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Publikasjoner

NIBIOs ansatte publiserer flere hundre vitenskapelige artikler og forskningsrapporter hvert år. Her finner du referanser og lenker til publikasjoner og andre forsknings- og formidlingsaktiviteter. Samlingen oppdateres løpende med både nytt og historisk materiale. For mer informasjon om NIBIOs publikasjoner, besøk NIBIOs bibliotek.

2022

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Sammendrag

A study was conducted to investigate the effect of different storage periods and temperatures on pollen viability in vitro and in vivo in plum genotypes ‘Valerija’, ‘Čačanska Lepotica’ and ‘Valjevka’. In vitro pollen viability was tested at day 0 (fresh dry pollen) and after 3, 6, 9 and 12 months of storage at four different temperatures (4, −20, −80 and −196 °C), and in vivo after 12 months of storage at distinct temperatures. In vitro germination and fluorescein diacetate (FDA) staining methods were used to test pollen viability, while aniline blue staining was used for observing in vivo pollen tube growth. Fresh pollen germination and viability ranged from 42.35 to 63.79% (‘Valjevka’ and ‘Čačanska Lepotica’, respectively) and 54.58 to 62.15%, (‘Valjevka’ and ‘Valerija’, respectively). With storage at 4 °C, pollen viability and germination decreased over the period, with the lowest value after 12 months of storage. Pollen germination and viability for the other storage temperatures (−20, −80 and −196 °C) were higher than 30% by the end of the 12 months. Pollination using pollen stored at 4 °C showed that pollen tube growth mostly ended in the lower part of the style. With the other storage temperatures, pollen tube growth was similar, ranging between 50 and 100% of the pistils with pollen tubes penetrated into the nucellus of the ovule in the genotype ‘Čačanska Lepotica’. The results of these findings will have implications for plum pollen breeding and conservation.

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An intensive planting of ‘Celina’ pears on quince ‘Adams’ rootstock was established in May 2015 at NIBIO Ullensvang, western Norway. Five training systems (super spindles, trees with two leaders parallel to the row directions, slender spindles, and V-hedges of trees with 2 or with 4 leaders) were evaluated. Row distance was 3.5 m, and planting distance was 1.0 m except for super spindle trees and V-hedge with two leaders (0.5 m). Cultivars ‘Anna’ and ‘Fritjof’, used as pollinizers, were evenly distributed in the orchard and had good overlapping in flowering time. To get a faster establishment, the trees were headed back in winter 2016 when the formation of the different training systems was started. The first fruits were harvested in 2018. Due to unfavorable pollination conditions, fruit set in 2018 was very low. Average yields varied between 2.7 t ha‑1 for the super spindle trees to 10 t ha‑1 for the spindle trees. As a result of ample flowering and optimum pollination conditions, fruit set in 2019 was excellent, and average yields varied between 17 t ha‑1 for the 2-leader trees planted parallel to the row direction to 47 t ha‑1 for the 2-leader V-hedge trees. Fruit size was inversely related to fruit number per tree. Fruit weight depended on crop load per canopy volume and varied between 130 g for the two smallest trees (super spindles and 2-leader V-hedge system) and 180 g for the 2-leader trees planted parallel to the row direction. Soluble solid contents were high (11% on average), with no differences between training systems. After three cropping years, the spindle trees and V-hedge with 4 leaders per tree were the most productive systems per tree. However, the super spindle and 2-leader V-hedge system with twice the number of trees were the most productive systems per hectare.

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Sammendrag

Using modern analytical techniques, a comprehensive study of the chemical composition of fruits from apple cultivars grown in Western Norway during 2019 and 2020 was done. Metals, sugars, organic acids, antioxidant tests, and polyphenol content have been observed. In all investigated samples, the most dominant sugars were glucose, fructose, and sucrose. Among 11 tested organic acids, the dominant was malic acid, followed by citric and maleic acid. The most common metal was potassium, followed by magnesium and zinc. The quantification of polyphenols showed that among the 11 quantified polyphenols, chlorogenic acid, quercetin 3-O-rhamnoside, quercetin 3-O-glucoside, quercetin, and phlorizin were the most abundant. A detailed study of the polyphenolic profile of nine investigated apple samples provided 30 identified polyphenolic compounds from the class of hydroxybenzoic and hydroxycinnamic acids, flavonoids, and dihydrochalcones. In addition to the identified 3-O-caffeoylquinic acid, its two isomers of 5-O-caffeoylquinic acid and three esters were also found. Present polyphenols of the tested apples provided significant data on the quality of Norwegian apples, and they contribute to the distinguishing of these apple samples.