Drying and soaking pretreatments affect germination in pedunculate oak

Abstract

-• Pedunculate oak (Quercus robur L.) acorns are recalcitrant so they are difficult to store. Therefore, deterioration in quality during storage may reduce seedling yield and quality. In an attempt to address this, the effects of drying and soaking treatments on acorn germination were assessed.• After harvesting on two occasions in October, the moisture content (MC) of acorns were adjusted using the following treatments: (1) fresh state or control (46-48% MC); (2) soaked in fresh state (46-48%); (3) dried (40-42%) (standard method); and (4) dried and then soaked (46-48%). The treated acorns were allowed to germinate at 15 • C, both before and after storage at -3 • C.• Treatment effects were generally consistent for each harvest date. Compared to the untreated controls, soaking alone and drying followed by soaking significantly increased germination both before and after storage. Storage reduced germination, except for the dried and soaked acorns.• The results confirmed that drying and soaking improved acorn germination, but this was not mediated through an effect on acorn MC. In a separate nursery experiment, acorns given this treatment resulted in higher seedling yields and better quality plants than those given the standard treatment (dried to 40-42% MC).Quercus robur / pretreatment / storage / harvest date Résumé -Séchage et trempage, des prétraitements qui influencent la germination du chêne pédonculé.• Les glands du chêne pédonculé (Quercus robur L.) sont difficiles à stocker. En conséquence, la détérioration de leur qualité pendant le stockage peut réduire la production et la qualité des semis. Pour répondre à ceci, les effets de prétraitements de séchage et de trempage sur la germination des glands ont été évalués.• Après récolte à deux occasions en octobre, la teneur en eau (MC) des glands a été ajustée en utilisant les traitements suivants : (1) état frais ou témoin (46-48 %MC), (2) trempage à l'état frais (46-48 % MC), (3) séché (40-42 % MC) (méthode standard), (4) séché puis trempé (46-48 % MC). Les traitements permirent une germination des glands à 15 • C, aussi bien avant qu'après un stockage à -3 • C.• Les effets des traitements furent en général cohérents pour chaque date de récolte. Comparés aux traitements témoins, le trempage seul et le séchage suivi par un trempage ont accru significativement la germination aussi bien avant qu'après stockage. Le stockage réduit la germination sauf dans le cas des glands séchés et trempés.• Les résultats confirment que le séchage et le trempage améliorent la germination des glands, mais ceci n'est pas obtenu par l'intermédiaire d'un effet sur la teneur en eau des glands. Dans une expérimentation séparée en pépinière, ces traitements entraînent une plus grande production de semis et une meilleure qualité des plants que ceux issus du traitement standard (séché à 40-42 % MC).Quercus robur / prétraitements / stockage / date de récolte

Holm Oak (Quercus ilex) Transcriptome. De novo Sequencing and Assembly Analysis

“…Nowadays, Q. ilex forest maintenance and sustainability are facing severe problems and challenges. Those are related to agricultural practices, low natural regeneration, seed viability, which may be due to their non-orthodox seed character (Doody and O'Reilly, 2008 ), plant mortality in both adult trees and young plants after field transplantation resulting from adverse environmental conditions like drought, the so-called decline syndrome (Gallego et al, 1999 ), especially considering the current and future climate change scenario (Plieninger et al, 2004 ; Bates et al, 2008 ; Corcobado et al, 2013 ). Overcoming those threats could be greatly facilitated if olm oak ecophysiological behavior was better understood at the molecular level.…”

Combined effects of cotyledon excision and nursery fertilization on root growth, nutrient status and outplanting performance of Quercus variabilis container seedlings

“…Although acorn dispersal is facilitated by predators, poor germinability can restrict acorn germination and seedling performance [ 17 – 19 ]. Acorn germination rates are usually low and seedling emergence is unsynchronised, so that the duration of germination can last for more than a few weeks [ 20 ].…”

Protein profile of cotyledon, tegument, and embryonic axis of mature acorns from a non-orthodox plant species: Quercus ilex

“…Ribulose-1.5-bisphosphate carboxylase/ oxygenase large subunit the dominant one within the Mediterranean woodland ecosystems, being widely used in forest restoration and reforestation. However, a failure has been observed in the natural regeneration of the dominant oak species over the last two decades (McCarthy et al 1987;Lorimer, 1993;McDonald et al 2003), which may be due to several causes (reviewed in Schmidt 2000) and especially to their nonorthodox seed character (McCreary 1996;Tilki and Alptekin 2006;Doody and O'Reilly 2008). The solution to those problems can be greatly facilitated if its biology is understood and, because of that, molecular studies have to be performed.…”