioxidant capacity and phenolic contents in fruit.

OBJECTIVE: We wanted to determine the total antioxidant capacity (6-hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid equivalent antioxidant assay; TEAC) of different species and cultivars (strawberry and apple) and to characterize the TEAC among fruits of the same varieties (peach and apricot) but grafted on different rootstocks. METHODS: The study was carried out with wild strawberry, six varieties of cultivated strawberry, and five varieties of apple and with apricot and peach grafted on five different rootstocks that are known to induce different plant vigor and fruit qualitative features. The TEAC (considering lipophilic and hydrophilic contributions) was determined for all fruit varieties, and total polyphenol contents were assayed. One-way analysis of variance was used to test differences among fruits and to identify possible correlations of TEAC versus total phenolics. RESULTS: The following hierarchy of antioxidant activities was found: wild strawberries >> cultivated strawberries >> kiwifruit = apples = apricots = peaches. Further, differences were found among strawberries with different genotypes and in apricots and peaches grafted from different rootstocks. CONCLUSIONS: These observations suggest the importance of genotype for determining antioxidant potential and phenolic contents. Variety manipulation may be a powerful tool for modifying antioxidant fruit patterns and contents.

Breeding and biotechnology for improving berry nutritional quality.

Breeding and biotechnological approaches are currently used to increase the content of specific bioactive components of plants, but the manipulation of plant metabolism is still not easy to address. There is an increasing awareness that multiple genetic and environmental factors affect production and accumulation of bioactive compounds, but these factors are rarely taken into account when fruit is marketed. Rigorous and unprejudiced evaluation of scientific evidence requires a defined set of criteria and methods of evaluation, particularly when breeding and biotech programs are aimed of producing new varieties with improved nutritional values combined with high plant production efficiency and fruit quality. In order to develop new genotypes and commercial cultivars the availability of new sources of Quality Attributes (QA) and Nutritional Attributes (NA) should be explored. In the strawberry, wild species such as F. virginiana glauca and F. vesca are good sources of bioactive compounds, but in raspberries the introduction of the wild germplasm (R. parvifolium) did not improve the nutritional quality of fruit. The methods available for detecting fruit TAC, combined with TPH and other quality parameters such as sugars, total acidity and fruit color, can be proposed as excellent tools for developing a fast and reliable program for screening large breeding populations for high nutritional quality genotypes. Furthermore, NA can represent a useful tool to facilitate analysis of "substantial equivalence" of transgenic and control derived fruit.