Early Shoot Development Affects Carbohydrate Supply and Fruit Quality of Red-Fleshed <i>Actinidia</i> <i>chinensis</i> var. <i>chinensis</i> ‘Zes008’

oleh: Annette Richardson, Victoria Eyre, Peggy Kashuba, Deborah Ellingham, Heather Jenkins, Simona Nardozza

Format: Article
Diterbitkan: MDPI AG 2020-12-01

Deskripsi

Fruit quality characteristics are highly variable across kiwifruit vines due to complex source-sink interactions. We investigated how variation in fruit quality of <i>Actinidia chinensis</i> (Planch.) var. <i>chinensis</i> ‘Zes008’ was influenced by different shoot types (short, medium or long) and rootstocks types (<i>Actinidia chinensis</i> (Planch.) var. <i>deliciosa</i> (A. Chev.) ‘Bruno’ or <i>Actinidia macrosperma</i> C.F. Liang). Short shoots had smaller leaves (−30 to −50%) and lower photosynthesis rates (−0.70 to −3.34 µmol m<sup>−2</sup> s<sup>−1</sup>) in the first cluster of nine leaves (Zone 1) compared with leaves on medium or long shoots. Later in the season, photosynthesis rates in Zone 1 declined with leaf age, but photosynthesis rates were higher (+0.5 to +6.1 µmol m<sup>−2</sup> s<sup>−1</sup>) in later developing leaves on medium or long shoots. Fruit from short shoots had lower dry matter (−0.3 percent units) and lower outer pericarp flesh red pigment scores than fruit from medium or long shoots. At harvest, fruit from vines on ‘Bruno’ rootstocks were larger (+3.7 g), had higher dry matter (+1.3 percent units), soluble solids concentration (+1.7° Brix) and firmness (+0.4 kgf) than fruit from vines on <i>A. macrosperma</i> rootstocks. Factors that prioritised early development of source leaves had a direct impact on the carbohydrate supply from photosynthesis to support flower and fruit development.