RELATIVE SUSCEPTIBILITY OF SOMEPRUNUSROOTSTOCKS IN HYDROPONICS TO IRON DEFICIENCY

Abstract

2 The susceptibility of eleven Prunus rootstocks to iron (Fe) deficiency was studied in hydroponics by growing them with 20 µM Fe, 0 µM Fe or 3 µM Fe+10 mM sodium bicarbonate. Based on the intensity of leaf chlorosis, the peach-almonds PR 204/84, Stylianidis K and KID2, produced at the Pomology Institute of Naoussa (Greece), showed the same or even greater tolerance than GF 677, the Greek peach-almond Retsou x Nemaguard, the plum-almond Myrandier 617 and the peaches GF 305, IDS 37, Greek wild peach seedling the greatest susceptibility whereas the plums St. Julien GF655/2 and Myrobalan 29C intermediate. Rootstocks without Fe presented significantly lower nitrogen and Fe whereas with bicarbonate significantly lower nitrogen, phosphorus, Fe and zinc.Root ferric chelate reductase activity was significantly increased in −Fe rootstocks but negatively correlated with their tolerance; physiological and morphological changes were observed along a zone of a few centimeters length, 1-2 mm behind the root tip.

Cultivar-rootstock interactions on growth, yield and mineral nutrition of newly planted peach trees in a pot experiment

“…The differences found in the literature among rootstocks have been attributed, among others, to the genetic background of each rootstock (Zarrouk et al, 2005;Ben Yahmed et al, 2020;Shahkoomahally et al, 2021). It seems that peach-almond rootstocks, such as 'GF677' and 'Garnem', respond better to iron deficiency under calcareous soils (Zarrouk et al, 2005;Assimakopoulou et al, 2011;Mestre et al, 2015;Ben Yahmed et al, 2020), as well as some plum rootstocks (Mestre et al, 2015;Ben Yahmed et al, 2020), while peach cultivars grafted on all these rootstocks present high Ca concentration too (Ben Yahmed et al, 2020) Among the tested rootstocks, it seems that 'Andross' in 2018, as well as both cultivars in 2019, presented high leaf N concentration when budded on 'GF 677' (2018 and 2019 were the years when first fruit production occurred).…”

“…The most common rootstocks used in Mediterranean countries are the 'almond x peach' hybrids, mainly due to their tolerance to Fe chlorosis (Zarrouk et al, 2005;Aras et al, 2021). The most widespread peach rootstock in Greece and generally southern Europe is 'GF 677' (Assimakopoulou et al, 2011), a 'peach x almond' rootstock, characterized by high vigor, resistance to limeinduced chlorosis, and replant disease (Jiménez et al, 2011). Another popular 'peach x almond' rootstock is 'Garnem', with similar characteristics to 'GF 677', regarding tree vigor and resistance to lime-induced chlorosis, as well as drought stress and root-knot nematode resistance (Reig et al, 2020).…”